000
FXUS63 KIWX 082310
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
610 PM EST SAT NOV 8 2008

.AVIATION...
CAA MVFR CLOUD DECK ON BACKSIDE OF LARGE LOW CENTERED OVER ERN
ONTARIO THIS EVE. THESE LOW CLOUDS SHOULD CONT OVER THE AREA INTO
SUNDAY MORNING. A WK TROF MOVG THROUGH THE AREA ATTM WAS
CAUSING AN AREA OF SHOWERS WHICH EXTRAPOLATES EAST OF FWA AROUND 02Z.
AT SBN WINDS WILL BE FAVORABLE FOR SOME LIGHT LAKE EFFECT SHOWERS
TO CONT OVERNIGHT BUT LIMITED LM FETCH SHOULD KEEP PRECIP LIGHT
ENOUGH TO HAVE LITTLE IMPACT ON VSBYS AT SBN. CONTD CAA EXPECTED
TO CAUSE RAIN SHOWERS TO MIX WITH OR PSBLY CHANGE TO SNOW LATE
TONIGHT AND SUNDAY MORNING. ANOTHER SHRTWV SEEN ON WATER VAPOR
LOOPS MOVG INTO SRN MN THIS EVE. THIS SHOULD MOVE ACROSS NRN
INDIANA SUNDAY MORNING WITH AN INCREASE IN SHOWER ACTIVITY
PRECEDING IT AND DRYING IN ITS WAKE EXPECTED TO RESULT IN RISING
CIGS DURING THE AFTN. BRISK SW-W WINDS WILL CONT AS LOW LEVELS
REMAIN UNSTABLE THROUGH THE PD PROMOTING GOOD MIXING.

&&

.PREV DISCUSSION... /ISSUED 409 PM EST SAT NOV 8 2008/

SHORT TERM...
TONIGHT THROUGH SUNDAY NIGHT...

CONTINUED UNSETTLED PATTERN TO PROVIDE AREA W/CLOUDS AND PRECIP CHCS
THROUGH THE WEEKEND.  SFC LOW NOW ANALYZED IN ONTARIO W/ELONGATED
SFC TROUGH EXTENDING THROUGH KGRB. THREE DISTINCT MID LVL IMPULSES
SEEN ON WV OF IMMEDIATE IMPACT TO CWA.  THE FIRST IMPULSE CLEARED
THE CWA THIS MORNING WITH A LULL IN PRECIP BEHIND IT. THE NEXT S/W
SLIDING IN THIS AFTERNOON ALLOWING FOR SCT DZ AND -SHRA OVER NE IL
INTO SW LOWER MICHIGAN WHERE LAKE ENHANCEMENT RESULTING IN
MEASURABLE RAINFALL.  THE THIRD IMPULSE OF PROMOTING -RA IN SE WISC
W/AID OF AFOREMENTIONED SFC TROUGH. A FINAL...MORE INTENSE
SHRTWV/SPD MAX WILL DIVE SWD THROUGH MN AND PROVIDE THE ENERGY
NEEDED TO MOVE PESKY UPR LOW OUT OF THE GREAT LAKES REGION.

THIS AFTERNOON...
DOWNGRADED TO SPRINKLES AND FLURRIES FOR MOST OF CWA AWAY FROM LAKE
MICHIGAN THIS AFTERNOON AS MEASURABLE PRECIPITATION EXTREMELY
DIFFICULT TO COME BY AWAY FROM THE LAKE THIS EVENT AND DO NOT SEE
IMPRESSIVE ENOUGH FORCING TO CHANGE THIS TREND.

TONIGHT...
GOING GRIDS IN DECENT SHAPE WITH LAKE ENHANCED RAIN AND SNOW SHOWERS
PENETRATING SLIGHTLY FURTHER SOUTH INTO CWA AS LL WINDS VEER TO
280-290 DEGREE FETCH AND LAKE PARAMETERS /DELTA T/S IN UPR
TEENS...MINIMAL LL SHEAR...AND LAKE INDUCED CAPES TO 400 J/KG/
COMBINED WITH PLENTIFUL AMBIENT ATMOSPHERIC MOISTURE TO SUPPORT RAIN
AND SNOW WITH MAIN FACTOR PRECLUDING ALL SNOW BEING RELATIVELY
SHALLOW INVERSION WITH CLOUD TOP TEMPS NOT IN DGZ. CONSIDERED
PULLING CHC POPS OUTSIDE LAKE EFFECT AREAS WITH AFOREMENTIONED
DIFFICULTY IN RECEIVING MEASURABLE PRECIP...BUT WILL REMAIN
CONSISTENT AS GUIDANCE NUMBERS AND PASSING S/W SUGGEST MEASURABLE
POPS STILL IN REALM OF POSSIBILITY. TEMPS-WISE...MIXING AND CLOUD
COVER TO OFFSET CAA SO WENT NEAR GUIDANCE FOR LOWS IN THE LOWER 30S
TONIGHT.

SUNDAY...
LAKE ENHANCEMENT/LAKE EFFECT WILL BE MAIN FACTOR IN
FORMATION/CONTINUATION OF PRECIP SUNDAY AS AMBIENT 1000-500 RH/S
PLUMMET TO AOB 50% AND WEAK S/W RIDGING SLIDES IN AHEAD OF YET
ANOTHER WAVE DIVING SOUTH THROUGH THE NRN PLAINS.  DIFFICULT TO
ASSESS PTYPE SUNDAY AS GFS AND NAM BOTH BRING IN CAA AND DROP H85
TEMPS TO AROUND -7C TO -10C BY LATE AFTERNOON...WITH GFS A TOUCH
COLDER. WITH CLOUD TOPS IN THE 750-800MB RANGE...EXPECT PRECIP WILL
EVENTUALLY CHANGE TO ALL SNOW IN THE AFTERNOON BUT LEFT RAIN AND
SLEET MENTION IN UNTIL 7 PM AS ICE CRYSTAL PRESENCE STILL UNCERTAIN.
BACKED OFF POPS AWAY FROM THE LAKE AND JUST MENTIONED SPRINKLES OR
FLURRIES AS COLUMN MOISTURE LOOKS MEAGER. UNDERCUT GUIDANCE BY 3
DEGREES OR SO FOR HIGHS WITH FAIRLY STG CAA AND CLOUD COVER
SUGGESTING HIGHS MAY STRUGGLE TO GET OUT OF THE MID 30S. THIS NOTION
BACKED BY TEMP PERFORMANCE TODAY WELL BELOW MOS.

SUNDAY NIGHT...
LAKE EFFECT MACHINE SHOULD REMAIN RUNNING AND AS SUCH BUMPED POPS TO
LIKELY FOR NRN BERRIEN AND CASS COUNTIES WITH A LITTLE BIT OF
ACCUMULATION POSSIBLE. MAIN CONCERN WILL BE LOWERING INVERSION HTS
AND LACK OF AMBIENT MOISTURE BUT EXPECT IMPRESSIVE DELTA T/S NEAR 20
AND WEAKLY SHEARED UNIDIRECTIONAL LL FLOW FROM 280-290 TO CONTINUE
TO PROMOTE MULTI-BAND SNOW SHOWERS. LOWERED LOW TEMPS IN THE SW AS
ANY CLEARING WILL LIKELY ALLOW TEMPS TO FALL TO THE LOW TO MID
20S...WHICH COULD BE THE COLDEST NIGHT OF THE FALL TO DATE.

LONG TERM...
MONDAY THROUGH SATURDAY...

AN UPPER LEVEL SYSTEM WILL BE LIFTING RAPIDLY NORTHEAST AWAY FROM
THE AREA EARLY MONDAY. LEFT A CHANCE OF SNOW EARLY OVER FAR SW
LOWER MICH AS ANY LAKE ENHANCED SNOW SHOULD END BY NOON MONDAY.
FOR THE REST OF THE PERIOD...THE MAIN CHALLENGE IS THE TIMING AND
STRENGTH OF SHORT WAVE/S EJECTING NORTHEAST OUT OF THE MAIN WESTERN
CONUS TROF. THE GFS CONTINUES TO HAVE POOR RUN TO RUN CONSISTENCY
WITH THIS PATTERN. THE 12Z GFS HAS SHIFTED THE BEST CHANCE FOR
PRECIPITATION LATER IN THE WEEK WEDNESDAY ALL OF THE WAY THROUGH
FRIDAY NIGHT. KEPT THE CHANCE FOR RAIN WEDNESDAY THEN DRY DUE TO
UNCERTAINTY. PRECIPITATION MAY NEED TO BE ADDED SOME TIME THURSDAY
THROUGH SATURDAY...BUT MOST OF THESE PERIODS SHOULD BE DRY. KEPT
TEMPERATURES MODERATING DURING THE SECOND HALF OF THE WEEK AS
UPPER LEVEL RIDGING BUILDS OVER THE AREA.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST MONDAY FOR LMZ043-046.

&&

$$

SHORT TERM...SIMPSON
LONG TERM...SKIPPER
AVIATION...JT

000
FXUS63 KIND 082250
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
550 PM EST SAT NOV 8 2008

.AVIATION...DISCUSSION FOR 09/00Z TAFS.

EXTENSIVE MVFR CIGS FOUND ACRS INDIANA AND UPSTREAM ACRS WI AND IL
IN BROAD CYCLONIC FLOW AROUND STRONG LOW PRES SYS OVR THE GRT LKS.
AN OCCASIONAL SPRINKLES WL CONTINUE TO BE POSSIBLE THIS
EVENING...HOWEVER VISIBILITY RESTRICTIONS ARE NOT EXPECTED.

MVFR CIGS WL REMAIN ACRS THE AREA THROUGH MUCH OF THE TAF PERIOD. AS
THE LOW PULLS TO THE NE ON SUNDAY...CIGS SHUD IMPROVE TO VFR AFT
09/20Z-22Z.

EXPECT CLEARING TO BE SLOWER THAN ADVERTISED BY THE NAM/GFS AS
USUALLY OCCURS WITH THIS TYPE OF SYSTEM.


&&

.DISCUSSION...
MAIN CONCERN WITH THIS AFTERNOONS FORECAST IS THE CHANCE OF PCPN
TONIGHT AND THE TEMPERATURES. VERY STRONG LOW PRESSURE OVER THE
NORTHERN GREAT LAKES WILL CONTINUE TO THE MOVE NORTH. COLD AND
UNSTABLE FLOW WAS ROTATING AROUND THE LOW. A WEAK SHORT WAVE WILL
MOVE THROUGH INDIANA TONIGHT. THIS AFTERNOON SFC OBS WERE SHOWING
SOME SPRINKLES/FLURRIES MOVING THROUGH INDIANA AND TO THE W AND NW.
THESE SHOULD CONTINUE TO MOVE THROUGH THE AREA TONIGHT. WILL KEEP
THIS CHC IN THE MORE UNSTABLE AIR OVER THE NRN HALF. TEMPS SHOULD
BE HIGH ENOUGH TO CAUSE A CHC OF SPRINKLES/FLURRIES THIS EVENING
THEN JUST FLURRIES LATER. THE FWC GUID WAS VERY CLOSE TO ACTUAL
CONDITIONS THIS AFTN. THE OTHER GUIDANCE WAS TOO WARM. DUE TO THIS
WILL GO CLOSER TO THE COLDER FWC GUID. THROUGH 36 HOURS CURRENT
SOUNDINGS CHANGED VERY LITTLE FROM PRVS RUN. GFS CONTINUES TO BE THE
WARMER MODEL. 850 MB SHOWS CONTINUING CAA. GFS 850 MB TEMPS DROP TO
-10 AT 00Z. WITH THIS CAA CONTINUING WILL GO NEAR THE COLDER ETA/NGM
GUID. SLOW WAA STARTS ON MONDAY AS HIGH PRESSURE BUILDS INTO AREA. A
WARM FRONT WILL MOVE THROUGH INDIANA ON TUESDAY. WILL BRING IN A
CHANCE OF PCPN WITH THE FRONT.

FOR THE EXTENDED PORTION ANOTHER COLD FRONT MOVES THROUGH INDIANA ON
THURSDAY. THIS WILL KEEP A CHANCE OF RAIN OVER THE AREA. THE FRONT
WILL MOVE EAST OF INDIANA THU NIGHT TO END THE CHC OF RAIN. SOME WAA
WILL BEGIN ON FRIDAY. TEMPS WILL REACH NEAR NORMAL.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

AVIATION...JP
PUBLIC...SH

000
FXUS63 KIWX 082109
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
409 PM EST SAT NOV 8 2008

.SHORT TERM...
TONIGHT THROUGH SUNDAY NIGHT...

CONTINUED UNSETTLED PATTERN TO PROVIDE AREA W/CLOUDS AND PRECIP CHCS
THROUGH THE WEEKEND.  SFC LOW NOW ANALYZED IN ONTARIO W/ELONGATED
SFC TROUGH EXTENDING THROUGH KGRB. THREE DISTINCT MID LVL IMPULSES
SEEN ON WV OF IMMEDIATE IMPACT TO CWA.  THE FIRST IMPULSE CLEARED
THE CWA THIS MORNING WITH A LULL IN PRECIP BEHIND IT. THE NEXT S/W
SLIDING IN THIS AFTERNOON ALLOWING FOR SCT DZ AND -SHRA OVER NE IL
INTO SW LOWER MICHIGAN WHERE LAKE ENHANCEMENT RESULTING IN
MEASURABLE RAINFALL.  THE THIRD IMPULSE OF PROMOTING -RA IN SE WISC
W/AID OF AFOREMENTIONED SFC TROUGH. A FINAL...MORE INTENSE
SHRTWV/SPD MAX WILL DIVE SWD THROUGH MN AND PROVIDE THE ENERGY
NEEDED TO MOVE PESKY UPR LOW OUT OF THE GREAT LAKES REGION.

THIS AFTERNOON...
DOWNGRADED TO SPRINKLES AND FLURRIES FOR MOST OF CWA AWAY FROM LAKE
MICHIGAN THIS AFTERNOON AS MEASURABLE PRECIPITATION EXTREMELY
DIFFICULT TO COME BY AWAY FROM THE LAKE THIS EVENT AND DO NOT SEE
IMPRESSIVE ENOUGH FORCING TO CHANGE THIS TREND.

TONIGHT...
GOING GRIDS IN DECENT SHAPE WITH LAKE ENHANCED RAIN AND SNOW SHOWERS
PENETRATING SLIGHTLY FURTHER SOUTH INTO CWA AS LL WINDS VEER TO
280-290 DEGREE FETCH AND LAKE PARAMETERS /DELTA T/S IN UPR
TEENS...MINIMAL LL SHEAR...AND LAKE INDUCED CAPES TO 400 J/KG/
COMBINED WITH PLENTIFUL AMBIENT ATMOSPHERIC MOISTURE TO SUPPORT RAIN
AND SNOW WITH MAIN FACTOR PRECLUDING ALL SNOW BEING RELATIVELY
SHALLOW INVERSION WITH CLOUD TOP TEMPS NOT IN DGZ. CONSIDERED
PULLING CHC POPS OUTSIDE LAKE EFFECT AREAS WITH AFOREMENTIONED
DIFFICULTY IN RECEIVING MEASURABLE PRECIP...BUT WILL REMAIN
CONSISTENT AS GUIDANCE NUMBERS AND PASSING S/W SUGGEST MEASURABLE
POPS STILL IN REALM OF POSSIBILITY. TEMPS-WISE...MIXING AND CLOUD
COVER TO OFFSET CAA SO WENT NEAR GUIDANCE FOR LOWS IN THE LOWER 30S
TONIGHT.

SUNDAY...
LAKE ENHANCEMENT/LAKE EFFECT WILL BE MAIN FACTOR IN
FORMATION/CONTINUATION OF PRECIP SUNDAY AS AMBIENT 1000-500 RH/S
PLUMMET TO AOB 50% AND WEAK S/W RIDGING SLIDES IN AHEAD OF YET
ANOTHER WAVE DIVING SOUTH THROUGH THE NRN PLAINS.  DIFFICULT TO
ASSESS PTYPE SUNDAY AS GFS AND NAM BOTH BRING IN CAA AND DROP H85
TEMPS TO AROUND -7C TO -10C BY LATE AFTERNOON...WITH GFS A TOUCH
COLDER. WITH CLOUD TOPS IN THE 750-800MB RANGE...EXPECT PRECIP WILL
EVENTUALLY CHANGE TO ALL SNOW IN THE AFTERNOON BUT LEFT RAIN AND
SLEET MENTION IN UNTIL 7 PM AS ICE CRYSTAL PRESENCE STILL UNCERTAIN.
BACKED OFF POPS AWAY FROM THE LAKE AND JUST MENTIONED SPRINKLES OR
FLURRIES AS COLUMN MOISTURE LOOKS MEAGER. UNDERCUT GUIDANCE BY 3
DEGREES OR SO FOR HIGHS WITH FAIRLY STG CAA AND CLOUD COVER
SUGGESTING HIGHS MAY STRUGGLE TO GET OUT OF THE MID 30S. THIS NOTION
BACKED BY TEMP PERFORMANCE TODAY WELL BELOW MOS.

SUNDAY NIGHT...
LAKE EFFECT MACHINE SHOULD REMAIN RUNNING AND AS SUCH BUMPED POPS TO
LIKELY FOR NRN BERRIEN AND CASS COUNTIES WITH A LITTLE BIT OF
ACCUMULATION POSSIBLE. MAIN CONCERN WILL BE LOWERING INVERSION HTS
AND LACK OF AMBIENT MOISTURE BUT EXPECT IMPRESSIVE DELTA T/S NEAR 20
AND WEAKLY SHEARED UNIDIRECTIONAL LL FLOW FROM 280-290 TO CONTINUE
TO PROMOTE MULTI-BAND SNOW SHOWERS. LOWERED LOW TEMPS IN THE SW AS
ANY CLEARING WILL LIKELY ALLOW TEMPS TO FALL TO THE LOW TO MID
20S...WHICH COULD BE THE COLDEST NIGHT OF THE FALL TO DATE.

&&

.LONG TERM...
MONDAY THROUGH SATURDAY...

AN UPPER LEVEL SYSTEM WILL BE LIFTING RAPIDLY NORTHEAST AWAY FROM
THE AREA EARLY MONDAY. LEFT A CHANCE OF SNOW EARLY OVER FAR SW
LOWER MICH AS ANY LAKE ENHANCED SNOW SHOULD END BY NOON MONDAY.
FOR THE REST OF THE PERIOD...THE MAIN CHALLENGE IS THE TIMING AND
STRENGTH OF SHORT WAVE/S EJECTING NORTHEAST OUT OF THE MAIN WESTERN
CONUS TROF. THE GFS CONTINUES TO HAVE POOR RUN TO RUN CONSISTENCY
WITH THIS PATTERN. THE 12Z GFS HAS SHIFTED THE BEST CHANCE FOR
PRECIPITATION LATER IN THE WEEK WEDNESDAY ALL OF THE WAY THROUGH
FRIDAY NIGHT. KEPT THE CHANCE FOR RAIN WEDNESDAY THEN DRY DUE TO
UNCERTAINTY. PRECIPITATION MAY NEED TO BE ADDED SOME TIME THURSDAY
THROUGH SATURDAY...BUT MOST OF THESE PERIODS SHOULD BE DRY. KEPT
TEMPERATURES MODERATING DURING THE SECOND HALF OF THE WEEK AS
UPPER LEVEL RIDGING BUILDS OVER THE AREA.

&&

.PREV DISCUSSION... /ISSUED 1255 PM EST SAT NOV 8 2008/

AVIATION...

PREDOMINATELY MVFR TAFS THIS PD WITH IFR CIGS A POSSIBILITY
TONIGHT...ESP AT KSBN. SEVERAL DISTURBANCES ROTATING AROUND H5
CLOSED LOW W/PLENTIFUL MOISTURE FOR LOW CEILINGS AND A FEW RAIN
AND SNOW SHOWERS. MOST PRECIPITATION TO STAY NORTH OF TAF SITES IN
MICHIGAN WHERE LL FLOW AND THERMAL PROFILES CONDUCIVE TO LAKE
ENHANCEMENT. FLOW SHOULD VEER JUST ENOUGH FOR SOUTH BEND TO GET IN
ON LAKE EFFECT/ENHANCED -SHRASN IN THE EARLY MORNING HOURS.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST MONDAY FOR LMZ043-046.

&&

$$

SHORT TERM...SIMPSON
LONG TERM...SKIPPER
AVIATION...SIMPSON

000
FXUS63 KIND 082008
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
220 PM EST SAT NOV 8 2008

.DISCUSSION...
MAIN CONCERN WITH THIS AFTERNOONS FORECAST IS THE CHANCE OF PCPN
TONIGHT AND THE TEMPERATURES. VERY STRONG LOW PRESSURE OVER THE
NORTHERN GREAT LAKES WILL CONTINUE TO THE MOVE NORTH. COLD AND
UNSTABLE FLOW WAS ROTATING AROUND THE LOW. A WEAK SHORT WAVE WILL
MOVE THROUGH INDIANA TONIGHT. THIS AFTERNOON SFC OBS WERE SHOWING
SOME SPRINKLES/FLURRIES MOVING THROUGH INDIANA AND TO THE W AND NW.
THESE SHOULD CONTINUE TO MOVE THROUGH THE AREA TONIGHT. WILL KEEP
THIS CHC IN THE MORE UNSTABLE AIR OVER THE NRN HALF. TEMPS SHOULD
BE HIGH ENOUGH TO CAUSE A CHC OF SPRINKLES/FLURRIES THIS EVENING
THEN JUST FLURRIES LATER. THE FWC GUID WAS VERY CLOSE TO ACTUAL
CONDITIONS THIS AFTN. THE OTHER GUIDANCE WAS TOO WARM. DUE TO THIS
WILL GO CLOSER TO THE COLDER FWC GUID. THROUGH 36 HOURS CURRENT
SOUNDINGS CHANGED VERY LITTLE FROM PRVS RUN. GFS CONTINUES TO BE THE
WARMER MODEL. 850 MB SHOWS CONTINUING CAA. GFS 850 MB TEMPS DROP TO
-10 AT 00Z. WITH THIS CAA CONTINUING WILL GO NEAR THE COLDER ETA/NGM
GUID. SLOW WAA STARTS ON MONDAY AS HIGH PRESSURE BUILDS INTO AREA. A
WARM FRONT WILL MOVE THROUGH INDIANA ON TUESDAY. WILL BRING IN A
CHANCE OF PCPN WITH THE FRONT.

FOR THE EXTENDED PORTION ANOTHER COLD FRONT MOVES THROUGH INDIANA ON
THURSDAY. THIS WILL KEEP A CHANCE OF RAIN OVER THE AREA. THE FRONT
WILL MOVE EAST OF INDIANA THU NIGHT TO END THE CHC OF RAIN. SOME WAA
WILL BRGIN ON FRIDAY. TEMPS WILL REACH NEAR NORMAL.

&&

.AVIATION...DISCUSSION FOR 08/18Z TAFS

MVFR CIGS EXPECTED THRU THE PD AS UPPER LOW CONTINUES TO INFLUENCE
THE AREA. WILL BE AREAS OF SPRINKLES OR EVEN A FEW FLURRIES BUT NO
VISBILITY RESTRICTIONS EXPECTED. WIND GUSTS AROUND 20KT ARE POSSIBLE
THIS AFTN BUT WILL DIMINISH BY EARLY EVENING.

UPSTREAM CIGS BELOW BKN020 SHOULD MOVE INTO LAF/IND BY 00Z. MORE
UNCERTAINTY OF WHETHER THESE CIGS WILL MAKE IT TO HUF/BMG SO HAVE
JUST STUCK WITH SCT015 THERE FOR NOW. GRADUAL IMPROVEMENT IN HEIGHTS
CAN BE EXPECTED ON SUNDAY WITH SOME BREAKS APPEARING AFT 18Z.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

AVIATION...CS
PUBLIC...SH

000
FXUS63 KIWX 081755
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1255 PM EST SAT NOV 8 2008

.AVIATION...

PREDOMINATELY MVFR TAFS THIS PD WITH IFR CIGS A POSSIBILITY
TONIGHT...ESP AT KSBN. SEVERAL DISTURBANCES ROTATING AROUND H5
CLOSED LOW W/PLENTIFUL MOISTURE FOR LOW CEILINGS AND A FEW RAIN
AND SNOW SHOWERS. MOST PRECIPITATION TO STAY NORTH OF TAF SITES IN
MICHIGAN WHERE LL FLOW AND THERMAL PROFILES CONDUCIVE TO LAKE
ENHANCEMENT. FLOW SHOULD VEER JUST ENOUGH FOR SOUTH BEND TO GET IN
ON LAKE EFFECT/ENHANCED -SHRASN IN THE EARLY MORNING HOURS.

&&

.PREV DISCUSSION... /ISSUED 645 AM EST SAT NOV 8 2008/

SHORT TERM... SLIGHT PREFERENCE TO GFS IN OVERALL HANDLING OF LRG
SCALE PATTERN OVR NAM. GFS IN SYNC WITH ECMWF PAST SVRL RUNS AND
ALSO PREFER MORE RAPID EWD PROGRESSION OF EPAC WAVE TO SERVE AS
KICKER FOR LWR GRTLKS EXTRTPCL CYCLONE. GFS A BIT SLOWER AND LESS
DIGGING OF FINAL WAVE CRNTLY N OF MN KEEPING THE TROF LESS
AMPLIFIED ACRS ERN GRTLKS SUNDAY NIGHT...IN LINE AS STRONG LIFTG
MID/ULVL JET SEGMENTS NOW INTO WESTERN APPLCHN SPINE WITH 120KT
SEGMENT AT 3H FM TN INTO WRN PA ALRDY THIS AM. DEEPER COLD AIR
ADVECTION IN CWA THIS AM/THICK CLOUD COVER FAVORS TEMPS TDY WITH
LITTLE DIURNAL RECOVERY/WELL BLO MOS TDY...WITH SLIGHT MOD LWR OVR
PREV FCST. DEEP SYNOPTIC MSTR W/LK ENHANCEMENT FAVORS CAT POPS FAR
NWRN CWA FOR MIXED PTYPE SHRA/SHSN. TEMP PROFILE NOT YET CONDUCIVE
FOR ALL SNOW WITH LK TEMP NR 11-12C...T0 HGHT ARND 1.5 KFT W/MAX
TEMP IN TOP/DOWN LYR AOA 3C FOR AT LEAST PARTIAL MELT THRU THE
DAY. 250-260 DEGREE CBL FETCH VEERS TO ABOUT 290 TONIGHT WITH
PASSAGE OF STRNG S/W CRNTLY ACRS WRN MN. STRONG LL LAPSE RATES
SFC-8H GT 7.5 C/KM LT TONIGHT INTO SUN AM WITH LK INDUCED EQL OVR
8KFT/LK BASED CAPSES TO NEAR 500 J/KG STILL SUGGESTS INCRSD
CONVECTIVE CLUSTERS OF RAIN/SNOW SHWRS W/SLEET POTNL WITH MAJORITY
OF ENVIRON LACKING SATURATED DEPTH INTO GROWTH ZONE FOR AN ALL
SNOW EVENT WITH POTNL SUPERCOOLED MOLECULES/HIGH COLLISION GROWTH
ENVIRONMENT. ADDED SML FRZN ACCUM COINCIDENT WITH INCREASED
CATEGORICAL POPS DOWNWIND OF LK MI...WITH SOME MINOR ACCUMS PSBL
ESPCLY A BIT FURTHER AWAY INLAND FM IMMEDIATE WINDWARD SHORE. GRDL
DCRS IN POPS SUN AFTN INTO SUNDAY NIGHT WITH BEST SYNPTC MSTR
STILL RAISED POPS OVR PREV FCST DURING THE DAY SUNDAY WITH YET ONE
LAST STRONG S/W PASSAGE WITH BEST LK/8H THERMAL INSTABILITY
PRESENT DURING EVENT WITH DELTA-T INTO THE LWR 20S/LK INDUCED
CAPES REMAINING 400-500 J/KG BEFORE INVERSION HGHTS CRASH FINALLY
SUNDAY NIGHT. LWRD TEMPS SUNDAY NIGHT AS WELL WITH DEEP CORE OF
COLD AIR IN PLACE/PARTIAL CLRG ALL BUT FAR NW-N CWA.

LONG TERM...

MONDAY THROUGH FRIDAY

NOT MANY CHANGES MADE TO THE LONG TERM PERIOD. FORECAST MODELS AND
ENSEMBLES ARE HAVING MAJOR ISSUES TRYING TO HANDLE THE EFFECTS OF
THE ROBUST PACIFIC UPPER JET/S ADVANCEMENT INTO THE WESTERN CONUS BY
EARLY NEXT WEEK. POSITIVE PNA PHASE WEST COAST RIDGING WILL SUPPORT
CENTRAL CONUS TROUGHING WITH THE DEVELOPMENT OF A DIGGING SW CONUS
UPPER LOW. FORECAST MODELS DO PROG THIS SCENARIO. HOWEVER...IT
IS THE EVOLUTION OF THE SYNOPTIC PATTERN AFTER THIS OCCURS THAT IS
CAUSING MODEL DISCREPANCY. THE 00Z GFS AND ECMWF OFFER DIFFERENT
DEPTHS OF THE SW CONUS UPPER TROUGH AS WELL AS OFFERING DIFFERENT
SCENARIOS OF EJECTING JET ENERGY TO THE NE. IT IS EXPECTED THAT JET
ENERGY WILL INFLUENCE THE REGION GIVEN A WEAK BAROCLINIC ZONE IN
PLACE FROM THE MID MISSISSIPPI REGION INTO THE GREAT LAKES...AND
PRECIP CHANCES REMAIN IN THE FORECAST TUE-WED. THE QUESTION LIES
WITH TIMING AND LOCATION. FORECAST MODELS GEM/GFS/ECWMF BRING
SEVERAL SCENARIOS TO THE TABLE...AS WOULD BE EXPECTED WITH RATHER
COMPLICATED UPPER FLOW. THE ONLY SEMI-RELIABLE SIGNALS REMAIN THE
MEAN GEFS AND NAEFS PROGS...WHICH CONTINUE TO OFFER A SOMEWHAT
CONSISTENT FORECAST...AT LEAST UP THROUGH DAY 5. HAVE REMAINED
CONSERVATIVE IN THE POP DEPARTMENT GIVEN AFOREMENTIONED
CONCERNS...NOT TO MENTION POSSIBLE IMPACTS OF THE NORTHERN STREAM IN
THIS SPLIT FLOW PATTER...WHICH COULD ALTER THINGS SIGNIFICANTLY.
WOULD NOT COUNT OUT A FAST MOVING CLIPPER TYPE SYSTEM GIVEN THE EVER
GROWING COLD AIR DOME IN CANADA...COLLOCATED WITH A RATHER
INTENSE/ACTIVE SERIES OF IMPULSES LIKELY TO TRAVERSE THE REGION
THERE.

MONDAY...HEIGHT RISES WILL BE ONGOING BY THE START OF THE FORECAST
PERIOD. LINGERING LAKE SHOWERS ANS CLOUDS CAN BE EXPECTED CROSS
THE NORTH. THINGS ARE EXPECTED TO WANE THROUGH THE DAY...WITH
CLEARING LIKELY BY EVENING IN THE NORTH. PREFERRED LOWER MAX T
VALUES IN THE NORTH...WHERE CLOUDS WILL LIKELY INHIBIT DIURNAL
RISES.

TUES-FRIDAY...VERY LITTLE CHANGES MADE TO THIS PERIOD GIVEN
CONTINUED POOR GUIDANCE. HAVE FOLLOWED CLOSE TO THE NAEFS/GEFS MEANS
WHICH SUPPORT PREVIOUS POP NUMBERS/LOCATION. BORDERLINE THERMAL
FIELDS STILL SUPPORT A RAIN/SNOW THREAT TUES NIGHT...GIVEN COOL T/S.
HAVE OPTED TO INCLUDE A TEMP TREND BACK TO TOWARD CLIMO THROUGH
FRIDAY...GIVEN LACK OF ANY H85 T ANOMALIES IN ENSEMBLE
PROGS...ESPECIALLY WITH MEAN GFS ENSEMBLE T CONFIDENCE LACKING BY
DAY 6. ECMWF/GFS DETERMINISTIC THERMAL PROGS ALSO SUPPORT THIS IDEA.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST MONDAY FOR LMZ043-046.

&&

$$

SHORT TERM...MURPHY
LONG TERM...CHAMBERLAIN
AVIATION...SIMPSON

000
FXUS63 KIND 081637
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1137 AM EST SAT NOV 8 2008

.AVIATION...DISCUSSION FOR 08/18Z TAFS

MVFR CIGS EXPECTED THRU THE PD AS UPPER LOW CONTINUES TO INFLUENCE
THE AREA. WILL BE AREAS OF SPRINKLES OR EVEN A FEW FLURRIES BUT NO
VISBILITY RESTRICTIONS EXPECTED. WIND GUSTS AROUND 20KT ARE POSSIBLE
THIS AFTN BUT WILL DIMINISH BY EARLY EVENING.

UPSTREAM CIGS BELOW BKN020 SHOULD MOVE INTO LAF/IND BY 00Z. MORE
UNCERTAINTY OF WHETHER THESE CIGS WILL MAKE IT TO HUF/BMG SO HAVE
JUST STUCK WITH SCT015 THERE FOR NOW. GRADUAL IMPROVEMENT IN HEIGHTS
CAN BE EXPECTED ON SUNDAY WITH SOME BREAKS APPEARING AFT 18Z.

&&

.DISCUSSION...DEEP UPPER LOW MOVING ACROSS THE GREAT LAKES WILL
DOMINATE OUR WEATHER THROUGH THE WEEKEND. BREEZY CLOUDY AND VERY
COOL WEATHER WILL BE THE RULE. ALTHOUGH SATELLITE SHOWS THERE COULD
BE A BRIEF PERIOD OF ONLY PARTLY CLOUDY CONDITIONS IN OUR SOUTH
LATER THIS MORNING.

MAIN FOCUS WILL BE WHETHER TO MENTION ANY WRAP AROUND PRECIPITATION
THIS WEEKEND AND ADJUSTMENT TO TEMPERATURES.

MODELS ARE IN PRETTY GOOD AGREEMENT AND WL USE A BLEND. WEATHER
DEPICTION SHOWS LIGHT SNOW SHOWERS ACROSS IOWA AND A FEW FLURRIES AS
CLOSE AS KPIA. MODELS BRING TRACE QPF AMOUNTS ACROSS OUR NORTH LATE
TODAY...TONIGHT INTO SUNDAY.  WILL GO ALONG WITH THIS TREND.
TEMPERATURES SHOULD BE WARM ENOUGH FOR ANY PRECIP TO BE MOSTLY
LIQUID EXCEPT IN THE NORTHWEST WHERE 1000-850 MB THICKNESS ARE CLOSE
TO 1300 METERS. AS FAR AS TEMPERATURES WILL GO BETWEEN MAV/MET
TEMPERATURES TODAY AND CLOSER TO COLDER MET TEMPERATURES ON SUNDAY
AS CLOUD COVER WILL BE THICKER AND COLD AIR WILL HAVE HAD MORE TIME
TO MOVE INTO OUR AREA.

NOT MUCH CHANGE TO EXTENDED.  THE STRONG UPPER LOW WILL MOVE FROM
THE EASTERN GREAT LAKES TO EASTERN CANADA BY TUESDAY AS THE NEXT S/W
MOVES TO THE LOWER AND MIDDLE MISSISSIPPI VALLEY.  BOTH NAM/GFS
BRING LIGHT PRECIP AT LEAST TO OUR SOUTHWEST HALF BY LATE MONDAY
NIGHT AND THE GFS ACROSS OUR REGION ON TUESDAY. PRECIP SHOULD BE ALL
LIQUID WITH THIS S/W. HOWEVER I WOULD NOT COMPLETELY RULE OUT IT
STARTING AS A MIXTURE LATE MONDAY NIGHT IN OUR NORTH IF IT COMES
IN QUICK ENOUGH.

THE EUROPEAN IS SLOWER AND STRONGER AND DOES NOT BRING IN ANY PRECIP
BEFORE WEDNESDAY. FOR NOW WILL GO WITH GFS SCENARIO WHICH GOES WELL
WITH OUR PREVIOUS FORECAST.  GFS INDICATES ANOTHER S/W COULD GIVE US
ANOTHER ROUND OF PRECIP WEDNESDAY AND WEDNESDAY NIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

AVIATION...CS
PUBLIC...JH

000
FXUS63 KIWX 081154
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
645 AM EST SAT NOV 8 2008

.AVIATION...
ONLY MINOR MODIFICATION FM EARLIER ISSUANCE WITH 12 UTC TAF SET.
SHORTWAVE IMMEDIATELY UPSTREAM OF KSBN TO BRING MVFR CIGS AND MIXED
PRECIP FOR NEXT COUPLE OF HOURS. THERMAL PROFILES SUPPORTIVE OF
RAIN/SNOW SHOWERS WITH JUST A VERY LOW POTNL FOR BRIEF HIGH END IFR
CONDITIONS IN HVIER BURSTS...BUT MAINLY EXPECT SIG VSBY REDUCTIONS
TO REMAIN NORTH OF KSBN GIVEN SWRLY IN-CLOUD FETCH ACRS SRN LK MI
THIS AM. SHORTWAVE TO KFWA AROUND 13 UTC TIMEFRAME WITH SATURATION
TO LOWER LEVELS AS COLD AIR ADVECTION IN CYCLONIC LVL FLOW BECOMES
DOMINANT. LOW CHCS OF VERY LIGHT RAIN/SNOW SHOWERS PRECLUDE MENTION
HERE...OTHER THAN VCSH FOR A PD THIS AM. NEXT S/W AGAIN LATER THIS
EVENING TO AGAIN AFFECT KSBN TO GREATER DEGREE AFTR CLOUD BEARING
WINDS VEER IN ITS WAKE...WITH LOW END MVFR/HIGH END SPORADIC IFR
CONDS IN MIXED RAIN/SNOW...INCREASED LOW LVL LAPSE RATES AND THERMAL
PROFILE ALSO SUGGESTIVE FOR POTNL OF CONVECTIVE SLEET SHOWERS TO MIX
IN AS WELL.

&&

.SHORT TERM...
SLIGHT PREFERENCE TO GFS IN OVERALL HANDLING OF LRG SCALE PATTERN
OVR NAM. GFS IN SYNC WITH ECMWF PAST SVRL RUNS AND ALSO PREFER
MORE RAPID EWD PROGRESSION OF EPAC WAVE TO SERVE AS KICKER FOR LWR
GRTLKS EXTRTPCL CYCLONE. GFS A BIT SLOWER AND LESS DIGGING OF
FINAL WAVE CRNTLY N OF MN KEEPING THE TROF LESS AMPLIFIED ACRS ERN
GRTLKS SUNDAY NIGHT...IN LINE AS STRONG LIFTG MID/ULVL JET
SEGMENTS NOW INTO WESTERN APPLCHN SPINE WITH 120KT SEGMENT AT 3H
FM TN INTO WRN PA ALRDY THIS AM. DEEPER COLD AIR ADVECTION IN CWA
THIS AM/THICK CLOUD COVER FAVORS TEMPS TDY WITH LITTLE DIURNAL
RECOVERY/WELL BLO MOS TDY...WITH SLIGHT MOD LWR OVR PREV FCST.
DEEP SYNOPTIC MSTR W/LK ENHANCEMENT FAVORS CAT POPS FAR NWRN CWA
FOR MIXED PTYPE SHRA/SHSN. TEMP PROFILE NOT YET CONDUCIVE FOR ALL
SNOW WITH LK TEMP NR 11-12C...T0 HGHT ARND 1.5 KFT W/MAX TEMP IN
TOP/DOWN LYR AOA 3C FOR AT LEAST PARTIAL MELT THRU THE DAY.
250-260 DEGREE CBL FETCH VEERS TO ABOUT 290 TONIGHT WITH PASSAGE
OF STRNG S/W CRNTLY ACRS WRN MN. STRONG LL LAPSE RATES SFC-8H GT
7.5 C/KM LT TONIGHT INTO SUN AM WITH LK INDUCED EQL OVR 8KFT/LK
BASED CAPSES TO NEAR 500 J/KG STILL SUGGESTS INCRSD CONVECTIVE
CLUSTERS OF RAIN/SNOW SHWRS W/SLEET POTNL WITH MAJORITY OF ENVIRON
LACKING SATURATED DEPTH INTO GROWTH ZONE FOR AN ALL SNOW EVENT
WITH POTNL SUPERCOOLED MOLECULES/HIGH COLLISION GROWTH
ENVIRONMENT. ADDED SML FRZN ACCUM COINCIDENT WITH INCREASED
CATEGORICAL POPS DOWNWIND OF LK MI...WITH SOME MINOR ACCUMS PSBL
ESPCLY A BIT FURTHER AWAY INLAND FM IMMEDIATE WINDWARD SHORE. GRDL
DCRS IN POPS SUN AFTN INTO SUNDAY NIGHT WITH BEST SYNPTC MSTR
STILL RAISED POPS OVR PREV FCST DURING THE DAY SUNDAY WITH YET ONE
LAST STRONG S/W PASSAGE WITH BEST LK/8H THERMAL INSTABILITY
PRESENT DURING EVENT WITH DELTA-T INTO THE LWR 20S/LK INDUCED
CAPES REMAINING 400-500 J/KG BEFORE INVERSION HGHTS CRASH FINALLY
SUNDAY NIGHT. LWRD TEMPS SUNDAY NIGHT AS WELL WITH DEEP CORE OF
COLD AIR IN PLACE/PARTIAL CLRG ALL BUT FAR NW-N CWA.

&&

.LONG TERM...

MONDAY THROUGH FRIDAY

NOT MANY CHANGES MADE TO THE LONG TERM PERIOD. FORECAST MODELS AND
ENSEMBLES ARE HAVING MAJOR ISSUES TRYING TO HANDLE THE EFFECTS OF
THE ROBUST PACIFIC UPPER JET/S ADVANCEMENT INTO THE WESTERN CONUS BY
EARLY NEXT WEEK. POSITIVE PNA PHASE WEST COAST RIDGING WILL SUPPORT
CENTRAL CONUS TROUGHING WITH THE DEVELOPMENT OF A DIGGING SW CONUS
UPPER LOW. FORECAST MODELS DO PROG THIS SCENARIO. HOWEVER...IT
IS THE EVOLUTION OF THE SYNOPTIC PATTERN AFTER THIS OCCURS THAT IS
CAUSING MODEL DISCREPANCY. THE 00Z GFS AND ECMWF OFFER DIFFERENT
DEPTHS OF THE SW CONUS UPPER TROUGH AS WELL AS OFFERING DIFFERENT
SCENARIOS OF EJECTING JET ENERGY TO THE NE. IT IS EXPECTED THAT JET
ENERGY WILL INFLUENCE THE REGION GIVEN A WEAK BAROCLINIC ZONE IN
PLACE FROM THE MID MISSISSIPPI REGION INTO THE GREAT LAKES...AND
PRECIP CHANCES REMAIN IN THE FORECAST TUE-WED. THE QUESTION LIES
WITH TIMING AND LOCATION. FORECAST MODELS GEM/GFS/ECWMF BRING
SEVERAL SCENARIOS TO THE TABLE...AS WOULD BE EXPECTED WITH RATHER
COMPLICATED UPPER FLOW. THE ONLY SEMI-RELIABLE SIGNALS REMAIN THE
MEAN GEFS AND NAEFS PROGS...WHICH CONTINUE TO OFFER A SOMEWHAT
CONSISTENT FORECAST...AT LEAST UP THROUGH DAY 5. HAVE REMAINED
CONSERVATIVE IN THE POP DEPARTMENT GIVEN AFOREMENTIONED
CONCERNS...NOT TO MENTION POSSIBLE IMPACTS OF THE NORTHERN STREAM IN
THIS SPLIT FLOW PATTER...WHICH COULD ALTER THINGS SIGNIFICANTLY.
WOULD NOT COUNT OUT A FAST MOVING CLIPPER TYPE SYSTEM GIVEN THE EVER
GROWING COLD AIR DOME IN CANADA...COLLOCATED WITH A RATHER
INTENSE/ACTIVE SERIES OF IMPULSES LIKELY TO TRAVERSE THE REGION
THERE.

MONDAY...HEIGHT RISES WILL BE ONGOING BY THE START OF THE FORECAST
PERIOD. LINGERING LAKE SHOWERS ANS CLOUDS CAN BE EXPECTED CROSS
THE NORTH. THINGS ARE EXPECTED TO WANE THROUGH THE DAY...WITH
CLEARING LIKELY BY EVENING IN THE NORTH. PREFERRED LOWER MAX T
VALUES IN THE NORTH...WHERE CLOUDS WILL LIKELY INHIBIT DIURNAL
RISES.

TUES-FRIDAY...VERY LITTLE CHANGES MADE TO THIS PERIOD GIVEN
CONTINUED POOR GUIDANCE. HAVE FOLLOWED CLOSE TO THE NAEFS/GEFS MEANS
WHICH SUPPORT PREVIOUS POP NUMBERS/LOCATION. BORDERLINE THERMAL
FIELDS STILL SUPPORT A RAIN/SNOW THREAT TUES NIGHT...GIVEN COOL T/S.
HAVE OPTED TO INCLUDE A TEMP TREND BACK TO TOWARD CLIMO THROUGH
FRIDAY...GIVEN LACK OF ANY H85 T ANOMALIES IN ENSEMBLE
PROGS...ESPECIALLY WITH MEAN GFS ENSEMBLE T CONFIDENCE LACKING BY
DAY 6. ECMWF/GFS DETERMINISTIC THERMAL PROGS ALSO SUPPORT THIS IDEA.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST MONDAY FOR LMZ043-046.

&&

$$

SHORT TERM...MURPHY
LONG TERM...CHAMBERLAIN
AVIATION...MURPHY

000
FXUS63 KIND 081044
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
540 AM EST SAT NOV 8 2008

.AVIATION...DISCUSSION FOR 081200Z TAF ISSUANCE. CHANNELED VORT
LOBE CURRENTLY ACRS NRN IL/NRN IND WITH FAIRLY WIDESPREAD MVFR CIGS
BEHIND FEATURE. MODEL DATA INDICATE THIS FEATURE WL DRFT SLOWLY SEWD
ACRS THE LOCAL AREA DURG THE DAY. AHEAD OF FEATURE...SFC OBS SUGGEST
AREAS VFR CIGS ARND 040 WITH SOME LYRD CLDS ABV SHOULD BE THE RULE
OVR THE CENTRAL/SRN TERMINALS. APPEARS MVFR CIGS HV ALREADY MOVD
INTO THE KLAF AREA...AND THESE CONDS SHOULD HOLD THERE FOR THE MOST
PART. AS VORT LOBE DRFTS SEWD...XPCTG MVFR CIGS TO SLOWLY SPREAD
SE...REACHING THE KBMG TERMINAL ARND 090000Z.

KIND VAD WND PROFILER/MODEL DATA SUGGEST OCNL SFC WND GUSTS IN THE
20-25KT RANGE FM 240-260 HEADINGS PROBABLE TDY...ESPECIALLY AFT
081600Z.

&&

.DISCUSSION...DEEP UPPER LOW MOVING ACROSS THE GREAT LAKES WILL
DOMINATE OUR WEATHER THROUGH THE WEEKEND. BREEZY CLOUDY AND VERY
COOL WEATHER WILL BE THE RULE. ALTHOUGH SATELLITE SHOWS THERE COULD
BE A BRIEF PERIOD OF ONLY PARTLY CLOUDY CONDITIONS IN OUR SOUTH
LATER THIS MORNING.

MAIN FOCUS WILL BE WHETHER TO MENTION ANY WRAP AROUND PRECIPITATION
THIS WEEKEND AND ADJUSTMENT TO TEMPERATURES.

MODELS ARE IN PRETTY GOOD AGREEMENT AND WL USE A BLEND. WEATHER
DEPICTION SHOWS LIGHT SNOW SHOWERS ACROSS IOWA AND A FEW FLURRIES AS
CLOSE AS KPIA. MODELS BRING TRACE QPF AMOUNTS ACROSS OUR NORTH LATE
TODAY...TONIGHT INTO SUNDAY.  WILL GO ALONG WITH THIS TREND.
TEMPERATURES SHOULD BE WARM ENOUGH FOR ANY PRECIP TO BE MOSTLY
LIQUID EXCEPT IN THE NORTHWEST WHERE 1000-850 MB THICKNESS ARE CLOSE
TO 1300 METERS. AS FAR AS TEMPERATURES WILL GO BETWEEN MAV/MET
TEMPERATURES TODAY AND CLOSER TO COLDER MET TEMPERATURES ON SUNDAY
AS CLOUD COVER WILL BE THICKER AND COLD AIR WILL HAVE HAD MORE TIME
TO MOVE INTO OUR AREA.

NOT MUCH CHANGE TO EXTENDED.  THE STRONG UPPER LOW WILL MOVE FROM
THE EASTERN GREAT LAKES TO EASTERN CANADA BY TUESDAY AS THE NEXT S/W
MOVES TO THE LOWER AND MIDDLE MISSISSIPPI VALLEY.  BOTH NAM/GFS
BRING LIGHT PRECIP AT LEAST TO OUR SOUTHWEST HALF BY LATE MONDAY
NIGHT AND THE GFS ACROSS OUR REGION ON TUESDAY. PRECIP SHOULD BE ALL
LIQUID WITH THIS S/W. HOWEVER I WOULD NOT COMPLETELY RULE OUT IT
STARTING AS A MIXTURE LATE MONDAY NIGHT IN OUR NORTH IF IT COMES
IN QUICK ENOUGH.

THE EUROPEAN IS SLOWER AND STRONGER AND DOES NOT BRING IN ANY PRECIP
BEFORE WEDNESDAY. FOR NOW WILL GO WITH GFS SCENARIO WHICH GOES WELL
WITH OUR PREVIOUS FORECAST.  GFS INDICATES ANOTHER S/W COULD GIVE US
ANOTHER ROUND OF PRECIP WEDNESDAY AND WEDNESDAY NIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

AVIATION...JAS
PUBLIC...JH

000
FXUS63 KIWX 081029
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
529 AM EST SAT NOV 8 2008

.SHORT TERM...
SLIGHT PREFERENCE TO GFS IN OVERALL HANDLING OF LRG SCALE PATTERN
OVR NAM. GFS IN SYNC WITH ECMWF PAST SVRL RUNS AND ALSO PREFER
MORE RAPID EWD PROGRESSION OF EPAC WAVE TO SERVE AS KICKER FOR LWR
GRTLKS EXTRTPCL CYCLONE. GFS A BIT SLOWER AND LESS DIGGING OF
FINAL WAVE CRNTLY N OF MN KEEPING THE TROF LESS AMPLIFIED ACRS ERN
GRTLKS SUNDAY NIGHT...IN LINE AS STRONG LIFTG MID/ULVL JET
SEGMENTS NOW INTO WESTERN APPLCHN SPINE WITH 120KT SEGMENT AT 3H
FM TN INTO WRN PA ALRDY THIS AM. DEEPER COLD AIR ADVECTION IN CWA
THIS AM/THICK CLOUD COVER FAVORS TEMPS TDY WITH LITTLE DIURNAL
RECOVERY/WELL BLO MOS TDY...WITH SLIGHT MOD LWR OVR PREV FCST.
DEEP SYNOPTIC MSTR W/LK ENHANCEMENT FAVORS CAT POPS FAR NWRN CWA
FOR MIXED PTYPE SHRA/SHSN. TEMP PROFILE NOT YET CONDUCIVE FOR ALL
SNOW WITH LK TEMP NR 11-12C...T0 HGHT ARND 1.5 KFT W/MAX TEMP IN
TOP/DOWN LYR AOA 3C FOR AT LEAST PARTIAL MELT THRU THE DAY.
250-260 DEGREE CBL FETCH VEERS TO ABOUT 290 TONIGHT WITH PASSAGE
OF STRNG S/W CRNTLY ACRS WRN MN. STRONG LL LAPSE RATES SFC-8H GT
7.5 C/KM LT TONIGHT INTO SUN AM WITH LK INDUCED EQL OVR 8KFT/LK
BASED CAPSES TO NEAR 500 J/KG STILL SUGGESTS INCRSD CONVECTIVE
CLUSTERS OF RAIN/SNOW SHWRS W/SLEET POTNL WITH MAJORITY OF ENVIRON
LACKING SATURATED DEPTH INTO GROWTH ZONE FOR AN ALL SNOW EVENT
WITH POTNL SUPERCOOLED MOLECULES/HIGH COLLISION GROWTH
ENVIRONMENT. ADDED SML FRZN ACCUM COINCIDENT WITH INCREASED
CATEGORICAL POPS DOWNWIND OF LK MI...WITH SOME MINOR ACCUMS PSBL
ESPCLY A BIT FURTHER AWAY INLAND FM IMMEDIATE WINDWARD SHORE. GRDL
DCRS IN POPS SUN AFTN INTO SUNDAY NIGHT WITH BEST SYNPTC MSTR
STILL RAISED POPS OVR PREV FCST DURING THE DAY SUNDAY WITH YET ONE
LAST STRONG S/W PASSAGE WITH BEST LK/8H THERMAL INSTABILITY
PRESENT DURING EVENT WITH DELTA-T INTO THE LWR 20S/LK INDUCED
CAPES REMAINING 400-500 J/KG BEFORE INVERSION HGHTS CRASH FINALLY
SUNDAY NIGHT. LWRD TEMPS SUNDAY NIGHT AS WELL WITH DEEP CORE OF
COLD AIR IN PLACE/PARTIAL CLRG ALL BUT FAR NW-N CWA.

&&

.LONG TERM...

MONDAY THROUGH FRIDAY

NOT MANY CHANGES MADE TO THE LONG TERM PERIOD. FORECAST MODELS AND
ENSEMBLES ARE HAVING MAJOR ISSUES TRYING TO HANDLE THE EFFECTS OF
THE ROBUST PACIFIC UPPER JET/S ADVANCEMENT INTO THE WESTERN CONUS BY
EARLY NEXT WEEK. POSITIVE PNA PHASE WEST COAST RIDGING WILL SUPPORT
CENTRAL CONUS TROUGHING WITH THE DEVELOPMENT OF A DIGGING SW CONUS
UPPER LOW. FORECAST MODELS DO PROG THIS SCENARIO. HOWEVER...IT
IS THE EVOLUTION OF THE SYNOPTIC PATTERN AFTER THIS OCCURS THAT IS
CAUSING MODEL DISCREPANCY. THE 00Z GFS AND ECMWF OFFER DIFFERENT
DEPTHS OF THE SW CONUS UPPER TROUGH AS WELL AS OFFERING DIFFERENT
SCENARIOS OF EJECTING JET ENERGY TO THE NE. IT IS EXPECTED THAT JET
ENERGY WILL INFLUENCE THE REGION GIVEN A WEAK BAROCLINIC ZONE IN
PLACE FROM THE MID MISSISSIPPI REGION INTO THE GREAT LAKES...AND
PRECIP CHANCES REMAIN IN THE FORECAST TUE-WED. THE QUESTION LIES
WITH TIMING AND LOCATION. FORECAST MODELS GEM/GFS/ECWMF BRING
SEVERAL SCENARIOS TO THE TABLE...AS WOULD BE EXPECTED WITH RATHER
COMPLICATED UPPER FLOW. THE ONLY SEMI-RELIABLE SIGNALS REMAIN THE
MEAN GEFS AND NAEFS PROGS...WHICH CONTINUE TO OFFER A SOMEWHAT
CONSISTENT FORECAST...AT LEAST UP THROUGH DAY 5. HAVE REMAINED
CONSERVATIVE IN THE POP DEPARTMENT GIVEN AFOREMENTIONED
CONCERNS...NOT TO MENTION POSSIBLE IMPACTS OF THE NORTHERN STREAM IN
THIS SPLIT FLOW PATTER...WHICH COULD ALTER THINGS SIGNIFICANTLY.
WOULD NOT COUNT OUT A FAST MOVING CLIPPER TYPE SYSTEM GIVEN THE EVER
GROWING COLD AIR DOME IN CANADA...COLLOCATED WITH A RATHER
INTENSE/ACTIVE SERIES OF IMPULSES LIKELY TO TRAVERSE THE REGION
THERE.

MONDAY...HEIGHT RISES WILL BE ONGOING BY THE START OF THE FORECAST
PERIOD. LINGERING LAKE SHOWERS ANS CLOUDS CAN BE EXPECTED CROSS
THE NORTH. THINGS ARE EXPECTED TO WANE THROUGH THE DAY...WITH
CLEARING LIKELY BY EVENING IN THE NORTH. PREFERRED LOWER MAX T
VALUES IN THE NORTH...WHERE CLOUDS WILL LIKELY INHIBIT DIURNAL
RISES.

TUES-FRIDAY...VERY LITTLE CHANGES MADE TO THIS PERIOD GIVEN
CONTINUED POOR GUIDANCE. HAVE FOLLOWED CLOSE TO THE NAEFS/GEFS MEANS
WHICH SUPPORT PREVIOUS POP NUMBERS/LOCATION. BORDERLINE THERMAL
FIELDS STILL SUPPORT A RAIN/SNOW THREAT TUES NIGHT...GIVEN COOL T/S.
HAVE OPTED TO INCLUDE A TEMP TREND BACK TO TOWARD CLIMO THROUGH
FRIDAY...GIVEN LACK OF ANY H85 T ANOMALIES IN ENSEMBLE
PROGS...ESPECIALLY WITH MEAN GFS ENSEMBLE T CONFIDENCE LACKING BY
DAY 6. ECMWF/GFS DETERMINISTIC THERMAL PROGS ALSO SUPPORT THIS IDEA.

&&

.AVIATION...
SHORTWAVE IMMEDIATELY UPSTREAM OF KSBN TO BRING MVFR CIGS AND MIXED
PRECIP IN COUPLE OF HOURS. THERMAL PROFILES SUPPORTIVE OF RAIN/SNOW
SHOWERS WITH A LOW POTNL FOR HIGH END IFR CONDITIONS IN HVIER SNOW
BURSTS...BUT MAINLY NORTH OF KSBN GIVEN IN CLOUD FETCH ACRS SRN LK
MI THIS AM. SHORTWAVE TO KFWA AROUND 11-12 UTC TIMEFRAME WITH
SATURATION TO LOWER LEVELS ONCE COLD AIR ADVECTION IN CYCLONIC LVL
FLOW BECOMES DOMINANT. LOW CHCS OF VERY LIGHT RAIN/SNOW TO PRECLUDE
MENTION HERE. NEXT S/W TO AGAIN LATE THIS EVENING TO AGAIN AFFECT
KSBN TO GREATER DEGREE WITH LOW END MVFR/HIGH END SPORADIC IFR CONDS
IN MIXED RAIN/SNOW...HIGH LOW LVL LAPSE RATES AND THERMAL PROFILE
ALSO SUGGEST POTNL FOR CONVECTIVE SLEET SHOWERS TO MIX IN AS WELL.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST MONDAY FOR LMZ043-046.

&&

$$

SHORT TERM...MURPHY
LONG TERM...CHAMBERLAIN
AVIATION...MURPHY

000
FXUS63 KIND 080844
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
330 AM EST SAT NOV 8 2008

.DISCUSSION...DEEP UPPER LOW MOVING ACROSS THE GREAT LAKES WILL
DOMINATE OUR WEATHER THROUGH THE WEEKEND. BREEZY CLOUDY AND VERY
COOL WEATHER WILL BE THE RULE. ALTHOUGH SATELLITE SHOWS THERE COULD
BE A BRIEF PERIOD OF ONLY PARTLY CLOUDY CONDITIONS IN OUR SOUTH
LATER THIS MORNING.

MAIN FOCUS WILL BE WHETHER TO MENTION ANY WRAP AROUND PRECIPITATION
THIS WEEKEND AND ADJUSTMENT TO TEMPERATURES.

MODELS ARE IN PRETTY GOOD AGREEMENT AND WL USE A BLEND. WEATHER
DEPICTION SHOWS LIGHT SNOW SHOWERS ACROSS IOWA AND A FEW FLURRIES AS
CLOSE AS KPIA. MODELS BRING TRACE QPF AMOUNTS ACROSS OUR NORTH LATE
TODAY...TONIGHT INTO SUNDAY.  WILL GO ALONG WITH THIS TREND.
TEMPERATURES SHOULD BE WARM ENOUGH FOR ANY PRECIP TO BE MOSTLY
LIQUID EXCEPT IN THE NORTHWEST WHERE 1000-850 MB THICKNESS ARE CLOSE
TO 1300 METERS. AS FAR AS TEMPERATURES WILL GO BETWEEN MAV/MET
TEMPERATURES TODAY AND CLOSER TO COLDER MET TEMPERATURES ON SUNDAY
AS CLOUD COVER WILL BE THICKER AND COLD AIR WILL HAVE HAD MORE TIME
TO MOVE INTO OUR AREA.

NOT MUCH CHANGE TO EXTENDED.  THE STRONG UPPER LOW WILL MOVE FROM
THE EASTERN GREAT LAKES TO EASTERN CANADA BY TUESDAY AS THE NEXT S/W
MOVES TO THE LOWER AND MIDDLE MISSISSIPPI VALLEY.  BOTH NAM/GFS
BRING LIGHT PRECIP AT LEAST TO OUR SOUTHWEST HALF BY LATE MONDAY
NIGHT AND THE GFS ACROSS OUR REGION ON TUESDAY. PRECIP SHOULD BE ALL
LIQUID WITH THIS S/W. HOWEVER I WOULD NOT COMPLETELY RULE OUT IT
STARTING AS A MIXTURE LATE MONDAY NIGHT IN OUR NORTH IF IT COMES
IN QUICK ENOUGH.

THE EUROPEAN IS SLOWER AND STRONGER AND DOES NOT BRING IN ANY PRECIP
BEFORE WEDNESDAY. FOR NOW WILL GO WITH GFS SCENARIO WHICH GOES WELL
WITH OUR PREVIOUS FORECAST.  GFS INDICATES ANOTHER S/W COULD GIVE US
ANOTHER ROUND OF PRECIP WEDNESDAY AND WEDNESDAY NIGHT.

&&

.AVIATION...DISCUSSION FOR 06Z TAFS.
VFR EXPECTED THROUGH THE TAF PD.  SOME BREAKS IN THE CLOUDS WAS SEEN
ON SATELLITE THIS EVENING.  SCT-BKN CLOUDS AT 4-5KFT ARE EXPECTED
THROUGH THE MAJORITY OF THE TAF PD.  THERE IS A CHANCE THAT SOME OF
THE MVFR...OVC025...CLOUDS OVER IOWA COULD REACH KLAF BY SATURDAY
MORNING SO WILL ADD THAT TO THIS ISSUANCE.

WIND WILL AGAIN PICK UP AND GUST INTO THE 18-24KT RANGE ON SATURDAY
THEN SUBSIDE AFTER SUNSET.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$
AVIATION...SALLY
PUBLIC...JH

000
FXUS63 KIWX 080546
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1255 AM EST SAT NOV 8 2008

.AVIATION...
SHORTWAVE IMMEDIATELY UPSTREAM OF KSBN TO BRING MVFR CIGS AND MIXED
PRECIP IN COUPLE OF HOURS. THERMAL PROFILES SUPPORTIVE OF RAIN/SNOW
SHOWERS WITH A LOW POTNL FOR HIGH END IFR CONDITIONS IN HVIER SNOW
BURSTS...BUT MAINLY NORTH OF KSBN GIVEN IN CLOUD FETCH ACRS SRN LK
MI THIS AM. SHORTWAVE TO KFWA AROUND 11-12 UTC TIMEFRAME WITH
SATURATION TO LOWER LEVELS ONCE COLD AIR ADVECTION IN CYCLONIC LVL
FLOW BECOMES DOMINANT. LOW CHCS OF VERY LIGHT RAIN/SNOW TO PRECLUDE
MENTION HERE. NEXT S/W TO AGAIN LATE THIS EVENING TO AGAIN AFFECT
KSBN TO GREATER DEGREE WITH LOW END MVFR/HIGH END SPORADIC IFR CONDS
IN MIXED RAIN/SNOW...HIGH LOW LVL LAPSE RATES AND THERMAL PROFILE
ALSO SUGGEST POTNL FOR CONVECTIVE SLEET SHOWERS TO MIX IN AS WELL.

&&

.SHORT TERM...
TONIGHT THROUGH SATURDAY NIGHT...

INTERESTING FORECAST NEXT 36 HRS AS PIECES OF S/W ENERGY DIVE
INTO AND INTERACT WITH UPR LOW THAT WILL WOBBLES ITS WAY NE
THROUGH THE GREAT LAKES. AMPLIFIED BUT PROGRESSIVE FLOW PATTERN
EXPECTED TO CONTINUE WILL KEEP FILLED UPR LOW MOVING...ALBEIT
SLOWLY...TO LAKE HURON BY 00Z SUNDAY. MODELS STRUGGLING MIGHTILY
TODAY WITH PRECIP OVER ILLINOIS WITH 12Z 4KM WRF NMM BEING THE
ONLY MODEL TO TRULY CATCH IT. WILL FAVOR THIS MODEL AND GFS FOR
THIS SHORT TERM PACKAGE.

TONIGHT...
EXPECT RADAR RETURNS OVER NRN IL/SRN WI...WHICH ARE REFLECTED BY
SEVERAL OBS OF RA/IP/SN...TO CONTINUE TO MOVE NE THIS AFTERNOON. AS
THIS BAND PIVOTS NE...EXPECT IT TO BRUSH THE NW CWA AROUND NIGHTFALL
AS MAINLY -RA.  DYNAMICAL AND DIURNAL COOLING SHOULD ALLOW ANY
PRECIP THAT FALLS AFTER 3Z TO BE ABLE TO MIX WITH SNOW OR SLEET. NO
SNOW ACCUMULATIONS WILL OCCUR. LOWERED POP CHCS IN THE SE CWA TO
KEEP SLIGHT CHC RUNNING THROUGH NIGHT AS FORCING FOR PRECIP LOOKS
TOO WEAK THAT FAR FROM UPR LOW. HUNG RIGHT AROUND GUIDANCE TONIGHT
FOR LOWS...MAYBE A DEGREE ABOVE AS STG CAA OF THIS AFTERNOON CEASES
AND CLOUD COVER AND MIXING KEEP TEMPS FROM FREE-FALLING.

SATURDAY...
UNSETTLED FLOW WILL CONTINUE AS UPR LOW MOVES FROM CENTRAL LAKE
MICHIGAN ACROSS THE LOWER PENINSULA.  ONCE AGAIN WLY LL FLOW WILL
KEEP LAKE MICHIGAN FROM BEING A FACTOR SAVE MICHIGAN COUNTIES. GOING
PROBS OF RAIN AND SNOW LOOK GOOD AND CANNOT SEE MUCH ADVANTAGE TO
ADJUSTING GRIDS WITH LIKELY POPS MICHIGAN COUNTIES TO CHC POPS
INDIANA AND OHIO COUNTIES LOOKING LIKE THE BEST BET ATTM. SOME
CONCERN PRECIP MAY STAY ALL RAIN IN LAKE MODIFIED AIRMASS
IMMEDIATELY UPWIND OF LAKE MICHIGAN ALONG THE MICHIGAN WEST COAST
BUT CANNOT RULE OUT FLAKES MIXING IN.

SATURDAY NIGHT...
SIMILAR STORY TO SATURDAY AS S/W DIVES SOUTH IN BEHIND DEPARTING UPR
LOW AND REINFORCES MEAN TROUGH. AS FIRST SFC LOW MOVES NE...CYCLONIC
FLOW WILL ALLOW WINDS TO VEER TO NEAR 290 DEGREES BUT NO FURTHER AS
SFC LOW MOVES NORTH TO THE HUDSON BAY BY 12Z SUN. AFOREMENTIONED 290
FETCH WILL ALLOW A FEW MORE COUNTIES FURTHER SOUTH TO GET INTO THE
FOLD AND AS SUCH WILL LEAVE POPS AS IS WITH CAT POP NEAR THE LAKE
FADING TO NO WX SW CWA AWAY FROM THE LAKE.

&&

.LONG TERM...
SUNDAY THROUGH FRIDAY...

CHALLENGES THIS PERIOD INCLUDE PRECIPITATION TYPE AND COVERAGE
SUNDAY AND SUNDAY NIGHT. A SECONDARY IMPULSE OR WEAK TROF WILL
MOVE SOUTHEAST INTO THE WESTERN GREAT LAKES REGION SUNDAY. THIS
SYSTEM WILL BRING A CHANCE FOR RAIN AND SNOW SUNDAY...WITH ANY
PRECIPITATION BECOMING ALL SNOW SUNDAY NIGHT EXCEPT POSSIBLY RIGHT
AT THE LAKE SHORE WHERE LOW LEVEL TEMPERATURES REMAIN WARM.
ISENTROPIC LIFT SUNDAY AND SUNDAY NIGHT ARE NOT IMPRESSIVE PER
NAM/WRF. A MID LEVEL INVERSION WITH VERY DRY AIR IN THE MID LEVELS
WILL ALSO INHIBIT PRECIPITATION. HOWEVER...GIVEN SOME LAKE EFFECT
ENHANCEMENT...KEPT THE CHANCE FOR A MIX SUNDAY...WITH HIGHEST
PRECIPITATION CHANCES OVER FAR LOWER MICHIGAN. LITTLE IF ANY SNOW
ACCUMULATION IS EXPECTED. THIS SYSTEM WILL LIFT RAPIDLY NORTHEAST
SUNDAY NIGHT. FOR THE REST OF THE PERIOD...THE LONGWAVE TROF WILL
PERSIST OVER THE WESTERN HALF OF THE CONUS AS SMALL SHORTWAVE TROFS
EJECT NORTHEAST. THIS TYPE OF PATTERN IS INHERENTLY LOW
CONFIDENCE...WHICH HAS BEEN REFLECTED IN THE RELATIVELY LARGE SPREAD
OF THE GFS ENSEMBLES IN HANDLING THESE SMALLER TROFS. FOR THIS
PACKAGE...KEPT A CHANCE FOR RAIN TUESDAY WITH A MIX POSSIBLE TUESDAY
NIGHT MAINLY SOUTH OF THE MICHIGAN LINE...THEN DRY WEDNESDAY AND
THURSDAY. THE ECMWF SUGGESTS A STRONG SYSTEM THURSDAY WITH THE BULK
OF THE MAIN TROF EJECTING NORTHEAST...SO THIS POSSIBILITY WILL NEED
TO BE WATCHED BY SUBSEQUENT SHIFT/S.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR LMZ043-046.

&&

$$

SHORT TERM...SIMPSON
LONG TERM...SKIPPER
AVIATION...MURPHY

000
FXUS63 KIND 080448
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1148 PM EST FRI NOV 7 2008

.AVIATION...DISCUSSION FOR 06Z TAFS.
VFR EXPECTED THROUGH THE TAF PD.  SOME BREAKS IN THE CLOUDS WAS SEEN
ON SATELLITE THIS EVENING.  SCT-BKN CLOUDS AT 4-5KFT ARE EXPECTED
THROUGH THE MAJORITY OF THE TAF PD.  THERE IS A CHANCE THAT SOME OF
THE MVFR...OVC025...CLOUDS OVER IOWA COULD REACH KLAF BY SATURDAY
MORNING SO WILL ADD THAT TO THIS ISSUANCE.

WIND WILL AGAIN PICK UP AND GUST INTO THE 18-24KT RANGE ON SATURDAY
THEN SUBSIDE AFTER SUNSET.

&&

.PREV DISCUSSION...DEEP LOW PRES SYS WAS CENTERED OVR IA TDY AND
INITIAL COLD FRONT WAS WELL EAST OF INDIANA...OVR CENTRAL OH. DRY
SLOT WAS IN PLACE OVR INDIANA AND VIS PIX SHOW WRAP AROUND CLOUDS
OVR IL ADVANCING TOWARD INDIANA.

MODELS ARE IN PRETTY GOOD AGREEMENT AND WL USE A BLEND. MAIN
FORECAST CHALLENGE TDY WL BE POPS.

THE STRONG LOW PRES SYSTEM IS EXPECTED TO PROPAGATE E-NE OVR THE
48HRS AND STRONG CAA IS EXPECTED TO BEGIN ACRS INDIANA LATE THIS
AFTERNOON AND EVENING. TIME HEIGHT SECTIONS SHOW SATURATED LOWER
LVLS...STRATUS CLDS...AS THE CD AIR ARRIVES LATER TDY. STRONG CAA WL
BE IN PLACE WITH H8 TEMPS FALLING TO NEAR -5C BY 12Z SAT AND
LINGERING NEAR THIS VALUE THROUGH SUNDAY. WITH THIS KIND OF TEMP
PROFILE EXPECT SC TO TO KEEP MUCH OF THE WEEKEND CLOUDY AND RATHER
COOL. IN THE UPPER LVLS A S/W WL PIVOT AROUND THE UPPER LOW ON SAT
AFTERNOON AND SWEEP ACRS INDIANA. THIS IN COMBINATION WITH THE COLD
AIR ALOFT AND WEAK INSTABILITY COULD LEAD TO SOME SCT SHRA ACRS
MAINLY THE NRN PARTS OF THE FA WHERE THE DYNAMICS ARE BEST.
FURTHERMORE...FORECAST SOUNDINGS HERE ARE COLD ENOUGH TO SUGGEST
THAT SHSN WL POSSIBLE WHEN MIXING IN. ONGOING FORECAST HANDLES THIS
WELL...AND WL NOT NEED TO MAKE MANY ADJUSTMENTS. HOWEVER WITH VRY
LIGHT PCPN EXPECTED...I AM NOT CONFIDENT THAT WE WILL HAVE
MEASURABLE PCPN ALONG AND SOUTH OF I-70. THUS WL REDUCE MENTION ON
SATURDAY TO JUST SPRINKLES.

PCPN SHUD COME TO AN END AS UPPER S/W DEPARTS AND MINIMAL DAYTIME
HEATING ENDS ON SAT EVENING. AS MENTIONED FOR PREVIOUS
REASONING...EXPECT MOCLDY SKIES SAT NIGHT AND SUNDAY.

HIGH PRES BEGINS TO BUILD IN ON SUNDAY NIGHT AS THE SFC FLOW BECOMES
FOR ANTICYCLONIC IN THE WAKE OF THE DEPARTING LOW. WL WAIT TIL THEN
TO REDUCE CLOUDINESS TO PTCLDY LEVELS.

AS FOR TEMPS...GIVEN THE STRONG CAA THAT WL BE IN PLACE OVR THE
WEEKEND WL LEAN TO THE COOLER SIDE OF THE MAVMOS BY 1-3 DEGREES ON
BOTH HIGHS AND LOWS.

AS FOR THE EXTENDED...RIDGE OF HIGH PRES IN THE WAKE OF THE UPPER
LOW WL RESIDE ACRS THE RGN ON SUN AND MONDAY...PROVIDING DRY BUT
COOL WX.

ECMWF AND GFS DIFFER ON THE HANDLING OF THE CYCLONE DEVELOPMENT AND
PROPAGATION ON TUES THROUGH WED. GFS DEVELOPS A STRONGER SYSTEM AND
PROPAGATES THE SYS NE FROM THE SOUTHERN PLAINS ACRS THE OHIO VALLEY.
ECMWF DIFFERS WITH THE DEVELOPMENT OF A WEAKER SYSTEM AND PROPAGATES
THE SYSTEM ACRS DIXIE. THIS MAY BE IN RESPONSE TO STRONGER UPPER
WAVE OVER SOUTH CENTRAL CANADA THAT IT ADVERTISES...DISALLOWING THE
NW PROPAGATION. FOR NOW HAVE TAKEN A MIDDLE OF THE ROAD APPROACH AS
NE FLOW AHEAD OF THIS SYSTEM IS AGREED UPON. STILL ATMOS MAY TAKE A
WHILE TO SATURATE AS DRY AIR WL BE PLACE AHEAD OF THE SYS.

MORE COOL BUT DRY WX APPEARS IN STORE FOR THURSDAY AND FRI IN THE
WAKE OF THE DEPARTING LOW.

&&


.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$
AVIATION...SALLY
PUBLIC...PUMA

000
FXUS63 KIWX 072321
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
621 PM EST FRI NOV 7 2008

.AVIATION...
SERIES OF SHRTWV`S EXPECTED TO ROTATE AROUND UPR LEVEL LOW AS IT
LIFTS NE FROM ITS CURRENT LOCATION OVER ERN IA TO NRN LH BY SAT EVE.
FIRST SHRTWV WILL LIFT NE ACROSS THE AREA THIS EVE CAUSING LOW VFR
CIGS TO OVERSPREAD THE AREA AS STORM`S DRY SLOT GRDLY MOISTENS UP.
NEXT SHRTWV OVER MS VALLEY ATTM WILL MOVE ACROSS THE AREA LATE
TONIGHT...LIKELY CAUSING SOME LIGHT SHOWERS AT SBN AND CIGS LOWERING
TO MVFR AT BOTH TERMINALS. MAIN UPR LEVEL TROF AXIS WILL MOVE EAST
ACROSS NRN INDIANA ON SATURDAY AFTN. DEEPER MOISTURE ON BACKSIDE OF
TROF SHOULD SPREAD INTO SBN IN THE AFTN RESULTING IN LIGHT RN/SN
SHOWERS AS LOW LEVEL CYCLONIC CONTS. SLIGHTLY MORE LOW LEVEL
MOISTURE AT SBN SHOULD KEEP CIGS MVFR ON SATURDAY WHILE EXPECT FWA
WILL MANAGE TO MIX OUT INTO THE LOW VFR RANGE DURING THE AFTN.
PROXIMITY OF STRONG LOW WILL CAUSE BRISK AND GUSTY SWLY WINDS
THROUGH THE PD.

&&

.SHORT TERM...
...TONIGHT THROUGH SATURDAY NIGHT...

INTERESTING FORECAST NEXT 36 HRS AS PIECES OF S/W ENERGY DIVE
INTO AND INTERACT WITH UPR LOW THAT WILL WOBBLES ITS WAY NE
THROUGH THE GREAT LAKES. AMPLIFIED BUT PROGRESSIVE FLOW PATTERN
EXPECTED TO CONTINUE WILL KEEP FILLED UPR LOW MOVING...ALBEIT
SLOWLY...TO LAKE HURON BY 00Z SUNDAY. MODELS STRUGGLING MIGHTILY
TODAY WITH PRECIP OVER ILLINOIS WITH 12Z 4KM WRF NMM BEING THE
ONLY MODEL TO TRULY CATCH IT. WILL FAVOR THIS MODEL AND GFS FOR
THIS SHORT TERM PACKAGE.

TONIGHT...
EXPECT RADAR RETURNS OVER NRN IL/SRN WI...WHICH ARE REFLECTED BY
SEVERAL OBS OF RA/IP/SN...TO CONTINUE TO MOVE NE THIS AFTERNOON. AS
THIS BAND PIVOTS NE...EXPECT IT TO BRUSH THE NW CWA AROUND NIGHTFALL
AS MAINLY -RA.  DYNAMICAL AND DIURNAL COOLING SHOULD ALLOW ANY
PRECIP THAT FALLS AFTER 3Z TO BE ABLE TO MIX WITH SNOW OR SLEET. NO
SNOW ACCUMULATIONS WILL OCCUR. LOWERED POP CHCS IN THE SE CWA TO
KEEP SLIGHT CHC RUNNING THROUGH NIGHT AS FORCING FOR PRECIP LOOKS
TOO WEAK THAT FAR FROM UPR LOW. HUNG RIGHT AROUND GUIDANCE TONIGHT
FOR LOWS...MAYBE A DEGREE ABOVE AS STG CAA OF THIS AFTERNOON CEASES
AND CLOUD COVER AND MIXING KEEP TEMPS FROM FREE-FALLING.

SATURDAY...
UNSETTLED FLOW WILL CONTINUE AS UPR LOW MOVES FROM CENTRAL LAKE
MICHIGAN ACROSS THE LOWER PENINSULA.  ONCE AGAIN WLY LL FLOW WILL
KEEP LAKE MICHIGAN FROM BEING A FACTOR SAVE MICHIGAN COUNTIES. GOING
PROBS OF RAIN AND SNOW LOOK GOOD AND CANNOT SEE MUCH ADVANTAGE TO
ADJUSTING GRIDS WITH LIKELY POPS MICHIGAN COUNTIES TO CHC POPS
INDIANA AND OHIO COUNTIES LOOKING LIKE THE BEST BET ATTM. SOME
CONCERN PRECIP MAY STAY ALL RAIN IN LAKE MODIFIED AIRMASS
IMMEDIATELY UPWIND OF LAKE MICHIGAN ALONG THE MICHIGAN WEST COAST
BUT CANNOT RULE OUT FLAKES MIXING IN.

SATURDAY NIGHT...
SIMILAR STORY TO SATURDAY AS S/W DIVES SOUTH IN BEHIND DEPARTING UPR
LOW AND REINFORCES MEAN TROUGH. AS FIRST SFC LOW MOVES NE...CYCLONIC
FLOW WILL ALLOW WINDS TO VEER TO NEAR 290 DEGREES BUT NO FURTHER AS
SFC LOW MOVES NORTH TO THE HUDSON BAY BY 12Z SUN. AFOREMENTIONED 290
FETCH WILL ALLOW A FEW MORE COUNTIES FURTHER SOUTH TO GET INTO THE
FOLD AND AS SUCH WILL LEAVE POPS AS IS WITH CAT POP NEAR THE LAKE
FADING TO NO WX SW CWA AWAY FROM THE LAKE.

&&

.LONG TERM...
SUNDAY THROUGH FRIDAY...

CHALLENGES THIS PERIOD INCLUDE PRECIPITATION TYPE AND COVERAGE
SUNDAY AND SUNDAY NIGHT. A SECONDARY IMPULSE OR WEAK TROF WILL
MOVE SOUTHEAST INTO THE WESTERN GREAT LAKES REGION SUNDAY. THIS
SYSTEM WILL BRING A CHANCE FOR RAIN AND SNOW SUNDAY...WITH ANY
PRECIPITATION BECOMING ALL SNOW SUNDAY NIGHT EXCEPT POSSIBLY RIGHT
AT THE LAKE SHORE WHERE LOW LEVEL TEMPERATURES REMAIN WARM.
ISENTROPIC LIFT SUNDAY AND SUNDAY NIGHT ARE NOT IMPRESSIVE PER
NAM/WRF. A MID LEVEL INVERSION WITH VERY DRY AIR IN THE MID LEVELS
WILL ALSO INHIBIT PRECIPITATION. HOWEVER...GIVEN SOME LAKE EFFECT
ENHANCEMENT...KEPT THE CHANCE FOR A MIX SUNDAY...WITH HIGHEST
PRECIPITATION CHANCES OVER FAR LOWER MICHIGAN. LITTLE IF ANY SNOW
ACCUMULATION IS EXPECTED. THIS SYSTEM WILL LIFT RAPIDLY NORTHEAST
SUNDAY NIGHT. FOR THE REST OF THE PERIOD...THE LONGWAVE TROF WILL
PERSIST OVER THE WESTERN HALF OF THE CONUS AS SMALL SHORTWAVE TROFS
EJECT NORTHEAST. THIS TYPE OF PATTERN IS INHERENTLY LOW
CONFIDENCE...WHICH HAS BEEN REFLECTED IN THE RELATIVELY LARGE SPREAD
OF THE GFS ENSEMBLES IN HANDLING THESE SMALLER TROFS. FOR THIS
PACKAGE...KEPT A CHANCE FOR RAIN TUESDAY WITH A MIX POSSIBLE TUESDAY
NIGHT MAINLY SOUTH OF THE MICHIGAN LINE...THEN DRY WEDNESDAY AND
THURSDAY. THE ECMWF SUGGESTS A STRONG SYSTEM THURSDAY WITH THE BULK
OF THE MAIN TROF EJECTING NORTHEAST...SO THIS POSSIBILITY WILL NEED
TO BE WATCHED BY SUBSEQUENT SHIFT/S.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR LMZ043-046.

&&

$$

SHORT TERM...SIMPSON
LONG TERM...SKIPPER
AVIATION...JT

000
FXUS63 KIND 072312
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
712 PM EST FRI NOV 7 2008

.AVIATION...DISCUSSION FOR 00Z TAFS.
VFR TO MVFR CONDITIONS WILL PREVAIL THROUGH THIS TAF PD.  A LARGE
AREA OF CLOUDS ASSOCIATED WITH A LOW PRESSURE SYSTEM WAS MOVING INTO
CENTRAL INDIANA.  BY 04Z ALL OF CENTRAL INDIANA WILL BE OVERCAST
AROUND 3-4KFT.

GUSTY WINDS WILL SUBSIDE BUT SUSTAINED WINDS WILL STAY UP AROUND
10KTS THROUGH THE PD.

&&

.PREV DISCUSSION...DEEP LOW PRES SYS WAS CENTERED OVR IA TDY AND
INITIAL COLD FRONT WAS WELL EAST OF INDIANA...OVR CENTRAL OH. DRY
SLOT WAS IN PLACE OVR INDIANA AND VIS PIX SHOW WRAP AROUND CLOUDS
OVR IL ADVANCING TOWARD INDIANA.

MODELS ARE IN PRETTY GOOD AGREEMENT AND WL USE A BLEND. MAIN
FORECAST CHALLENGE TDY WL BE POPS.

THE STRONG LOW PRES SYSTEM IS EXPECTED TO PROPAGATE E-NE OVR THE
48HRS AND STRONG CAA IS EXPECTED TO BEGIN ACRS INDIANA LATE THIS
AFTERNOON AND EVENING. TIME HEIGHT SECTIONS SHOW SATURATED LOWER
LVLS...STRATUS CLDS...AS THE CD AIR ARRIVES LATER TDY. STRONG CAA WL
BE IN PLACE WITH H8 TEMPS FALLING TO NEAR -5C BY 12Z SAT AND
LINGERING NEAR THIS VALUE THROUGH SUNDAY. WITH THIS KIND OF TEMP
PROFILE EXPECT SC TO TO KEEP MUCH OF THE WEEKEND CLOUDY AND RATHER
COOL. IN THE UPPER LVLS A S/W WL PIVOT AROUND THE UPPER LOW ON SAT
AFTERNOON AND SWEEP ACRS INDIANA. THIS IN COMBINATION WITH THE COLD
AIR ALOFT AND WEAK INSTABILITY COULD LEAD TO SOME SCT SHRA ACRS
MAINLY THE NRN PARTS OF THE FA WHERE THE DYNAMICS ARE BEST.
FURTHERMORE...FORECAST SOUNDINGS HERE ARE COLD ENOUGH TO SUGGEST
THAT SHSN WL POSSIBLE WHEN MIXING IN. ONGOING FORECAST HANDLES THIS
WELL...AND WL NOT NEED TO MAKE MANY ADJUSTMENTS. HOWEVER WITH VRY
LIGHT PCPN EXPECTED...I AM NOT CONFIDENT THAT WE WILL HAVE
MEASURABLE PCPN ALONG AND SOUTH OF I-70. THUS WL REDUCE MENTION ON
SATURDAY TO JUST SPRINKLES.

PCPN SHUD COME TO AN END AS UPPER S/W DEPARTS AND MINIMAL DAYTIME
HEATING ENDS ON SAT EVENING. AS MENTIONED FOR PREVIOUS
REASONING...EXPECT MOCLDY SKIES SAT NIGHT AND SUNDAY.

HIGH PRES BEGINS TO BUILD IN ON SUNDAY NIGHT AS THE SFC FLOW BECOMES
FOR ANTICYCLONIC IN THE WAKE OF THE DEPARTING LOW. WL WAIT TIL THEN
TO REDUCE CLOUDINESS TO PTCLDY LEVELS.

AS FOR TEMPS...GIVEN THE STRONG CAA THAT WL BE IN PLACE OVR THE
WEEKEND WL LEAN TO THE COOLER SIDE OF THE MAVMOS BY 1-3 DEGREES ON
BOTH HIGHS AND LOWS.

AS FOR THE EXTENDED...RIDGE OF HIGH PRES IN THE WAKE OF THE UPPER
LOW WL RESIDE ACRS THE RGN ON SUN AND MONDAY...PROVIDING DRY BUT
COOL WX.

ECMWF AND GFS DIFFER ON THE HANDLING OF THE CYCLONE DEVELOPMENT AND
PROPAGATION ON TUES THROUGH WED. GFS DEVELOPS A STRONGER SYSTEM AND
PROPAGATES THE SYS NE FROM THE SOUTHERN PLAINS ACRS THE OHIO VALLEY.
ECMWF DIFFERS WITH THE DEVELOPMENT OF A WEAKER SYSTEM AND PROPAGATES
THE SYSTEM ACRS DIXIE. THIS MAY BE IN RESPONSE TO STRONGER UPPER
WAVE OVER SOUTH CENTRAL CANADA THAT IT ADVERTISES...DISALLOWING THE
NW PROPAGATION. FOR NOW HAVE TAKEN A MIDDLE OF THE ROAD APPROACH AS
NE FLOW AHEAD OF THIS SYSTEM IS AGREED UPON. STILL ATMOS MAY TAKE A
WHILE TO SATURATE AS DRY AIR WL BE PLACE AHEAD OF THE SYS.

MORE COOL BUT DRY WX APPEARS IN STORE FOR THURSDAY AND FRI IN THE
WAKE OF THE DEPARTING LOW.

&&


.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$
AVIATION...SALLY
PUBLIC...PUMA

000
FXUS63 KIWX 072041
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
341 PM EST FRI NOV 7 2008

.SHORT TERM...
...TONIGHT THROUGH SATURDAY NIGHT...

INTERESTING FORECAST NEXT 36 HRS AS PIECES OF S/W ENERGY DIVE
INTO AND INTERACT WITH UPR LOW THAT WILL WOBBLES ITS WAY NE
THROUGH THE GREAT LAKES. AMPLIFIED BUT PROGRESSIVE FLOW PATTERN
EXPECTED TO CONTINUE WILL KEEP FILLED UPR LOW MOVING...ALBEIT
SLOWLY...TO LAKE HURON BY 00Z SUNDAY. MODELS STRUGGLING MIGHTILY
TODAY WITH PRECIP OVER ILLINOIS WITH 12Z 4KM WRF NMM BEING THE
ONLY MODEL TO TRULY CATCH IT. WILL FAVOR THIS MODEL AND GFS FOR
THIS SHORT TERM PACKAGE.

TONIGHT...
EXPECT RADAR RETURNS OVER NRN IL/SRN WI...WHICH ARE REFLECTED BY
SEVERAL OBS OF RA/IP/SN...TO CONTINUE TO MOVE NE THIS AFTERNOON. AS
THIS BAND PIVOTS NE...EXPECT IT TO BRUSH THE NW CWA AROUND NIGHTFALL
AS MAINLY -RA.  DYNAMICAL AND DIURNAL COOLING SHOULD ALLOW ANY
PRECIP THAT FALLS AFTER 3Z TO BE ABLE TO MIX WITH SNOW OR SLEET. NO
SNOW ACCUMULATIONS WILL OCCUR. LOWERED POP CHCS IN THE SE CWA TO
KEEP SLIGHT CHC RUNNING THROUGH NIGHT AS FORCING FOR PRECIP LOOKS
TOO WEAK THAT FAR FROM UPR LOW. HUNG RIGHT AROUND GUIDANCE TONIGHT
FOR LOWS...MAYBE A DEGREE ABOVE AS STG CAA OF THIS AFTERNOON CEASES
AND CLOUD COVER AND MIXING KEEP TEMPS FROM FREE-FALLING.

SATURDAY...
UNSETTLED FLOW WILL CONTINUE AS UPR LOW MOVES FROM CENTRAL LAKE
MICHIGAN ACROSS THE LOWER PENINSULA.  ONCE AGAIN WLY LL FLOW WILL
KEEP LAKE MICHIGAN FROM BEING A FACTOR SAVE MICHIGAN COUNTIES. GOING
PROBS OF RAIN AND SNOW LOOK GOOD AND CANNOT SEE MUCH ADVANTAGE TO
ADJUSTING GRIDS WITH LIKELY POPS MICHIGAN COUNTIES TO CHC POPS
INDIANA AND OHIO COUNTIES LOOKING LIKE THE BEST BET ATTM. SOME
CONCERN PRECIP MAY STAY ALL RAIN IN LAKE MODIFIED AIRMASS
IMMEDIATELY UPWIND OF LAKE MICHIGAN ALONG THE MICHIGAN WEST COAST
BUT CANNOT RULE OUT FLAKES MIXING IN.

SATURDAY NIGHT...
SIMILAR STORY TO SATURDAY AS S/W DIVES SOUTH IN BEHIND DEPARTING UPR
LOW AND REINFORCES MEAN TROUGH. AS FIRST SFC LOW MOVES NE...CYCLONIC
FLOW WILL ALLOW WINDS TO VEER TO NEAR 290 DEGREES BUT NO FURTHER AS
SFC LOW MOVES NORTH TO THE HUDSON BAY BY 12Z SUN. AFOREMENTIONED 290
FETCH WILL ALLOW A FEW MORE COUNTIES FURTHER SOUTH TO GET INTO THE
FOLD AND AS SUCH WILL LEAVE POPS AS IS WITH CAT POP NEAR THE LAKE
FADING TO NO WX SW CWA AWAY FROM THE LAKE.

&&

.LONG TERM...
SUNDAY THROUGH FRIDAY...

CHALLENGES THIS PERIOD INCLUDE PRECIPITATION TYPE AND COVERAGE
SUNDAY AND SUNDAY NIGHT. A SECONDARY IMPULSE OR WEAK TROF WILL
MOVE SOUTHEAST INTO THE WESTERN GREAT LAKES REGION SUNDAY. THIS
SYSTEM WILL BRING A CHANCE FOR RAIN AND SNOW SUNDAY...WITH ANY
PRECIPITATION BECOMING ALL SNOW SUNDAY NIGHT EXCEPT POSSIBLY RIGHT
AT THE LAKE SHORE WHERE LOW LEVEL TEMPERATURES REMAIN WARM. ISENTROPIC
LIFT SUNDAY AND SUNDAY NIGHT ARE NOT IMPRESSIVE PER NAM/WRF. A MID
LEVEL INVERSION WITH VERY DRY AIR IN THE MID LEVELS WILL ALSO
INHIBIT PRECIPITATION. HOWEVER...GIVEN SOME LAKE EFFECT
ENHANCEMENT...KEPT THE CHANCE FOR A MIX SUNDAY...WITH HIGHEST
PRECIPITATION CHANCES OVER FAR LOWER MICHIGAN. LITTLE IF ANY SNOW
ACCUMULATION IS EXPECTED. THIS SYSTEM WILL LIFT RAPIDLY NORTHEAST
SUNDAY NIGHT. FOR THE REST OF THE PERIOD...THE LONGWAVE TROF WILL
PERSIST OVER THE WESTERN HALF OF THE CONUS AS SMALL SHORTWAVE TROFS
EJECT NORTHEAST. THIS TYPE OF PATTERN IS INHERENTLY LOW
CONFIDENCE...WHICH HAS BEEN REFLECTED IN THE RELATIVELY LARGE
SPREAD OF THE GFS ENSEMBLES IN HANDLING THESE SMALLER TROFS. FOR
THIS PACKAGE...KEPT A CHANCE FOR RAIN TUESDAY WITH A MIX POSSIBLE
TUESDAY NIGHT MAINLY SOUTH OF THE MICHIGAN LINE...THEN DRY
WEDNESDAY AND THURSDAY. THE ECMWF SUGGESTS A STRONG SYSTEM
THURSDAY WITH THE BULK OF THE MAIN TROF EJECTING NORTHEAST...SO
THIS POSSIBILITY WILL NEED TO BE WATCHED BY SUBSEQUENT SHIFT/S.

&&

.PREV DISCUSSION... /ISSUED 1257 PM EST FRI NOV 7 2008/

AVIATION...DISCUSSION FOR 18Z TAFS...

VFR CONDS THIS AFTERNOON UNDER DRY SLOT EXPECTED TO GIVE WAY TO
MVFR TONIGHT...FIRST AT KSBN BY 00Z...THEN KFWA NEAR DAYBREAK AS
UPR LOW MEANDERS EAST TO CEN LAKE MICHIGAN BY 12Z SAT. HELD OFF ON
ANY PRECIP MENTION AS BEST VERTICAL MOTION FIELDS APPEAR TO REMAIN
NORTH OF AREA AND LAKE ENHANCEMENT...PER DELTA T/S IN THE UPR
TEENS...STAYS NORTH OF BOTH TAF SITES W/230-250 DEGREE FETCH.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR LMZ043-046.

&&

$$

SHORT TERM...SIMPSON
LONG TERM...SKIPPER
AVIATION...SIMPSON

000
FXUS63 KIND 071923
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
224 PM EST FRI NOV 7 2008

.DISCUSSION...DEEP LOW PRES SYS WAS CENTERED OVR IA TDY AND INITIAL
COLD FRONT WAS WELL EAST OF INDIANA...OVR CENTRAL OH. DRY SLOT WAS
IN PLACE OVR INDIANA AND VIS PIX SHOW WRAP AROUND CLOUDS OVR IL
ADVANCING TOWARD INDIANA.

MODELS ARE IN PRETTY GOOD AGREEMENT AND WL USE A BLEND. MAIN
FORECAST CHALLENGE TDY WL BE POPS.

THE STRONG LOW PRES SYSTEM IS EXPECTED TO PROPAGATE E-NE OVR THE
48HRS AND STRONG CAA IS EXPECTED TO BEGIN ACRS INDIANA LATE THIS
AFTERNOON AND EVENING. TIME HEIGHT SECTIONS SHOW SATURATED LOWER
LVLS...STRATUS CLDS...AS THE CD AIR ARRIVES LATER TDY. STRONG CAA WL
BE IN PLACE WITH H8 TEMPS FALLING TO NEAR -5C BY 12Z SAT AND
LINGERING NEAR THIS VALUE THROUGH SUNDAY. WITH THIS KIND OF TEMP
PROFILE EXPECT SC TO TO KEEP MUCH OF THE WEEKEND CLOUDY AND RATHER
COOL. IN THE UPPER LVLS A S/W WL PIVOT AROUND THE UPPER LOW ON SAT
AFTERNOON AND SWEEP ACRS INDIANA. THIS IN COMBINATION WITH THE COLD
AIR ALOFT AND WEAK INSTABILITY COULD LEAD TO SOME SCT SHRA ACRS
MAINLY THE NRN PARTS OF THE FA WHERE THE DYNAMICS ARE BEST.
FURTHERMORE...FORECAST SOUNDINGS HERE ARE COLD ENOUGH TO SUGGEST
THAT SHSN WL POSSIBLE WHEN MIXING IN. ONGOING FORECAST HANDLES THIS
WELL...AND WL NOT NEED TO MAKE MANY ADJUSTMENTS. HOWEVER WITH VRY
LIGHT PCPN EXPECTED...I AM NOT CONFIDENT THAT WE WILL HAVE
MEASURABLE PCPN ALONG AND SOUTH OF I-70. THUS WL REDUCE MENTION ON
SATURDAY TO JUST SPRINKLES.

PCPN SHUD COME TO AN END AS UPPER S/W DEPARTS AND MINIMAL DAYTIME
HEATING ENDS ON SAT EVENING. AS MENTIONED FOR PREVIOUS
REASONING...EXPECT MOCLDY SKIES SAT NIGHT AND SUNDAY.

HIGH PRES BEGINS TO BUILD IN ON SUNDAY NIGHT AS THE SFC FLOW BECOMES
FOR ANTICYCLONIC IN THE WAKE OF THE DEPARTING LOW. WL WAIT TIL THEN
TO REDUCE CLOUDINESS TO PTCLDY LEVELS.

AS FOR TEMPS...GIVEN THE STRONG CAA THAT WL BE IN PLACE OVR THE
WEEKEND WL LEAN TO THE COOLER SIDE OF THE MAVMOS BY 1-3 DEGREES ON
BOTH HIGHS AND LOWS.

AS FOR THE EXTENDED...RIDGE OF HIGH PRES IN THE WAKE OF THE UPPER
LOW WL RESIDE ACRS THE RGN ON SUN AND MONDAY...PROVIDING DRY BUT
COOL WX.

ECMWF AND GFS DIFFER ON THE HANDLING OF THE CYCLONE DEVELOPMENT AND
PROPAGATION ON TUES THROUGH WED. GFS DEVELOPS A STRONGER SYSTEM AND
PROPAGATES THE SYS NE FROM THE SOUTHERN PLAINS ACRS THE OHIO VALLEY.
ECMWF DIFFERS WITH THE DEVELOPMENT OF A WEAKER SYSTEM AND PROPAGATES
THE SYSTEM ACRS DIXIE. THIS MAY BE IN RESPONSE TO STRONGER UPPER
WAVE OVER SOUTH CENTRAL CANADA THAT IT ADVERTISES...DISALLOWING THE
NW PROPAGATION. FOR NOW HAVE TAKEN A MIDDLE OF THE ROAD APPROACH AS
NE FLOW AHEAD OF THIS SYSTEM IS AGREED UPON. STILL ATMOS MAY TAKE A
WHILE TO SATURATE AS DRY AIR WL BE PLACE AHEAD OF THE SYS.

MORE COOL BUT DRY WX APPEARS IN STORE FOR THURSDAY AND FRI IN THE
WAKE OF THE DEPARTING LOW.

&&

.AVIATION...DISCUSSION FOR 08/18Z TAFS

AS COLDER AIR MOVES IN THIS AFTN BKN035-040 DECK WILL SPREAD WEST TO
EAST ACROSS THE TAF SITES. W/SW WINDS WILL GUST TO AROUND 20KT AS
WELL. DURING THE NIGHT WINDS WILL DIMINISH...BUT CLOUDS WILL REMAIN.
MODELS ARE HINTING AT MVFR CIGS AFT 06Z...ESPECIALLY AT LAF AND IND
AS COLDER AIR CONTINUES TO FLOW IN. AM CONFIDENT ENOUGH TO PUT IN
MVFR CIGS AT OVC025 AT LAF...BUT NOT SO SURE AT IND OR OTHER SITES.
WILL PUT IN A SCT025 LAYER TO HINT AT THE POSSIBILITY ELSEWHERE.
LATER ISSUANCES WILL BE ABLE TO REFINE. DURING THE DAY ON SATURDAY
EXPECT CIGS TO CONTINUE ALONG WITH A THREAT FOR MVFR CONDS. SCT
-SHRA ALSO POSSIBLE...BUT ATTM DOES NOT LOOK LIKE THEY SHOULD IMPACT
VSBYS.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

AVIATION...CS
PUBLIC...PUMA

000
FXUS63 KIWX 071757
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1257 PM EST FRI NOV 7 2008

.AVIATION...DISCUSSION FOR 18Z TAFS...

VFR CONDS THIS AFTERNOON UNDER DRY SLOT EXPECTED TO GIVE WAY TO
MVFR TONIGHT...FIRST AT KSBN BY 00Z...THEN KFWA NEAR DAYBREAK AS
UPR LOW MEANDERS EAST TO CEN LAKE MICHIGAN BY 12Z SAT. HELD OFF ON
ANY PRECIP MENTION AS BEST VERTICAL MOTION FIELDS APPEAR TO REMAIN
NORTH OF AREA AND LAKE ENHANCEMENT...PER DELTA T/S IN THE UPR
TEENS...STAYS NORTH OF BOTH TAF SITES W/230-250 DEGREE FETCH.


&&

.PREV DISCUSSION... /ISSUED 645 AM EST FRI NOV 7 2008/

SHORT TERM... TODAY THROUGH SATURDAY NIGHT. COMPLEX SHORT TERM
FCST ISSUES WRT NON-DIURNAL TEMPS TDY FOLLOWED BY TIMING OF S/W
FOLLOWED BY LK EFFECT PRECIP CHC AS WRAPPED UL LOW TRAVERSES EWD
TO LK HURON LT SAT NIGHT. PREFERENCE LIES WITH GFS WITH GOOD
CAPTURE OF UL SYSTEM ACRS SWRN MN AND ID OF S/W ACRS SERN NW
TERRITORIES WITH 07/00 UTC RUN FOLLOWED UP WITH GOOD ECMWF/UKMET
AGREEMENT. NAM A BIT SUSPECT WITH KEEPING OCLD SYSTEM DEEPENING
AND WITH CAN S/W SLOW TO DROP SSE...WHICH ALREADY EVIDENT IN W/V
IMAGERY WITH HIGH PVU/TROP FOLD BREAKING THRU WEAKENING COL.

TODAY CWA LRGLY TO REMAIN IN DRY SLOT BEHIND FIRST COLD FRONT
SWEEPING EWD INTO ERN GRLKTS. 1000-8H LYR TEMPS FALLING 4-5C THIS
AFTERNOON ACRS CWA SUPPORTIVE OF NON-DIURNAL/FALLING TEMPS ACRS
ENTIRE CWA. AS UL LW NEARS TONIGHT...POTENT COMPACT S/W FM SRN MN
INTO SERN NE WITH STRONG SFC FNT REFLECTION/EXTREME MIXDOWN IN
STRONG CAA IN WAKE OF FNT WITH EARLIER KMHE PKWND 28061KTS IN
BLIZZARD CONDITIONS ACRS ERN SD. SATURATION OF LW LVLS TONIGHT AS
THIS FEATURE AND UL NEARS WITH INCREASING LK-8H LAPSE RATES TO
SUPPORT PRIMARILY MIXED SHRA/SHSN ACRS BERRIEN INTO CASS MI WITH
INITIAL 240-250 DEGREE FETCH...BETTER CHCS ESPCLY AFTR MIDNIGHT
ONCE COLDER AIR BCMS BETTER ESTABLISHED/IN CLD SHEAR DIMINISHES.
WL HOLD OFF ON ANY ACCUM MENTION GIVEN WARM GROUND AND MIXED PTYPE
AS ENVIRON HIGHLY MODIFED BY WARM LK. LK INDUCED CAPES RUN 350-550
J/KG THRU THE DAY SAT WITH DELTA-T NEAR 20C. FETCH VEERS TO ABOUT
260 FAVORING A LARGER PORTION OF NRN CWA. YET ANOTHER STRG S/W
PASSAGE SAT NIGHT WITH STRONG 7H JET DIVING THRU SWRN
GRTLKS...SOME CONCERN WITH DCRSD MSTR DEPTH HOWEVER INTENSE LAPSE
RATES ACRS SRN LK MI WITH DELTA-T IN UPPER TEENS TO NEAR
20C CONTD VEERING OF CBL WINDS/CONVERGENT SIGNALS ACRS SERN LK MI.
HIGHLY TURBULENT/CONVECTIVE MESOOSCALE PROCESSES MAY ALSO ALLOW
FOR CHC OF SLEET SHOWERS AT TIMES SAT NIGHT. GRTR WINDS/GUSTS INTO
NSH WATERS FOR NR GALE CONDS BRIEFLY SAT NIGHT...DEBATED NEED FOR
GL.W COLLABORATION AND BREVITY OF HIR GUSTS SUGGESTS HOLDING ONTO
SC.Y FOR NOW.

LONG TERM...

SUNDAY THROUGH THURSDAY

WATER VAPOR IMAGERY OVER THE WESTERN PACIFIC IN ADDITION TO 00Z
SYNOPTIC OBS REVEAL A VERY POTENT UPPER TROUGH WITH AN ASSOCIATED
POWERHOUSE UPPER JET. NERLY ZONAL WESTERLY FLOW OVER THE PACIFIC
WILL LEND TO THE EASTWARD ADVANCEMENT OF THIS STORM
SYSTEM...SUPPORTING AN EASTWARD SHIFT OF THIS ENHANCED EASTERN ASIAN
JET...BRINGING THE EXIT REGION TO THE WESTERN US BY EARLY NEXT WEEK.
THIS WILL SUPPORT A SHIFT TO A POSITIVE PNA REGIME...A SIGNAL THAT
MEAN GFS ENSEMBLES ARE LOCKING ONTO WITH ABOVE NORMAL CONFIDENCE.
HENCE...EXPECTING A SHIFT TO AN ACTIVE SPLIT FLOW PATTERN WITH THE
LOCAL REGION REMAINING BELOW NORMAL WRT TEMPS. FORECAST MODELS AND
ENSEMBLES CONTINUE TO FAVOR ADVANCING THE RATHER INTENSE UPPER
TROUGH OVER THE EASTERN PACIFIC /NEAR 40N 150W CURRENTLY/ INTO THE
WESTERN US WITH A PERIOD OF DIGGING...WHICH WILL DEEPEN AND SHIFT
THIS SYSTEM SOUTH...ESPECIALLY GIVEN THE LOCATION OF THE SETTLING
BAROCLINIC ZONE. WILL PREFER TO SIDE WITH MODEL SOLUTIONS THAT OFFER
A STORM TRACK FARTHER SOUTH AND SLOWER...VERY SIMILAR TO THE 00Z
ECMWF AND 12Z GEFS. THE NORTHERN STREAM WILL ALSO HAVE TO BE
MONITORED AS ANOTHER CLIPPER TYPE SYSTEM IS POSSIBLE TO DIVE
INTO THE GREAT LAKES IN THE MON-TUES TIME FRAME...ACTING TO
REINFORCE COOLER THERMAL PROFILES AS WELL AS SHIFTING FAVORED
BAROCLINIC REGIONS SOUTH. HAVE REMAINED CLOSE TO A BLEND OF THE
GEFS AND ECMWF.

SUNDAY...THE SLOWLY DEPARTING/FILLING UPPER LOW WILL CONTINUE TO
BRING VERY COOL/CLOUDY/AND BREEZY CONDITIONS. A SECONDARY IMPULSE
WILL SHIFT SE AROUND THE BACK SIDE OF THIS SYSTEM...BRINGING A
REINFORCING SHOT OF COLD AIR WITH H85 T/S PLUMMETING TO -9C BY 12Z
MON. LARGE SCALE ASCENT COUPLED WITH FRONTOGENETIC FORCING WILL
SUPPORT AN INCREASED CHANCE FOR RAIN OR SNOW SHOWERS SUNDAY...MAINLY
NORTH...WITH A TRANSITION TO LAKE EFFECT PROCESS AS CAA OVER THE
WARM LAKE WATERS SUPPORTS DELTA T VALUES PUSHING 20C. EXPECTING
BEST COVERAGE TO BE IN MI AT THIS TIME GIVEN WESTERLY WINDS. HAVE
INCREASED POPS IN THE NORTH FOR THIS. THINGS SHOULD WIND DOWN SUNDAY
NIGHT AS HEIGHT RISES SUPPORT QUICKLY FALLING INVERSION
HEIGHTS...DIMINISHING LAKE INDUCED CAPE. SOME ACCUMULATION MAY BE
POSSIBLE SUNDAY EVENING...MAINLY ON GRASSY SURFACES IN MI.

MON THROUGH THURSDAY...SPLIT FLOW WILL DOMINATE IN THIS PERIOD. HAVE
INTRODUCED LOW POPS IN THE SOUTH TUES-TUES NIGHT WITH THE APPROACH
OF THE SW CONUS UPPER TROUGH. THETA-E ADVECTION ALOFT WILL SUPPORT A
PRECIP THREAT AS THIS SYSTEM NEARS THE REGION. GIVEN THE ECMWF/S
PORTRAYAL OF A NORTHERN STREAM MID LVL TROUGH DIVING SOUTH INTO THE
GREAT LAKES /TYPICAL OF A POSITIVE PNA PATTERN/ AHEAD OF THIS SYSTEM
TUES...HAVE SOME CONCERN ON A POSSIBLE SNOW THREAT GIVEN SOME OF THE
PROGGED SOUNDINGS/DRY NORTHERLY FLOW/AND A COOLING BL PER DIURNAL
EFFECTS...ALTHOUGH TOO MUCH DRY AIR WOULD BE DETRIMENTAL TO PRECIP
CHANCES. HENCE HAVE ADDED RAIN OR SNOW WORDING TUES NIGHT. NOT
GETTING OVERLY EXCITED ABOUT THIS SYSTEM YET DO TO A FAIRLY HIGH
TRACK SPREAD...BUT IT CERTAINLY BARES WATCHING. BEYOND TUES
NIGHT...FORECAST MODELS BECOME HIGHLY DIVERGENT AND HAVE OPTED TO
HOLD TEMPS SLIGHTLY BELOW NORMAL IN LINE WITH THE REGIME...KEEPING A
DRY FORECAST AT THIS TIME UNTIL BETTER SIGNALS ARE PRESENT.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR LMZ043-046.

&&

$$

SHORT TERM...MURPHY
LONG TERM...CHAMBERLAIN
AVIATION...SIMPSON

000
FXUS63 KIND 071633
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1133 AM EST FRI NOV 7 2008

.AVIATION...DISCUSSION FOR 08/18Z TAFS

AS COLDER AIR MOVES IN THIS AFTN BKN035-040 DECK WILL SPREAD WEST TO
EAST ACROSS THE TAF SITES. W/SW WINDS WILL GUST TO AROUND 20KT AS
WELL. DURING THE NIGHT WINDS WILL DIMINISH...BUT CLOUDS WILL REMAIN.
MODELS ARE HINTING AT MVFR CIGS AFT 06Z...ESPECIALLY AT LAF AND IND
AS COLDER AIR CONTINUES TO FLOW IN. AM CONFIDENT ENOUGH TO PUT IN
MVFR CIGS AT OVC025 AT LAF...BUT NOT SO SURE AT IND OR OTHER SITES.
WILL PUT IN A SCT025 LAYER TO HINT AT THE POSSIBILITY ELSEWHERE.
LATER ISSUANCES WILL BE ABLE TO REFINE. DURING THE DAY ON SATURDAY
EXPECT CIGS TO CONTINUE ALONG WITH A THREAT FOR MVFR CONDS. SCT
-SHRA ALSO POSSIBLE...BUT ATTM DOES NOT LOOK LIKE THEY SHOULD IMPACT
VSBYS.

&&

.DISCUSSION...SHOWERS WERE STILL ACROSS OUR SOUTHEAST SECTIONS BUT
THEY WILL BE OUT OF OUR FORECAST AREA BEFORE SUNRISE.  SATELLITE
SHOWED CLEARING HAD ALREADY OCCURRED ACROSS WEST CENTRAL SECTIONS.
SURFACE ANALYSIS INDICATED COLD FRONT WAS ACROSS EAST CENTRAL
INDIANA.  HOWEVER BULK OF COLDER AIR WAS STILL OFF TO OUR WEST.

MAIN FORECAST CONCERNS WILL PRECIP CHANCES AND TYPE TONIGHT AND
SATURDAY AND ALSO HOW QUICK CLOUDS MOVE BACK INTO OUR AREA.
SATELLITE LOOPS INDICATE MOSTLY CLEAR CONDITIONS WILL SPREAD ACROSS
OUR AREA THIS MORNING AS DRY SLOT AHEAD OF STRONG UPPER LOW MOVES
ACROSS OUR AREA.  AFTER THAT WRAP AROUND CLOUDS FROM UPPER LOW WILL
SPREAD EAST ACROSS OUR REGION LATER TODAY. BUFKIT ALSO INDICATES
WIND GUSTS IN EXCESS OF 25 KNOTS POSSIBLE LATER TODAY.

BOTH NAM/GFS MOVE STRONG UPPER LOW INTO THE GREAT LAKES SATURDAY
BRINGING VERY LIGHT QPF INTO OUR NW LATER TONIGHT AND ACROSS OUR
NORTH SATURDAY. 1000-850 MB THICKNESS DROP TO NEAR OR SLIGHTLY BELOW
1300 METERS IN OUR NORTHWEST LATE TONIGHT AND REMAIN NEAR THAT VALUE
ON SATURDAY IN THE NORTHWEST. SO WILL MENTION CHANCE OF LIGHT RAIN
AND SNOW SHOWERS THERE.

NOT MUCH CHANGE TO REST OF FORECAST. STRONG UPPER LOW REMAINS NEAR
OR JUST NORTHEAST OF THE GREAT LAKES TO MONDAY. THEN NAM/GFS
INDICATE ANOTHER S/W COMING IN FROM THE PACIFIC COAST COULD AFFECT
US BY MONDAY NIGHT OR TUESDAY.  EUROPEAN IS A LITTLE SLOWER AND A
LITTLE WEAKER WITH THIS SYSTEM HOWEVER.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

AVIATION...CS
PUBLIC...JH

000
FXUS63 KIWX 071148
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
645 AM EST FRI NOV 7 2008

.AVIATION...
LITTLE CHNG WITH 12 UTC TAFS. MUCH DRIER AIR CONTS TO ADVANCE EWD
ACRS NRN IN...MAJORITY OF FCST VFR WITH DETAIL OF MVFR SHRA/SHSN
POTNL LATE IN FCST PD AT KSBN AS UL LOW NEARS. STRONG SFC-8H LAPSE
RATES TO DEVELOP WITH SUN IN DRY SLOT BY MID-LATE AM FOR INCREASED
MIXING/MOMENTUM XFER FOR GUSTS INTO LWR/MID 20KT RANGE. DEEPER
COLDER AIR TO FOLLOW BEHIND SECONDARY COLD FRNTL/SHORTWAVE PASSAGE
THIS EVENING/FOLLOWED BY APPROACH OF COLDER MIDLVL TEMPS AS 5H LOW
DROPS ESE INTO SRN WI LATE IN FCST PD TO ALLOW FOR SATURATION IN
030-035 LYR...WITH SOME SCT SHRA/SHSN INVOF KSBN...WITH GRTR
COVERAGE/PROBABILITY N OF SITE...GIVEN SWRLY FETCH ACRS SRN LK MI.

&&

.SHORT TERM...
TODAY THROUGH SATURDAY NIGHT. COMPLEX SHORT TERM FCST ISSUES WRT
NON-DIURNAL TEMPS TDY FOLLOWED BY TIMING OF S/W FOLLOWED BY LK
EFFECT PRECIP CHC AS WRAPPED UL LOW TRAVERSES EWD TO LK HURON LT
SAT NIGHT. PREFERENCE LIES WITH GFS WITH GOOD CAPTURE OF UL SYSTEM
ACRS SWRN MN AND ID OF S/W ACRS SERN NW TERRITORIES WITH 07/00 UTC
RUN FOLLOWED UP WITH GOOD ECMWF/UKMET AGREEMENT. NAM A BIT SUSPECT
WITH KEEPING OCLD SYSTEM DEEPENING AND WITH CAN S/W SLOW TO DROP
SSE...WHICH ALREADY EVIDENT IN W/V IMAGERY WITH HIGH PVU/TROP
FOLD BREAKING THRU WEAKENING COL.

TODAY CWA LRGLY TO REMAIN IN DRY SLOT BEHIND FIRST COLD FRONT
SWEEPING EWD INTO ERN GRLKTS. 1000-8H LYR TEMPS FALLING 4-5C THIS
AFTERNOON ACRS CWA SUPPORTIVE OF NON-DIURNAL/FALLING TEMPS ACRS
ENTIRE CWA. AS UL LW NEARS TONIGHT...POTENT COMPACT S/W FM SRN MN
INTO SERN NE WITH STRONG SFC FNT REFLECTION/EXTREME MIXDOWN IN
STRONG CAA IN WAKE OF FNT WITH EARLIER KMHE PKWND 28061KTS IN
BLIZZARD CONDITIONS ACRS ERN SD. SATURATION OF LW LVLS TONIGHT AS
THIS FEATURE AND UL NEARS WITH INCREASING LK-8H LAPSE RATES TO
SUPPORT PRIMARILY MIXED SHRA/SHSN ACRS BERRIEN INTO CASS MI WITH
INITIAL 240-250 DEGREE FETCH...BETTER CHCS ESPCLY AFTR MIDNIGHT
ONCE COLDER AIR BCMS BETTER ESTABLISHED/IN CLD SHEAR DIMINISHES.
WL HOLD OFF ON ANY ACCUM MENTION GIVEN WARM GROUND AND MIXED PTYPE
AS ENVIRON HIGHLY MODIFED BY WARM LK. LK INDUCED CAPES RUN 350-550
J/KG THRU THE DAY SAT WITH DELTA-T NEAR 20C. FETCH VEERS TO ABOUT
260 FAVORING A LARGER PORTION OF NRN CWA. YET ANOTHER STRG S/W
PASSAGE SAT NIGHT WITH STRONG 7H JET DIVING THRU SWRN
GRTLKS...SOME CONCERN WITH DCRSD MSTR DEPTH HOWEVER INTENSE LAPSE
RATES ACRS SRN LK MI WITH DELTA-T IN UPPER TEENS TO NEAR
20C CONTD VEERING OF CBL WINDS/CONVERGENT SIGNALS ACRS SERN LK MI.
HIGHLY TURBULENT/CONVECTIVE MESOOSCALE PROCESSES MAY ALSO ALLOW
FOR CHC OF SLEET SHOWERS AT TIMES SAT NIGHT. GRTR WINDS/GUSTS INTO
NSH WATERS FOR NR GALE CONDS BRIEFLY SAT NIGHT...DEBATED NEED FOR
GL.W COLLABORATION AND BREVITY OF HIR GUSTS SUGGESTS HOLDING ONTO
SC.Y FOR NOW.

&&

.LONG TERM...

SUNDAY THROUGH THURSDAY

WATER VAPOR IMAGERY OVER THE WESTERN PACIFIC IN ADDITION TO 00Z
SYNOPTIC OBS REVEAL A VERY POTENT UPPER TROUGH WITH AN ASSOCIATED
POWERHOUSE UPPER JET. NERLY ZONAL WESTERLY FLOW OVER THE PACIFIC
WILL LEND TO THE EASTWARD ADVANCEMENT OF THIS STORM
SYSTEM...SUPPORTING AN EASTWARD SHIFT OF THIS ENHANCED EASTERN ASIAN
JET...BRINGING THE EXIT REGION TO THE WESTERN US BY EARLY NEXT WEEK.
THIS WILL SUPPORT A SHIFT TO A POSITIVE PNA REGIME...A SIGNAL THAT
MEAN GFS ENSEMBLES ARE LOCKING ONTO WITH ABOVE NORMAL CONFIDENCE.
HENCE...EXPECTING A SHIFT TO AN ACTIVE SPLIT FLOW PATTERN WITH THE
LOCAL REGION REMAINING BELOW NORMAL WRT TEMPS. FORECAST MODELS AND
ENSEMBLES CONTINUE TO FAVOR ADVANCING THE RATHER INTENSE UPPER
TROUGH OVER THE EASTERN PACIFIC /NEAR 40N 150W CURRENTLY/ INTO THE
WESTERN US WITH A PERIOD OF DIGGING...WHICH WILL DEEPEN AND SHIFT
THIS SYSTEM SOUTH...ESPECIALLY GIVEN THE LOCATION OF THE SETTLING
BAROCLINIC ZONE. WILL PREFER TO SIDE WITH MODEL SOLUTIONS THAT OFFER
A STORM TRACK FARTHER SOUTH AND SLOWER...VERY SIMILAR TO THE 00Z
ECMWF AND 12Z GEFS. THE NORTHERN STREAM WILL ALSO HAVE TO BE
MONITORED AS ANOTHER CLIPPER TYPE SYSTEM IS POSSIBLE TO DIVE
INTO THE GREAT LAKES IN THE MON-TUES TIME FRAME...ACTING TO
REINFORCE COOLER THERMAL PROFILES AS WELL AS SHIFTING FAVORED
BAROCLINIC REGIONS SOUTH. HAVE REMAINED CLOSE TO A BLEND OF THE
GEFS AND ECMWF.

SUNDAY...THE SLOWLY DEPARTING/FILLING UPPER LOW WILL CONTINUE TO
BRING VERY COOL/CLOUDY/AND BREEZY CONDITIONS. A SECONDARY IMPULSE
WILL SHIFT SE AROUND THE BACK SIDE OF THIS SYSTEM...BRINGING A
REINFORCING SHOT OF COLD AIR WITH H85 T/S PLUMMETING TO -9C BY 12Z
MON. LARGE SCALE ASCENT COUPLED WITH FRONTOGENETIC FORCING WILL
SUPPORT AN INCREASED CHANCE FOR RAIN OR SNOW SHOWERS SUNDAY...MAINLY
NORTH...WITH A TRANSITION TO LAKE EFFECT PROCESS AS CAA OVER THE
WARM LAKE WATERS SUPPORTS DELTA T VALUES PUSHING 20C. EXPECTING
BEST COVERAGE TO BE IN MI AT THIS TIME GIVEN WESTERLY WINDS. HAVE
INCREASED POPS IN THE NORTH FOR THIS. THINGS SHOULD WIND DOWN SUNDAY
NIGHT AS HEIGHT RISES SUPPORT QUICKLY FALLING INVERSION
HEIGHTS...DIMINISHING LAKE INDUCED CAPE. SOME ACCUMULATION MAY BE
POSSIBLE SUNDAY EVENING...MAINLY ON GRASSY SURFACES IN MI.

MON THROUGH THURSDAY...SPLIT FLOW WILL DOMINATE IN THIS PERIOD. HAVE
INTRODUCED LOW POPS IN THE SOUTH TUES-TUES NIGHT WITH THE APPROACH
OF THE SW CONUS UPPER TROUGH. THETA-E ADVECTION ALOFT WILL SUPPORT A
PRECIP THREAT AS THIS SYSTEM NEARS THE REGION. GIVEN THE ECMWF/S
PORTRAYAL OF A NORTHERN STREAM MID LVL TROUGH DIVING SOUTH INTO THE
GREAT LAKES /TYPICAL OF A POSITIVE PNA PATTERN/ AHEAD OF THIS SYSTEM
TUES...HAVE SOME CONCERN ON A POSSIBLE SNOW THREAT GIVEN SOME OF THE
PROGGED SOUNDINGS/DRY NORTHERLY FLOW/AND A COOLING BL PER DIURNAL
EFFECTS...ALTHOUGH TOO MUCH DRY AIR WOULD BE DETRIMENTAL TO PRECIP
CHANCES. HENCE HAVE ADDED RAIN OR SNOW WORDING TUES NIGHT. NOT
GETTING OVERLY EXCITED ABOUT THIS SYSTEM YET DO TO A FAIRLY HIGH
TRACK SPREAD...BUT IT CERTAINLY BARES WATCHING. BEYOND TUES
NIGHT...FORECAST MODELS BECOME HIGHLY DIVERGENT AND HAVE OPTED TO
HOLD TEMPS SLIGHTLY BELOW NORMAL IN LINE WITH THE REGIME...KEEPING A
DRY FORECAST AT THIS TIME UNTIL BETTER SIGNALS ARE PRESENT.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR LMZ043-046.

&&

$$

SHORT TERM...MURPHY
LONG TERM...CHAMBERLAIN
AVIATION...MURPHY

000
FXUS63 KIND 071035
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
535 AM EST FRI NOV 7 2008

.AVIATION...DISCUSSION FOR 071200Z TAF ISSUANCE. LOCALIZED VSBY
RESTRICTIONS IN THE KBMG AREA XPCTD TO DISSIPATE BY OR SHORTLY AFT
SUNRISE AS MIXING SHOULD DVLP RATHER EARLY TDY. WITH UPPR JET CORE
PASSING OVR THE AREA TDY...SFC WND GUSTS ARND 25 KTS FM 220-240
HEADINGS LOOK PROBABLE AFT 071600Z. OTRW...AS CAA DVLPS WITH
APPROACH OF UPPR LO...XPCTG VFR CIGS 040-050 TO OVERSPREAD THE
TERMINALS FM W TO E AFT 072000Z.

&&

.DISCUSSION...SHOWERS WERE STILL ACROSS OUR SOUTHEAST SECTIONS BUT
THEY WILL BE OUT OF OUR FORECAST AREA BEFORE SUNRISE.  SATELLITE
SHOWED CLEARING HAD ALREADY OCCURRED ACROSS WEST CENTRAL SECTIONS.
SURFACE ANALYSIS INDICATED COLD FRONT WAS ACROSS EAST CENTRAL
INDIANA.  HOWEVER BULK OF COLDER AIR WAS STILL OFF TO OUR WEST.

MAIN FORECAST CONCERNS WILL PRECIP CHANCES AND TYPE TONIGHT AND
SATURDAY AND ALSO HOW QUICK CLOUDS MOVE BACK INTO OUR AREA.
SATELLITE LOOPS INDICATE MOSTLY CLEAR CONDITIONS WILL SPREAD ACROSS
OUR AREA THIS MORNING AS DRY SLOT AHEAD OF STRONG UPPER LOW MOVES
ACROSS OUR AREA.  AFTER THAT WRAP AROUND CLOUDS FROM UPPER LOW WILL
SPREAD EAST ACROSS OUR REGION LATER TODAY. BUFKIT ALSO INDICATES
WIND GUSTS IN EXCESS OF 25 KNOTS POSSIBLE LATER TODAY.

BOTH NAM/GFS MOVE STRONG UPPER LOW INTO THE GREAT LAKES SATURDAY
BRINGING VERY LIGHT QPF INTO OUR NW LATER TONIGHT AND ACROSS OUR
NORTH SATURDAY. 1000-850 MB THICKNESS DROP TO NEAR OR SLIGHTLY BELOW
1300 METERS IN OUR NORTHWEST LATE TONIGHT AND REMAIN NEAR THAT VALUE
ON SATURDAY IN THE NORTHWEST. SO WILL MENTION CHANCE OF LIGHT RAIN
AND SNOW SHOWERS THERE.

NOT MUCH CHANGE TO REST OF FORECAST. STRONG UPPER LOW REMAINS NEAR
OR JUST NORTHEAST OF THE GREAT LAKES TO MONDAY. THEN NAM/GFS
INDICATE ANOTHER S/W COMING IN FROM THE PACIFIC COAST COULD AFFECT
US BY MONDAY NIGHT OR TUESDAY.  EUROPEAN IS A LITTLE SLOWER AND A
LITTLE WEAKER WITH THIS SYSTEM HOWEVER.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

AVIATION...JAS
PUBLIC...JH

000
FXUS63 KIWX 071016
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
516 AM EST FRI NOV 7 2008

.SHORT TERM...
TODAY THROUGH SATURDAY NIGHT. COMPLEX SHORT TERM FCST ISSUES WRT
NON-DIURNAL TEMPS TDY FOLLOWED BY TIMING OF S/W FOLLOWED BY LK
EFFECT PRECIP CHC AS WRAPPED UL LOW TRAVERSES EWD TO LK HURON LT
SAT NIGHT. PREFERENCE LIES WITH GFS WITH GOOD CAPTURE OF UL SYSTEM
ACRS SWRN MN AND ID OF S/W ACRS SERN NW TERRITORIES WITH 07/00 UTC
RUN FOLLOWED UP WITH GOOD ECMWF/UKMET AGREEMENT. NAM A BIT SUSPECT
WITH KEEPING OCLD SYSTEM DEEPENING AND WITH CAN S/W SLOW TO DROP
SSE...WHICH ALREADY EVIDENT IN W/V IMAGERY WITH HIGH PVU/TROP
FOLD BREAKING THRU WEAKENING COL.

TODAY CWA LRGLY TO REMAIN IN DRY SLOT BEHIND FIRST COLD FRONT
SWEEPING EWD INTO ERN GRLKTS. 1000-8H LYR TEMPS FALLING 4-5C THIS
AFTERNOON ACRS CWA SUPPORTIVE OF NON-DIURNAL/FALLING TEMPS ACRS
ENTIRE CWA. AS UL LW NEARS TONIGHT...POTENT COMPACT S/W FM SRN MN
INTO SERN NE WITH STRONG SFC FNT REFLECTION/EXTREME MIXDOWN IN
STRONG CAA IN WAKE OF FNT WITH EARLIER KMHE PKWND 28061KTS IN
BLIZZARD CONDITIONS ACRS ERN SD. SATURATION OF LW LVLS TONIGHT AS
THIS FEATURE AND UL NEARS WITH INCREASING LK-8H LAPSE RATES TO
SUPPORT PRIMARILY MIXED SHRA/SHSN ACRS BERRIEN INTO CASS MI WITH
INITIAL 240-250 DEGREE FETCH...BETTER CHCS ESPCLY AFTR MIDNIGHT
ONCE COLDER AIR BCMS BETTER ESTABLISHED/IN CLD SHEAR DIMINISHES.
WL HOLD OFF ON ANY ACCUM MENTION GIVEN WARM GROUND AND MIXED PTYPE
AS ENVIRON HIGHLY MODIFED BY WARM LK. LK INDUCED CAPES RUN 350-550
J/KG THRU THE DAY SAT WITH DELTA-T NEAR 20C. FETCH VEERS TO ABOUT
260 FAVORING A LARGER PORTION OF NRN CWA. YET ANOTHER STRG S/W
PASSAGE SAT NIGHT WITH STRONG 7H JET DIVING THRU SWRN
GRTLKS...SOME CONCERN WITH DCRSD MSTR DEPTH HOWEVER INTENSE LAPSE
RATES ACRS SRN LK MI WITH DELTA-T IN UPPER TEENS TO NEAR
20C CONTD VEERING OF CBL WINDS/CONVERGENT SIGNALS ACRS SERN LK MI.
HIGHLY TURBULENT/CONVECTIVE MESOOSCALE PROCESSES MAY ALSO ALLOW
FOR CHC OF SLEET SHOWERS AT TIMES SAT NIGHT. GRTR WINDS/GUSTS INTO
NSH WATERS FOR NR GALE CONDS BRIEFLY SAT NIGHT...DEBATED NEED FOR
GL.W COLLABORATION AND BREVITY OF HIR GUSTS SUGGESTS HOLDING ONTO
SC.Y FOR NOW.

&&

.LONG TERM...

SUNDAY THROUGH THURSDAY

WATER VAPOR IMAGERY OVER THE WESTERN PACIFIC IN ADDITION TO 00Z
SYNOPTIC OBS REVEAL A VERY POTENT UPPER TROUGH WITH AN ASSOCIATED
POWERHOUSE UPPER JET. NERLY ZONAL WESTERLY FLOW OVER THE PACIFIC
WILL LEND TO THE EASTWARD ADVANCEMENT OF THIS STORM
SYSTEM...SUPPORTING AN EASTWARD SHIFT OF THIS ENHANCED EASTERN ASIAN
JET...BRINGING THE EXIT REGION TO THE WESTERN US BY EARLY NEXT WEEK.
THIS WILL SUPPORT A SHIFT TO A POSITIVE PNA REGIME...A SIGNAL THAT
MEAN GFS ENSEMBLES ARE LOCKING ONTO WITH ABOVE NORMAL CONFIDENCE.
HENCE...EXPECTING A SHIFT TO AN ACTIVE SPLIT FLOW PATTERN WITH THE
LOCAL REGION REMAINING BELOW NORMAL WRT TEMPS. FORECAST MODELS AND
ENSEMBLES CONTINUE TO FAVOR ADVANCING THE RATHER INTENSE UPPER
TROUGH OVER THE EASTERN PACIFIC /NEAR 40N 150W CURRENTLY/ INTO THE
WESTERN US WITH A PERIOD OF DIGGING...WHICH WILL DEEPEN AND SHIFT
THIS SYSTEM SOUTH...ESPECIALLY GIVEN THE LOCATION OF THE SETTLING
BAROCLINIC ZONE. WILL PREFER TO SIDE WITH MODEL SOLUTIONS THAT OFFER
A STORM TRACK FARTHER SOUTH AND SLOWER...VERY SIMILAR TO THE 00Z
ECMWF AND 12Z GEFS. THE NORTHERN STREAM WILL ALSO HAVE TO BE
MONITORED AS ANOTHER CLIPPER TYPE SYSTEM IS POSSIBLE TO DIVE
INTO THE GREAT LAKES IN THE MON-TUES TIME FRAME...ACTING TO
REINFORCE COOLER THERMAL PROFILES AS WELL AS SHIFTING FAVORED
BAROCLINIC REGIONS SOUTH. HAVE REMAINED CLOSE TO A BLEND OF THE
GEFS AND ECMWF.

SUNDAY...THE SLOWLY DEPARTING/FILLING UPPER LOW WILL CONTINUE TO
BRING VERY COOL/CLOUDY/AND BREEZY CONDITIONS. A SECONDARY IMPULSE
WILL SHIFT SE AROUND THE BACK SIDE OF THIS SYSTEM...BRINGING A
REINFORCING SHOT OF COLD AIR WITH H85 T/S PLUMMETING TO -9C BY 12Z
MON. LARGE SCALE ASCENT COUPLED WITH FRONTOGENETIC FORCING WILL
SUPPORT AN INCREASED CHANCE FOR RAIN OR SNOW SHOWERS SUNDAY...MAINLY
NORTH...WITH A TRANSITION TO LAKE EFFECT PROCESS AS CAA OVER THE
WARM LAKE WATERS SUPPORTS DELTA T VALUES PUSHING 20C. EXPECTING
BEST COVERAGE TO BE IN MI AT THIS TIME GIVEN WESTERLY WINDS. HAVE
INCREASED POPS IN THE NORTH FOR THIS. THINGS SHOULD WIND DOWN SUNDAY
NIGHT AS HEIGHT RISES SUPPORT QUICKLY FALLING INVERSION
HEIGHTS...DIMINISHING LAKE INDUCED CAPE. SOME ACCUMULATION MAY BE
POSSIBLE SUNDAY EVENING...MAINLY ON GRASSY SURFACES IN MI.

MON THROUGH THURSDAY...SPLIT FLOW WILL DOMINATE IN THIS PERIOD. HAVE
INTRODUCED LOW POPS IN THE SOUTH TUES-TUES NIGHT WITH THE APPROACH
OF THE SW CONUS UPPER TROUGH. THETA-E ADVECTION ALOFT WILL SUPPORT A
PRECIP THREAT AS THIS SYSTEM NEARS THE REGION. GIVEN THE ECMWF/S
PORTRAYAL OF A NORTHERN STREAM MID LVL TROUGH DIVING SOUTH INTO THE
GREAT LAKES /TYPICAL OF A POSITIVE PNA PATTERN/ AHEAD OF THIS SYSTEM
TUES...HAVE SOME CONCERN ON A POSSIBLE SNOW THREAT GIVEN SOME OF THE
PROGGED SOUNDINGS/DRY NORTHERLY FLOW/AND A COOLING BL PER DIURNAL
EFFECTS...ALTHOUGH TOO MUCH DRY AIR WOULD BE DETRIMENTAL TO PRECIP
CHANCES. HENCE HAVE ADDED RAIN OR SNOW WORDING TUES NIGHT. NOT
GETTING OVERLY EXCITED ABOUT THIS SYSTEM YET DO TO A FAIRLY HIGH
TRACK SPREAD...BUT IT CERTAINLY BARES WATCHING. BEYOND TUES
NIGHT...FORECAST MODELS BECOME HIGHLY DIVERGENT AND HAVE OPTED TO
HOLD TEMPS SLIGHTLY BELOW NORMAL IN LINE WITH THE REGIME...KEEPING A
DRY FORECAST AT THIS TIME UNTIL BETTER SIGNALS ARE PRESENT.

&&

.AVIATION...
LAST VESTIGES OF MVFR CONDITIONS CLEARING KSBN/KFWA NEXT COUPLE OF
HOURS AS DEEP/SHARP DISCONTINUITY BNDRY OF MUCH DRIER AIR INVADES
WEST TO EAST ACRS NRN IN...OF DRY LINE ORIGINATION ACRS SRN PLAINS
FM EARLY THU AM CONTS TO BE DRAWN NEWD IN RAPID/CONVERGENT SFC-5H
FLOW. MAJORITY OF FCST VFR WITH DETAIL OF MVFR SHRA CONDS INVOF KFWA
EXITING BY 08 UTC AS IN CLOUD WINDS CONT TO VEER. STRONG SFC-8H
LAPSE RATES TO DEVELOP WITH SUN IN DRY SLOT BY LATE AM FOR INCREASED
MIXING/MOMENTUM XFER FOR GUSTS INTO LWR/MID 20KT RANGE. DEEPER
COLDER AIR TO FOLLOW BEHIND SECONDARY COLD FRNTL PASSAGE THIS
EVENING/FOLLOWED BY APPROACH OF COLDER MIDLVL TEMPS AS 5H LOW DROPS
ESE INTO SRN WI LATE IN FCST PD TO ALLOW FOR SATURATION IN 030-035
LYR...PERHAPS SOME ISOLD LIGHT SHRA/SHSN...THOUGH BETTER PRECIP CHCS
REMAIN BEYOND CURRENT FCST TIMEFRAME.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR LMZ043-046.

&&

$$

SHORT TERM...MURPHY
LONG TERM...CHAMBERLAIN
AVIATION...MURPHY

000
FXUS63 KIND 070834
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
325 AM EST FRI NOV 7 2008

.DISCUSSION...SHOWERS WERE STILL ACROSS OUR SOUTHEAST SECTIONS BUT
THEY WILL BE OUT OF OUR FORECAST AREA BEFORE SUNRISE.  SATELLITE
SHOWED CLEARING HAD ALREADY OCCURRED ACROSS WEST CENTRAL SECTIONS.
SURFACE ANALYSIS INDICATED COLD FRONT WAS ACROSS EAST CENTRAL
INDIANA.  HOWEVER BULK OF COLDER AIR WAS STILL OFF TO OUR WEST.

MAIN FORECAST CONCERNS WILL PRECIP CHANCES AND TYPE TONIGHT AND
SATURDAY AND ALSO HOW QUICK CLOUDS MOVE BACK INTO OUR AREA.
SATELLITE LOOPS INDICATE MOSTLY CLEAR CONDITIONS WILL SPREAD ACROSS
OUR AREA THIS MORNING AS DRY SLOT AHEAD OF STRONG UPPER LOW MOVES
ACROSS OUR AREA.  AFTER THAT WRAP AROUND CLOUDS FROM UPPER LOW WILL
SPREAD EAST ACROSS OUR REGION LATER TODAY. BUFKIT ALSO INDICATES
WIND GUSTS IN EXCESS OF 25 KNOTS POSSIBLE LATER TODAY.

BOTH NAM/GFS MOVE STRONG UPPER LOW INTO THE GREAT LAKES SATURDAY
BRINGING VERY LIGHT QPF INTO OUR NW LATER TONIGHT AND ACROSS OUR
NORTH SATURDAY. 1000-850 MB THICKNESS DROP TO NEAR OR SLIGHTLY BELOW
1300 METERS IN OUR NORTHWEST LATE TONIGHT AND REMAIN NEAR THAT VALUE
ON SATURDAY IN THE NORTHWEST. SO WILL MENTION CHANCE OF LIGHT RAIN
AND SNOW SHOWERS THERE.

NOT MUCH CHANGE TO REST OF FORECAST. STRONG UPPER LOW REMAINS NEAR
OR JUST NORTHEAST OF THE GREAT LAKES TO MONDAY. THEN NAM/GFS
INDICATE ANOTHER S/W COMING IN FROM THE PACIFIC COAST COULD AFFECT
US BY MONDAY NIGHT OR TUESDAY.  EUROPEAN IS A LITTLE SLOWER AND A
LITTLE WEAKER WITH THIS SYSTEM HOWEVER.


&&

.AVIATION...DISCUSSION FOR 06Z TAFS.
COLD FRONT WAS WORKING ITS WAY INTO WESTERN INDIANA AT 0430Z.  WINDS
WERE SLOWLY SHIFTING TO THE SOUTHWEST AND ARE EXPECTED TO STAY IN
THE 5-10 KT RANGE THROUGH THE NIGHT.  THAT SAID FEEL THAT FOG WONT
BE WIDESPREAD TONIGHT ALTHOUGH THERE IS A LOW CHANCE THAT LAF AND
BMG WILL DROP TO MVFR FOG AROUND 10Z FOR AN HOUR OR TWO.

CIGS WILL STAY VFR THROUGH THE OVERNIGHT.  WRAPAROUND CLOUDS FROM A
LARGE LOW PRESSURE SYSTEM OVER THE NORTHERN PLAINS WILL ARRIVE OVER
THE TERMINALS ON FRIDAY AFTERNOON AND HANG AROUND THROUGH MOST OF
THE DAY INTO THE NIGHT.  CLOUDS WILL START OUT SCATTERED AROUND 5K
THEN GO OVERCAST AROUND 21Z ON FRIDAY.

WIND WILL PICK UP AGAIN ON FRIDAY WITH GUSTS AROUND 20KTS POSSIBLE.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$
AVIATION...SALLY
PUBLIC...JH

000
FXUS63 KIWX 070613
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
110 AM EST FRI NOV 7 2008


.AVIATION...
LAST VESTIGES OF MVFR CONDITIONS CLEARING KSBN/KFWA NEXT COUPLE OF
HOURS AS DEEP/SHARP DISCONTINUITY BNDRY OF MUCH DRIER AIR INVADES
WEST TO EAST ACRS NRN IN...OF DRY LINE ORIGINATION ACRS SRN PLAINS
FM EARLY THU AM CONTS TO BE DRAWN NEWD IN RAPID/CONVERGENT SFC-5H
FLOW. MAJORITY OF FCST VFR WITH DETAIL OF MVFR SHRA CONDS INVOF KFWA
EXITING BY 08 UTC AS IN CLOUD WINDS CONT TO VEER. STRONG SFC-8H
LAPSE RATES TO DEVELOP WITH SUN IN DRY SLOT BY LATE AM FOR INCREASED
MIXING/MOMENTUM XFER FOR GUSTS INTO LWR/MID 20KT RANGE. DEEPER
COLDER AIR TO FOLLOW BEHIND SECONDARY COLD FRNTL PASSAGE THIS
EVENING/FOLLOWED BY APPROACH OF COLDER MIDLVL TEMPS AS 5H LOW DROPS
ESE INTO SRN WI LATE IN FCST PD TO ALLOW FOR SATURATION IN 030-035
LYR...PERHAPS SOME ISOLD LIGHT SHRA/SHSN...THOUGH BETTER PRECIP CHCS
REMAIN BEYOND CURRENT FCST TIMEFRAME.

&&

.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
NEAR VERTICALLY STACKED LOW NEAR SE SD/NE NEB SLOWLY MAKING ITS
WAY NE INTO NORTHERN WISCONSIN BY FRI NITE.  ASSOC COLD FRONT
CURRENTLY LOCATED MIDWAY THROUGH ILLINOIS PROGRESSING EWARD WITH
AN AREA OF WEAK CONVECTION ALONG IT WITH ONLY SPORADIC LIGHTING
STRIKES. THIS AREA OF POST FRONTAL SHOWERS/ISO THUNDER MOVING NNE
THROUGH EASTERN ILLINOIS BEGINNING TO IMPACT EXTREME WESTERN CWA.
AS FRONT MOVES EWARD THUNDER CHANCES SHOULD DIMINISH FURTHER AS
MODELS DECREASE ALREADY WEAK INSTABILITY QUICKLY AFTER 00Z AND
AFTERNOON SUNSHINE HAS FAILED TO DESTABILIZE THE ENVIRONMENT PER
SPC MESOSCALE ANALYSIS. STILL ISOLATED THUNDER OCCURRING JUST TO
THE WEST AND HAVE HELD ISO THUNDER WORDING WEST HALF THROUGH LATE
EVENING. GUSTY WINDS STILL A POSSIBILITY WITH SHRA/TS ESP IN WEST
WITH 30-40KT WINDS ALOFT.

SCT PRECIP ENDS FROM WEST TO EAST BEHIND FROPA AS DRY SLOT WORKS
INTO THE FORECAST AREA AND TEMPS CLIMB TO 50S WEST/LOW 60S EAST ON
FRIDAY AS COLD AIR IS SLOW TO ARRIVE BEHIND SECONDARY TROF. POPS
INTRODUCED LATE FRIDAY AS COLD AIR ALOFT RAPIDLY FOLLOWS COOLING
TO -5C BY SAT NIGHT AND FZ LEVELS LOWER TO 1500 FT PER NAM BUFR
WARRANTING RA/SN MIX MENTION FOR LIGHT PRECIP FRI NIGHT.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
FEW CHANGES MADE TO LONG TERM FORECAST AS MODELS ATTEMPTING TO TRY
TO COME INTO SOME AGREEMENT ON TRACK/POSITION OF UPPER LOW.

AT THE START OF THE PERIOD MODELS ARE FAIRLY SIMILAR WITH UPPER LOW
CENTERED OVER EASTERN WISCONSIN AND MOVING TO SOMEWHERE AROUND THE
EASTERN U.P OF MICHIGAN OR NORTHERN LK MI. THIS MUCH FURTHER TRACK
MAY END UP TAKING THE BULK OF THE PRECIPITATION NORTH WITH IT BUT
MAY ALSO ALLOW THE AREA TO GET MORE INTO THE COLDER AIR MASS TO
ARRIVE SUNDAY AND MONDAY. AS A RESULT OF THESE POSSIBLE CHANGES HAVE
DECIDED TO MAINTAIN STATUS QUO IN THE GRIDS. BEST CHANCE FOR ANY
PRECIP DOES REMAIN IN THE NORTH ON SATURDAY WITH DECREASING CHANCES
INTO LATER PERIODS.

HIGH PRESSURE WILL STILL MOVE IN FOR THE START OF THE WEEK AND
APPEARS TO KEEP PRECIP CHANCES SUPPRESSED. WAS TEMPTED TO INTRODUCE
SOME LOW POPS IN THE SOUTH FOR TUES TO WEDS TIME FRAME BUT FEEL IT
JUST TOO QUESTIONABLE AT THIS POINT. TEMPS WILL REMAIN GENERALLY AT
OR BELOW NORMAL THROUGH THE PERIOD WITH SUNDAY LIKELY BEING THE
COLDEST DAY.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR LMZ043-046.

&&

$$

SHORT TERM...LUDINGTON
LONG TERM...FISHER
AVIATION...MURPHY

000
FXUS63 KIND 070446
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1145 PM EST THU NOV 6 2008

.AVIATION...DISCUSSION FOR 06Z TAFS.
COLD FRONT WAS WORKING ITS WAY INTO WESTERN INDIANA AT 0430Z.  WINDS
WERE SLOWLY SHIFTING TO THE SOUTHWEST AND ARE EXPECTED TO STAY IN
THE 5-10 KT RANGE THROUGH THE NIGHT.  THAT SAID FEEL THAT FOG WONT
BE WIDESPREAD TONIGHT ALTHOUGH THERE IS A LOW CHANCE THAT LAF AND
BMG WILL DROP TO MVFR FOG AROUND 10Z FOR AN HOUR OR TWO.

CIGS WILL STAY VFR THROUGH THE OVERNIGHT.  WRAPAROUND CLOUDS FROM A
LARGE LOW PRESSURE SYSTEM OVER THE NORTHERN PLAINS WILL ARRIVE OVER
THE TERMINALS ON FRIDAY AFTERNOON AND HANG AROUND THROUGH MOST OF
THE DAY INTO THE NIGHT.  CLOUDS WILL START OUT SCATTERED AROUND 5K
THEN GO OVERCAST AROUND 21Z ON FRIDAY.

WIND WILL PICK UP AGAIN ON FRIDAY WITH GUSTS AROUND 20KTS POSSIBLE.

&&

.PREV DISCUSSION...SFC ANALYSIS EARLY THIS AFTERNOON SHOWS LOW PRES
OVR MN WITH A CD FONT EXTENDING SE ACRS IL TO WRN KY AND WRN TN.
RADAR MOSAICS SHOW A THIN AREA OF SCT SHRA OVR CENTRAL IL PUSHING
NE. SFC DEW POINT TEMPS WERE IN THE LOWER 40S EAST TO THE UPPER 40S
WEST ACRS THE FA.

MAIN FORECAST CHALLENGE TDY WL BE TIMING PCPN.

GIVEN THE LATEST RADAR TRENDS...THE QUICKER NAM APPEARS TO HAVE A
BETTER HANDLE ON THE APPROACHING GFS WHICH APPEARS TO BE A BIT
SLOWER. A KEY PLAYER IN GENERATING TDYS PCPN IS THE LLJ...WHICH
ACCORDING TO 12Z H8 ANALYSIS WAS NEAR 40-50KNTS ACRS IL THIS
MORNING. AS THE BROAD UPPER LOW SLOWLY PUSHES EAST...THE MAIN
DYNAMICS OF THE LLJ APPEAR TO WEAKEN CONSIDERABLY LATE THIS
AFTERNOON AND EARLY THIS EVENING. FURTHERMORE...DRY AIR IN PLACE
ACRS INDIANA...DEW POINTS IN THE 40S...WL MAKE IT MORE DIFFICULT FOR
SATURATION TO OCCUR. NAM POINTS TO PCPN SHEARING OUT A BIT AND
DIMINISHING THIS AFTERNOON AS IT PUSHES ACRS INDIANA. HENCE WL FOCUS
MAIN POPS PRIOR TO 00Z...AND GO DRY AFT 00Z ACRS THE WEST...WITH
VERY LOW CHC POPS ACRS THE EAST.

WITH DRY AIR WORKING IN OVERNIGHT AND WINDS EXPECTED TO CONTINUE
MIXING DUE TO THE BROAD CYCLONIC FLOW DO NOT EXPECT MUCH RAD COOLING
TONIGHT. MAVMOS AND METMOS HANDLE THIS PRETTY WELL AND WL MAKE
LITTLE IN THE WAY OF CHANGES.

THE UPPER LOW WL REMAIN TO OUR NORTH ON FRI AND FRI NIGHT...WITH THE
REAL CAA STARTING ON FRI EVENING. TIME SECTIONS AND FORECAST
SOUNDINGS SHOW A DRY COLUMN ON FRIDAY AND WL KEEP A DRY
FORECAST...BUT GIVEN THE CAA STARTING...WL LEAN TOWARD THE 3 HRLY
MAVMOS TEMPS FOR HIGHS. H8 TEMPS FALL TO -2C BY SAT MORNING AND WL
ONCE AGAIN USE A BLEND ON TEMPS.

FORECAST SOUNDINGS ON SAT INDICATE ENOUGH COLD AIR ALOFT THAT
INSTABILITY SHRA COULD DEVELOP...PARTICULARLY ACRS THE NORTH WHERE
UPPER SUPPORT IS BETTER DUE TO THE LARGE UPPER LOW OVR THE GRT LKS.
BROAD CYCLONIC FLOW AT THE SFC WL ONLY AID THE LGT PCPN CHCS.
EXPECTED MINIMAL RISES IN TEMPS ON SAT AS H8 TEMPS WL BE ONLY NEAR
-4C WITH PLENTY OF CLOUDS. FOR A START...THE 3HRLY MAVMOS TEMPS LOOK
LIKE THE BETTER WAY TO GO ON SAT.

AS FOR THE EXTENDED...DRY WEATHER WILL FILL IN BEHIND THE BROAD LOW
PRES SYS AS IT DEPARTS TO THE EAST AND A BROAD SFC HIGH PRES SYS
SETTLES ACRS INDIANA ON SUNDAY AND MONDAY.

MFR/ECMWF AGREE THAT THE NEXT SYSTEM WILL APPROACH FROM THE LOW
MISSISSIPPI VALLEY AND PUSH NE...BUT SOUTH OF THE OH RIVER. THIS SYS
SHUD PROVIDE A DECENT OVERRUNNING SITUATION FOR INDIANA...BUT DRY
AIR AHEAD OF THE SYSTEM ON NE SFC FLOW MAY RESULT IN DELAYING
SATURATION. THUS HAVE PUSHED PCPN CHCS BACK TO LATE MONDAY
NIGHT...AND MAINLY SOUTH OF I70. WL KEEP PCPN IN THE FORECAST FOR
TUESDAY AND WED AS THIS SYSTEM PUSHES TO OUR EAST AND NE FLOW
BECOMES NORTHWEST. LOOK FOR TEMPS IN THE EXTENDED PART OF THE
FORECAST TO REMAIN BELOW NORMAL VALUES AS NO SIGNIFICANT WAA IS
EXPECTED ALONG WITH PLENTY OF CLOUDS WITH THE PASSING SYSTEM.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$
AVIATION...SALLY
PUBLIC...PUMA