000
FXUS63 KLMK 271057 CCA
AFDLMK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
657 AM EDT MON OCT 27 2008

.SHORT TERM (TODAY AND TONIGHT)...

COLD AIR WILL FILTER INTO THE FORECAST AREA TODAY AND TONIGHT.
CURRENTLY...TEMPERATURES ACROSS CENTRAL ILLINOIS AND INDIANA WERE
WERE IN THE MID AND UPPER 30S WITH SOME LOCATIONS REPORTING SOME
FLURRIES. CLOUD COVER AND WESTERLY WINDS OF 10 TO 20 MPH WERE
KEEPING TEMPERATURES IN THE 40S ACROSS THE FORECAST AREA BUT THESE
SHOULD DROP A FEW DEGREES MORE BY MORNING. HIGH TEMPERATURES TODAY
ARE EXPECTED TO BE FROM THE MID 40S TO NEAR 50 DEGREES. CLOUD COVER
WILL LIKELY STICK AROUND TODAY AND MAY EVEN THICKEN WITH LOWERING
CEILINGS BY MIDDAY. WINDS WILL ALSO BE GUSTY AGAIN TODAY...ALTHOUGH
NOT AS MUCH AS YESTERDAY EVENING. EXPECT WESTERLY TO NORTHWESTERLY
WINDS BETWEEN 10 AND 15 MPH GUSTING TO AROUND 20 MPH TODAY.

IT IS DUE TO THE CLOUD COVER AND WINDS REMAINING AROUND 10 MPH
OVERNIGHT TONIGHT THAT WE HAVE RAISED TEMPERATURES A FEW DEGREES
OVERNIGHT. THIS LIKELY WILL MEAN THAT A WIDESPREAD FREEZE WILL NOT
OCCUR OVERNIGHT. HOWEVER...HAVE LEFT THE FREEZE WATCH GOING AT THIS
TIME. IF CLOUD COVER DOES BREAK OVERNIGHT...RADIATIONAL COOLING MAY
BE GREAT ENOUGH TO ALLOW SOME AREAS TO STILL SEE FREEZING OR JUST
BELOW FREEZING TEMPERATURES. THEREFORE WILL LET THE DAY SHIFT
EVALUATE THIS FURTHER. HOWEVER...BASED ON DOWNSTREAM TEMPERATURES
CURRENTLY AS FAR NORTH AS IA/WI AND MN STILL BEING IN THE MID
30S...DO NOT FEEL VERY CONFIDENT ABOUT FREEZING TEMPERATURES
TONIGHT. RAISED TEMPERATURES TO AROUND 33 TO 35 DEGREES IN MOST
LOCATIONS WITH THE SOUTHERN INDIANA COUNTIES JUST AT FREEZING AS
THIS LOCATION WOULD BE MOST LIKELY TO SEE SOME BREAKS IN CLOUDS NEAR
MORNING. TUESDAY NIGHT DEFINITELY LOOKS TO BE THE COLDER NIGHT AT
THIS TIME. AT THIS TIME...EXPECT A WATCH TO BE ISSUED FOR TUESDAY
NIGHT DURING THE DAY SHIFT TODAY.

TODAY WILL REMAIN DRY BUT LEFT THE MENTION OF SLIGHT CHANCE OF
SPRINKLES AND FLURRIES ACROSS THE BLUE GRASS REGION LATE TONIGHT
INTO EARLY TUESDAY MORNING. THERE IS A DECENT AMOUNT OF MOISTURE
WITH AN UPPER LEVEL JET NOSING INTO THE AREA SO WILL LET THAT RIDE
FOR NOW.


.LONG TERM (TUE THRU SUN)...

TUE AND WED...

FOCUS HERE ON TUE NIGHT MIN TEMPS AND POTENTIAL FIRST WIDESPREAD
FREEZE...FOLLOWED BY MODERATING TEMPS WED.

UPPER LEVEL NW FLO WILL BE RELAXING AND BACKING A BIT THRU THIS
PERIOD WITH SIGNIFICANT HEIGHT RISES AS RIDGE BUILDS ACRS THE
NATIONS MID-SECTION. CANADIAN HIGH PRES CENTERED ACRS THE CENTRAL
PLAINS/MID MS VLY...EXPECTED TO SLIDE SEWD INTO THE GULF STATES BY
WED EVE. BASED ON MODEL TIME HEIGHT CROSS SECTIONS...LOW LEVEL
MOISTURE (STATOCU OR DEVELOPING CU) SHUD STILL BE LINGERING EARLY
OVER MUCH OF OUR FA WED...WITH A DECREASING TREND DURING THE DAY AS
WINDS BACK FROM NW TO WEST. THIS IS REFLECTD IN MOS GUIDANCE WITH
WITH CLOUDS OR CLOUD DEVELOPMENT...ESPECIALLY FOR OUR ERN FA. SKIES
SHUD GO MOCLR TUE NIGHT PER MOS...THOUGH CROSS SECTIONS INDICATE
SOME MID CLOUDS. AT THIS POINT WILL SIDE WITH MOS AND TAKE TEMPS TO
FREEZING OR BELOW UNDER MOCLR SKIES AND W/SW WINDS OF 5-10 MPH.
THINK TEMPS WILL BOTTOM OUT FROM THE MID 20S TO LOWER 30S WITH OUR
USUAL COLD BIAS LOW LYING AREAS IN OUR ERN CWFA THE COLDEST WITH
THIS RADIATIONAL COOLING SITUATION AS OPPOSED TO COLD AIR ADVECTION.
INTERESTING TO SEE THE ENSEMBLE MEAN MOS MIN FOR SDF COLDER (30)
THAN THE MAV (35). ITS OUR GUESS...THAT THE DAYSHIFT WILL ISSUE A
FREEZE WATCH FOR LATE TUE NIGHT/EARLY WED MRNG WITH THIS NIGHT THE
COLDEST OF THIS COLD SNAP.

TEMPS SHUD REBOUND BY ABOUT 5 DEGS FOR WED OVER TUE WITH MORE
SUNSHINE.

NO CHANGES FOR THE WED NIGHT THRU SUN PERIOD...PREV DISC FOR THAT
PERIOD FOLLOWS:

WEDNESDAY NIGHT THROUGH SUNDAY...

SOMEWHAT LESS INTERESTING WEATHER IN THE LONG TERM THOUGH NOT
ENTIRELY WITHOUT ITS CHALLENGES. OPERATIONAL ECMWF SHOWS A COLD
FRONT CROSSING THE OHIO VALLEY FROM NORTHWEST TO SOUTHEAST
SATURDAY NIGHT...BUT THIS IS NOT SUPPORTED BY GFS ENSEMBLE MEAN OR
GEM ENSEMBLE MEAN...BOTH OF WHICH SHOW HIGH PRESSURE MOVING FROM
THE LOWER MISSISSIPPI VALLEY UP THROUGH THE APPALACHIANS KEEPING
US DRY. HPC HAS MENTIONED THAT THE ECMWF ENSEMBLES ARE NOT AS
POTENT WITH THE SATURDAY NIGHT FRONT AS THE OPERATIONAL RUN OF THE
MODEL IS. SO WILL KEEP THE ENTIRE LONG TERM DRY FOR NOW.

&&

.AVIATION (12Z TAFS)...

GUSTY WEST WINDS ARE EXPECTED AGAIN TODAY. EXPECT WESTERLY WINDS
AROUND 10 TO 15 KTS GUSTING AROUND 20 KTS FROM MID MORING THROUGH
THE EARLY EVENING HOURS. VFR CONDITIONS WILL PREVIAL THROUGH THE TAF
PERIOD. MID LEVEL CLOUDS AROUND 8 KFT WILL MOVE SOUTH ACROSS THE
AREA THIS MORNING AND CEILINGS AROUND 4 KFT WILL DEVELOP LATER THIS
AFTERNOON. MOSTLY CLOUDY CONDITIONS WILL CONTINUE THROUGH THE
OVERNIGHT HOURS. A SLIGHT CHANCE OF A FEW FLURRIES OR SPRINKLES WILL
BE POSSIBLE AT LEX LATE TONIGHT BUT DID NOT INCLUDE IN THE TAF AT
THIS TIME AS IT IS NOT EXPECTED TO BE MUCH OF AN IMPACT.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...FREEZE WATCH FROM LATE MONDAY NIGHT THROUGH TUESDAY MORNING FOR
     KYZ023>043-045>049-053>057-061>067-070>078-081-082.

IN...FREEZE WATCH FROM LATE MONDAY NIGHT THROUGH TUESDAY MORNING FOR
     INZ076>079-083-084-089>092.

&&

$$

SHORT TERM...JSD
LONG TERM...13
AVIATION...LS