FXUS63 KGRR 201658
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1158 AM EST TUE JAN 20 2009
LATEST UPDATE...AVIATION...
.SYNOPSIS...(343 AM EST TUE JAN 20 2009)
HIGH PRESSURE WILL MOVE SOUTHEAST FROM THE PLAINS TO THE SOUTHEAST 
US BY WEDNESDAY. AS WINDS BECOME WESTERLY TEMPERATURES WILL 
GRADUALLY WARM TO NEAR 30 DEGREES BY THURSDAY. OTHER THAN A FEW 
FLURRIES...DRY WEATHER IS EXPECTED THROUGH THURSDAY.
&&
.SHORT TERM...(430 AM EST TUE JAN 20 2009)
(TODAY THROUGH THURSDAY)
FORECAST CONCERNS ARE MINIMAL TODAY. HIGH PRESSURE WILL REMAIN IN 
CONTROL OF OUR WEATHER FOR THE NEXT FEW DAYS. BOUNDARY LAYER FLOW 
WILL BECOME NORTHWESTERLY LATE TODAY WHICH SHOULD SEND LAKE EFFECT 
CLOUDS INLAND. RH PROFILES SHOW MOISTURE IS VERY LIMITED WHICH 
SHOULD PRECLUDE SHSN. SCATTERED FLURRIES ARE POSSIBLE THOUGH. 
ANOTHER SHORT WAVE MOVING SOUTHEAST ACROSS LAKE SUPERIOR WILL BE TOO 
FAR NORTHEAST TO GENERATE MEASURABLE SNOW ACROSS THE CWA WED AM. 
WE/LL ADD FLURRIES TO THE ERN CWA WITH DRY WX THEN EXPECTED THROUGH 
THURSDAY.
THE UPPER TROUGH WILL CONTINUE TO MOVE EAST AND BE REPLACED BY 
HIGHER HEIGHTS AND SLOWLY MODERATING TEMPS.
&&
.LONG TERM...(430 AM EST TUE JAN 20 2009)
(THURSDAY NIGHT THROUGH MONDAY)
EUROPEAN AND GFS BOTH INDICATE A SYSTEM MOVING THROUGH THE GREAT 
LAKES REGION THURSDAY NIGHT AND FRIDAY. HAVE CHANCE POPS (30/40 PCT) 
FOR SNOW IN THE FORECAST AS THIS SYSTEM SLIDES THROUGH. IT DOES NOT 
LOOK LIKE ANYTHING VERY HEAVY IN OUR AREA WITH THE HIGHER PCPN 
STAYING NORTH OF THE GRR CWA. COLD AIR FILTERS BACK INTO THE AREA 
OVER THE WEEKEND WITH -20 C AIR IN PLACE ONCE AGAIN AT 850MB/S. LAKE 
EFFECT SNOW APPEARS LIKELY MUCH OF THE WEEKEND. AS STATED IN THE 
PREVIOUS DISCUSSION THROUGH SURFACE RIDGING SHOULD KEEP IT FROM 
GETTING TOO OUT OF HAND. SURFACE RIDGING REMAINS IN PLACE INTO EARLY 
NEXT WEEK. 
OVERALL...A FAIRLY QUIET PERIOD COMPARED TO MOST OF THE WINTER. 
THURSDAY NIGHT AND FRIDAY WILL BE NEAR TO ABOVE NORMAL IN REGARD TO 
TEMPERATURES...WITH A PLUNGE BACK INTO DEEP WINTER BY SATURDAY IT 
APPEARS. THE COLD AIR WILL THEN LINGER INTO MONDAY.
 
&&
.MARINE...(430 AM EST TUE JAN 20 2009)
NORTH WINDS 5 TO 10 KNOTS WILL RESULT IN WAVES LESS THAN 4 FEET 
TODAY. A SMALL CRAFT ADVISORY MAY BE NEEDED TONIGHT AS WINDS ARE 
EXPECTED TO TURN TO THE WEST WITH WAVES BUILDING TO 3 TO 5 FEET.  
&&
.AVIATION...(1158 AM EST TUE JAN 20 2009)
CLEAR SKIES PREVAIL ACROSS ALL THE TAF SITES THIS AFTERNOON IN 
NORTHERLY FLOW. WINDS WILL BECOME WEST TONIGHT WHICH WILL PUSH LOW 
CLOUDS...MVFR CEILINGS...BACK INTO THE TAF SITES BETWEEN 02Z AND 
06Z. LAN AND JXN WILL TAKE LONGER TO CLOUD OVER AND MAY NOT GO MVFR 
UNTIL AFTER 06Z.
&&
.HYDROLOGY...(430 AM EST TUE JAN 20 2009)
ICE JAMS WILL CONTINUE TO AFFECT AREA RIVERS DURING THE NEXT FEW 
DAYS. WITH CONTINUED SUB FREEZING TEMPERATURES EXPECTED FOR THE NEXT 
SEVERAL DAYS...ANYONE LIVING NEAR RIVERS SHOULD KEEP AN EYE OUT FOR 
ICE JAMS AND POTENTIAL RAPID FLUCTUATIONS ON RIVERS. 
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE. 
&&
$$
SYNOPSIS:     93
SHORT TERM:   93
LONG TERM:    DUKE
MARINE:       93 
AVIATION      OSTUNO
HYDROLOGY:    93