FXUS63 KLMK 222321
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
621 PM EST TUE DEC 22 2009
...UPDATED AVIATION DISCUSSION...
.SHORT TERM (TONIGHT AND WEDNESDAY)...
A DEVELOPING STORM SYSTEM OVER THE WESTERN UNITED STATES WILL BEGIN
TO AFFECT THE LOWER OHIO VALLEY WEDNESDAY.
FIRST... FOR THE REST OF THE AFTERNOON TEMPERATURES WILL TOP OUT IN
THE 40S AND LOWER 50S UNDER MOSTLY SUNNY SKIES. WE WILL BEGIN TO SEE
SOME HIGH CLOUDS SPREAD ACROSS THE AREA TONIGHT AND CONTINUE TO
INCREASE DURING THE DAY WEDNESDAY. SURFACE LOW PRESSURE WILL TRACK
FROM TEXAS INTO OKLAHOMA AND A WARM FROM WILL MOVE ACROSS THE MID
MISSISSIPPI VALLEY INTO THE THE LOWER OHIO VALLEY. I THINK MOST OF
THE PRECIPITATION WITH THIS WARM FRONT WILL REMAIN WEST OF THE
FORECAST AREA BUT SOME SHOWERS MAY BE POSSIBLE ESPECIALLY DURING THE
AFTERNOON.
TEMPERATURES TONIGHT WILL FALL INTO THE MID 30S WITH HIGHS WEDNESDAY
REACHING INTO THE 40S AND 50S.
.LONG TERM (WEDNESDAY NIGHT - TUESDAY)...
THE DEEP LOW PRESSURE SYSTEM THAT HAS BEEN THE CONCERN THE LAST
SEVERAL DAYS WILL CONTINUE TO BE THE MAIN WEATHER SYSTEM OF THE
EXTENDED FORECAST PERIOD. BY WEDNESDAY NIGHT...THIS SURFACE LOW WILL
BE CENTERED OVER EASTERN PORTIONS OF KS AND OK AND LIFT TO THE
NORTHEAST SLOWLY ON WEDNESDAY NIGHT. AND UPPER LEVEL RIDGE WILL BE
CENTERED OVER THE OHIO VALLEY WITH STRONG SOUTHERLY FLOW OVER THE
REGION BRINGING MOISTURE INTO THE REGION FROM THE GULF COAST.
PRECIPITATION WILL BEGIN TO MOVE INTO WESTERN PORTIONS OF THE
FORECAST AREA WEDNESDAY NIGHT AND SLOWLY MOVE EASTWARD TOWARD
MORNING BUT THE BULK OF THE HEAVIEST PRECIP WILL REMAIN ALONG THE
MISSISSIPPI RIVER IN EAST CENTRAL MO/WEST CENTRAL IL AND WESTERN KY.
DURING THE DAY WEDNESDAY...THE LOW WILL BE OVER THE ST. LOUIS AREA
AND THE HEAVY PRECIPITATION WILL SHIFT EASTWARD OVER SOUTHERN
INDIANA AND CENTRAL KENTUCKY. GIVEN AN 850 MB JET OF 50 TO 70 KTS
OVER THE AREA THURSDAY AFTERNOON INTO THURSDAY NIGHT...WINDS WILL
INCREASE DURING THE DAY AND BECOME GUSTY IN THE AFTERNOON AND
OVERNIGHT HOURS. PRECIPITATION AMOUNTS OF UP TO AN INCH OR TWO WILL
BE POSSIBLE BY FRIDAY MORNING. TEMPERATURES WILL ALSO CONTINUE TO BE
WARM WITH HIGHS IN THE 40S AND 50S THURSDAY AND FRIDAY AND OVERNIGHT
LOWS IN THE UPPER 30S TO LOW 40S.
ON FRIDAY...PRECIPITATION INTENSITY WILL DIMINISH DURING THE MORNING
AS A DRY SLOT WORKS INTO THE AREA. COLDER AIR WILL START TO FUNNEL
INTO THE REGION DURING THE DAY AND TEMPERATURES WILL LIKELY FALL
THROUGH THE DAY FROM SOMEWHERE IN THE LOW 40S TO AROUND 30 BY
SUNSET. BY THIS TIME...MOST OF THE PRECIPITATION WILL BE OUT OF THE
AREA AND ONLY VERY LIGHT SNOW SHOWERS OR FLURRIES WILL BE POSSIBLE
FRIDAY NIGHT AND THROUGH THE REMAINDER OF THE WEEKEND AS THE UPPER
LOW STALLS OVER THE GREAT LAKES REGION. TEMPS DURING THE WEEKEND
WILL BE COLDER WITH HIGHS IN THE 30S AND LOWS IN THE 20S.
BY MONDAY AND TUESDAY THE UPPER LOW WILL FINALLY START TO MOVE OFF
TO THE EAST AND A BECOME AN OPEN WAVE TROUGH OVER NEW ENGLAND AND
THE MID ATLANTIC. THIS WILL BUILD A RIDGE OVER THE CENTRAL PLAINS
AND MOVE IT EASTWARD FOR TUESDAY KEEPING THE BEGINNING OF THE WORK
WEEK DRY AND SOMEWHAT WARMER.
&&
.AVIATION (00Z TAF ISSUANCE)...
LATE AFTERNOON/EARLY EVE IR SAT IMAGERY SHOWING QUITE A BIT OF
CLOUDS MOVING EASTWARD TOWARD THE REGION. MID-HIGH LEVEL CLOUDS ARE
ALREADY HERE AND WILL GRADUALLY THICKEN OVERNIGHT. LATEST MODEL
DATA AND OBSERVATIONS UPSTREAM SUGGEST THAT CIGS WILL REMAIN VFR
OVERNIGHT. HOWEVER...LIGHT WINDS WILL AGAIN RESULT IN SOME LIGHT
FOG/MIST DEVELOPING ACROSS THE TAF SITES...BEGINNING AFTER 23/05Z.
VSBYS WILL LIKELY DROP INTO THE BOTTOM END OF THE MVFR RANGE. VSBYS
WILL QUICKLY RISE TO VFR CONDITIONS AFTER 23/14Z. DRY WEATHER LOOKS
TO HOLD OFF UNTIL THE AFTERNOON AT KSDF AND KBWG. GIVEN THE CURRENT
MODEL PROGS...PRECIP CHANCES SHOULD INCREASE AT KBWG AFTER 23/21Z
AND AT KSDF AFTER 24/00Z. KLEX LOOKS TO REMAIN DRY UNTIL AFTER THE
FCST PD.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
SHORT TERM........JA
LONG TERM.........LMS
AVIATION..........MJ
