FXUS63 KLMK 231702
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
1202 PM EST WED DEC 23 2009
...UPDATED AVIATION DISCUSSION...
.SHORT TERM (TODAY AND TONIGHT)...
TEMPS EARLY THIS MORNING ARE IN THE MID 30S TO LOWER 40S ACROSS MUCH
OF THE FCST AREA...AND SHOULD NOT FALL TOO MUCH MORE THRU DAYBREAK.
SOME MID AND HIGH LEVEL CLOUD COVER AND A LIGHT EAST BREEZE ARE
KEEPING VISIBILITIES HIGHER THIS MORNING THAN YESTERDAY MORNING.
ALTHOUGH THERE MAY BE PATCHY FOG EARLY THIS MORNING...IT SHOULD NOT
CAUSE PROBLEMS NOR RESULT IN FREEZING FOG LIKE YESTERDAY MORNING.
WATER VAPOR IMAGERY AT THIS TIME SHOWS UPPER LOW JUST SOUTH OF THE
FOUR CORNERS IN THE SW U.S. WITH ABUNDANT MID AND HIGH LEVEL
MOISTURE WELL IN ADVANCE OF THIS SYSTEM OVER THE CNTRL U.S. AND INTO
THE LOWER OH VALLEY. A SUBTLE SHORTWAVE MOVING THRU A MID-LEVEL
RIDGE ACROSS THE OH VALLEY ALONG WITH WEAK WARM ADVECTION ALOFT HAS
RESULTED IN AN AREA OF SCT SHOWERS OVER PARTS OF CNTRL/SRN IND. THE
LIGHT SHOWERS CONTINUE TO MOVE EAST AND COULD GRAZE A FEW COUNTIES
IN OUR NERN FCST AREA...MAINLY N OF LEX...EARLY THIS MORNING. SCT
SHOWERS ALSO WERE OVER SWRN IND AND NWRN KY...WHICH WILL SLIDE ENEWD
NEAR AND N OF OH RIVER THIS MORNING.
FOR TODAY AND TONIGHT...MID-LEVEL FLOW WILL BACK AS SWRN U.S. UPPER
LOW MIGRATES INTO SRN PLAINS TONIGHT...PUSHING RIDGE OVER THE OH
VALLEY SLOWLY TO OUR EAST. ALL SHORT RANGE MODELS KEEP BULK OF
MOISTURE JUST TO OUR WEST TODAY AND TONIGHT...WHICH APPEARS CORRECT.
HOWEVER...SCT SHOWERS WILL REMAIN POSSIBLE ESPECIALLY OVER WRN PARTS
OF FCST AREA AS MID-LEVEL MOISTURE SPREADS INTO AND THRU RIDGE.
SHOULD SEE A BETTER CHANCE OF SHOWERS LATE TONIGHT WEST OF
INTERSTATE 65 AS DEEPER LAYER MOISTURE MOVES NORTHEAST FROM WRN KY.
HIGH TEMPS THIS AFTERNOON SHOULD REACH THE MID 50S OVER S-CNTRL KY
COOLING TO THE LOWER TO MID 40S OVER OUR FAR NERN COUNTIES OF FCST
AREA. EXPECT LOWS TONIGHT FROM THE LOWER 40S OVER WRN PARTS OF
S-CNTRL KY TO 33-36 OVER E-CNTRL KY.
.LONG TERM (THURSDAY - WEDNESDAY)...
THURSDAY - SUNDAY...
A RAINY CHRISTMAS EVE STILL LOOKS ON TRACK AS THE UPPER LOW OVER THE
SE CONUS THIS MORNING STRENGTHENS A SFC LOW OVER TX TODAY. THE SFC
LOW IS STILL EXPECTED TO TRACK UP THROUGH MISSOURI THURS
EVENING...PUSHING A COLD FRONT ACROSS OUR AREA FRIDAY MORNING. RAIN
ASSOCIATED WITH THIS SYSTEM HAS ALREADY BEGAN TO PUSH EASTWARD INTO
OUR AREA THIS MORNING. BY THURSDAY MORNING...PRECIPITATION WILL
BECOME LIKELY WEST OF INTERSTATE 65. RAIN COVERAGE WILL INCREASE
AND SPREAD EAST THROUGHOUT THE AFTERNOON HOURS. THE HEAVIEST RAIN
LOOKS TO COME THROUGH THURSDAY EVENING INTO THE WEE HOURS OF FRIDAY
MORNING. DYNAMIC FORCING LOOKS TO BE QUITE STRONG WITH THIS SYSTEM
AS WE SIT ON THE NOSE OF A 300MB JET...AND AN H85 LL JET PASSES
OVERHEAD THURSDAY EVENING AHEAD OF THE COLD FRONT. WITH PWATS NEAR
1 INCH AND PLENTY OF DYNAMIC FORCING...WE COULD SEE 1-2 INCHES OF
RAIN OUT OF THIS SYSTEM. GENERALLY ANY FLOODING PROBLEMS SHOULD BE
MINOR. WITH SUCH A STRONG LL JET OVERHEAD...CAN/T RULE OUT THE
POSSIBILITY OF A STRONG SHOWER OR ISOLATED T-STORM WITH GUSTY WINDS
UP TO 50 MPH. HOWEVER...THINK THIS IS UNLIKELY DUE TO A LOW LEVEL
STABLE LAYER. BELIEVE WIND GUSTS SHOULD STAY IN THE 30-40 MPH RANGE
IN AND OUTSIDE OF ANY CONVECTION. GUSTY WINDS WILL LAST THURS
EVENING THROUGH FRIDAY AFTERNOON. AT THIS POINT...NO WIND ADVY IS
PLANNED AS WE SHOULD REMAIN BELOW CRITERIA ACCORDING TO THE LATEST
MODEL GUIDANCE.
PRECIPITATION SHOULD BE ON THE DECLINE FRIDAY MORNING AFTER THE COLD
FROPA. COLDER AIR WILL MOVE IN ON FRIDAY. WITH THE UPPER LOW
LINGERING OVER THE GREAT LAKES REGION FOR A FEW DAYS...WE SHOULD
HAVE A SHOT AT SOME FLURRIES FRIDAY NIGHT THROUGH SUNDAY.
TEMPERATURES WILL BE QUITE WARM ON THURS RISING INTO THE UPPER 40S
TO MID 50S FOR HIGHS AHEAD OF THE LOW PRESSURE SYSTEM. TEMPS WILL
TOP OUT IN THE LOW TO MID 40S FRIDAY MORNING BEFORE FALLING
THROUGHOUT THE AFTERNOON HOURS INTO THE 30S. SAT-SUN WILL BE COLDER
WITH HIGHS IN 30S AND LOWS IN THE 20S.
THE REST OF THE FORECAST REMAINS UNCHANGED. THE PREVIOUS DISCUSSION
IS AS FOLLOWS:
MONDAY - TUESDAY...
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 (18Z TAF ISSUANCE)...
A DEEPENING UPPER LEVEL LOW OVER OVER THE WESTERN FOUR CORNER STATES
TODAY WILL CAUSE LOW LEVEL WINDS TO BACK TO THE SOUTHEAST ACROSS THE
LOWER OHIO VALLEY. THIS BRING SOME DRIER AIR INTO THE AREA AND WILL
KEEP THE BULK OF THE PRECIPITATION TO THE WEST OF THE TAF SITES FOR
MUCH OF THIS FORECAST PERIOD. IT LOOKS AS IF CIGS AND VSBYS WILL
REMAIN IN THE VFR CATEGORY THROUGH 18Z THURSDAY. WINDS WILL INCREASE
FROM THE SOUTH AFTER 12Z THURSDAY WITH SOME GUSTS TO 20KTS EXPECTED.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
SHORT TERM........TWF
LONG TERM.........AML
AVIATION..........JA
