FXUS63 KLMK 080511
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
1211 AM EST TUE DEC 8 2009
...UPDATED AVIATION DISCUSSION...
...FORECAST UPDATE...
A WEAK SURFACE BOUNDARY JUST TO THE NORTH OF THE OHIO RIVER WILL
MOVE THROUGH CENTRAL KENTUCKY OVER THE NEXT FEW HOURS. CLOUDS ARE
CONTINUING TO OVERSPREAD THE AREA FROM THE SOUTHWEST. OTHER THAN
ADJUSTING THE LOW TEMPS UP A DEGREE HERE OR THERE THE ONLY
SIGNIFICANT UPDATE MADE WAS TO REMOVE PRECIPITATION FROM THE GRIDS
FOR THE OVERNIGHT HOURS. WITH VERY DRY AIR NOTED ON THE OHX SOUNDING
ABOVE 850MB IT LOOKS LIKE ANY RAIN WILL HAVE A HARD TIME MAKING IT INTO
SOUTHERN KY BEFORE 12Z. OTHERWISE ONLY MINOR ADJUSTMENT MADE TO
REFLECT CURRENT TRENDS. UPDATED GRIDS ALREADY SENT AND UPDATED ZONES
OUT SOON.
.SHORT TERM (TODAY AND TONIGHT)...
WE/LL HAVE QUIET WEATHER FOR MOST OF TONIGHT AS WE SIT IN BETWEEN
WEATHER SYSTEMS. WE SHOULD SEE A FEW BREAKS IN THE CLOUDS EARLY THIS
EVENING ALTHOUGH CLOUDS WILL QUICKLY THICKEN BACK UP AFTER 6Z
TONIGHT. THE LOW PRESSURE SYSTEM OF INTEREST WILL BE DIGGING ON THE
LEE SIDE OF THE ROCKIES TOWARD MORNING. OVERRUNNING PRECIP AHEAD OF
ONE OF THE LOW PRESSURE SYSTEM/S WARM FRONTS SITTING OVER THE
WESTERN GULF STATES...WILL PUSH INTO OUR SOUTHERN FORECAST AREA (FA)
AROUND SUNRISE. PRECIPITATION WILL OVERSPREAD THE REGION FROM SOUTH
TO NORTH DURING THE MORNING HOURS TOMORROW. BY EARLY
AFTERNOON...EVERYONE SHOULD BE SEEING LIGHT TO MODERATE RAIN WITH
RAINFALL INTENSITY INCREASING THROUGHOUT THE AFTERNOON. SOUNDINGS
ARE FAVORABLE FOR MODERATE OR EVEN POCKETS OF HEAVY RAIN WITH A DEEP
LAYER OF MOISTURE...INCREASING OMEGA...AND PWATS AROUND 1 INCH
(DECENT FOR THIS TIME OF YEAR). THE BEST TIME FOR THE HEAVIER RAINS
WILL BE TOWARD LATE AFTERNOON/EARLY EVENING TOMORROW. QPF FOR
TOMORROW SHOULD RANGE FROM 0.5-1.0 INCH...NOT ENOUGH TO CAUSE ANY
FLOODING PROBLEMS.
AS FOR TEMPERATURES...LOWS TONIGHT WILL DIP INTO THE UPPER 20S TO
MID 30S. THE BLUEGRASS AND SOUTHEAST INDIANA WILL BE THE COLDEST
AND MIGHT ACTUALLY SEE A RAIN/SNOW MIX TO START OUT WITH TOMORROW
MORNING. HOWEVER IT WILL QUICKLY CHANGE TO ALL RAIN. TEMPERATURES
TOMORROW WILL BE ON A STEADY INCLINE AS WARM AIR SURGES AHEAD OF THE
LOW PRESSURE SYSTEM. WE/LL SEE HIGHS TOP OUT IN THE LOW 40S TO
AROUND 50 IN THE EARLY EVENING HOURS.
.LONG TERM (WEDNESDAY - MONDAY)...
...STRONG STORM SYSTEM TUESDAY NIGHT-WEDNESDAY...
TUESDAY NIGHT AND WEDNESDAY NIGHT...
HIGHLY ANTICIPATED WEATHER SYSTEM WILL BRING A VARIETY OF WEATHER TO
THE LOWER OHIO VALLEY TUES NITE - WED NITE. A STRONG LOW OVER
WESTERN MISSOURI WILL DEEPEN QUICKLY UNDERNEATH THE LEFT-EXIT REGION
OF A 150-KT JET. THIS SYSTEM WILL BRING AMPLE RAINFALL AND POSSIBLE
THUNDERSTORMS TO THE AREA (POSSIBLY DAMAGING WINDS)...FOLLOWED BY A
CHANGEOVER TO POSSIBLY SNOW ON WEDNESDAY ACCOMPANIED BY STRONG
GRADIENT WINDS. HERE ARE THE MAIN THREATS AND TIMING OF THOSE:
TUESDAY NIGHT...SFC LOW WILL DEEPEN AND MOVE NORTHEAST TOWARDS THE
GREAT LAKES. ITS ATTENDANT WARM FRONT WILL PUSH INTO FAR SOUTHERN KY
BY THIS TIME. ANYWHERE FROM ONE HALF TO ONE WHOLE INCH OF RAIN WILL
BE POSSIBLE MAINLY OVER THE SERN CWA. EMBEDDED ISOLATED
THUNDERSTORMS WILL ALSO BE POSSIBLE. WITH THE PRESENCE OF A 65-80KT
850MB LOW-LEVEL JET OVER THE ERN CWA...IT IS POSSIBLE SOME DAMAGING
WINDS COULD OCCUR DESPITE THE LACK OF EVEN WEAK INSTABILITY. THE
DIRECTIONAL WIND SHEAR WILL BE MAXIMIZED AROUND THE WARM
FRONT...WITH SFC WINDS ESE AND 850MB WINDS SW (STORM-RELATIVE
HELICITY VALUES FROM 0-3KM ARE FROM 300-500 M2S2). GIVEN THIS STRONG
DIRECTIONAL AND SPEED SHEAR...AN ISOLATED TORNADO OR TWO MAY ALSO BE
POSSIBLE.
THE BEST CHANCE FOR THE T WORD THOUGH MAY BE BETWEEN 06-12Z TUES
NIGHT/WED MORNING...ESPECIALLY BETWEEN 09-12Z WHERE THE WARM FRONT
HAS TIME TO MOVE NORTHWARD ACROSS THE CWA...ALLOWING FOR SOME WEAK
SFC INSTABILITY TO WORK INTO THE SRN AND SERN CWA. THE 09Z BUFKIT
SOUNDING FOR LEX 09Z WED SHOWS A CAPE OF AROUND 300 J/KG AND 0-2KM
BULK SHEAR OF 50 KTS.
...THIS 09-12Z WINDOW LOOKS LIKE THE BEST CHANCE FOR SEVERE WINDS OR
A POSSIBLY TORNADO OR TWO...MAINLY SE OF A LINE FROM LEXINGTON TO
GLASGOW...
WITH THAT BEING SAID...MOST OF THE DEEP MOISTURE WORKS NORTHEAST OF
THE AREA WHEN THE BEST INSTABILITY GETS INTO THE REGION...SO IF A
SQUALL LINE DOES FORM TOWARDS SUNRISE WEDNESDAY...IT SHOULD BE A
FAIRLY THIN AND HIGHLY SHEARED LINE (LOW-TOPPED--POSSIBLY NO
LIGHTNING). IT SHOULD BE NOTED THAT ANY LOOSE ITEMS OUTSIDE SHOULD
BE STOWED AWAY TUESDAY NIGHT AS EVEN GRADIENT WINDS COULD BLOW
GARBAGE CANS...ETC AROUND YOUR NEIGHBORHOOD.
SPEAKING OF WINDS...ON WEDNESDAY...THE COLD FRONT FROM THE SFC LOW
WILL PUSH THROUGH AROUND 12Z WED MORNING. TEMPERATURES WILL BE
STEADY FOR A COUPLE OF HOURS AND THEN WILL LIKELY PLUMMET THE REST
OF THE DAY. DURING WED MORNING...THE MODELS SHOW A GOOD CLEAR SLOT
FORMING JUST BEHIND THE COLD FROPA. GIVEN THE GOOD PROGGED MIXED
LAYER AND LOW-LEVEL WINDS FROM 40-57 KTS IN THIS LAYER...WE WILL SEE
STRONG GRADIENT WINDS FROM THE WEST (AROUND 30MPH SUSTAINED) AND
GUSTS UP TO 50 MPH AND EVEN HIGHER...POSSIBLY MEETING SEVERE
CRITERIA W/O PRECIP. THIS IS ESPECIALLY TRUE BETWEEN 12-16Z
WEDNESDAY OVER THE HIGHER TERRAIN OF THE BLUEGRASS...AND ACROSS
SOUTHERN INDIANA AND FAR NORTH-CENTRAL KY. BECAUSE OF THIS
POTENTIAL...WILL ISSUE A HIGH WIND WATCH OVER THE NORTH HALF OF THE
CWA. ALL LOCATIONS SHOULD REACH AT LEAST WIND ADVISORY CRITERIA
WEDNESDAY.
BY WED AFTERNOON...MORE CLOUDS WILL DEVELOP ACROSS THE NORTH AND
RAIN/SNOW OR JUST SNOW SHOWERS WILL BE POSSIBLE MAINLY IN THE
AFTERNOON. ANY PRECIP WILL BE LIGHT AND NO ACCUMS ARE EXPECTED AT
THIS TIME. WINDS SHOULD DIVE BELOW HIGH WIND CRITERIA...WEDNESDAY
LATE AFTERNOON...THOUGH GUSTS TO 35-40MPH WILL STILL BE POSSIBLE WED
EVENING. WINDS WILL SLOW TAPER OFF WED NIGHT AS TEMPS DIP DOWN INTO
THE LOW 20S.
THURSDAY THROUGH MONDAY...
SPENT MOST OF THE DAY ON THE TUES-WED SYSTEM...BUT THURSDAY WILL BE
A VERY COLD DAY. MOST PLACES MAY NOT EVEN REACH THE FREEZING MARK
FOR HIGHS AND WITH GUSTY WEST WINDS CONTINUING...WIND CHILLS WILL BE
IN THE TEENS...POSSIBLY SINGLE DIGITS ACROSS THE NORTH THAT MORNING.
ALTHOUGH TEMP WISE...HIGH PRESSURE WILL MOVE OVERHEAD THRS NIGHT-FRI
MORNING...AND THOSE LOWS FRI MORN WILL BE IN THE TEENS.
THE NEXT CHANCE OF PRECIP WILL COME LATE FRIDAY NITE...BUT MAINLY
SATURDAY FROM A SOUTHERN STREAM LOW. THE BEST CHANCE FOR SNOW WILL
BE THE FIRST HALF OF SATURDAY...WITH A POSSIBLE RASN MIX IN THE
AFTERNOON AT LEAST ACROSS THE SOUTH. THERE IS A POTENTIAL FOR
ACCUMULATING SNOW BUT ONLY HAVE A FEW TENTHS IN THE GRIDS FOR NOW.
SUNDAY-MONDAY ARE DRY FOR NOW.
&&
.AVIATION (06Z TAF ISSUANCE)...
A FOUR CORNERS LOW WILL QUICKLY MOVE ACROSS THE COUNTY AND INTO THE
MID MISSISSIPPI VALLEY BY 06Z WEDNESDAY. FOR THE LOWER OHIO VALLEY A
SOUTHERLY FLOW WILL DEVELOP AND INTENSIFY WITH RAIN OVERSPREADING
THE TAF SITES AFTER 15Z. FOR THE OVERNIGHT PERIOD WE EXPECT MAINLY
MVFR CIGS WITH SOME IFR CIGS POSSIBLE BY 12Z. MVFR CIGS AND VSBYS
EXPECTED ONCE THE RAIN BEGINS.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...HIGH WIND WATCH FROM LATE TONIGHT THROUGH WEDNESDAY AFTERNOON
FOR KYZ023>025-028>043-045>049-053>057-065>067.
IN...HIGH WIND WATCH FROM LATE TONIGHT THROUGH WEDNESDAY AFTERNOON
FOR INZ076>079-083-084-089>092.
&&
$$
UPDATE.........EES
SHORT TERM.....AL
LONG TERM......AML
AVIATION.......JA
