FXUS63 KLMK 021117
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
617 AM EST WED DEC 2 2009
.SHORT TERM (TODAY AND TONIGHT)...
SURFACE LOW PRESSURE WAS LOCATED OVER NEW ORLEANS AT 07Z THIS
MORNING. THIS LOW WILL TRAVEL TO THE NNE TODAY...REACHING CENTRAL
KENTUCKY BY 00Z THIS EVENING AND THEN PROCEEDING TO NEW YORK BY 12Z
TOMORROW MORNING. SHOWERS WERE WIDESPREAD THIS MORNING FROM TEXAS
ALL THE WAY EAST TO THE CAROLINAS...WITH THUNDERSTORMS OUT OVER THE
GULF. AS THE LOW MAKES ITS WAY TO THE NORTH IT WILL BRING DEEP
MOISTURE ALONG WITH IT AND WILL BRING RAIN TO ALL PARTS OF SOUTHERN
INDIANA AND CENTRAL KENTUCKY TODAY. RAINFALL AMOUNTS WILL LIKELY BE
IN THE ONE-THIRD TO THREE-QUARTER INCH RANGE.
THIS AFTERNOON A DRY SLOT ATTEMPTS TO WORK INTO THE REGION WHICH MAY
HELP TO MAKE THE RAIN MORE SCATTERED. ALSO THIS AFTERNOON SOME WEAK
ELEVATED INSTABILITY DEVELOPS WITH COLD AIR ADVECTION ALOFT CAUSING
LAPSE RATES TO STEEPEN. NO REAL SUNSHINE IS EXPECTED SO
SURFACE-BASED INSTABILITY WILL REMAIN MINIMAL. HOWEVER AN ISOLATED
ELEVATED LOW TOP THUNDERSTORM OR TWO COULD DEVELOP OVER SOUTHEASTERN
PORTIONS OF THE DISTRICT...ESPECIALLY TOWARDS THE LAKE CUMBERLAND
REGION. BECAUSE OF LOW FREEZING HEIGHTS A BIT OF SMALL SOFT HAIL
COULD BE PRODUCED BY ANY ELEVATED CONVECTION THAT MIGHT MANAGE TO
DEVELOP.
AS THE LOW SCOOTS OFF TO THE NORTHEAST TONIGHT COLD AIR WILL WRAP IN
BEHIND IT. HOWEVER SURFACE TEMPERATURES WILL LIKELY REMAIN ABOVE
FREEZING AND BY THE TIME THE COLDEST PART OF THE NIGHT ARRIVES THE
DEEP MOISTURE WILL HAVE DEPARTED...LEAVING ONLY A SMALL PORTION OF
THE ATMOSPHERE SATURATED AND ALMOST ALL OF IT BELOW THE SNOW CRYSTAL
GROWTH ZONE. SO...WE COULD SEE A FEW FLAKES MIX IN WITH THE LIGHT
RAIN AROUND MIDNIGHT TONIGHT AND THEN MAYBE JUST SOME DRIZZLE OR
SPRINKLES AND FLURRIES AFTER MIDNIGHT.
HIGH TEMPERATURES TODAY WILL BE TRICKY. THERE SHOULD BE VERY LITTLE
TEMPERATURE RISE IN THE NORTHWEST WITH CLOUDS AND RAIN...MID 40S
SOUNDS GOOD THERE. THE SOUTHEAST HOWEVER WILL REMAIN EAST OF THE
TRACK OF THE LOW AND WILL BE MOST AFFECTED BY ANY DRY SLOT THIS
AFTERNOON SO A BIT MORE OF A RISE IS POSSIBLE THERE...INTO THE 50S.
LOW TEMPERATURES TONIGHT WILL GENERALLY BE IN THE 33 TO 38 DEGREE
RANGE. THIS PLUS THE FACT THAT THE GROUND WILL BE WET AND PAVEMENT
TEMPERATURES REMAIN RELATIVELY WARM...NO TRAVEL PROBLEMS ARE
ANTICIPATED AT THIS TIME EVEN IF WE DO GET A FEW SNOWFLAKES TO MIX
IN WITH THE LIGHT RAIN/SPRINKLES/DRIZZLE.
.LONG TERM (THURSDAY - TUESDAY)...
AS THE SURFACE LOW DEPARTS WELL OFF TO THE NORTHEAST ON THURSDAY A
MUCH COLDER AIRMASS WILL CONTINUE TO SINK INTO THE AREA. ANY
RESIDUAL MOISTURE IN THE AIR WILL LEAD TO LIGHT PRECIPITATION ON
THURSDAY IN THE FORM OF VERY LIGHT SNOW SHOWERS OR FLURRIES. WITH
TEMPERATURES RISING INTO THE LOWER 40S NO ACCUMULATION WILL RESULT
FROM THESE FLURRIES. PRECIPITATION WILL END BY THE LATE AFTERNOON
HOURS ON THURSDAY.
SURFACE HIGH PRESSURE WILL BEGIN TO BUILD IN OVER THE FORECAST AREA
FRIDAY MORNING AND WILL CONTINUE TO DO SO THROUGH THE WEEKEND. AN
UPPER LEVEL TROUGH WITH AN EMBEDDED SHORTWAVE WILL CROSS THE OHIO
VALLEY ON SATURDAY. PRECIPITATION ASSOCIATED WITH THIS SHORTWAVE
LOOKS TO STAY MAINLY EAST OF THE FORECAST AREA AT THIS TIME. HOWEVER
IF THIS DEVIATES SLIGHTLY TO THE WEST SOME LIGHT SNOW SHOWERS COULD
BE SEEN OVER FAR EASTERN PORTIONS OF THE FORECAST AREA ON SATURDAY
MORNING. AFTER THE UPPER LEVEL TROUGH PASSES THROUGH THE PATTERN
WILL SHIFT TO MORE ZONAL FLOW THROUGH THE REMAINDER OF THE LONG TERM.
WITH THE VERY COLD AIRMASS SETTLING INTO THE AREA TEMPERATURES ON
FRIDAY AND SATURDAY WILL BE QUITE COLD WITH HIGHS IN THE MID TO
UPPER 30S AND LOWS IN THE LOWER TO MID 20S. THEREAFTER A GRADUAL
WARM UP WILL TAKE PLACE INTO EARLY NEXT WEEK. HOWEVER HIGHS DURING
THE DAY WILL REMAIN A FEW DEGREES BELOW NORMALS FOR THIS TIME OF
YEAR...TOPPING OUT IN THE MID 40S..
&&
.AVIATION (12Z TAF ISSUANCE)...
LOW PRESSURE OVER SOUTHWEST MISSOURI AT 11Z WILL MOVE NNE TO THE
TN/MS/AL BORDER AT 18Z...CENTRAL KENTUCKY AT 00Z...CENTRAL OHIO AT
06Z...AND THEN OFF TO LAKE ONTARIO BY 12Z. AS IT DOES SO WIDESPREAD
RAIN WILL PASS THROUGH OUR REGION...ALONG WITH MVFR CEILINGS AND
POSSIBLY SOME HIGH-END IFR CEILINGS. A DRY SLOT THIS AFTERNOON MAY
HELP TO MAKE THE RAIN MORE SCATTERED...AND POSSIBLY MORE CONVECTIVE
THOUGH ANY THUNDERSTORMS WILL BE ISOLATED. AS THE DEEP MOISTURE
MOVES OFF TONIGHT THE RAIN AND SHOWERS WILL DIMINISH TO PATCHY
DRIZZLE AND SPRINKLES.
WITH THE LOW PASSING RIGHT OVER THE TAF SITES...WINDS WILL BE VERY
CHALLENGING TODAY. IN THE FORECAST TRIED TO SHOW AN EAST WIND THIS
MORNING GRADUALLY VEERING THROUGH SOUTHEAST AND SOUTH TO BECOME
SOUTHWEST AND EVENTUALLY WEST TONIGHT. THE LOW WILL BE DEEPENING
TODAY AND TONIGHT AND SO WE EXPECT WIND SPEEDS WILL BE ON THE
INCREASE...REACHING PREVAILING SPEEDS OF 10 TO 15 KNOTS TONIGHT.
THE WIND SHEAR THIS MORNING IS LOOKING A BIT WEAKER THAN IT WAS ON
PREVIOUS MODEL RUNS...BUT SINCE LLWS INCLUDES A DIRECTIONAL
COMPONENT TO THE VECTOR AS WELL AS SPEED...WILL KEEP A MENTION OF
SHEAR AT BWG AND LEX FOR A FEW HOURS THIS MORNING AS SOUTHEAST WINDS
INCREASE JUST ABOVE SLOWER EASTERLY SURFACE WINDS. THIS IS ALREADY
BEGINNING TO SHOW UP ON AREA VWP/S.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
SHORT TERM........13
LONG TERM.........EES
AVIATION..........13
