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000
FXUS63 KJKL 151940 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON KY
340 PM EDT WED MAY 15 2013

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 340 PM EDT WED MAY 15 2013

18Z SFC ANALYSIS SHOWS A DECENT PRESSURE GRADIENT THROUGH EAST
KENTUCKY ATTM FROM A DEEP SFC LOW PASSING OFF TO THE NORTHEAST AND
HIGH PRESSURE OVER THE SOUTHEAST. THIS GRADIENT HAS KEPT BREEZY WEST
SOUTHWEST WINDS GOING OVER EAST KENTUCKY TODAY. AT THE SAME TIME...
CLEAR SKIES ALLOWED FOR PLENTY OF SUNSHINE. ALL TOGETHER THIS HAS
LED TO LIKELY THE WARMEST DAY OF THE YEAR THUS FAR...ONCE THE HIGHS
ARE TALLIED...WITH READINGS PRETTY UNIFORM THROUGH THE CWA IN THE
MID 80S. DEWPOINTS ARE UP FROM YESTERDAY...BY STILL NOT TOO HUMID
WITH VALUES IN THE LOW TO MID 50S.

THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION
OF THE FORECAST AS THEY ALL TAKE A SOUTHERN STREAM LOW EAST FROM THE
SOUTHERN PLAINS TONIGHT AND THURSDAY. THIS WILL OPEN UP AS IT
APPROACHES KENTUCKY ON THURSDAY...KNOCKING DOWN THE MODERATE RIDGING
THAT WE ENJOYED TODAY. AS THE LOW OPENS UP...ITS ENERGY WILL STREAM
OVER KENTUCKY AND KEEP THE WEATHER UNSETTLED INTO FRIDAY MORNING.
GIVEN THE MODEL SIMILARITIES HAVE MAINLY FOLLOWED THE HIGHER
RESOLUTION NAM12 FOR WEATHER SPECIFICS THROUGH THE FORECAST.

SENSIBLE WEATHER WILL FEATURE ANOTHER MILD NIGHT...BUT NOT QUITE AS
BREEZY. DO EXPECT A SMALL TO MODERATE RIDGE TO VALLEY SPLIT WITH
SOME OF THE SHELTERED LOCATIONS LIKELY BOTTOMING OUT AROUND MIDNIGHT
BEFORE SEEING THEIR TEMPS RISE A TAD TOWARD DAWN. AGAIN...JUST A HINT
OF PATCHY FOG CAN BE EXPECTED IN THE RIVER VALLEYS AND NEAR THE
LAKES. A BACK DOOR COLD FRONT WILL SLIP TOWARD THE AREA LATE TONIGHT
FROM THE NORTH. FROM THIS SCATTERED SHOWERS OR A STRAY THUNDERSTORM
WILL BE POSSIBLE BY DAWN...MAINLY NORTH OF THE MOUNTAIN PARKWAY. THIS
BOUNDARY...STALLING JUST TO THE NORTH OF THE CWA...AND THE APPROACH
OF THE UPPER LOW FROM THE WEST WILL LIKELY BE ENOUGH FOR SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPING BY MIDDAY THURSDAY.
EXPECT PRETTY GOOD COVERAGE THROUGH THE AFTERNOON...BUT THE DIRECT
HITS MAYBE AROUND 50 PERCENT FOR ANY SPECIFIC LOCATION. THE DIURNAL
NATURE OF THE CONVECTION WILL MEAN A TAPERING BACK TO MAINLY ISOLATED
SHOWERS BY MIDNIGHT AND ANOTHER MILD NIGHT WITH A POTENTIAL FOR
PATCHY FOG IN THE VALLEYS BY DAWN FRIDAY.

FOR TEMPERATURES...USED THE CONSSHORT AS A STARTING POINT WITH ONLY
MINOR ADJUSTMENTS BASED ON TERRAIN TONIGHT. AS FOR POPS...ENDED UP
HIGHER THAN MOS THROUGH THE PERIOD GIVEN THE ANTICIPATED GOOD
COVERAGE ON THURSDAY AND LINGERING CHANCES INTO THAT NIGHT.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 245 PM EDT WED MAY 15 2013

MODELS IN GOOD AGREEMENT FOR THE LONG TERM PORTION OF THE FORECAST
WITH THE OVERALL PATTERN...AND WITH THE EXPECTATION OF ABOVE NORMAL
TEMPERATURES. AT THE BEGINNING OF THE PERIOD A FRONTAL BOUNDARY IS
FORECAST TO BE OVER SOUTHERN OHIO. THIS IDEA IS SUPPORTED BY
OPERATIONAL MODELS...AS WELL AS THE SREF AND GFS ENSEMBLE. THE
FRONTAL BOUNDARY WILL MEANDER IN THE OH VALLEY THROUGH THE UPCOMING
WEEKEND...AND WILL REMAIN THE FOCUS FOR CONVECTION. FRONT MAY SLIP
INTO NORTHERN PART OF FORECAST AREA DURING WEEKEND...BUT DO NOT
EXPECT IT TO GET MUCH FURTHER SOUTH THAN THAT. A SHORT WAVE TROF
MOVES EAST FOR THE FIRST PART OF THE WEEKEND...THOUGH THERE IS NOT
GOOD MODEL AGREEMENT ON THE IMPACT OF THIS. THE EXPECTATION IS THAT
THIS MAY INCREASE PRECIPITATION CHANCES FOR EARLY PART OF THE
WEEKEND.

BY MONDAY PRECIPITATION CHANCES SHOULD BE ON THE DECREASE AS UPPER
RIDGING BUILDS ACROSS THE AREA...AND THE SURFACE FRONT LIFTS NORTH.
MODELS ARE IN GOOD AGREEMENT WITH THE UPPER LOW OVER THE NORTHERN
PLAINS EARLY NEXT WEEK. IN FACT FOR THE 12Z TUESDAY FORECAST THE 12Z
GFS...00Z ECMWF AND 00Z GFS ENSEMBLE MEAN ALL HAVE THE 5H LOW IN THE
VICINITY OF THE MN SD BORDER...WITH THE 12Z ECMWF PLACING IT NEAR
THE IA SD NE TRI STATE AREA. WITH THE NORTHERN PLAINS MID AND UPPER
LOW CLOSING OFF THE ASSOCIATED SURFACE LOW AND COLD FRONT WILL BE
SLOW TO MOVE EAST. AT THIS TIME IT APPEARS THE MOST LIKELY SCENARIO
WILL BE THAT THE COLD FRONT WILL MOVE INTO THE AREA SOMETIME ON
WEDNESDAY...WITH AN INCREASED CHANCE OF SHOWERS AND THUNDERSTORMS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 220 PM EDT WED MAY 15 2013

VFR CONDITIONS ARE EXPECTED THROUGH THE BULK OF THE FORECAST PERIOD
FOR MOST SITES. BY MIDDAY THURSDAY SHOWERS AND THUNDERSTORMS WILL
LIKELY BE DEVELOPING THROUGHOUT THE AREA BY NOON. FOR THIS...HAVE
ADDED A VCTS AND CB TO THE TAFS. DID ALSO INCLUDE A TEMPO FOR THE
POSSIBILITY OF SOME MVFR CIGS OR VIS AFFECTING SME AND LOZ AT THE
CLOSE OF THE TAF PERIOD. WINDS WILL BE GENERALLY FROM THE SOUTHWEST
AT 10 TO 15 KTS DURING THE FORECAST PERIOD.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...GREIF
LONG TERM...SBH
AVIATION...GREIF