Area Forecast Discussion
Issued by NWS Jackson, KY

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000
FXUS63 KJKL 241148
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
648 AM EST WED DEC 24 2014

.UPDATE...
ISSUED AT 648 AM EST WED DEC 24 2014

UPDATED TO LOWER POPS THIS MORNING AS SOUTHEAST FLOW CONTINUES TO
STRENGTHEN WITH CLOUD HEIGHTS CONTINUING TO GO UP. THEY ARE NOW OVER
10KFT. THUS...CHANCES FOR MEASURABLE RAIN ARE DECREASING THROUGH THE
MORNING HOURS. BEST CHANCE OF RAIN STILL LOOKS TO COME WITH THE COLD
FRONT AS IT CROSSES THE AREA THIS AFTERNOON. LATEST HI-RES MODELS
CONTINUE TO SHOW THE POSSIBILITY OF A FEW THUNDERSTORMS AS THE FRONT
PUSHES ACROSS OUR AREA. SHOULD WARM UP NICELY GIVEN THE SOUTHEAST
FLOW AND LIMITED LOW CEILINGS THIS MORNING. WOULDN`T BE SURPRISED TO
SEE US GET EVEN WARMER THAN THE FORECAST CURRENTLY REFLECTS.

&&

.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 316 AM EST WED DEC 24 2014

AREA OF LOW PRESSURE IS NOW STARTING TO MAKE ITS MOVE NORTH ACROSS
CENTRAL KENTUCKY...AND WILL END UP OVER SOUTHEAST MICHIGAN BY THIS
EVENING. STRONG LIFT ASSOCIATED WITH THE LOW PRESSURE SYSTEM WILL
SPREAD ACROSS THE AREA THROUGH DAYBREAK WITH RAIN BECOMING WIDESPREAD
ONCE AGAIN AFTER A BRIEF LULL OVER THE PAST FEW HOURS. HRRR AND RAP
ARE IN GOOD AGREEMENT THAT THIS LIFT WILL EXIT TO THE NORTH BY 9 OR
10 AM...WITH ANOTHER LULL IN PRECIPITATION EXPECTED THROUGH MIDDAY.
WITH THE MIDDAY LULL IN PRECIPITATION...HIGHS WILL WARM INTO THE 60S
FOR ONE MORE DAY.

FINALLY AS THE LOW SHIFTS NORTH THOUGH...A STRONG COLD FRONT WILL
PUSH EAST ACROSS THE AREA THIS AFTERNOON. WITH THE MILD
TEMPERATURES...WE MAY GENERATE SOME WEAK INSTABILITY TO SUPPORT
CONVECTIVE SHOWERS DEVELOPING ALONG THE FRONT AS IT PUSHES ACROSS THE
AREA. WHILE THUNDER CHANCES REMAIN LOW...CANNOT RULE OUT SOME THUNDER
WITH THE STRONGER CELLS...ESPECIALLY ACROSS NORTHERN KENTUCKY. GIVEN
THE ABUNDANCE OF MID LEVEL DRY AIR...AND STRONG 850MB WINDS AROUND 45
KNOTS...WE COULD SEE THE POTENTIAL FOR SOME HIGHER WINDS TO GET MIXED
DOWN WITH THE SHOWERS. HOWEVER...EVEN WITHOUT THE CONVECTIVE SUPPORT
FOR WINDS...THE SYNOPTIC SETUP BEHIND THE FRONT SHOULD SUPPORT 40+
MPH WINDS...ESPECIALLY ACROSS THE NORTHERN HALF OF THE AREA.
THUS...WILL GO AHEAD WITH A WIND ADVISORY FOR THE NORTHERN HALF OF
THE AREA. CONDITIONS ARE MORE MARGINAL FARTHER SOUTH...BUT A WIND
ADVISORY FOR THE HIGH TERRAIN NEAR THE VIRGINIA BORDER ALSO SEEMS IN
ORDER GIVEN THE STRONG WINDS AT 850MB. BEST THREAT FOR THE HIGHER
WINDS WILL BE AFTER 17Z AND BEFORE 03Z TONIGHT.

CONDITIONS WILL QUITE DOWN SOME THIS EVENING AS SUBSIDENCE SPREADS IN
BEHIND THE DEPARTING FRONT. HOWEVER...A SHORTWAVE TROUGH WILL PUSH
EAST ACROSS THE AREA LATE TONIGHT...WITH THE MOISTURE DEPTH
INCREASING TO SUPPORT SOME LIGHT RAIN/DRIZZLE. COLDER AIR WILL ALSO
BE SPILLING INTO THE AREA TONIGHT BEHIND THE FRONT. WHILE MOST AREAS
WILL STAY MILD ENOUGH FOR JUST RAIN...THE HIGHER TERRAIN IN THE
SOUTHEAST WILL SUPPORT SOME SNOW CHANCES. IN FACT...CONDITIONS ALIGN
GOOD ENOUGH TONIGHT WE COULD SEE A LIGHT COATING OF SNOW ON THE HIGH
TERRAIN ABOVE 2500 FEET LATE TONIGHT.

HEIGHTS WILL BE QUICK TO BUILD BACK ACROSS THE AREA ON CHRISTMAS.
CLOUDS MAY BE STUBBORN THROUGH THE FIRST HALF OF THE DAY...BUT WE
SHOULD DEFINITELY SEE A DECREASING TREND THROUGH THE AFTERNOON AND
EVENING AS THE RIDGE CENTERS ITSELF OVER THE REGION. HIGHS WILL
STRUGGLE TO WARM GIVEN THE ABUNDANCE OF CLOUDS THROUGH THE FIRST HALF
OF THE DAY...SO PLAN TO KEEP HIGHS LIMITED TO THE LOW TO MID 40S WITH
30S ON THE HIGHER TERRAIN IN THE SOUTHEAST.

.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 420 AM EST WED DEC 24 2014

THE PERIOD IS EXPECTED TO BEGIN WITH A CLOSED UPPER LOW CONTINUING TO
DEPART TO THE NORTHEAST OF THE REGION WITH UPPER LEVEL RIDGING
BUILDING ACROSS THE AREA AT THE START OF THE PERIOD. FURTHER TO THE
WEST A TROUGH IS EXPECTED TO EXTEND FROM THE NORTHERN PLAINS SOUTH
INTO THE SOUTHERN ROCKIES AND NORTHERN MEXICO. SFC AND UPPER LEVEL
RIDGING WILL GRADUALLY WORK ACROSS THE AREA FOR THU NIGHT INTO FRIDAY
AND THEN DEPART TO THE EAST FRIDAY NIGHT INTO SATURDAY. MEANWHILE A
SHORTWAVE TROUGH IS ANTICIPATED TO EJECT FROM THE WESTERN TROUGH
ACROSS THE PLAINS TOWARD THE GREAT LAKES FROM FRIDAY INTO SATURDAY.
THIS WILL LEAD TO GRADUALLY LOWERING HEIGHTS ACROSS THE GREAT LAKES
AND OH VALLEY AND A COLD FRONT DROPPING TOWARD THE REGION TO START
THE WEEKEND. THIS SHOULD BEGIN THE START OF AN UNSETTLED PERIOD.

OVER TIME...A RATHER BROAD TROUGH IS EXPECTED TO DEVELOP FROM CENTRAL
CANADA SOUTH INTO THE ROCKIES AND THEN EAST INTO THE EASTERN CONUS.
MODELS VARY FROM RUN TO RUN AND MODEL TO MODEL WITH THE HANDLING OF
INDIVIDUAL SHORTWAVES IN WEST SOUTH TO SOUTHWEST FLOW DURING THIS
PERIOD AND THE INTERACTION WITH A BAROCLINIC ZONE...THE FRONT THAT
MOVES INTO THE AREA EARLY IN THE WEEKEND...RESULTING IN SFC WAVES
DEVELOPING ALONG THE FRONT. THE ECMWF IS GENERALLY SLOWER BRINGING
THIS FRONT ACROSS THE AREA AND IS ALSO STRONGER AND FURTHER SOUTHEAST
WITH A SFC WAVE SUN NIGHT INTO MONDAY. AS THIS LAST SYSTEM DEPARTS AN
ARCTIC BOUNDARY SHOULD APPROACH THE AREA TUE OR WED.

DUE TO AN OVERALL LACK OF COLDER AIR FOR MOST OF THE PERIOD...MUCH OF
THE PRECIPITATION SHOULD FALL AS RAIN...ALTHOUGH SOME SNOW MAY MIX IN
ON SUNDAY NIGHT INTO EARLY ON MONDAY IN THE HIGHEST TERRAIN AND NORTH
OF THE MTN PARKWAY. A MIX OF RAIN AND SNOW WILL REMAIN POSSIBLE INTO
THE DAY ON TUESDAY AS WE HELD ONTO SLIGHT CHANCE POPS TO ACCOUNT FOR
THE ECMWF RUN. BOTH THE GFS AND ECMWF RUNS SUPPORT A WET END TO THE
WEEKEND.

AS FOR TEMPERATURES...THE PATTERN FAVORS A RIDGE VALLEY TEMPERATURE
SPLIT ON THU NIGHT AS SKIES WILL HAVE CLEARED OR SHOULD BE CLEARING
AS SFC AND UPPER LEVEL RIDGING WORK INTO THE AREA. A RELATIVELY DRY
AIRMASS AND A DOWNSLOPE COMPONENT SHOULD LEAD TO A RATHER MILD DAY ON
FRIDAY...ESPECIALLY FOR VALLEYS NEAR THE VA BORDER. THE DEPARTING
RIDGE SHOULD AGAIN FAVOR MILDER LOWS ON FRI NIGHT...BUT YET ANOTHER
RIDGE/VALLEY SPLIT. SATURDAY SHOULD AGAIN BE MILD AHEAD OF THE
BOUNDARY. WITH THE BAROCLINIC ZONE OVER OR NEAR THE REGION A GENERALLY
NW TO SOUTH OR SOUTHEAST GRADIENT IN TEMPERATURES IS ANTICIPATED FOR
THE REMAINDER OF THE PERIOD.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 648 AM EST WED DEC 24 2014

DRY AIR HAS INVADED THE AREA THANKS TO SOUTHEAST DOWNSLOPING FLOW OFF
THE HIGH TERRAIN. THIS HAS PUSHED CEILINGS UP TO OVER 10KFT. THIS
SHOULD REMAIN THE CASE THIS MORNING. COLD FRONT WILL BRING LOWER CIGS
LATER THIS AFTERNOON AND EVENING...EVENTUALLY REACHING MVFR LATE THIS
AFTERNOON. SOME SHOWERS WILL STILL BE POSSIBLE AS THE FRONT CROSSES
THE AREA. THE BIGGER STORY WILL BE THE POTENTIAL FOR STRONG GUSTY
WINDS AS THE FRONT BLOWS ACROSS HERE TODAY. WIND GUSTS UP TO 40 KNOTS
WILL BE POSSIBLE WITH THE HIGHEST READINGS EXPECTED ACROSS NORTHERN
KENTUCKY. WINDS WILL SLOWLY SUBSIDE THIS EVENING...BUT SHOULD REMAIN
SOMEWHAT GUSTY THROUGH THE NIGHT. A CHANCE OF RAIN WILL RETURN LATE
TONIGHT AS DEEPER MOISTURE SPREADS ACROSS THE AREA.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TODAY TO 10 PM EST THIS EVENING FOR
KYZ044-050>052-058>060-068-069-088-104-106>112-114-118>120.

&&

$$

UPDATE...KAS
SHORT TERM...KAS
LONG TERM...JP
AVIATION...KAS





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