Area Forecast Discussion
Issued by NWS Jackson, KY

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FXUS63 KJKL 150300 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON KY
1100 PM EDT MON APR 14 2014

.UPDATE...
ISSUED AT 1100 PM EDT MON APR 14 2014

DID A FINAL EVENING UPDATE TO THE GRIDS AND ZONES TO REFLECT THE
LATEST OBSERVATIONAL TRENDS AND HI-RES MODEL GUIDANCE. THEY CONTINUE
TO INDICATE THAT THE PCPN WILL CHANGE OVER TO A BIT OF SNOW JUST
ABOUT EVERYWHERE FROM 09Z WEST TO 12Z EAST AND THEN TAPER OFF QUICKLY
DURING THE MORNING. WARM GROUND TEMPERATURES AND THE STILL UN-CHILLED
LOWEST BOUNDARY LAYER OF AIR WILL MAKE ANY ACCUMULATIONS INTO EARLY
TUESDAY VERY FLEETING ON DECKS OR GRASSY SPOTS...EXCEPT UP TO 2
INCHES WILL BE POSSIBLE ABOVE 2000 FEET NEAR THE VIRGINIA BORDER. THE
SNOW WILL BE MIXED WITH RAIN AS SOME OF IT SHOULD BE ABLE TO MELT IN
THE LAST COUPLE OF HUNDRED FEET DESPITE QUITE COOL TEMPS JUST A BIT
HIGHER ALOFT. THE GRIDS...AND A FRESHENED SET OF ZONES...HAVE BEEN
SENT TO THE NDFD AND WEB SERVERS.

UPDATE ISSUED AT 820 PM EDT MON APR 14 2014

TWEAKED THE TEMP...DEWPOINT...POP...AND SKY COVER GRIDS TO REFLECT
CURRENT CONDITIONS AND TRENDS. HAVE TIMED THE RETURN OF SHOWERS...
AND A POSSIBLE THUNDERSTORM...INTO THE AREA AFTER 10 PM SPREADING
GRADUALLY EAST JUST AHEAD OF THE COLD FRONT. THIS WILL REACH FAR EAST
KENTUCKY LAST...LIKELY NOT UNTIL AFTER 06Z...PER THE LATEST HRRR.
THE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.

UPDATE ISSUED AT 620 PM EDT MON APR 14 2014

21Z SFC ANALYSIS SHOWS A POTENT COLD FRONT APPROACHING CENTRAL
KENTUCKY IN CONJUNCTION WITH THE DEEP SPRING LOW SPINNING OVER THE
EASTERN GREAT LAKES. A WAVE WILL LIFT NORTH ALONG THIS BOUNDARY
LATER TONIGHT AND SPREAD...MORE SUBSTANTIAL...PCPN BACK OVER EAST
KENTUCKY. ON RADAR...A LARGE AREA OF SHOWERS AND A FEW EMBEDDED
THUNDERSTORMS ARE MOVING THROUGH WESTERN KENTUCKY ACCOMPANYING THE
COLD FRONT. HERE IN THE EAST WE ARE DRY WITH TEMPERATURES IN THE
UPPER 60S AND LOWER 70S ALONG WITH A FEW BREAKS IN THE CLOUD COVER.
DESPITE THESE BREAKS...WINDS HAVE BEEN CONTAINED IN THE 10 TO 20 MPH
RANGE WITH ONLY OCCASIONAL GUSTS TO 30 MPH. MEANWHILE...DEWPOINTS
REMAIN LOWEST THROUGH FAR EAST KENTUCKY WHERE SOME UPPER 40S ARE
FOUND WHILE MID 50S EXIST FURTHER WEST. THIS EXTRA BIT OF DRY AIR
WILL HELP TO HOLD OFF THE RETURNING RAIN SHOWERS FOR A BIT LONGER.

WENT AHEAD AND UPDATED THE FORECAST TO DROP THE LAKE WIND ADVISORY
AS THE WINDS ARE RUNNING AROUND 10 MPH BELOW CRITERIA. ALSO ADJUSTED
THE FORECAST INTO TUESDAY MORNING FOR TIMING THE SHOWERS...AND
POSSIBLY THUNDERSTORMS...INTO THE AREA LATER THIS EVENING AND
OVERNIGHT. ALSO ADJUSTED THE WX GRIDS FOR THE SNOW CHANCES LATE
TONIGHT AND THROUGH THE DAY TUESDAY. MADE SOME MINOR TWEAKS TO
TEMPERATURES AND DEWPOINTS THIS EVENING AND INTO TUESDAY MORNING
BASED ON THE CURRENT CONDITIONS...TRENDS...AND THE LATEST MODEL
GUIDANCE. HAVE UNDERCUT THE CONSSHORT TEMPERATURES LATE TONIGHT AND
EARLY TUESDAY AS IT APPEARS TO BE UNDER DOING THE POST FRONTAL CAA.
THESE GRIDDED FORECAST UPDATES HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS WHILE THE TEXT PRODUCTS HAVE BEEN UPDATED WITH THE CHANGES
DESCRIBED ABOVE.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 340 PM EDT MON APR 14 2014

AFTER COMPARING ALL THE LATEST MODEL DATA TO THE ACTUAL WEATHER
CONDITIONS OVER THE PAST FEW HOURS...THE NAM12 BY FAR AND AWAY HAS
BEEN HANDLING THINGS THE BEST AND HAD THE BEST INITIALIZATION.
THEREFORE...THE NAM12 SOLUTION WAS USED TO CREATE THIS AFTERNOONS
FORECAST PACKAGE THROUGH WEDNESDAY MORNING. WITH NO PRECIPITATION
ONGOING...AND NOTHING AT ALL APPROACHING FROM UPSTREAM...THE AREA
SHOULD REMAIN FREE OF RAIN FOR THE NEXT SEVERAL HOURS. ISOLATED RAIN
SHOWERS SHOULD BEGIN POPPING UP AND MOVING INTO THE AREA EARLY THIS
EVENING...AS A STRONG COLD FRONT BEGINS TO PUSH EASTWARD TOWARD THE
AREA. NUMEROUS RAIN SHOWERS AND A FEW THUNDERSTORMS WILL BE POSSIBLE
OVERNIGHT...AS THE FRONT MOVES ACROSS THE AREA. THE PERIOD BETWEEN 4
AND 8Z LOOKS TO BE THE IDEAL TIME FOR ANY THUNDER WE EXPERIENCE AS
THAT WILL BE THE TIME OF BEST LOW LEVEL WARM MOISTURE FEED. ONCE THE
FRONT MOVES BY...MUCH COLDER AIR WILL QUICKLY SPILL INTO THE AREA
BEHIND IT. THIS WILL BE WHEN WE COULD SEE SOME SNOW FLAKES FLYING AND
PERHAPS EVEN A BIT OF SLEET. WITH GROUND TEMPERATURES EXTREMELY WARM
THE PAST SEVERAL DAYS...AND WITH THE SOILS ALREADY WET FROM RAIN...IT
WILL VERY HARD FOR ANY SNOW TO ACCUMULATE. THE ONE EXCEPTION WOULD BE
THE HIGHER TERRAIN ALONG THE VIRGINIA AND WEST VIRGINIA
BORDERS...WHERE THE TALLEST PEAKS COULD SEE MAYBE UP TO AN INCH OF
SNOW.

ONCE THE FRONT MOVES ACROSS THE AREA LATER TONIGHT...TEMPERATURES
WILL BEGIN FALLING STEADILY THROUGH THE PREDAWN HOURS. TEMPERATURES
WILL STILL RISE DURING THE DAY ON TUESDAY...BUT WILL NOT RISE VERY
MUCH AS A COLD AIR MASS SETTLES OVER THE AREA. HIGH TEMPERATURES FOR
MOST LOCATIONS ON TUESDAY WILL LIKELY STRUGGLE TO REACH 40 DEGREES.
THE MOST PRESSING MATTER FOR THIS PERIOD OF THE FORECAST WILL BE THE
FRIGID TEMPERATURES WE ARE EXPECTING TUESDAY NIGHT INTO WEDNESDAY
MORNING. AN ARCTIC AIR MASS WILL HAVE FULLY SETTLED OVER THE REGION
TOMORROW NIGHT...ALLOWING TEMPERATURES TO PLUMMET INTO THE LOW TO MID
20S FOR MOST FOLKS. SOME OF OUR COLDER VALLEYS AND TALLEST MOUNTAIN
PEAKS MAY EVEN SEE THE MERCURY DIP INTO THE UPPER TEENS. WITH WINDS
GOING NEAR CALM MOST OF THE NIGHT...AND WITH SKIES BEING MOSTLY
CLEAR...THE STAGE WILL BE SET FOR A WIDESPREAD KILLING FREEZE EVENT.
WIDESPREAD FROST WILL BE POSSIBLE FOR MOST OF THE NIGHT AND INTO
EARLY WEDNESDAY MORNING. TEMPERATURES THIS COLD WILL EASILY KILL ANY
SENSITIVE OUTDOOR VEGETATION THAT IS LEFT UNPROTECTED. A FREEZE
WATCH IS CURRENTLY IN EFFECT TO ADDRESS THIS ISSUE...BUT THIS PRODUCT
WILL LIKELY BE UPGRADED TO A FREEZE WARNING BY THE UPCOMING NIGHT
SHIFT EARLY TOMORROW MORNING.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 348 PM EDT MON APR 14 2014

THE MODELS START OUT IN GOOD AGREEMENT WITH AN UPPR TROUGH EXITING
THE EAST COAST FAIRLY ZONAL FLOW ACROSS THE REST OF THE CONUS. AN
UPPER TROUGH AND ASSOCIATED FRONT SYSTEM IS OVER THE DAKOTAS. THIS
UPPER TROUGH DEEPENS WITH TIME AND SLOWLY PUSHES A COLD FRONT TOWARD
THE AREA. THE FRONT SHOULD BE MOVING ACROSS EASTERN KENTUCKY ON
FRIDAY NIGHT. LEFT SOME PRECIPITATION IN THE FORECAST FOR
FRIDAY...HOWEVER WOULD NOT BE TOO SURPRISED TO SEE ANY PRECIPITATION
TO BE DELAYED UNTIL FRIDAY NIGHT. THIS IS WHERE THE MODES BEGIN TO
DISAGREE WITH THE GFS A LITTLE FASTER THAN THE ECMWF...WHICH IS THE
PREFERRED MODEL. HIGH PRESSURE BUILDS IN BEHIND THE FRONT AND WILL
KEEP THINGS DRY THROUGH THE END OF THE PERIOD.

FOR TEMPERATURES...NUDGED THE MODEL BLENDS TOWARD THE NEW ECMWF
WHICH WAS TYPICALLY COOLER THAN THE BLEND.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 745 PM EDT MON APR 14 2014

VFR CONDITIONS SHOULD HOLD FOR SEVERAL MORE HOURS BEFORE LOWER
CLOUDS AND PATCHY VIS RESTRICTIONS MOVE INTO THE AREA WITH THE
RETURN OF SHOWERS AND POSSIBLE THUNDERSTORMS. MVFR CIGS CAN BE
EXPECTED CLOSER TOWARDS DAWN AS THE FRONT MOVES ON THROUGH...WITH IFR
CIGS POSSIBLE FOR A TIME INTO TUESDAY MORNING. VIS WILL ALSO BE
FAIRLY LOW FOR A TIME AS THE RAIN SHOWERS SWITCH OVER TO SNOW IN MOST
PLACES AROUND DAWN. CONDITIONS IMPROVE BY MIDDAY TUESDAY AS THE PCPN
PULLS OUT AND DRIER AIR MOVES ON INTO THE AREA LIFTING CIGS AND
CLEARING ANY VIS ISSUES. SOUTHWEST WINDS OF 10 TO 20 KTS WILL SWITCH
TO THE WEST...THEN NORTHWEST...AS A COLD FRONT TRANSITIONS THROUGH
THE AREA LATE TONIGHT INTO TUESDAY MORNING. EXPECT THE WINDS TO
DIMINISH BY NOON TUESDAY.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING FOR
KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120.

&&

$$

UPDATE...GREIF
SHORT TERM...AR
LONG TERM...JJ
AVIATION...GREIF






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