Area Forecast Discussion
Issued by NWS Jackson, KY

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000
FXUS63 KJKL 270402
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
1102 PM EST MON JAN 26 2015

.UPDATE...
ISSUED AT 1100 PM EST MON JAN 26 2015

NO CRUCIAL CHANGES SINCE THE PREVIOUS UPDATE. NEAR TERM TEMPERATURES
CONTINUE TO BE WELL ON TRACK...FRESHENED THEM UP WITH THE LATEST
OBSERVATIONAL DATA...AS WELL AS THE DEW POINTS AND WINDS. FOCUS
CONTINUES TO BE THE SNOW POTENTIAL AS WE HEAD INTO THE OVERNIGHT
HOURS. HRRR HAD A GOOD HANDLE ON THE SNOW EARLIER THIS
EVENING...SHOWING AN EVENTUAL LESSENING AS WE HEADED INTO THE
CURRENT PERIOD. WHILE A FEW LIGHT SNOW SHOWERS AND/OR FLURRIES ARE
LIKELY ONGOING IN PORTIONS OF THE SW CWA...THERE IS A NOTICEABLE
BREAK IN THE WIDESPREAD PRECIP WE HAD OVER CENTRAL KY EARLIER. THAT
BEING SAID...ANOTHER BAND OF ENHANCED PRECIP IS CURRENTLY MAKING ITS
WAY FROM SOUTHERN LAKE MICHIGAN AND SOUTHWARD ACROSS INDIANA. THIS
WILL LIKELY MAKE IT INTO THE CWA OVER THE NEXT FEW HOURS.
UNFORTUNATELY...THE LATEST HRRR HAS A NOTICEABLE LACK IN
INITIALIZATION...AND FURTHERMORE IT IS SHOWING UNLIKELY ARTIFACTS AS
THIS NEXT ROUND OF PRECIP MOVES IN. NOT PUTTING MUCH FAITH INTO THE
HRRR AT THIS POINT FOR THE INCOMING PRECIP. THE LATEST NAM12 AND
ECMWF ALSO PICK UP ON THIS SECOND BAND...THOUGH THE ECMWF LIKELY HAS
THE BETTER HANDLE ON QPF TOTALS. THIS WILL BE THE THING TO MONITOR
FOR POTENTIAL UPDATES THROUGH THE NEXT FEW HOURS.

UPDATE ISSUED AT 658 PM EST MON JAN 26 2015

A BAND OF RADAR REFLECTIVITIES IS CURRENTLY MAKING ITS WAY INTO THE
SW PORTION OF THE CWA. HIGHER REFLECTIVITIES...WHICH HAVE BEEN
REPORTED TO BE PUTTING DOWN SOME QUICK SNOW IS CURRENTLY OVER CENTRAL
KY AND MAKING ITS WAY EASTWARD. WHILE MOST OF THE REFLECTIVITIES OVER
OUR CWA CURRENTLY ARE ONLY PRODUCING FLURRIES...GIVEN THE UPSTREAM
REPORTS...DID GO AHEAD AND INCREASE POPS OVER OUR SW
COUNTIES...BRINGING IN SNOW POTENTIAL A COUPLE HOURS SOONER THAN WAS
PREVIOUSLY FORECAST. ALSO ENDED UP BUMPING UP THE QPF BY A COUPLE
HUNDREDTHS IN THE SW BASED ON THE UPSTREAM REPORTS...BRINGING SNOW
TOTALS UP TO ABOUT HALF AN INCH OVERNIGHT FOR PULASKI...WAYNE...AND
MCCREARY COUNTIES. NEAR TERM TEMPERATURES SEEM TO BE IN FAIRLY GOOD
SHAPE BASED ON THE LATEST INGEST OF OBSERVATIONAL DATA.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 410 PM EST MON JAN 26 2015

AS OF MID TO LATE AFTERNOON...A SHORTWAVE TROUGH IS MOVING EAST OF
THE REGION INTO THE DEVELOPING DEEP TROUGH ACROSS THE EASTERN CONUS.
MEANWHILE THE CLIPPER SYSTEM THAT MOVED ACROSS THE AREA LAST NIGHT
INTO THIS MORNING IS BEGINNING TO REORGANIZE INTO A DEEP
NOR`EASTER/BLIZZARD EAST OF THE MID ATLANTIC STATES. THE REGION WILL
REMAIN UNDER THE INFLUENCE OF NW ALOFT BETWEEN THE DEEPENING TROUGH
ALONG THE EASTERN SEABOARD AND RIDGING EXTENDING FROM MEXICO INTO THE
ROCKIES. AT THE SFC...HIGH PRESSURE WILL ALSO GRADUALLY BUILD INTO THE
GREAT LAKES AND LOWER OH VALLEY REGION ONCE THE CLIPPER SFC LOW
APPROACHING FROM THE OH VALLEY DEPARTS ON TUESDAY.

THE SHORTWAVE TROUGH MOVING INTO WV WILL TAKE THE STEADIER SNOW WITH
IT. LOW LEVEL MOISTURE WILL REMAINS ACROSS THE AREA WITH UPSLOPE
FLOW AND SATURATION IN THE LOW CLOUDS TO COLDER THAN -8C...USUALLY
ENOUGH FOR SMALL SNOWFLAKES OF LIGHT SNOW AND FLURRIES. THE CLIPPER
SYSTEM WILL TRACK TO OUR SW FROM WESTERN KY TO THE SOUTHERN
APPALACHIANS. THIS TRACK WILL FAVOR LOCATIONS ACROSS THE SW PART OF
THE AREA FOR LIGHT SNOW OR SCATTERED SNOW SHOWER CHANCES...ALTHOUGH
MODEL TIMEHEIGHT SECTIONS FORM THE NAM AND GFS MODELS DO HAVE A
WINDOW OF RATHER DEEP MOISTURE AND RATHER WEAK OMEGA NEAR 12Z...OR 7
AM ON TUESDAY. SNOW SHOWER CHANCES WILL REMAIN NEAR THE VA BORDER ON
THE UPSLOPE FLOW INTO THIS EVENING...WITH CHANCES FOR SNOW INCREASING
ACROSS THE SOUTHWEST PART OF THE AREA THROUGH THE EVENING AND INTO
THE OVERNIGHT HOURS. DAYTIME HEATING AND COLD TEMPERATURES ALOFT WILL
LEAD TO A CONTINUED CHANCE FOR SNOW SHOWERS AND FLURRIES ON TUESDAY
AND UNTIL THE FLOW BECOMES MORE NORTHERLY LATE TUE INTO TUESDAY
EVENING. QPF WITH THIS WILL BE LIGHT WITH ANY ACCUMULATIONS OF
A HALF AN INCH OR LESS ON AVERAGE WHERE SNOW DOES OCCUR. AN SPS WAS
REISSUED TO HIGHLIGHT THE LIGHT SNOW ACCUMULATION POTENTIAL AND
REFREEZE POTENTIAL THIS EVENING AND TONIGHT.

LOWS TONIGHT WILL BE COLDEST IN THE NORTH AND EAST WHERE 850 MB TEMPS
ARE PROGGED TO BE COLDEST. WE HAVE UNDERCUT MOST GUIDANCE TEMPS ON
AVERAGE ON TUESDAY AS THERE WILL BE SNOW ON THE GROUND IN SOME AREAS
AND MODELS WERE GENERALLY TOO WARM WITH TEMPS TODAY. GRADUAL CLEARING
SHOULD OCCUR FROM LATE TUE INTO TUE NIGHT AND WITH A DRY AIRMASS
PROGGED AND SNOW COVER LIKELY REMAINING IN SOME AREAS...VALLEYS
SHOULD FALL WELL INTO THE TEENS.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 PM EST MON JAN 26 2015

THE EXTENDED PERIOD BEGINS WITH A TROUGH EXITING TO OUR EAST AS SHORTWAVE
RIDGING BUILDS INTO EASTERN KENTUCKY. THIS RIDGING SHOULD PROVIDE A
TEMPORARY RELIEF OF PRECIP WEDNESDAY AFTERNOON INTO THURSDAY
MORNING. BY 12Z THURSDAY... BOTH GFS/ECMWF SHOW A LOW PRESSURE
SYSTEM CLIPPING NORTHERN KENTUCKY AND LIFTING NEWD FROM THE OHIO
VALLEY TOWARDS NEW ENGLAND... WITH THE GFS PROVIDING MORE SUPPORT
FOR THE MORE ROBUST ECMWF SOLUTION. ANOTHER LULL IN PRECIP FOLLOWS
UNTIL SUNDAY MORNING. AT THAT POINT... MODELS DEPICT A LARGE CLOSED
LOW IN THE SOUTHERN STREAM...OPENING UP AND SPILLING ITS ENERGY EAST
INTO THE FLOW RIDGING OVER THE TENNESSEE VALLEY. THE MODELS CONTINUE
TO SHOW SOME CONNECTION TO THE NORTHERN AND SOUTHERN STREAMS WHICH
WOULD CERTAINLY MAKE THINGS MORE INTERESTING FOR THE UPCOMING
WEEKEND IF THAT PANS OUT. FOR NOW... WILL SHOW ONLY LIMITED
INTERACTION AND EASE INTO A MORE DYNAMIC SCENARIO GIVEN THE
UNCERTAINTY AND LACK OF MODEL RUN TO RUN CONSISTENCY WITH THIS PART
OF THE FORECAST.

SENSIBLE WEATHER WILL FEATURE THE ENDING OF THE UPSLOPE SNOW
SHOWERS/FLURRIES IN THE FAR EAST EARLY WEDNESDAY MORNING WITH SOME
SUNSHINE RETURNING. THE NEXT CLIPPER SYSTEM WILL THEN MOVE INTO THE
OHIO VALLEY ON THURSDAY WITH A CHANCE FOR RAIN AND SNOW ACROSS THE
AREA FRIDAY MORNING. ONLY A BRIEF WINDOW FOR DRYING CAN BE EXPECTED
FROM FRIDAY NIGHT INTO SATURDAY NIGHT BEFORE THE POTENTIAL FOR
MAINLY SNOW ARRIVES FROM THE SOUTHWEST IN FAST LOW AND MID LEVEL
FLOW RIDING ALONG A WEST TO EAST ARCTIC BOUNDARY LYING OVER THE OHIO
VALLEY. THIS BOUNDARY IS EXPECTED TO PUSH ON THROUGH KENTUCKY BY
MONDAY MORNING WITH SNOW CHANCES CONTINUING...MAINLY IN THE
SOUTHERN PARTS OF THE CWA. THIS SYSTEM WILL HAVE TO BE CLOSELY
MONITORED AS MODELS COME INTO BETTER AGREEMENT WITH THE PHASING OF
THE NORTHERN AND SOUTHERN STREAM ENERGY AS WELL AS HOW QUICKLY THE
COLD AIR SETTLES INTO THE REGION.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 717 PM EST MON JAN 26 2015

UPSLOPE FLOW...MIXED WITH A SHORTWAVE AND FRONTAL BOUNDARY WHICH IS
TRAVERSING THE STATE FROM EAST TO WEST OVERNIGHT...WILL RESULT IN
ANOTHER ROUND OF LIGHT SNOW ACROSS A GOOD PORTION OF SE KY
OVERNIGHT. THESE SNOW SHOWERS ARE CURRENTLY LOCATED OVER CENTRAL
KY...AND COULD BEGIN AFFECTING KSME OVER THE NEXT HOUR OR TWO...WITH
KLOZ SOON TO FOLLOW. BASED ON THE CURRENT PROJECTION OF PRECIP...THE
NORTHERN MOST TAF SITES /KSYM AND KSJS/ MAY MISS OUT ON THE SNOW ALL
TOGETHER...WITH THE EXCEPTION OF SOME PERIODS OF FLURRIES THROUGHOUT
THE NIGHT. EXPECT CIGS TO FLUCTUATE BETWEEN ALTERNATE FUEL
REQUIREMENTS AND IFR CONDITIONS AT ALL TAF SITES...WITH VIS EXPECTED
TO DROP TO THE SAME THRESHOLDS DURING ANY SNOW SHOWERS AT KSME AND
KLOZ. CONDITIONS WILL SLOWLY IMPROVE BETWEEN LATE MORNING AND EARLY
AFTERNOON TOMORROW...WITH A STRONG SURGE OF DRY AIR FALLING IN BEHIND
THE EXITING SNOW AND SHORTWAVE. VFR CONDITIONS SHOULD TAKE HOLD AT


&&

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

$$

UPDATE...JMW
SHORT TERM...JP
LONG TERM...JVM
AVIATION...JMW






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