000
FXUS63 KJKL 071727
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
1227 PM EST SAT DEC 7 2013

.UPDATE...
ISSUED AT 1227 PM EST SAT DEC 7 2013

UPDATED TO KEEP CLOUDS IN HERE FOR THE REMAINDER OF THE DAY. NO OTHER
CHANGES MADE AT THIS TIME.

UPDATE ISSUED AT 1125 AM EST SAT DEC 7 2013

CLOUDS ARE HANGING IN PRETTY GOOD TODAY AND NOT SURE TO WHAT EXTENT
SKIES WILL ACTUALLY CLEAR TODAY. SHOULD BE A SHORT PERIOD OF ANY
CLEARING AS CLOUDS WILL BE ON THE INCREASE AGAIN THIS EVENING AS THE
NEXT WAVE TAKES SHAPE TO OUR SOUTH. HAVE UPDATED POPS/WX/TEMPERATURES
TO REFLECT THE LATEST 12Z MODEL GUIDANCE. IT LOOKS LIKE THE DURATION
OF FREEZING RAIN WILL BE HIGHLY DEPENDENT ON HOW QUICKLY SURFACE
TEMPERATURES CLIMB ABOVE FREEZING. NOT CONFIDENT TEMPERATURES WILL
RESPOND AS QUICKLY AS MODELS ADVERTISE. REGARDLESS...AT LEAST 2 TO 5
HOURS OF FREEZING RAIN LOOKS LIKELY WHICH WILL CREATE SOME OBVIOUS
PROBLEMS. HAVE UPDATED SNOWFALL/ICE FORECAST AS WELL. LOOKS LIKE THE
BETTER SNOW TOTALS 2 TO 3 INCHES WILL BE IN THE NORTH WITH ICE
ACCUMULATIONS ACROSS THE EAST CENTRAL PART OF THE STATE INTO THE
SOUTHERN PART OF THE STATE. IT WILL CERTAINLY BE MESSY TOMORROW
MORNING.

UPDATE ISSUED AT 1006 AM EST SAT DEC 7 2013

UPDATED THE FORECAST PACKAGE FOR THE WINTER WEATHER ADVISORY TONIGHT
INTO SUNDAY AND FOR THE FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH
EARLY MONDAY MORNING. OTHERWISE ONLY MINOR CHANGES TO THE HOURLY
GRIDS. ALSO UPDATED RELATED PRODUCTS...HWO...ETC.

UPDATE ISSUED AT 720 AM EST SAT DEC 7 2013

QUICK UPDATE FOR EXPIRATION OF WINTER WEATHER ADVISORY...AND TO
BRING GRIDS IN LINE WITH LATEST HOURLY OBS. REMAINING LIGHT ECHOS ON
RADAR ARE DISSIPATING RAPIDLY. HOWEVER...STILL A REPORT OR TWO OF
SOME FREEZING DRIZZLE. BUT ROAD REPORTS HAVE BEEN FAVORABLE SO FAR
THIS MORNING AND ROAD SURFACE TEMPS ARE HOVERING IN THE MID TO UPPER
30S. BOTTOM LINE...IMPACTS FROM THE LIGHT SNOW AND FREEZING DRIZZLE
APPEAR TO HAVE BEEN MINIMAL THUS FAR. THEREFORE ALLOWED THE ADVISORY
TO EXPIRE AS SCHEDULED.

WILL NOW BEGIN FOCUS ON INCOMING SYSTEM FOR TONIGHT.

&&

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 532 AM EST SAT DEC 7 2013

PATCHY LIGHT PRECIPITATION CONTINUES TO POP UP OCCASIONALLY ON
RADAR. LIGHT SNOW SHOWING UP OCCASIONALLY IN A FEW OBS AROUND THE
AREA AS WELL...BUT VSBYS REMAIN GENERALLY HIGH ATTM. SURFACE
TEMPERATURES ARE RUNNING IN THE MID 30S...WITH KY MESONET INDICATING
TEMPERATURES RIGHT AROUND 30 DEGREES. FOR NOW WILL LET CURRENT
HEADLINES RUN THEIR COURSE FOR ANOTHER COUPLE OF HOURS AND WILL
REEVALUATE POSSIBLE CANCELLATION.

WILL LIKELY REISSUE A WINTER WEATHER ADVISORY FOR LATE TONIGHT INTO
SUNDAY WITH ONE OF THE MORNING UPDATES ONCE OUR CURRENT ADVISORY HAS
BEEN EITHER CANCELLED OR EXPIRED...WITH THE INTENT TO LIMIT ANY
CONFUSING HEADLINES.

MODELS IN PRETTY GOOD AGREEMENT WITH OUR NEXT DISTURBANCE POISED TO
MOVE THROUGH THE REGION LATE TONIGHT...OR EARLY SUNDAY MORNING
THROUGH EARLY MONDAY MORNING. MUCH OF THE DYNAMICS OF THIS NEXT
SYSTEM APPEAR TO BE FOCUSED IN THE LOWER LEVELS...GENERALLY BELOW
H500 WITH A BOOST FROM SOME FAVORABLE JET INTERACTION AS AN H850 40KT
LLJ INTERACTS WITH A 130-150KT H300 JET STREAK PASSING THROUGH THE
GREAT LAKES REGION. INTERESTINGLY THE 0Z GFS CAME IN CONSIDERABLY
SLIMMER ON OVERALL QPF POTENTIAL VERSUS THE BEEFIER 06Z RUN. IN
GENERAL THE NAM AND 06Z RUN OF THE GFS ARE ADVERTISING BETWEEN 1 AND
2 INCHES...BUT WITH THE CORE OF THE NAMS HEAVIER QPF CENTER MORE
ACROSS THE CENTER OF OUR CWA. THE LATEST GFS KEEPS THE AXIS OF
HEAVIER PRECIPITATION ACROSS OUR SOUTHEAST. REGARDLESS IT APPEARS OUR
AREA IS UNDER THE THREAT OF YET ADDITIONAL MODERATE TO AT TIMES
HEAVIER RAINFALL. CONSEQUENTLY SUSPECT ANOTHER FLOOD WATCH MAY NEED
TO BE ISSUED WITH ONE OF THE MORNING UPDATES AS WELL. BUT FIRST WE
MUST GET THROUGH A BOUT OF WINTRY WEATHER LATE TONIGHT INTO SUNDAY
MORNING.

MODEL SOUNDINGS CLEARLY INDICATE WARM MOIST AIR OVERRIDING THE ARCTIC
AIR MASS THAT WILL BE IN PLACE LATE TONIGHT. THE END RESULT WILL BE
ADDITIONAL WINTRY MIX OF SNOW...SLEET AND EVENTUALLY FREEZING RAIN.
FOR NOW LEANED TOWARDS THE NAM SOLUTION AS IT HAS BEEN A BIT MORE
CONSISTENT THAN THE LAST 2 RUNS OF THE GFS...AND OFTEN HANDLES
DETAILS BETTER DURING THE FIRST 12 TO 24 HOURS. THAT BEING SAID IT
APPEARS THE HEART OF OUR CWA COULD PICK UP A SLUSHY 1 TO 3 INCHES OF
A WINTRY MIX LATE TONIGHT INTO SUNDAY MORNING. LESSER AMOUNTS IN OUR
NORTH WITH LESS QPF EXPECTED...AND LESS IN THE SOUTH AS WARM AIR
SCOURS OUT THE COLD BEFORE MUCH ACCUMULATION OCCURS.

WARM AIR PUSHING INTO THE AREA DURING THE DAY SUNDAY WILL BE STRONG
ENOUGH THAT EVENTUALLY ALL THE COLD AIR WILL BE SCOURED OUT. THEN
WITH MODERATE TO HEAVY RAIN FOR A GOOD PART OF THE DAY SUNDAY INTO
SUNDAY EVENING...THE POTENTIAL FOR FLOODING ONCE AGAIN BECOMES THE
FOCUS. HOWEVER...ANY FLOODING THREAT WILL MOST LIKELY BE LIMITED TO
AREAS SOUTH OF THE INTERSTATE 64 CORRIDOR OR POSSIBLY FURTHER
SOUTH...ALONG AND SOUTH OF THE MOUNTAIN PARKWAY. EXACT AREA OF ANY
FLOOD WATCH SHOULD ONE BE ISSUED WILL DEPENDING ON HOW AND IF MODELS
COME TO A BETTER CONSENSUS WITH THE AXIS OF HEAVIEST PRECIPITATION.

.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 532 AM EST SAT DEC 7 2013

THE MODELS WERE PRETTY AGREEMENT TO BEGIN THE EXTENDED PERIOD...WITH
AN AREA OF LOW PRESSURE DEPARTING THE REGION TO THE EAST. WIDESPREAD
RAIN SHOWERS ARE EXPECTED TO DRENCH THE AREA ONCE AGAIN SUNDAY NIGHT
THROUGH MID MORNING ON MONDAY. A SECOND AREA OF LOW PRESSURE IS
EXPECTED TO FORM ALONG A STALLED FRONTAL BOUNDARY LATE IN THE DAY ON
MONDAY...BRINGING ANOTHER ROUND OF LIGHT PRECIPITATION TO EASTERN
KENTUCKY MONDAY NIGHT AND TUESDAY. BASED ON THE LATEST MODEL
DATA...THE PRECIPITATION WILL INITIALLY AFFECT ONLY AREAS ALONG THE
VIRGINIA BORDER MONDAY NIGHT...BEFORE SPREADING NORTHWESTWARD ACROSS
THE ENTIRE AREA FROM AROUND DAWN ON TUESDAY THROUGH THE END OF THE
DAY ON TUESDAY. THIS PRECIPITATION WILL BE LIGHT...WITH VERY LIGHT
ACCUMULATIONS OF SNOW POSSIBLE MONDAY NIGHT ACROSS PORTIONS OF THE
AREA...WITH SAY A TENTH OF AN INCH OR SO OF SNOW ACCUMULATION
POSSIBLE ON GRASSY AREAS AND ELEVATED SURFACES. AFTER THIS ROUND OF
PRECIPITATION EXITS THE AREA LATE TUESDAY...THE WEATHER SHOULD BE
HIGH AND DRY FOR THE REST OF THE PERIOD.

HOWEVER...THE END OF THE PERIOD IS WHERE THE MODELS GREATLY DIVERGE.
THE GFS MODEL HAS A VERY LARGE AND VIGOROUS STORM SYSTEM PROGGED TO
MOVE OUT OF THE WESTERN GULF OF MEXICO AND EVENTUALLY UP INTO THE
TENNESSEE AND OHIO VALLEY REGIONS SATURDAY AND SUNDAY. THE ECMWF
MODEL...ON THE OTHER HAND...IS KEEPING THE AREA FREE OF
PRECIPITATION FROM LATE TUESDAY THROUGH THE BEGINNING OF THE
WEEKEND. WITH SO MUCH UNCERTAINTY INVOLVED HERE...DECIDED TO KEEP
THE REST OF THE WEEK DRY FROM TUESDAY AFTERNOON ONWARD...AT LEAST
UNTIL THE MODELS CONVERGE ON A SOLUTION ONE WAY OR THE OTHER.

TEMPERATURES WILL BE CLOSE TO NORMAL ON MONDAY FOR AREAS ALONG AND
NORTH OF THE HAL ROGERS PARKWAY. MOST LOCATIONS WILL SEE HIGHS
TOPPING OUT AROUND 40 DEGREES ON MONDAY. SOME LOCATIONS ALONG THE
VIRGINIA BORDER AND PORTIONS OF THE TENNESSEE BORDER MAY COME IN
ABOVE NORMAL. TEMPERATURES FROM TUESDAY THROUGH THURSDAY LOOK TO BE
WELL BELOW NORMAL...AS A LARGE AREA OF CANADIAN HIGH PRESSURE
SETTLES OVER THE AREA. HIGHS ON THESE THREE DAYS WILL GENERALLY BE
IN THE 30S ACROSS THE BOARD. WE CAN EXPECT A WARMING TREND THURSDAY
NIGHT THROUGH FRIDAY NIGHT...HOWEVER...AS WINDS SHIFT AROUND TO THE
SOUTH...BRINGING A BIT OF WARM MOIST AIR OFF THE GULF OF MEXICO INTO
THE REGION.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1227 PM EST SAT DEC 7 2013

IFR/MVFR CIGS WILL REMAIN LOCKED IN ACROSS THE AREA THROUGH THE REST
OF THE DAY. ANOTHER STORM SYSTEM WILL TAKE SHAPE TONIGHT AND PUSH
NORTH INTO THE REGION. THIS WILL SEND ANOTHER SURGE OF MOISTURE
ACROSS THE AREA LATE TONIGHT THROUGH TOMORROW NIGHT. CEILINGS WILL
AGAIN REMAIN IN THE IFR CATEGORY THROUGH MUCH OF THE FORECAST PERIOD.
IN ADDITION...SNOW...FREEZING RAIN...AND SLEET WILL BE POSSIBLE
TONIGHT INTO TOMORROW MORNING BEFORE CHANGING OVER TO RAIN. THE RAIN
COULD BE HEAVY AT TIMES THROUGH MONDAY NIGHT. THIS WILL YIELD SOME
PATCHY FOG AT TIMES AS WELL.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 AM TO 4 PM EST SUNDAY FOR KYZ044-
050>052-059-060-104-106-107-119.

FLOOD WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING FOR
KYZ058>060-068-069-079-080-083>088-104-106>120.

WINTER WEATHER ADVISORY FROM 3 AM TO 1 PM EST SUNDAY FOR KYZ058-
068-069-108>114-120.

WINTER WEATHER ADVISORY FROM 1 AM TO 10 AM EST SUNDAY FOR KYZ079-
080-083>088-115>118.

&&

$$

UPDATE...KAS
SHORT TERM...RAY
LONG TERM...AR
AVIATION...KAS