Area Forecast Discussion
Issued by NWS Jackson, KY

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000
FXUS63 KJKL 021328
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
928 AM EDT THU OCT 2 2014

.UPDATE...
ISSUED AT 928 AM EDT THU OCT 2 2014

UPDATED TO INCORPORATE LATEST OBSERVATIONS INTO THE GRIDDED
FORECAST...BLENDING TO THE ALREADY EXISTING AFTERNOON FORECAST. NO
SUBSTANTIVE CHANGES TO THE OVERALL OUTLOOK.

UPDATE ISSUED AT 720 AM EDT THU OCT 2 2014

ISSUED AN UPDATE MAINLY TO FINE TUNE THE NEAR TERM T...TD...AND SKY
GRIDS BASED ON THE LATEST OBS AND TRENDS. BASED ON THE METARS...
SATELLITE IMAGES...AND AREA WEB CAMS THE FOG APPEARS TO BE CONFINED TO
THE DEEPER VALLEYS THROUGH EAST KENTUCKY THIS MORNING IN CONTRAST TO
YESTERDAY/S FAVORING OF THE RIDGES. OTHERWISE...THE FORECAST IS ON
TRACK. HAVE ISSUED AN UPDATE MAINLY TO FINE TUNE THE NEAR TERM
T...TD...AND SKY GRIDS BASED ON THE LATEST OBS AND TRENDS. THESE HAVE
BEEN SENT TO THE NDFD AND WEB SERVERS.

&&

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 355 AM EDT THU OCT 2 2014

07Z SFC ANALYSIS SHOWS HIGH PRESSURE STILL AFFECTING THE EASTERN
HALF OF THE OHIO VALLEY...THOUGH IT IS RETREATING OFF TO THE EAST. SO
FAR THIS HAS BEEN ENOUGH TO KEEP THE SKIES MOSTLY CLEAR OVER EAST
KENTUCKY WITH JUST A SMALL AREA OF SC AT 5K FEET SPOTTED JUST NORTH
OF JKL. DESPITE THE GOOD RADIATIONAL COOLING AND A DECENT RIDGE TO
VALLEY SPLIT THE FOG HAS NOT BEEN AS THICK IN THE VALLEYS AND
ELSEWHERE AS IT HAS THE PAST FEW NIGHTS. DO EXPECT SOME INCREASE
TOWARD DAWN WITH PATCHY DENSE POSSIBLE IN THE DEEPER VALLEYS.
READINGS RANGE FROM THE LOW TO MID 60S ON THE RIDGES TO THE MID 50S
IN THE VALLEYS WHILE WINDS REMAIN LIGHT AND VARIABLE.

THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE MAJOR TRANSITION
THAT WILL TAKE PLACE DURING THE LATTER PART OF THE SHORT TERM
FORECAST. THEY ALL DEPICT A SHARP TROUGH DIGGING THROUGH THE MID
MISSISSIPPI VALLEY AND INTO THE OHIO VALLEY ON FRIDAY. A LEAD
SHORTWAVE/PORTION OF THIS TROUGH MOVES THROUGH EAST KENTUCKY EARLY
FRIDAY WITH THE CORE OF THE UNSEASONABLY DEEP TROUGH PASSING PLOWING
INTO OUR AREA LATER FRIDAY. AHEAD OF THIS...MODERATE RIDGING WILL BE
SHUNTED OUT THE OHIO VALLEY TODAY AND TONIGHT. GIVEN THE MODEL
AGREEMENT HAVE FOLLOWED THE HIGHER RESOLUTION NAM12 FOR FORECAST
SPECIFICS ALONG WITH SOME ADDED BLENDING FROM THE LATEST ECMWF.

SENSIBLE WEATHER WILL FEATURE WHAT COULD BE THE WARM SEASON/S LAST
HURRAH AS WARMTH IS PUMPED OVER KENTUCKY TODAY AHEAD OF A SIGNIFICANT
FRONTAL PASSAGE. THE FRONT WILL GET CLOSE TO THE AREA LATER TONIGHT
WITH SHOWERS AND A FEW THUNDERSTORMS A GOOD BET. THIS INITIAL FRONT
THEN CROSSES EAST KENTUCKY EARLY FRIDAY WITH SHOWERS AND POSSIBLE
THUNDERSTORMS LINGERING THROUGH THE DAY IN RESPONSE TO ADDITIONAL MID
LEVEL ENERGY PACKETS AND SECONDARY BOUNDARIES MOVING THROUGH THE
SOUTHERN OHIO VALLEY. CANNOT RULE OUT A STRONG STORM OR TWO ON FRIDAY
GIVEN THE HEALTHY WIND FIELD THAT WILL BE IN PLACE...THOUGH LOW
INSTABILITY WILL LIKELY LIMIT THEIR DEVELOPMENT. IN GENERAL...EXPECT
AROUND A HALF AN INCH OF RAIN WITH THIS SYSTEM...FOLLOWED BY
UNSEASONABLY COLD AIR IN ITS WAKE FOR LATE FRIDAY INTO THE WEEKEND.

USED THE CONSSHORT AS A STARTING POINT FOR THE T/TD/WIND GRIDS
THROUGH THE FIRST 18 TO 24 HOURS OF THE FORECAST AND THE SUPERBLEND
THEREAFTER. MADE SOME MINOR ADJUSTMENT TO TEMPERATURES TONIGHT
KEEPING THEM UP ON THE RIDGE WHILE ALLOWING THE EASTERN VALLEYS TO
BRIEFLY DECOUPLE BEFORE THE CONVECTION MOVES IN. AS FOR POPS...ENDED
UP PRETTY SIMILAR TO A BLEND OF THE RATHER HIGH MOS GUIDANCE THROUGH
THE PERIOD.

.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 340 AM EDT THU OCT 2 2014

...A COLD WEEKEND ON TAP...

AT THE START OF THE PERIOD...THE COLD FRONT WILL BE EXITING EASTERN
KENTUCKY WITH STRONG CAA KICKING INTO FULL GEAR FRIDAY NIGHT.
TEMPERATURES WILL TUMBLE THROUGH THE NIGHT...EVENTUALLY FALLING INTO
THE LOW TO MID 40S BY DAYBREAK SATURDAY. WHILE PRECIPITATION
CHANCES WILL DIMINISH THROUGH THE NIGHT...A FEW SHOWERS OR SPRINKLES
COULD LINGER THROUGH THE NIGHT AS WESTERLY UPSLOPE FLOW...COMBINED
WITH SHALLOW LOW LEVEL MOISTURE MAY KEEP THE ACTIVITY GOING A BIT
LONGER THAN MODELS ARE ANTICIPATING. HAVE ALSO BEEFED UP SKY
COVER...ESPECIALLY INTO SATURDAY. 00Z ECMWF ACTUALLY HAS A FAIRLY
VIGOROUS SHORTWAVE DROPPING ACROSS THE AREA ON SATURDAY...AND GIVEN
THE STRONG TROUGH...CANNOT DISCOUNT THIS POSSIBILITY. THUS...PLAN TO
KEEP SOME SPRINKLES IN THE FORECAST INTO SATURDAY EVENING. WOULDN`T
BE SURPRISED TO ACTUALLY SEE A FEW SHOWERS AS UPSLOPE FLOW CONTINUES
THROUGH THIS TIME. HOWEVER...AT THIS TIME...MODEL SUPPORT IS LACKING
FOR ANY SHOWERS ON SATURDAY. NOT SURE WE WILL SEE MUCH SUN THROUGH
THE DAY SATURDAY AS THE INFLUENCE OF THE TROUGH MAY KEEP THE CLOUD
COVER HELD IN OVER THE REGION. HOWEVER...MODELS LOOK TO BE HANDLING
THE SKY COVER VERY POORLY. REGARDLESS...CAA ALONE WILL KEEP HIGHS IN
THE LOW TO MID 50S...IF NOT LOWER THAN THIS. IT CERTAINLY WILL NOT
BE A PLEASANT DAY...ESPECIALLY WITH A BLUSTERY WEST WIND...PUTTING
EVEN MORE OF A CHILL INTO THE AIR.

SATURDAY NIGHT REMAINS VERY UNCERTAIN AT THIS TIME. IF CLOUDS HOLD
INTO SATURDAY NIGHT...THEY MAY ACT TO INSULATE THE AREA AND KEEP
TEMPERATURES FROM FALLING OFF WELL INTO THE 30S. HOWEVER...IF WE
CLEAR...SOME LOW TO MID 30 READINGS MAY BE POSSIBLE. HOWEVER...GIVEN
THE THERMAL RIDGE IS STILL UPSTREAM BY SUNDAY MORNING...ITS MORE
LIKELY WE KEEP SOME CLOUDS AROUND...AND THUS...LIMITING THE FROST
POTENTIAL. HOWEVER...AS MENTIONED...SINCE MODELS ARE TRYING TO CLEAR
THINGS OUT...THEY ARE GENERALLY COLDER. THUS...PLAN TO STAY ABOVE
MODEL GUIDANCE WITH LOWS FOR NOW GIVEN THE PATTERN. IN FACT...00Z
ECMWF BRINGS ANOTHER SHORTWAVE ACROSS THE AREA SATURDAY
NIGHT...SUPPORTING MORE CLOUD COVER.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 750 AM EDT THU OCT 2 2014

MOSTLY CLEAR SKIES AND LIGHT WINDS FOR THE PAST NIGHT RESULTED IN FOG
FORMATION THAT HAS IMPACTED THE DEEPER VALLEYS...THOUGH THE LOWER
ELEVATION TAF SITE OF SME DID SEE THEIR VIS DROP BELOW 2 MILES ALONG
WITH THE DEVELOPMENT OF A LOW DECK OF STRATUS. ONCE THE FOG BURNS
OFF...VFR CONDITIONS WILL PREVAIL THROUGH 06Z FRIDAY...THOUGH A
LOWER DECK OF CLOUDS...AROUND 4K FEET...IS EXPECTED TO DEVELOP FROM
WEST TO EAST LATER THURSDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT.
A CHANCE OF SHOWERS AND THUNDERSTORMS WILL SPREAD ACROSS EAST
KENTUCKY DURING THE LATTER PART OF THE NIGHT WITH LLWS A POTENTIAL
ISSUE FROM 06 TO 12Z FRIDAY AS THE WINDS WILL BE RATHER LIGHT AT
GROUND LEVEL AND POTENTIALLY BREEZY AT 35 TO 40 KTS JUST OFF THE SFC.
WINDS WILL BE LIGHT AND VARIABLE THROUGH THE DAY TODAY BEFORE
PICKING UP FROM THE SOUTH AT BETWEEN 5 AND 10 KTS LATER THIS EVENING
AND INTO THE NIGHT.


&&

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

$$

UPDATE...HAL
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF






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