Area Forecast Discussion
Issued by NWS Jackson, KY

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000
FXUS63 KJKL 231817
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
217 PM EDT THU OCT 23 2014

.UPDATE...
ISSUED AT 1215 PM EDT THU OCT 23 2014

QUICK UPDATE TO REMOVE MORNING WORDING FROM THE ZONES. UPDATED
HOURLY GRIDS FOR TRENDS IN SKY AND TEMPS. NO OTHER CHANGES ATTM.

UPDATE ISSUED AT 1007 AM EDT THU OCT 23 2014

FORECAST IS IN PRETTY GOOD SHAPE THIS MORNING. LOW SC IS BEGINNING TO
ERODE...MIX OUT THIS MORNING. ONLY MADE SOME MINOR TWEAKS TO HOURLY
TEMPS AS WE ARE STARTING OUT OF THE GATE A BIT SLOW ON DIURNAL RISES.
AFTERNOON HIGHS STILL LOOK GOOD AND NO UPDATES TO THE ZONE PACKAGE
ATTM.

UPDATE ISSUED AT 637 AM EDT THU OCT 23 2014

HIGH END MVFR CLOUDS CONTINUE TO PLAGUE ALL OF THE JKL CWA THIS
MORNING. LUCKILY...SATELLITE TRENDS OVER THE LAST COUPLE HOURS IS
FINALLY STARTING TO SHOW A BIT OF A DISSIPATING TREND...WHICH SHOULD
CONTINUE AS WE HEAD INTO THE DAY AND MIXING IS ALLOWED TO OCCUR.
UNLIKE PREVIOUS THOUGHTS...IT SEEMS AS THOUGH THE BEST DIMINISHMENT
IS ACTUALLY ACROSS THE NORTHERN CWA...PROGRESSING SOUTHWARD. TRENDS WILL
CONTINUE TO NEED TO BE MONITORED THROUGH THE MORNING IN CASE
ADJUSTMENTS TO THE FORECAST NEED TO BE MADE...AS MODELS STILL HAVE A
POOR HANDLE ON THE ONGOING CLOUD COVER.

DUE TO THE CLOUD COVER...TEMPERATURES HAVE FALLEN SHORT OF THEIR
ORIGINAL FORECASTED LOWS. AS A RESULT...ENDED UP ADJUSTING BOTH THE
LOW TEMPERATURE AND THE DIURNAL CURVE FOR THE REST OF THE NIGHT/EARLY
MORNING TO BETTER REFLECT CONDITIONS. THIS WILL COMPLETELY ELIMINATE
ANY CHANCES OF FURTHER FROST DEVELOPMENT ACROSS THE WESTERN CWA AS
WAS ORIGINALLY MENTIONED IN THE MORNING SHORT TERM DISCUSSION.

&&

.SHORT TERM...(THIS AFTERNOON THROUGH FRIDAY EVENING)
ISSUED AT 404 AM EDT THU OCT 23 2014

HIGH PRESSURE IS CURRENTLY BEARING DOWN ACROSS THE REGION...AS A
STRONG LOW CONTINUES TO ROTATE OFF TO OUR EAST ALONG THE ATLANTIC
SEABOARD. EXPECT THIS AREA OF HIGH PRESSURE TO REMAIN IN PLACE
THROUGHOUT THE SHORT TERM. A UPPER LEVEL SHORT WAVE WILL MOVE ACROSS
THE REGION FRIDAY. HOWEVER...ALL MODELS ARE SUPPORTING THAT THIS
WAVE WILL LOSE CONSIDERABLE STRENGTH AS IT NEARS US...DUE TO THE
LONG WAVE PATTERN BECOMING INFLUENCED BY THE STRONG COASTAL LOW. AS
SUCH...DON/T EXPECT MUCH IMPACTS TO THE REGION OTHER THAN A FEW MORE
CLOUDS FRIDAY.

GIVEN THE AREA OF HIGH PRESSURE...ALL THE MODELS SHOWED EASTERN KY
CLEARING OUT AS OF YESTERDAY AFTERNOON...AND STAYING CLEAR INTO THIS
MORNING. UNFORTUNATELY...THIS HAS NOT HAPPENED. WRAP AROUND MOISTURE
FROM THE LOW CONTINUES TO FLOW SOUTHWARD INTO EASTERN KY...RESULTING
IN QUITE THE PERSISTENT BANK OF LOW END VFR AND HIGH END MVFR CLOUDS
CENTERED OVER OUR CWA AND POINTS TO THE NE. HOPEFULLY WITH THE
INFLUENCE OF DAYTIME HEATING/MIXING BEGINNING THIS MORNING...AS WELL
AS MOVEMENT OF THE LOW TO THE NE...THESE CLOUDS SHOULD EVENTUALLY
DISSIPATE FROM WEST TO EAST ACROSS THE AREA. GIVEN THE LACK OF MODEL
SUPPORT FOR ONGOING CONDITIONS...TRIED TO USE A BEST GUESS APPROACH
BASED ON THESE ABOVE FACTORS...IN WHICH CASE THE CLOUDS SHOULD BEGIN
BREAKING UP JUST AFTER DAWN. WITHOUT THE AFFECT OF THESE
CLOUDS...TEMPS WOULD HAVE BEEN MUCH COOLER THIS MORNING...WITH THE
POTENTIAL FOR VALLEY FROST ACROSS MUCH OF THE REGION.
HOWEVER...CLOUDS HAVE KEPT THE TEMPS WELL ABOVE FREEZING...AND HAVE
PREVENTED ADEQUATE INVERSIONS. THE EXCEPTION IS SITE EKQ ON THE FAR
SW FRINGE OF THE CWA. HERE...ACCORDING TO THE SURFACE
OBSERVATIONS...CLEARING HAS LED TO COOLER TEMPS AND FOG /AS WELL AS
POSSIBLE FROST/ DEVELOPMENT. AS SUCH...IF ANY OF THE WESTERN PORTION
OF THE CWA CLEARS OUT JUST BEFORE DAWN...IT WOULD BE POSSIBLE THAT
TEMPS DROP JUST ENOUGH AS TO ALLOW FOR SOME BRIEF FOG DEVELOPMENT
HERE TOO. WENT AHEAD AND INCLUDED PATCHY FOG AND FROST FOR MOSTLY
CLEAR VALLEY REGIONS BETWEEN NOW AND 12Z.

.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 AM EDT THU OCT 23 2014

THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE WEEKEND AS THEY
ALL SHIFT A TROUGH EAST AND OUT OF THE OHIO VALLEY WHILE A LARGE
RIDGE BUILDS OVER THE BIG BEND AREA OF TEXAS. THIS RIDGE WILL THEN
EXPAND TO DOMINATE OUR FORECAST THROUGH MUCH OF THE EXTENDED BEFORE
IT FLATTENS OUT A BIT OVER THE WEEKEND AND THE FLOW ACROSS THE
REGION BECOMES MORE ZONAL...FOR A TIME. THERE WILL BE A RESURGENCE
IN THE RIDGE OVER THE TENNESSEE VALLEY FOR MONDAY IN RESPONSE TO A
TROUGH DIGGING THROUGH THE ROCKIES. THE 00Z ECMWF HAS TRENDED TOWARD
THE GFS WITH THIS SO THAT THEY ARE COMING INTO BETTER AGREEMENT. AS
A RESULT...CONFIDENCE HAS IMPROVED THAT A BROAD TROUGH WILL BRUSH
THROUGH THE OHIO VALLEY BY MIDWEEK WITH HEIGHT FALLS AND SOME OF ITS
ASSOCIATED ENERGY PASSING OVER THE AREA TO CLOSE OUT THE FORECAST.
GIVEN THE IMPROVING MODEL AGREEMENT HAVE FAVORED A GENERAL BLEND
FOR THE LONG TERM PORTION OF THE FORECAST.

SENSIBLE WEATHER WILL FEATURE A WEAK AND DRY COLD FRONT PASSING
THROUGH EASTERN KENTUCKY LATE SATURDAY AS SFC HIGH PRESSURE WILL
DOMINATE FOR MOST OF THE PERIOD. THIS HIGH WILL MODERATE ALLOWING
FOR HIGHER TEMPERATURES HEADING INTO THE START OF THE NEW WORK
WEEK...PARTICULARLY ON TUESDAY AHEAD OF A DEVELOPING SYSTEM TO THE
NORTHWEST - WHOSE SOUTHWEST WINDS WILL PUSH WARMER AIR INTO THIS
PART OF THE STATE. AS THE COLD FRONT ASSOCIATED WITH THIS LOW
APPROACHES THE AREA...SHOWER...AND PERHAPS THUNDER...CHANCES WILL BE
ON THE RISE FROM LATE TUESDAY THROUGH THE DAY WEDNESDAY.

THE CR GRID LOAD PROVED TO BE A PRETTY GOOD START WITH CHANGES MADE
MAINLY TO BETTER TIME THE HOURLY POPS TOWARD THE END OF THE
FORECAST. DID ALSO ADD SOME RIDGE AND VALLEY EFFECTS INTO THE LOW
TEMPERATURES GRIDS EACH NIGHT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 217 PM EDT THU OCT 23 2014

PERSISTENT LOW SC DECK IS FINALLY DISSIPATING ACROSS MOST OF THE
AREA. EASTERN LOCATIONS...SJS HAVE BEEN EVEN SLOWER TO MIX OUT AND
ARE ONLY NOW BEGINNING TO SEE SOME BREAKS AND SUNSHINE. LOW CLOUDS
WILL CONTINUE TO MIX OUT THROUGH THE AFTERNOON. NOT MUCH TO CONCERN
US THEREAFTER. WILL SEE AN INCREASE IN HIGH CLOUDS...POSSIBLY SOME
MID LEVEL DURING THE NEXT 24 HOURS. MAIN FORECAST CHALLENGE WILL BE
POTENTIAL FOR FOG. DRIER AIR IS MIXING DOWN BUT SFC DEW POINTS SHOULD
RECOVER QUICKLY AFTER SUNSET. WITH SFC RIDGE AXIS SETTLING OVER THE
AREA DECENT RADIATIVE COOLING WILL ALLOW FOR THE FORMATION OF FOG
OVERNIGHT IN THE RIVER VALLEYS. MAIN THREAT WOULD EXIST AT SME AND
SJS...BUT CONFIDENCE IS NOT REAL HIGH. FOR NOW MENTIONED SOME MVFR AT
SME. COULD SEE SOME FOG AT SJS...IT BEING ASSOCIATED MORE WITH THE
BIG SANDY BUT FOR NOW WENT OPTIMISTIC WITH PLANS TO REEVALUATE TRENDS
IN AFTERNOON DEW POINTS. LIGHT WINDS THROUGH THE PERIOD...GENERALLY
NORTHEAST BACKING TO THE NORTHWEST.

&&

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

&&

$$

UPDATE...RAY
SHORT TERM...JMW
LONG TERM...GREIF
AVIATION...RAY







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