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...
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(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.
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&& .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...RAY SHORT TERM...JMW LONG TERM...GREIF AVIATION...RAY

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