Area Forecast Discussion
Issued by NWS Jackson, KY

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS63 KJKL 311434 AAA AFDJKL AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE JACKSON KY 1034 AM EDT SUN MAY 31 2015 .UPDATE... ISSUED AT 1035 AM EDT SUN MAY 31 2015 14Z SFC ANALYSIS SHOWS A COMPACT AREA OF LOW PRESSURE RIDING INTO OHIO WITH A COLD FRONT STRETCHING TO THE SOUTHWEST THROUGH CENTRAL KENTUCKY. THIS FRONT WILL ATTEMPT TO BRING SOME DRIER AND COOLER AIR INTO THE STATE THROUGH THE DAY. HOWEVER...FOR EAST KENTUCKY IT WILL MORE LIKELY SPUR MORE DEVELOPMENT OF CONVECTION...PARTICULARLY IN THE FAR SOUTHEAST PER THE LATEST HRRR AND NAM12. CURRENTLY THE RADAR IS RATHER QUIET THROUGH THE AREA WITH JUST A FEW CELLS FOUND IN EASTERN TENNESSEE DRIFTING NORTHEAST. ON SATELLITE...SKIES ARE MOSTLY SUNNY AHEAD OF THE FRONT WHILE MORE CLOUDS ARE NOTED OVER CENTRAL AND WESTERN PARTS OF THE STATE. CLOUDS WILL DEVELOP AND OVERTAKE EASTERN KENTUCKY THROUGH THE LATE MORNING AND EARLY AFTERNOON HOURS...BUT NOT BEFORE THE SUNSHINE DRIVES TEMPERATURES INTO THE 80S AND HELPS TO BUILD INSTABILITY AS A PRIME INGREDIENT FOR STORM DEVELOPMENT. WITH ANY STORMS LATER THIS AFTERNOON...THERE COULD BE STRONG WIND GUSTS...CLOUD TO GROUND LIGHTNING...AND BRIEF HEAVY RAINS. READINGS ARE IN THE LOW TO MID 70S AT 10 AM WITH DEWPOINTS GENERALLY IN THE LOW AND MID 60S. WINDS HAVE PICKED UP AHEAD OF THE FRONT FROM THE SOUTHWEST AT AROUND 10 KTS MOST PLACES AND GUSTS UP TO 20 KTS NOTED. HAVE UPDATED THE GRIDS TO INCORPORATE THE LATEST GUIDANCE FROM THE HRRR IN PARTICULAR BUT ALSO THE SHORTBLEND IN THE T/TD GRIDS ALONG WITH CURRENT OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. UPDATE ISSUED AT 712 AM EDT SUN MAY 31 2015 LATEST RADAR IS SHOWING A FEW SPOTTY SHOWERS POPPING UP ACROSS EASTERN KY. BUT OVERALL...THIS IS LESS COVERAGE THAN WE HAVE SEEN THROUGH MUCH OF THE NIGHT. EXPECT COVERAGE TO START PICKING UP AS THE SUN CONTINUES TO RISE AND WE BEGIN HEATING UP...AND THE FRONTAL BOUNDARY CONTINUES TO NEAR THE REGION. WILL KEEP WITH ONGOING ISOLATED TO SCATTERED POPS THROUGH THE MORNING HOURS. ACCORDING TO THE LATEST OBSERVATIONS...THE COLD FRONT IS CURRENTLY LOCATED OVER WESTERN KY AND SLOWLY SHIFTING EASTWARD. CLOUD COVER HAS NOW OVERSPREAD ACROSS MUCH OF THE CWA...AND SHOULD CONTINUE TO THICKEN AND LOWER THROUGHOUT THE MORNING. WINDS ARE ALSO BEGINNING TO PICK UP ALONG AND JUST AHEAD OF THE FRONT AS WELL. WHAT FOG IS LEFT ACROSS THE REGION IS CAUSING LITTLE PROBLEMS...AND IS LIKELY LIFTING OR MIXING OUT. AS SUCH...WENT AHEAD AND REMOVED ANY MENTION OF FOG FROM THE FORECAST. AS OF THIS LAST HOUR...THE LATEST OBSERVATIONAL DATA FOR TEMPS...DEW POINTS...AND WINDS WERE LOADED INTO THE NEAR TERM FORECAST TO MAKE SURE THESE PARAMETERS WERE WELL ON TRACK WITH THE ONGOING CONDITIONS. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 359 AM EDT SUN MAY 31 2015 UPPER LEVEL RIDGING OVER THE FAR SE CONUS IS CONTINUING TO BREAK DOWN AS AN UPPER LEVEL TROUGH SHIFTS EASTWARD AND INTO THE OHIO RIVER VALLEY. A SURFACE LOW PRESSURE CENTER IS CURRENTLY LOCATED OVER SOUTHERN INDIANA AND WILL BE DIRECTED EASTWARD WITH THE MOVEMENT OF THE UPPER LEVEL TROUGH. THIS WILL RESULT IN DIRECT IMPACTS ACROSS MUCH OF KY OVER THE NEXT 24 TO 48 HOURS. AS THIS SURFACE LOW CONTINUES TO SHIFT ALMOST DUE EASTWARD...JUST NORTH OF THE OHIO RIVER...A COLD FRONT EXTENDING SOUTHWARD FROM THE LOW WILL TRAVERSE KY...REACHING THE WESTERN CWA BY ABOUT 15Z THIS MORNING...AND THE FAR SE BETWEEN 18 AND 0Z. IT IS AT THIS POINT IT WILL BECOME STALLED OUT ALONG THE HIGH TERRAIN...REMAINING IN PLACE THROUGH MUCH OF THE DAY MONDAY. SHORT TERM MODELS ARE ALL IN REASONABLY GOOD AGREEMENT WITH THIS SET UP OVER THE NEXT 36 HOURS. FAVORED THE GFS DURING TODAY GIVEN ITS STRONG CONSISTENCY WITH THIS SYSTEM...THEN USED MORE OF THE SUPERBLEND FOR TONIGHT INTO TOMORROW...MAKING MANUAL TWEAKS AS DEEMED NECESSARY. SOUTHERLY FLOW HAS BEEN IN PLACE ACROSS THE REGION AHEAD OF THIS APPROACHING FRONTAL PASSAGE. THIS IS CONTINUING THE TREND OF WARM AND HUMID CONDITIONS ACROSS THE REGION. THIS WARM UNSTABLE AIRMASS...COUPLED WITH LIFT FROM THE INCOMING FRONT...HAS LED TO ISOLATED SHOWER DEVELOPMENT ACROSS CENTRAL KY OVERNIGHT. MOST OF THE ONGOING SHOWERS ARE LOCATED ALONG THE WESTERN FRINGES OF OUR CWA AND POINTS WESTWARD...NEARER TO THE APPROACHING BOUNDARY. EXPECT THESE TO CONTINUE TO SHIFT EASTWARD ACROSS THE CWA THROUGH THE EARLY MORNING HOURS...AND INCREASE IN COVERAGE AND INTENSITY AS WE GAIN INFLUENCE FROM THE SUN AND BETTER LIFT AS THE FRONT APPROACHES. LATEST FORECAST SOUNDINGS ARE SILL SUPPORTING GOOD CONVECTIVE DEVELOPMENT IN THE AFTERNOON...ESPECIALLY OVER THE SE AS THIS IS WHERE THE FRONTAL BOUNDARY AND AFTERNOON HEATING/INSTABILITY WILL LINE UP THE BEST. A DECENT MOIST LEVEL IN THE LOW LEVELS...AS WELL AS DRYING ALOFT...COULD LEAD TO THE POTENTIAL FOR HAIL GROWTH AS WELL AS SOME POTENTIALLY STRONG CELLS. LI/S ALSO CONTINUE TO STAY IN THE -4 TO - 7 RANGE INDICATING GOOD POTENTIAL FOR THUNDERSTORM GROWTH...THOUGH OVERALL WIND SHEER DOES SEEM A BIT LACKING FOR ANYTHING TO BE ROTATIONAL. OTHERWISE... PWATS CONTINUE TO BE UNIMPRESSIVE AND WINDS ARE QUITE LIGHT ALOFT...SO UNLESS YOU HAVE SEVERAL STORMS IMPACTING THE SAME AREA...STILL NOT LOOKING AT MUCH IN THE WAY OF HYDRO CONCERNS. AS WE GO INTO TONIGHT...LOSS OF DAYTIME HEATING WILL CUT DOWN ON A LOT OF THE CONVECTIVE ACTIVITY ONCE MORE...THOUGH SOME LINGERING STORMS ALONG THE FRONTAL BOUNDARY CANNOT BE RULED OUT. RATHER...EXPECT ISOLATED TO SCATTERED RAIN SHOWERS TO LIKELY CONTINUE ACROSS THE FAR SE THROUGHOUT THE NIGHT. ANY PLACE THAT RECEIVED RAIN TODAY...AS WELL AS MANY OF THE VALLEY LOCATIONS...WILL BE SUBJECT TO FOG DEVELOPMENT OVERNIGHT AS WINDS DIE DOWN AND TEMPERATURES COOL WHILE DEW POINTS REMAIN HIGH. WITH THE FRONT STALLING OUT JUST TO OUR SOUTHEAST...IT WILL STILL PROVIDE ENOUGH INFLUENCE FOR ANOTHER SURGE OF CONVECTIVE ACTIVITY DURING THE DAY ON MONDAY. FORECAST SOUNDINGS ARE SHOWING A LOSS OF HAIL DEVELOPMENT GIVEN THE SATURATED NATURE OF THE ENTIRE PROFILE. STILL...SEVERAL LOCATION DO SHOW SOME DECENT POTENTIAL FOR THUNDERSTORM DEVELOPMENT...SO ENDED UP ADDING ISOLATED THUNDER POTENTIAL BACK INTO THE MONDAY DAYTIME FORECAST. WHILE MUCH OF THE GENERAL FLOW WILL REMAIN FROM THE SW EVEN AFTER THE FRONTAL PASSAGE...SURFACE WINDS WILL HAVE MORE OF A NRLY INFLUENCE. THIS...COUPLED WITH CLOUD COVER AND ONGOING PRECIP...WILL KEEP TEMPERATURES MUCH COOLER THAN THE DAY BEFORE...WITH ONLY LOW TO MID 70S EXPECTED ACROSS THE CWA. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 339 AM EDT SUN MAY 31 2015 THE EXTENDED FORECAST PERIOD BEGINS ON MONDAY NIGHT WITH A STAGNANT UPPER LEVEL PATTERN BREWING OVER THE SOUTHEASTERN CONUS. BOTH THE GFS AND EURO BEGIN THE PERIOD AS A SHORTWAVE TROUGH MOVES INTO THE SOUTHEASTERN CONUS BUT BECOMES CUT OFF FROM THE MAIN FLOW OVER THE NORTH LEAVING A STALLED CLOSED LOW OVER THE SOUTHEAST FOR PRETTY MUCH THE REMAINDER OF THE EXTENDED. SOME WAVES PASSING OVER THE NORTHERN STREAM MAY INTERACT WITH THE LOW FOR SOME INCREASED LIFT AS THEY PASS BY BUT CONSISTENCY AND AGREEMENT SEEMS A BIT LACKING. NEAR THE SURFACE THROUGH THE PERIOD...THE COLD FRONT THAT PASSED THROUGH OVER THE WEEKEND DOES SEEM TO STALL OVER THE KY/TN BORDER REGION. HOWEVER...THE MODELS STRUGGLE WITH CONSISTENCY OF WHERE THE BOUNDARY SETS UP AND ANY SHIFTING IS CERTAINLY MISSED. THROUGH THE PERIOD...TRENDS WILL CONTINUE TO BE DIURNAL WITH MAX POTENTIAL OF POPS DURING THE AFTERNOON AND CAPE VALUES REACHING 1500 OR ABOVE. OVERALL...THE MOIST AND UNSTABLE SOUTHERLY FLOW THROUGH MUCH OF THE PERIOD WILL KEEP SOME CHANCE OF PRECIP EACH DAY. WITH THE SOLUTION OF THE SUPER BLEND...THE MODELS CONTINUE TO FAVOR THE MORE MOIST PATTERN WITH A BETTER CHANCE OF POPS THROUGH THE PERIOD. THE BLEND ALSO KEEP A MORE CONCENTRATED AREA OF POPS ALONG WHERE THE FRONT STALLS. A DIURNAL TREND TO THE THUNDERSTORM ACTIVITY WILL CONTINUE THROUGH THE PERIOD AS WELL. AFTER THE FRONT PASSES THROUGH...THE COOLER AIR MASS STILL KEEPS TEMPS IN THE 70S FOR TUESDAY BUT THOSE WILL MODERATE QUICKLY BY WEDNESDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 722 AM EDT SUN MAY 31 2015 A COLD FRONT IS CURRENTLY LOCATED OVER WESTERN KY AND WILL CONTINUE ITS TREK EASTWARD THROUGHOUT THE DAY. AS IT NEARS EASTERN KY...EXPECT ISOLATED SHOWERS AND THUNDERSTORMS THIS MORNING...INCREASING IN INTENSITY AND COVERAGE AS WE HEAD INTO THE PEAK HEATING OF THE AFTERNOON. THE FRONT WILL LIKELY PASS THROUGH KSME AND KLOZ FIRST SOMETIME AROUND 18Z...MAKING IT TO KSJS CLOSER TO 0Z THIS EVENING. WINDS WILL DECOUPLE DURING THIS TIME...WITH THE RETURN OF BREEZY CONDITIONS IN THE 10 TO 20KT RANGE GENERALLY FROM THE SW. EXPECT GENERALLY VFR CONDITIONS THROUGHOUT THE DAY DESPITE CLOUDY CONDITIONS...THOUGH IF TAF SITES ARE IMPACTED BY ANY OF THE DEVELOPING SHOWERS AND THUNDERSTORMS...VIS COULD BE TEMPORARILY LOWERED. SOME STRONG WINDS AND MAYBE EVEN SOME SMALL HAIL COULD BE OBSERVED IN SOME OF THE HEAVIER STORMS. THE FRONT WILL STALL OUT OVER FAR SOUTHEASTERN KY THIS EVENING...KEEPING CONTINUED CHANCES FOR SHOWERS AND ISOLATED THUNDERSTORMS OVERNIGHT. IT IS ALSO LIKELY THAT WITH THE AMOUNT OF MOISTURE AND RAIN POTENTIAL...MANY AREAS WILL EXPERIENCE FOG OVERNIGHT ONCE TEMPERATURES COOL AND WINDS DIE DOWN. WENT AHEAD AND INCLUDED MVFR CONDITIONS AT ALL THE TAF SITES AFTER 6Z...BUT ULTIMATELY CONFIDENCE IS LOW ON THE EXACT IMPACTS AND SEVERITY THE FOG WILL HAVE AT EACH SITE. WHILE HIGH PRESSURE RIDGING REMAINS OVER THE FAR SE PORTION OF THE STATE...AN INCOMING FRONTAL SYSTEM IS PROVIDING JUST ENOUGH ENERGY IN THE WARM AND HUMID ENVIRONMENT FOR SOME ISOLATED SHOWERS TO DEVELOP AND PASS THROUGH THE WESTERN PORTION OF OUR FORECAST AREA. AS A RESULT...KEPT VCSH IN TAFS TO ACCOUNT FOR THESE ISOLATED CELLS. AS THE COLD FRONT CONTINUES TO SHIFT EASTWARD EARLY THIS MORNING AND INTO TODAY...EXPECT COVERAGE TO SHOW AN INCREASING TREND. THE FRONT IS EXPECTED TO TRAVERSE EASTERN KY DURING THE DAY TODAY...REACHING FAR SE KY DURING PEAK HEATING LATE THIS AFTERNOON/EARLY EVENING. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE PRESENT ACROSS ALL OF EASTERN KY DURING THE AFTERNOON AS A RESULT...THOUGH EXACT TIMING AND LOCATIONS ARE STILL UNKNOWN. SOME BRIEF DROPS IN VISIBILITY WILL BE POSSIBLE UNDER ANY STORM...BUT CIGS SHOULD GENERALLY REMAIN VFR. LIKE YESTERDAY...DECENT MIXING WILL TAKE PLACE...ALLOWING FOR BREEZY CONDITIONS...GENERALLY BETWEEN 10 AND 20 KNOTS DURING THE AFTERNOON. BEST INSTABILITY WILL BE LOST AS WE HEAD INTO TONIGHT AND TEMPS COOL AND WINDS CEASE...THOUGH A FEW ISL SHOWERS/TSTORMS CANNOT BE RULED OUT. THE BIGGER CONCERN WILL BE THE FOG DEVELOPMENT DUE TO LARGE AMOUNTS OF LINGERING LOW LEVEL MOISTURE. GIVEN THIS WILL LIKELY OCCUR JUST AFTER THE END OF THE TAF PERIOD...AND IMPACTS ARE STILL UNKNOWN...WILL WAIT UNTIL LATER ISSUANCE/S TO INCLUDE. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...JMW LONG TERM...SHALLENBERGER AVIATION...JMW

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.