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 291219 AAA AFDJKL AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE JACKSON KY 819 AM EDT FRI MAY 29 2015 .UPDATE... ISSUED AT 819 AM EDT FRI MAY 29 2015 FRESHENED UP THE TEMPERATURES...DEW POINTS...AND SKY COVER OVER THE NEXT FEW HOURS TO JIVE BETTER WITH CURRENT OBSERVATIONAL TRENDS. ALSO SLOWED THE POPS A BIT MORE...ACCORDING TO THE LATEST TRENDS IN THE HRRR MODEL. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 357 AM EDT FRI MAY 29 2015 NEARLY STATIONARY FRONTAL BOUNDARY IS CURRENTLY ALIGNED NORTH OF THE OHIO RIVER. EASTERN KENTUCKY REMAINS ON THE MORE HUMID SIDE OF THE BOUNDARY...WITH THE AIR MASS NOTICEABLY MORE STICKY COMPARED TO THE LAST FEW DAYS. A WEAK IMPULSE OR TWO WILL ONCE AGAIN PASS THROUGH THE MISSISSIPPI VALLEY IN BETWEEN THE UPPER RIDGE ALONG THE EASTERN SEABOARD...AND THE TROUGH ESTABLISHED ACROSS THE CENTRAL CONUS. EASTERN KENTUCKY WILL BE ON THE EDGE OF THE TRAJECTORY OF THESE IMPULSES...HOWEVER GIVEN THE WEAKER CAP IN PLACE AND LIKELY MORE INSTABILITY BUILDING TODAY COMPARED TO YESTERDAY...SCATTERED CONVECTION SEEMS LIKE A GOOD BET. HIGHS WILL BE WARMER COMPARED TO YESTERDAY...WITH LESS CLOUDS...GENERALLY IN THE LOW TO MID 80S. CONVECTION WILL DIE OFF WITH THE LOSS OF HEATING TONIGHT...WITH LOWS GENERALLY IN THE LOW TO MID 60S...AND PATCHY FOG SETTING UP...PARTICULARLY AT LOCATIONS THAT SEE SUSTAINED RAINFALL. A COLD FRONT WILL BEGIN TO MAKE ITS PUSH ACROSS THE OHIO VALLEY ON SATURDAY...HOWEVER THERE ALSO BE DRIER AIR IN THE LOW TO MID-LEVELS. THIS WILL KEEP MORE OF A GRADIENT OF POPS ACROSS THE AREA...WITH BETTER STORM CHANCES NEAR I-64...AND LESSER CHANCES TO THE SOUTHEAST. HIGHS WILL RANGE FROM THE LOWER 80S IN THE NORTH...TO THE UPPER 80S IN THE SOUTHEAST. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 412 AM EDT FRI MAY 29 2015 UPPER LEVEL RIDGING IS EXPECTED TO CONTINUE OFF THE SOUTHEAST CONUS ACROSS THE WESTERN ATLANTIC THROUGH THE EXTENDED. MEANWHILE... ANOTHER AREA OF UPPER LEVEL RIDGING MOVING INTO THE SOUTHWEST CONUS WILL HELP TO BREAK DOWN THE OVERALL LONGWAVE TROUGHING PATTERN THAT HAS EXISTED OVER MUCH OF THE LAST WEEK ACROSS THE REMAINDER OF THE CONUS. BY SATURDAY NIGHT...KY WILL FIND ITSELF WEDGED IN BETWEEN THESE TWO RIDGES...WITH UPPER LEVEL TROUGHING AMPLIFYING OVER THE SOUTHERN MISSISSIPPI VALLEY AS IT BECOMES BLOCKED. EXPECT THIS TROUGH TO FINALLY CLOSE OFF INTO A CLOSED LOW BY MONDAY NIGHT...STAYING NEARLY STATIONARY THROUGH THE REMAINDER OF THE EXTENDED...WHILE WEAK RIDGING SLIDES IN JUST NORTH OF THE OHIO RIVER VALLEY. THIS PATTERN TO OUR SOUTH WILL KEEP UNSETTLED WEATHER ACROSS MUCH OF KY THROUGH MUCH OF THE EXTENDED PERIOD. AT THE SURFACE...EXPECT A LOW PRESSURE SYSTEM TO BE COLLOCATED WITH THE UPPER LEVEL LOW...ACROSS THE SOUTHERN MISSISSIPPI VALLEY AT THE START OF THE EXTENDED. A COLD FRONT WILL EXTEND FROM THIS LOW NEWRD...ATTACHING TO ANOTHER LOW PRESSURE SYSTEM OFF THE EASTERN COAST OF CANADA. AS SUCH...THIS BOUNDARY IS EXPECTED TO SPAN ACROSS MUCH OF THE STATE OF KY THROUGH THE DAY SUNDAY...CREATING A DRIVING FORCE FOR CONVECTIVE DEVELOPMENT...ESPECIALLY GIVEN THE WARM MOIST AIRMASS IN PLACE ACROSS THE REGION. AND GIVEN THE BLOCKED NATURE OF THIS CLOSED UPPER LEVEL LOW...EXPECT THERE TO BE LITTLE MOVEMENT OF THE COLD FRONT...SHIFTING ONLY SLIGHTLY SOUTHWARD TOWARDS THE TN BORDER THROUGHOUT THE REMAINDER OF THE EXTENDED. THIS SLIGHT SHIFT WILL AT LEAST ALLOW SOME INFLUENCE OF THE DEVELOP UPPER LEVEL RIDGING INTO THE NORTHERN HALF OF THE CWA. EXPECT BEST CONVECTIVE DEVELOPMENT TO BE ON SUNDAY...AS HAS BEEN HIGHLIGHTED IN PREVIOUS FORECASTS...GIVEN THE LOCATION OF THE BOUNDARY OVER MUCH OF THE STATE. LITTLE IN THE WAY OF DIRECTIONAL SHEER OR SPEED SHEER...AND SOUNDINGS WHICH SHOW HIGH AMOUNTS OF MOISTURE THROUGHOUT THE COLUMN...WILL OFFSET ANY OF THE HIGHER CAPE AMOUNTS DURING THE AFTERNOON. THUNDERSTORMS ARE LIKELY...BUT ISOLATED HEAVY RAIN AND FREQUENT LIGHTNING WILL BE THE MAIN CONCERNS WITH ANY STORMS THAT DEVELOP. THE BOUNDARY THEN SHIFTS SOUTHWARD...WITH HIGH PRESSURE MOVING INTO THE NORTHERN HALF OF THE CWA. THIS WILL CREATE A WIND SHIFT ACROSS MUCH OF THE CWA...WITH COOLER AND MORE STABLE NW FLOW TAKING HOLD. TEMPERATURES WILL TAKE A SLIGHT DOWNWARD TREND IN THIS REGIME...AS WILL THE AMOUNT OF MOISTURE IN THE ATMOSPHERE. THAT BEING SAID...THE BOUNDARY WILL STILL BE IN SUCH A CLOSE PROXIMITY THAT AFTERNOON CONVECTIVE DEVELOPMENT...ESPECIALLY OVER THE SOUTH AND SE CWA...CANNOT BE RULED OUT EACH DAY. SO ESSENTIALLY...POPS WILL REMAIN IN THE FORECAST DURING THE DAYTIME HOURS THROUGH THE REMAINDER OF THE FORECAST PERIOD. OVERALL COVERAGE ACROSS THE CWA WILL INCREASE THURSDAY AND FRIDAY AS SOUTHERLY FLOW RETURNS AND MORE MOISTURE IS ADVECTED INTO THE CWA. GIVEN DECENT MODEL AGREEMENT DURING THE EXTENDED PERIOD...THE SUPERBLEND OF MODELS SEEMED TO HANDLE POPS AND OTHER PARAMETERS FAIRLY WELL. THE ONLY MAJOR ADJUSTMENT TO THE MODEL BLEND WAS TO UNDERCUT POPS SOME DURING THE LATE NIGHT HOURS DUE TO LOSS OF INSTABILITY IN THE ATMOSPHERE WHICH THE SUPERBLEND 12 HOUR GRIDS ARE JUST NOT CAPABLE OF PICKING UP ON. TEMPS...WINDS...AND CLOUD COVER ALL SEEMED QUITE REASONABLE AND WITHIN GOOD AGREEMENT OF SURROUNDING OFFICES. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 819 AM EDT FRI MAY 29 2015 IFR OR WORSE FOG WILL BE BURNING OFF THROUGH 13Z. SCATTERED CONVECTION IS EXPECTED ONCE AGAIN DURING THE AFTERNOON HOURS...WARRANTING AT LEAST A VCTS MENTION AT ALL TAF LOCATIONS. CONVECTION WILL DISSIPATE AT DUSK...WITH SOME PATCHY FOG LIKELY DEVELOPING ONCE AGAIN IN THE VALLEYS AFTER 06Z. SOUTHERLY WINDS WILL PEAK IN THE 5 TO 10 KT RANGE THIS AFTERNOON...OTHERWISE WINDS WILL REMAIN AT 5 KTS OR LESS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEOGERIAN SHORT TERM...GEOGERIAN LONG TERM...JMW AVIATION...GEOGERIAN

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