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 220801 AFDJKL AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON KY 401 AM EDT FRI AUG 22 2014 .SHORT TERM...
-- Changed Discussion --
(TODAY THROUGH SATURDAY) ISSUED AT 400 AM EDT FRI AUG 22 2014 THE LATEST SURFACE MAP FEATURES SURFACE HIGH PRESSURE ACROSS THE GULF COAST STATES...WITH BROADENING LOW PRESSURE ACROSS THE PLAINS. A STATIONARY FRONTAL BOUNDARY EXTENDS EAST FROM THE PLAINS INTO THE GREAT LAKES/OHIO VALLEY. ALOFT...AN UPPER LEVEL RIDGE IS CURRENTLY CENTERED NEAR LOUISIANA WITH ITS INFLUENCE EXTENDING FURTHER NORTH INTO THE MISSISSIPPI VALLEY. TROUGHING REMAINS POISED ACROSS THE WESTERN CONUS. THUNDERSTORM COMPLEXES CONTINUE TO GEN UP ON THE NORTHERN PERIPHERY OF THE RIDGE AXIS AND THEN PROCEED TO ADVANCE ESE ACROSS THE OHIO VALLEY. CURRENTLY...A WEAKENING COMPLEX IS SKIRTING NORTHEASTERN KENTUCKY...LIKELY CLEARING OUR FORECAST AREA IN THE NEXT 2 TO 3 HOURS. THE MODELS REMAIN IN GOOD AGREEMENT THROUGH THE SHORT TERM...WITH THE UPPER LEVEL RIDGE GRADUALLY AMPLIFYING ACROSS THE MISSISSIPPI VALLEY. DETAILS ASSOCIATED WITH CONVECTIVE INITIATION CONTINUE TO BE PROBLEMATIC HOWEVER...AND HAVE STUCK WITH A GENERAL MODEL BLEND...WHICH FAVORS MORE VIGOROUS CONVECTION DURING THE WARMER PART OF THE DAY. TODAY LOOKS TO BE SOMEWHAT OF A REPEAT OF YESTERDAY...WITH STOUT INSTABILITY BUILDING BY EARLY THIS AFTERNOON. WHILE THE MCS TRACK HAS SHIFTED A BIT FURTHER NORTHEAST TODAY COMPARED TO YESTERDAY...OUTFLOW BOUNDARIES CONTINUE TO BE THE MAIN PLAYER...LEAVING MOST LOCATIONS IN THE LINE OF FIRE AT SOME POINT. SOME SEVERE THUNDERSTORMS CAN NOT BE RULED OUT ONCE AGAIN TODAY...ALONG WITH ISOLATED FLASH FLOODING...WHERE STORMS CAN ALIGN ALONG OUTFLOW BOUNDARIES PARALLEL TO THE STEERING FLOW. ANOTHER HOT AND HUMID DAY LOOKS TO BE ON TAP...WITH A FEW SPOTS NEARING THE 100 DEGREE MARK IN HEAT INDICES. STORMS WILL GRADUALLY WEAKEN INTO THE EVENING HOURS...ALTHOUGH SOME NOCTURNAL ACTIVITY REMAINS AT LEAST SOMEWHAT OF A POSSIBILITY. LOWS WILL BE MUGGY ONCE AGAIN AROUND THE 70 DEGREE MARK. SATURDAY WILL FEATURE ANOTHER WARM AND HUMID DAY...ALONG WITH THE THREAT OF MORE SCATTERED CONVECTION ACROSS THE AREA. THERE WILL BE LESS INSTABILITY AVAILABLE AS MID-LEVEL WARMING TAKES PLACE FROM THE INFLUENCE OF THE UPPER RIDGE. THIS WILL KEEP THE SEVERE AND FLASH FLOOD THREAT LOWER. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 400 AM EDT FRI AUG 22 2014 UPPER LEVEL RIDGING WILL REMAIN IN PLAY DURING THE DURATION OF THE EXTENDED...WITH HEIGHTS EXPECTED TO BUILD AS THE HIGH SHIFTS NEWARD ACROSS THE OHIO RIVER VALLEY. BUILDING HEIGHTS WILL THEN TRANSLATE TO RISING TEMPERATURES. HOWEVER...MID AND UPPER LEVEL WINDS WILL GENERALLY REMAIN OUT OF THE NORTH DURING THE FIRST FEW DAYS OF THE EXTENDED. THIS...COUPLED WITH CLOUD COVER THAT WILL HAMPER MAXIMUM SOLAR RADIATION...WILL KEEP HIGHS IN THE MID AND UPPER 80S THROUGH TUESDAY. TEMPS MAY THEN COOL DOWN A COUPLE DEGREES AFTER TUESDAY AS HIGH PRESSURE SITS OVERHEAD AND UPPER LEVEL HEIGHTS ASSOCIATED WITH THE RIDGE BECOME MORE STATIC. BASED ON THE LATEST FORECAST SOUNDINGS...WILL AGREE WITH PREVIOUS FORECAST THAT EACH DAY SHOULD POSE A SHOWER/THUNDERSTORM THREAT MAINLY IN THE AFTERNOON AND EVENING. GIVEN THE MID LEVEL DRYING FROM MONDAY ON...WOULDN/T BE SURPRISED IF SOME OF THESE STORMS PRODUCE SOME POTENTIAL HAIL. IN PROMISING NEWS...WITH THE RIDGING PATTERN IN PLACE...WE WILL EXPERIENCE NO BOUNDARY FORCING UNTIL VERY LATE IN THE FORECAST...SO THIS WILL HAMPER SOME OF THE BEST INSTABILITY AND WIDESPREAD INITIATION. WINDS WILL BE LIGHT AT THE SURFACE...AND REMAIN SO AS WE HEAD UP HIGHER INTO THE ATMOSPHERE. THAT BEING SAID...AFTERNOON CAPE VALUES WILL BE ABOVE THE 2K J/KG RANGE THROUGH MUCH OF THE EXTENDED...AND LAPSE RATES WILL RISE SLIGHTLY BY TUES/WED TO 6 TO 6.5 C/KM...SO AFTERNOON HEATING AND INSTABILITY MAY BE ALL THAT IS NECESSARY FOR SCATTERED CELL DEVELOPMENT EACH DAY. A BOUNDARY WILL FINALLY PUSH INTO THE AREA BY THURS/FRI DAY 7/8 /PER THE LATEST GFS MODEL RUN/. THIS WILL BRING A MORE WIDESPREAD CHANCE FOR RAIN AND THUNDERSTORMS ACROSS THE AREA. HOWEVER...THERE IS QUITE A BIT OF DISAGREEMENT IN THE EXTENDED MODELS THIS FAR OUT...SO DECIDED TO LEAN ON THE ALLBLEND FOR POPS AT THIS TIME.
-- End Changed Discussion --
&& .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 159 AM EDT FRI AUG 22 2014 A COMPLEX OF THUNDERSTORMS WILL WEAKEN AS IT SKIRTS BY ACROSS NORTHEASTERN KENTUCKY BETWEEN 06 AND 10Z. THIS WILL LIKELY AFFECT A LINE FROM KSYM TO KSJS BETWEEN 07 AND 09Z. MVFR VISIBILITIES ALONG WITH SOME GUSTY NORTHWESTERLY WINDS UP TO AROUND 20 KTS WILL ACCOMPANY THE LEADING EDGE OF THE SHOWERS AND STORMS. EXPECT MVFR OR WORSE FOG WILL SET IN ACROSS THE REST OF THE AREA THROUGH DAWN...WITH IFR OR WORSE FOG RESTRICTED TO THE DEEPER VALLEYS...PARTICULARLY THOSE THAT SAW RECENT HEAVY RAINFALL. ONCE THE FOG BURNS OFF THROUGH AROUND 13Z...A RENEWED THREAT OF CONVECTION WILL RETURN...MAINLY DURING THE AFTERNOON HOURS. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 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.