Severe Thunderstorm Warning 64, NWS Jackson, KY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
329 PM EDT TUE JUL 9 2013

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 329 PM EDT TUE JUL 9 2013

ISOLD TO SCT SHOWERS AND THUNDERSTORMS ARE DEVELOPING ACROSS THE
AREA THIS AFTERNOON. MORE SUBSTANTIAL AREA OF CONVECTION HAS FIRED
OVER OHIO. HRRR HAS ACTUALLY BEEN DOING DECENT WITH CONVECTIVE
INITIATION ACROSS AREAS NORTH OF THE OHIO RIVER. IN GENERAL IT KEEPS
THE BULK OF ACTIVITY NORTH AND EAST OF OUR CWA...THOUGH RADAR TRENDS
WOULD SUGGEST THAT OUR NORTHERN AND EASTERN COUNTIES MAY GET BRUSHED.
INCREASED POPS ACROSS THE NORTHERN/EASTERN PORTIONS OF OUR CWA FOR
THE LATE AFTERNOON AND EARLY EVENING TIME FRAME. PER THE HRRR...WITH
COMPLEX OF STORMS PASSING GENERALLY TO OUR EAST THIS EVENING AND LOSS
OF DIURNAL HEATING GRADUALLY DROPPED POPS OFF THROUGH THE NIGHT.
HOWEVER...RAMPED POPS BACK UP TOWARDS DAWN AS SHORT TERM HIGH
RESOLUTION MODELS SUGGEST THE POSSIBILITY OF THE REMNANTS OF ANOTHER
COMPLEX OF STORMS ENTERING THE AREA FROM THE NORTHWEST.

OTHERWISE...MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH THE SHORT
TERM. A DEEPENING UPPER LEVEL TROUGH AND REFLECTED SFC COLD FRONT
WILL GRADUALLY PUSH THROUGH THE REGION WEDNESDAY NIGHT INTO EARLY
THURSDAY MORNING. PWATS OVER THE NEXT 36 TO 48 HOURS ARE SIGNIFICANT
HITTING CLIMATOLOGICAL HIGHS AT TIMES. FORECAST SOUNDINGS ARE NOT IN
AS GOOD AGREEMENT WITH RESPECT TO STORM MOTION THOUGH. THE GFS IS
MORE PROGRESSIVE WITH MOVEMENT WHEN COMPARED TO THE HIGHER RESOLUTION
RAP AND NAM. REGARDLESS...WITH SUCH HIGH PWATS AND CONSIDERING A
FAIRLY SATURATED GROUND FEEL THERE WILL BE THE POTENTIAL FOR SOME
LOCALLY HEAVY RAINFALL AND MINOR HYDRO ISSUES...ESPECIALLY WITH THE
STRONGER STORMS. CONFIDENCE WAS LACKING WITH RESPECT TO A WIDESPREAD
THREAT SO OPTED NOT TO ISSUE ANY TYPE OF FFA. BUT MAY RECONSIDER A
FLASH FLOOD WATCH WITH FUTURE FORECAST PACKAGES SHOULD MODELS COME
INTO A LITTLE BETTER AGREEMENT WITH RESPECT TO DETAILS...AND SHOW A
MORE SIGNIFICANT THREAT. FOR NOW WILL CONTINUE TO COVER THIS
POTENTIAL IN THE HWO AND PASS CONCERNS ON TO FUTURE SHIFTS. GENERALLY
FOLLOWED INHERITED TEMPS...NUDGING SLIGHTLY TOWARDS A BLEND OF MODEL
GUIDANCE.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 329 PM EDT TUE JUL 9 2013

THE MODELS HAVE A SIMILAR IDEA...THROUGH THE EXTENDED...OF A MID
LEVEL PATTERN DOMINATED BY A LARGE AREA OF RIDGING...INITIALLY OVER
THE SOUTHERN ROCKIES EXPANDING NORTHEAST WITH TIME...AND DOWNSTREAM
TROUGHING THROUGH THE GREAT LAKES LATER AFFECTING MUCH OF THE EAST
AND DEEP SOUTH. THE GREAT LAKES TROUGH STRENGTHENS A BIT ON
THURSDAY AS ITS CORE MOVES EAST AND INTO UPSTATE NEW YORK BY 12Z
FRIDAY. AT THE SAME TIME...ITS TRAILING AXIS AND MAIN ENERGY BAND
WILL SWEEP SOUTHEAST THROUGH THE LOWER OHIO VALLEY AND ACROSS EAST
KENTUCKY. THIS WILL ALLOW HEIGHTS TO BUILD IN FROM THE NORTHWEST
THROUGH THE WEEKEND WHILE THE SOUTHERN PORTION OF THE TROUGH CUTS
OFF OVER THE DEEP SOUTH AND STARTS TO CONSOLIDATE. THOUGH THE MODELS
GENERALLY AGREE ON THE RIDGE PLACEMENT...THEY DIFFER ON THE DETAILS
REGARDING THE LOWER HEIGHT CENTERS TO THE SOUTH AND EAST. INTO THIS
MIX WILL ENTER THE UPPER HEIGHT FIELD OF CHANTAL...OR WHATEVER
BECOMES OF HER...THAT COULD MOVE TO THE SOUTHEAST COAST PER THE GEM
OR STAY LOCKED OUT TO THE SOUTH AS SEEN IN THE GFS AND ECMWF. EITHER
WAY...ITS MOISTURE MAY START TO IMPACT THE AREA AS EARLY AS LATE
SUNDAY...LINGERING THROUGH THE REST OF THE EXTENDED. FOR EAST
KENTUCKY...THE RIDGE TO THE NORTH WILL BE A KEY COMPONENT IN
DETERMINING OUR WEATHER INTO THE START OF NEXT WEEK. WITH THE MODELS
IN BETTER AGREEMENT ON THIS FEATURE CONFIDENCE IS HIGHER IN GOING
DRY THROUGH AT LEAST MIDDAY SUNDAY. THEREAFTER...THE GFS...AND TO A
LESSER EXTENT THE ECMWF...DOES BRING AN UPPER LOW WEST TOWARD THE
AREA FOR TUESDAY. WITH THE DECENT AGREEMENT AMONG THE MODELS ON THE
RIDGE THROUGH THE WEEKEND...EXPECT THAT A BLEND WILL BE AN EFFECTIVE
STARTING POINT THROUGH SUNDAY. AFTER THAT...WILL LEAN MORE TOWARD
THE WEAKER...LESS AMPLIFIED...00Z ECMWF.

SENSIBLE WEATHER WILL LIKELY FEATURE SOME ONGOING CONVECTION MOVING
SOUTHEAST THROUGH THIS PART OF THE STATE ON THURSDAY MORNING AS A
COLD FRONT PASSES THROUGH EARLY IN THE DAY. HIGH PRESSURE WILL THEN
BUILD IN AND BRING A RARE SUMMER TIME SHOT OF COOLER AND DRIER AIR
FROM THE NORTH. THIS SFC HIGH...AND THE DRY WEATHER...WILL BE
SUSTAINED BY THE RIDGING BUILDING ALOFT AND SHOULD SERVE TO KEEP ANY
TROPICAL DERIVED MOISTURE OFF TO THE SOUTH AND EAST FOR THE BULK OF
THE WEEKEND. HOWEVER...THE RIDGE ALOFT WILL WEAKEN AND MOVE BACK
WEST BY LATE SUNDAY WHILE THE CORRESPONDING SFC HIGH WILL ALSO BREAK
DOWN AND ALLOW HIGH DEWPOINTS INTO THE REGION FROM THE SOUTHEAST. A
DIURNAL REGIME SHOULD THEN GUIDE THE CONVECTIVE DEVELOPMENTS ON
MONDAY AND TUESDAY WITH BUILDING INSTABILITY AND LITTLE IN THE WAY
OF CAPPING LEADING TO SCATTERED SHOWERS AND THUNDERSTORMS EACH
AFTERNOON...PARTICULARLY ACROSS OUR SOUTHEAST COUNTIES.

THE CR GRID LOAD CAME IN REASONABLE...THOUGH DID ADJUST POPS A BIT
ON SUNDAY AND MONDAY NIGHTS TO BETTER EMPHASIZE THE DIURNAL NATURE
OF THE CONVECTION. ALSO...TWEAKED OVERNIGHT LOWS ON THURSDAY THROUGH
SATURDAY NIGHTS TO ACCOUNT FOR TERRAIN BASED DIFFERENCES IN
RADIATIONAL COOLING WHILE WE ARE BENEFITING FROM THE DRIER AIR MASS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 215 PM EDT TUE JUL 9 2013

EXTENSIVE CUMULUS FIELD WILL BE IN PLACE THROUGH THE REMAINDER OF THE
AFTERNOON WITH GENERALLY SCT SKY CONDITIONS AND CLOUD BASES FROM 3000
TO 5000 FEET. WENT WITH VFR CONDITIONS THROUGH THE ENTIRE FORECAST
PERIOD. HOWEVER...STILL HAVE TO DEAL WITH CONVECTION THIS AFTERNOON
AND INTO TONIGHT. DIURNAL HEATING AND INSTABILITY IS HELPING TO KICK
OFF SOME SHOWERS ACROSS THE AREA AT TAF ISSUANCE. ASSESSING THE
DIRECT IMPACTS OF SHOWERS AND THUNDERSTORMS AT EACH TERMINAL IS AT
BEST DIFFICULT...ESPECIALLY SINCE CELLS APPEAR TO HAVE A RELATIVELY
SHORT LIFE CYCLE...BUILDING AND THEN DISSIPATING WITHIN AN HOUR.
MORE ORGANIZED CONVECTION MAY DROP SOUTHWARD INTO PORTIONS OF THE
AREA LATER THIS EVENING. CLOSELY WATCHING THE DEVELOPMENT AND
EVOLUTION OF UPSTREAM ACTIVITY. JKL WOULD BE MOST LIKELY TO BE
EFFECTED BY ANYTHING. PRECIP POTENTIAL...LATE AFTERNOON AND EARLY
EVENING RAINFALL WOULD BOOST POTENTIAL FOR BR/FOG DEVELOPMENT
OVERNIGHT. BUT FOR NOW WENT MORE OPTIMISTIC THAN MODEL GUIDANCE WITH
ONLY SOME LIGHT MIST. WINDS WILL RELATIVELY LIGHT THROUGH THE
PERIOD...AND GENERALLY FROM THE SOUTHWEST.

&&

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

&&

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

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE JACKSON KY
425 PM EDT TUE JUL 9 2013

KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120-102330-
FLEMING-MONTGOMERY-BATH-ROWAN-ESTILL-POWELL-MENIFEE-ROCKCASTLE-
JACKSON-PULASKI-LAUREL-WAYNE-MCCREARY-WHITLEY-KNOX-BELL-HARLAN-
ELLIOTT-MORGAN-JOHNSON-WOLFE-MAGOFFIN-FLOYD-LEE-BREATHITT-KNOTT-
OWSLEY-PERRY-CLAY-LESLIE-LETCHER-MARTIN-PIKE-
425 PM EDT TUE JUL 9 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN KENTUCKY.

.DAY ONE...LATE THIS AFTERNOON AND TONIGHT.

THUNDERSTORMS ARE POSSIBLE LATE THIS AFTERNOON AND TONIGHT. LOCALLY
HEAVY RAIN CAN BE EXPECTED FROM ANY STRONGER THUNDERSTORM. IN
ADDITION...THUNDERSTORMS THAT FORM GENERALLY ALONG AND NORTH OF THE
INTERSTATE 64 CORRIDOR COULD BECOME SEVERE...WITH DAMAGING WINDS AND
LARGE HAIL AS THE MAIN THREATS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

THUNDERSTORMS ARE POSSIBLE AT TIMES FROM WEDNESDAY THROUGH THURSDAY
EVENING...AND AGAIN ON SUNDAY AND MONDAY.

THE BEST CHANCE FOR WIDESPREAD THUNDERSTORMS WILL COME WEDNESDAY
AFTERNOON INTO THURSDAY WITH THE PASSAGE OF A COLD FRONT. SOME OF THE
STORMS FROM WEDNESDAY AFTERNOON THROUGH THURSDAY WILL CONTAIN HEAVY
RAIN. IN ADDITION...SOME OF THE STRONGER STORMS LATER WEDNESDAY COULD
ALSO PRODUCE GUSTY WINDS.

OUTSIDE OF THE WEDNESDAY AFTERNOON INTO THURSDAY PERIOD...MOST
THUNDERSTORMS WILL BE ISOLATED TO SCATTERED...FAVORING THE AFTERNOON
AND EARLY EVENING HOURS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ARE ENCOURAGE TO REPORT HEAVY RAINFALL...ANY HAIL...OR
DAMAGING WIND GUSTS.

JMW/GREIF