Area Forecast Discussion
Issued by NWS Jackson, KY

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000
FXUS63 KJKL 010600
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
200 AM EDT WED JUL 1 2015

.UPDATE...
ISSUED AT 1000 PM EDT TUE JUN 30 2015

THE WATCH HAS BEEN DROPPED AS EVEN THE OUTFLOW BOUNDARY HAS NOT
BEEN ABLE TO GENERATE STRONG STORMS. HOWEVER...A COUPLE STRONG
ONES ARE DIVING SOUTHEAST FROM THE BLUEGRASS WHICH WILL LIKELY
AFFECT OUR CWA THROUGH MIDNIGHT. ELSEWHERE...JUST A FEW SHOWERS OR
STRAY STORMS ARE FOUND. WILL CONTINUE THE SMALL CHANCES FOR
CONVECTION THROUGH THE REST OF THE NIGHT...PER RADAR TRENDS AND
THE LATEST HRRR. ADDITIONALLY...AREAS OF FOG...LOCALLY DENSE...
WILL BE POSSIBLE OVERNIGHT AND THROUGH DAWN. HAVE UPDATED THE
GRIDS FOR THIS AS WELL AS SENT OUT FRESHENED ZONES AND A CALMER
HWO. THE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.

UPDATE ISSUED AT 750 PM EDT TUE JUN 30 2015

A WELL DEFINED OUTFLOW BOUNDARY IS SLOWLY DESCENDING THROUGH THE
NORTHERN HALF OF THE CWA WITH STORMS JUST TRAILING AND SOME
DEVELOPING ALONG IT TO THE WEST. THE WORST OF THE STORMS HAVE BEEN
JUST TOUCHING SEVERE LIMITS WITH EVERY SCAN OF THE RADAR PROVIDING
CRITICAL DATA FOR THE EVOLVING CELLS. TO THE SOUTH...EARLIER
STORMS DURING THE AFTERNOON HAVE SEEMED TO MAKE FOR QUIETER
WEATHER SOUTH OF THE HAL ROGERS PARKWAY AS THE OUTFLOW IS NOW THE
FOCUS FOR CONVECTIVE INITIATION. AS SUCH...HAVE DROPPED THE
WATCH...DUE TO EXPIRE IN AN HOUR...FROM THE SOUTH WHILE KEEPING IT
IN THE NORTH. HAVE UPDATED THE GRIDS TO REFLECT THE TIMING OF THE
NORTHERN STORMS AND THIS OUTFLOW BOUNDARY. ALSO...INCORPORATED THE
LATEST GUIDANCE FROM THE HRRR AND NAM12 FOR POPS THROUGH THE REST
OF THE NIGHT. ADDITIONALLY...DID TWEAK THE TEMP AND DEWPOINT
GRIDS PER THE LATEST OBS...COLD POOLS...AND TRENDS. THESE HAVE
BEEN SENT TO THE WEB AND NDFD SERVERS ALONG WITH FRESH SETS OF
ZONES AND HWO.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 313 PM EDT TUE JUN 30 2015

CURRENT CONDITIONS ACROSS THE AREA AS OF 19Z FEATURE THE AREA IN
THE MIDST OF WEAK SURFACE GRADIENT AND AHEAD OF A WEAKENING COLD
FRONT TO THE NORTH. THIS AFTERNOONS ACTIVITY SEEMS TO BE LARGELY
TIED TO SURFACE INSTABILITY ACROSS THE AREA AND THIS EVEN HAS BEEN
HINDERED DUE TO LINGERING LOW LEVEL CLOUD COVER...MAINLY IN THE
NORTH. THE SOUTHERN AREA OF EASTERN KENTUCKY HAS GOTTEN ENOUGH
SUNSHINE FOR SOME INSTABILITY AND MOSTLY ALL THE ACTIVITY HAS BEEN
TIED TO OVER SOUTHERN KENTUCKY.

HEADING INTO THIS EVENING AND TONIGHT AND LOOKING AT TRENDS IN THE
HI RES MODELS...THE NMM MODEL SEEMS TO BE HANDLING THE CONVECTION
MOST ADMIRABLY WITH THE DEAD AREA OF CONVECTION BEING OVER JACKSON
AND NORTH DUE TO THE EARLY MORNING CLOUD COVER AND REST OF THE
ACTIVITY BEING OVER THE SOUTH WITH A DEVELOPING LINE AHEAD OF THE
FRONT TO THE NORTH DIVING SOUTH AS IT BEGINS TO COLD POOL AND
ACCELERATE. BASED UPON THE MODEL AND LIVE TRENDS...THINKING THAT
THIS WILL BE THE CASE AND HAVE ADJUSTED POPS FOR THIS.

SINCE ACTIVITY WILL BE LARGELY ON INSTABILITY...WILL RAMP DOWN
POPS SHORTLY AFTER 00Z TONIGHT WITH A FEW AREAS OF FOG ALSO
EXPECTED...ESPECIALLY WHERE AREAS RECEIVE RAIN. BY WEDNESDAY AND
INTO WEDNESDAY NIGHT...THE NAM AND GFS HINT AT A MORE PRONOUNCED
COMPLEX DIVING SOUTH INTO CENTRAL KY AND THEN EAST INTO EASTERN
KENTUCKY. THIS HAS BEEN ADVERTISED IN THE MODELS OVER THE LAST FEW
DAYS AND WILL KEEP THIS IN THE FORECAST. FOR THIS...WILL KEEP
LIKELY POPS IN THE FORECAST THROUGH WEDNESDAY AND WEDNESDAY NIGHT.
INSTABILITY FOR THIS EVENT SEEMS IN QUESTION BUT WILL AT THE VERY
LEAST BE DEALING WITH CONTINUED SHOWERS AND THUNDERSTORMS THROUGH
THE LAST TWO PERIODS.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 313 PM EDT TUE JUN 30 2015

PATTERN WILL REMAIN UNCHANGED THROUGH THE EXTENDED...WITH A
PERSISTENT TROUGH IN THE EAST AND RIDGING OUT WEST. THIS WILL KEEP
THE WEATHER ACTIVE THROUGH EARLY NEXT WEEK. AT THE START OF THE
PERIOD...PRETTY DECENT WAVE DIGGING ACROSS KENTUCKY WITH WIDESPREAD
SHOWERS AND STORMS EXPECTED. THURSDAY LOOKS FAIRLY DAMP AND PERHAPS
WE WILL NOT SEE AS MUCH THUNDER COMPARED WITH RECENT STANDARDS GIVEN
THE CLOUD COVER. REGARDLESS...IT LOOKS VERY WET FROM THURSDAY INTO
THURSDAY NIGHT. FRONTAL ZONE STALLS OVER THE AREA INTO THE WEEKEND
WHICH WILL KEEP A THREAT OF SHOWERS AND STORMS GOING THROUGH THE
HOLIDAY WEEKEND. TEMPERATURES WILL REMAIN A BELOW NORMAL THROUGH THE
PERIOD GIVEN THE TROUGH OVER THE REGION.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 200 AM EDT WED JUL 1 2015

SHOWERS CONTINUE TO DIMINISH ACROSS THE REGION OVERNIGHT WITH LOSS
OF HEAT INDUCED INSTABILITY. HOWEVER...A LARGE AMOUNT OF MOISTURE
HAS BEEN LEFT OVER ACROSS MUCH OF EASTERN KY...ESPECIALLY IN AREAS
THAT RECEIVED RAINFALL THIS EVENING. AS TEMPERATURES CONTINUE TO
COOL OVERNIGHT...FOG WILL CONTINUE TO FORM AND THICKEN. SEVERAL
TAF SITES ARE ALREADY REPORTING FOG...AND IF THEY CONTINUE TO DROP
IN VISIBILITY SOME MAY ACTUALLY GO BELOW AIRPORT MINS FOR A PERIOD BY
LATE TONIGHT/EARLY MORNING. THAT BEING SAID...SOME TAF SITES MAY
CONTINUE TO FLUCTUATE BETWEEN CATEGORIES DEPENDING ON THE VARYING
DEGREE OF THE FOG OVERNIGHT. AS THE FOG BURNS OFF IN THE
MORNING...IT WILL BE REPLACED BY A RENEWED CHANCE OF SHOWERS AND
THUNDERSTORMS...ESPECIALLY IN THE AFTERNOON AND EVENING. TRIED TO
GEAR TAFS TOWARD THIS IDEA...BUT ACTUAL VIS AND CIGS WILL VARY
THROUGHOUT THE DAY AS STORMS DEVELOP AND PASS NEARBY...OR EVEN
OVER THE TAF SITE. A HEAVIER AREA OF RAIN WILL MOVE IN LATE IN THE
EVENING...WITH ALL TAF SITES EXPECTED TO BE AFFECTED. THE EXACT
IMPACTS ARE STILL UNCERTAIN...BUT TRENDED TOWARDS MVFR CIGS AND
MVFR/HIGH END IFR VIS AT THIS TIME.

&&

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

$$

UPDATE...GREIF
SHORT TERM...SHALLENBERGER
LONG TERM...KAS
AVIATION...JMW



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