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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS63 KJKL 221127 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON KY
727 AM EDT WED MAY 22 2013

.UPDATE...
-- Changed Discussion --
ISSUED AT 728 AM EDT WED MAY 22 2013

GRIDS WERE UPDATED TO ACCOUNT FOR RECENT OBSERVATIONS AND SATELLITE
TRENDS AND TO ACCOUNT FOR SOME ISOLATED TO SCATTERED SHRA AND TSRA
MOVING NORTHEAST FROM EASTERN MIDDLE TN/CUMBERLAND PLATEAU REGION.
THIS SHOULD WORK NORTHEAST ACROSS THE WESTERN PART OF THE CWA THIS
MORNING AND PROBABLY WEAKEN WITH TIME. OTHERWISE...WE STILL EXPECT A
GENERAL INCREASE IN CONVECTION THIS AFTERNOON...WITH SOME OF IT IN
THE AFTERNOON AND EVENING POSSIBLY BEING SEVERE.
-- End Changed Discussion --

&&

.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 355 AM EDT WED MAY 22 2013

EARLY THIS MORNING...AN UPPER LEVEL LOW HAD MEANDERED TO THE UPPER
MIDWEST/UPPER MS VALLEY REGION. TO ITS SOUTH A RATHER SIGNIFICANT
SHORTWAVE TROUGH WAS WORKING TOWARD THE MID AND LOWER MS VALLEY
REGIONS. THE UPPER LEVEL SYSTEM WILL WEAKEN TO AN OPEN WAVE THROUGH
THE PERIOD...WITH THE LEAD SHORTWAVE TROUGH TO WORK INTO THE AREA
THIS AFTERNOON/EVENING AND THE MAIN UPPER LEVEL SYSTEM TO REACH THE
CENTRAL GREAT LAKES/LOWER TO MID OH VALLEY AND TN VALLEY REGION BY
THE END OF THE PERIOD. AT THE SAME TIME...THE ASSOCIATED SFC LOW
SHOULD TRACK WELL INTO THE ST LAWRENCE VALLEY THROUGH THE END OF THE
PERIOD WITH THE TRIALING COLD FRONT ENTERING THE COMMONWEALTH
TODAY...THOUGH IT SHOULD NOT CROSS EASTERN KY UNTIL THU AFTERNOON.

THE REGION IS CURRENTLY IN A LULL IN CONVECTIVE ACTIVITY.
HOWEVER...AN OUTFLOW BOUNDARY FROM CONVECTION THAT OCCURRED OVER
WESTERN KY AND IN THE MS RIVER VALLEY ON TUE EVENING HAS WORKED INTO
THE CWA. IT IS LIKELY RATHER ILL DEFINED ATTM...BUT STILL MAY BE
ENOUGH TO BE A FOCUS FOR CONVECTIVE DEVELOPMENT TODAY. ALSO...DEBRIS
CLOUDS OR PERHAPS SOME SCATTERED CONVECTION MAY BE ONGOING EARLY IN
THE DAY AS REMAINING CONVECTION OVER WESTERN AND MIDDLE TN WORKS
NORTHEAST TOWARD CENTRAL AND EASTERN KY. HOWEVER...BREAKS IN THE
CLOUDS AND SOME LIMITED HEATING SHOULD ALLOW TEMPS TO RATHER QUICKLY
REACH THE 80S BY MIDDAY TO AFTERNOON ON WEDNESDAY. THIS SHOULD LEAD
TO MODERATE INSTABILITY AT ABOUT THE SAME TIME THAT WINDS ALOFT WILL
ALSO BE INCREASING WITH LOW LEVEL JET CORE REMAINING GENERALLY TO OUR
WEST AND NORTH. WITH THE COLD FRONT WORKING INTO THE COMMONWEALTH
AND A SHORTWAVE TROUGH APPROACHING FROM THE SOUTHWEST...A LINE OR
SEVERAL LINE SEGMENTS OF CONVECTION SHOULD DEVELOP TO OUR WEST OR
PERHAPS OVER THE REGION THIS AFTERNOON AND WORK ACROSS THE AREA INTO
THE EVENING. THE FORECAST WIND PROFILE IS RATHER UNIDIRECTIONAL AND
MID LEVEL DRY AIR IS LIMITED AND CONSIDERING FEW HAIL REPORTS FROM
TUE AFTERNOON...IT WOULD SEEM THAT DAMAGING WIND GUSTS WOULD BE THE
MAIN THREAT FROM STORMS THIS AFTERNOON THROUGH EARLY EVENING. SHEAR
WILL BE A BIT BETTER GENERALLY ALONG/NORTH OF THE I 64 CORRIDOR AND
AN ISOLATED TORNADO CANNOT BE RULED OUT. IN THE HWO...THE SLIGHT RISK
AND DAMAGING WIND THREAT WILL BE HIGHLIGHTED.

DEEPER MOISTURE WILL GRADUALLY BE DEPARTING TO THE EAST TONIGHT...BUT
AT THE SAME TIME...THE MAIN UPPER LEVEL TROUGH AND LEAD SHORTWAVE
WILL STILL BE CROSSING THE AREA. CONVECTION CANNOT BE RULED OUT WELL
INTO THE NIGHT...ESPECIALLY IN THE EAST...BUT COVERAGE OF THUNDER
SHOULD BECOME MORE ISOLATED AS THE NIGHT WEARS ON AND WITH LOSS OF
DAYTIME HEATING INTENSITY SHOULD WANE BY 3Z...OR 11 PM EDT...IF NOT
EARLIER.

DAYTIME HEATING ON THU COMBINED WITH THE COLD FRONT WORKING ACROSS
EASTERN KY AND THE UPPER LEVEL SHORTWAVE TROUGH AXIS TO WORK THROUGH
SHOULD GENERALLY COINCIDE WITH DAYTIME HEATING SO HIGH CHANCE TO
LIKELY POPS WERE USED FOR SHOWERS THOUGH ENOUGH INSTABILITY WILL
LINGER FOR A FEW THUNDERSTORMS AS WELL.

.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 433 AM EDT WED MAY 22 2013

THE MODELS CONTINUE TO AGREE WITH THE LONG WAVE BLOCKY PATTERN THAT
WILL DOMINATE THE CONUS THROUGH EARLY NEXT WEEK.

A DEEP UPPER TROUGH WILL SWING THROUGH THE OHIO VALLEY AND EVENTUALLY
REACH THE EASTERN SEABOARD BY FRIDAY. RAIN SHOWERS WILL GRADUALLY
WIND DOWN THURSDAY NIGHT ACROSS EASTERN KENTUCKY. MUCH COOLER AND
DRIER AIR WILL SETTLE IN THROUGH THE FIRST HALF OF THE WEEKEND AS A
LARGE RIDGE OF HIGH PRESSURE NOSES IN FROM CANADA. HIGHS ON FRIDAY
WILL BE IN THE MID 60S...WITH LOWS FRIDAY NIGHT DOWN INTO THE LOWER
TO MIDDLE 40S.

THE NEXT FEATURE OF INTEREST WILL BE AN INVERTED SURFACE TROUGH THAT
WILL MOVE IN FROM THE NORTHWEST LATE THIS WEEKEND INTO EARLY NEXT
WEEK. THE LATEST 00Z ECMWF HAS BACKED OFF ON THE EARLY ARRIVAL OF
THIS FEATURE COMPARED TO PREVIOUS RUNS...HOWEVER IT STILL KEEPS THIS
BOUNDARY POSITIONED MUCH FURTHER SOUTH AND MORE ACROSS OUR AREA THAN
THE GFS...WHICH KEEPS THE BOUNDARY MORE ALONG THE OHIO RIVER. AS
SUCH...WILL CONTINUE TO COMPROMISE WITH A BLEND FOR NOW...BRINGING IN
SLIGHT CHANCE POPS LATE SUNDAY NIGHT AND THEN CHANCE POPS MONDAY
THROUGH TUESDAY. TEMPERATURES WILL RECOVER TO SLIGHTLY ABOVE NORMAL
BY EARLY NEXT WEEK...WITH HIGHS TOPPING OUT AT AROUND 80 BY TUESDAY.

&&

.AVIATION...
-- Changed Discussion --
(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 725 AM EDT WED MAY 22 2013

ISOLATED TO SCATTERED SHRA AND TSRA SHOULD AFFECT SME AND LOZ OVER
THE NEXT COUPLE OF HOURS AS IT MOVES NORTHEAST ACROSS THE LAKE
CUMBERLAND REGION. AFTER ABOUT 17Z...CONVECTION SHOULD CONTINUE TO
DEVELOP AND/OR STRENGTHEN AS IT MOVES IN SOUTH CENTRAL AND EASTERN
KY. THERE IS A SEVERE THREAT WITH THIS AND STRONG TO DAMAGING WIND
GUSTS COULD IMPACT ALL THREE TAF SITES AT SOME POINT BETWEEN 18Z AND
0Z. OUTSIDE OF ANY CONVECTION...GENERALLY VFR IS EXPECTED...ALTHOUGH
VALLEY FOG MAY REDEVELOP BY 6Z AND POSSIBLY BRING MVFR OR LOWER VIS
TO THE TAF SITES.
-- End Changed Discussion --

&&

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

$$

UPDATE...JP
SHORT TERM...JP
LONG TERM...GEOGERIAN
AVIATION...JP