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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS63 KJKL 190817
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
417 AM EDT SUN MAY 19 2013

.SHORT TERM...
-- Changed Discussion --
(TODAY THROUGH MONDAY)
ISSUED AT 246 AM EDT SUN MAY 19 2013

THE UPPER LEVEL LOW IS CURRENTLY PARKED ACROSS NORTHEASTERN
KENTUCKY...WITH MOST SHOWER ACTIVITY STAYING ACROSS EASTERN TENNESSEE
AND SOUTHWEST VIRGINIA. THIS FEATURE WILL GRADUALLY SHIFT EAST AND
DAMPEN WITH TIME AS UPPER LEVEL RIDGING WORKS IN FROM THE WEST. THE
MODELS HAVE BEEN OVERDOING THE CONVECTIVE COVERAGE LATELY...SO WILL
DOWNPLAY THE GIVEN POPS THROUGH THE NEXT 36 HOURS.

EXPECT SCATTERED SHOWERS AND A FEW THUNDERSTORMS TO POP UP THIS
AFTERNOON WITH HEATING...BEFORE DIMINISHING EARLY THIS EVENING. HIGHS
WILL TOP OUT IN THE UPPER 70S TO AROUND 80 DEGREES. ANY CONVECTION
WILL DWINDLE QUICKLY TONIGHT WITH BETTER CLEARING LIKELY AND
CONSEQUENTLY FOG. LOWS WILL BOTTOM OUT IN THE LOWER 60S ONCE AGAIN.

THE UPPER LEVEL RIDGE WILL BUILD IN OVERHEAD ON MONDAY...WITH HIGHS
REACHING WELL INTO THE 80S. WILL MAINTAIN THE INHERITED SLIGHT
CHANCE POPS FOR MOST LOCATIONS AT BEST GIVEN THE CAPPING THAT WILL BE
IN PLACE.

.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 405 AM EDT SUN MAY 19 2013

THE START OF THE PERIOD WILL BE DOMINATED BY UPPER LEVEL RIDGING THAT
IS EXPECTED TO EXTEND FROM THE WESTERN GULF OF MEXICO NORTH INTO THE
OHIO VALLEY. AT THAT POINT...A LARGE CLOSED UPPER LEVEL LOW IS
EXPECTED TO BE ANCHORED OVER THE NORTHERN PLAINS. AT THAT POINT...THE
MAIN BAND OF WESTERLIES IS EXPECTED TO LINE FROM THE PACIFIC
NORTHWEST NORTHEAST INTO CENTRAL CANADA AND THEN SOUTHEAST TOWARD THE
NORTHEASTERN CONUS. THIS MEANS THAT THE CLOSED LOW WILL ONLY SLOWLY
MOVE TOWARD THE EAST AND NORTHEAST INTO THE GREAT LAKES AND OPEN UP
THROUGH THU INTO FRI WHEN IT SHOULD GET PICKED UP BY THE WESTERLIES
AND MOVE INTO THE NORTHEAST OR MID ATLANTIC STATES. ALTHOUGH THERE IS
A GENERAL CONSENSUS ON THE OVERALL UPPER LEVEL PATTERN DIFFERENCES
REMAIN IN TIMING AND TRACK OF THIS SYSTEM AS IT MOVES FROM THE PLAINS
AND INTO THE GREAT LAKES. THIS LEADS TO TIMING DIFFERENCES IN THE
PASSAGE OF THE ASSOCIATED FRONT AND HOW QUICKLY IT DEPARTS TO THE
SOUTHEAST OF THE AREA.

OVERALL...CONVECTIVE ACTIVITY SHOULD BE MINIMAL EARLY IN THE PERIOD
AS THE RIDGING SHOULD BRING CAPPING AND COVERAGE OF CONVECTION
SHOULD ON AVERAGE NOT BE MORE THAN ISOLATED MON EVENING. RIDGING
SHOULD ALLOW FOR SOME CLEARING ON MON NIGHT AND AREAS OF FOG MAY FORM
AND THESE COULD BECOME DENSE DEPENDING ON THE DEGREE OF CLEARING.
DIURNAL HEATING MAY BE SUFFICIENT FOR ISOLATED TO POSSIBLY SCATTERED
ON TUE NEAR THE VA LINE...BUT MOST LOCATIONS SHOULD EXPERIENCE NOT
MUCH MORE THAN A DIURNAL INCREASE IN CU. THE CHANCES FOR CONVECTION
WILL INCREASE AT MIDWEEK AS THE RIDGING DEPARTS TO THE EAST AND
DISTURBANCES ROTATING AROUND THE UPPER LEVEL SYSTEM WORK INTO THE
LOWER OH VALLEY REGION. AT THE SAME TIME...THE SFC COLD FRONT
ASSOCIATED WITH THE UPPER LEVEL SYSTEM TO MOVE INTO THE LAKES SHOULD
ALSO APPROACH.

ALTHOUGH THE SFC BOUNDARY SHOULD WORK ACROSS THE REGION THU NIGHT
INTO FRIDAY...THE GFS RUNS HAVE REMAINED SLOWER WORKING THE SFC
BOUNDARY AND UPPER LEVEL SYSTEM SOUTH AND EAST RESPECTIVELY AND TRACK
THE UPPER SYSTEM CLOSER TO THE AREA. FOR THIS REASON...CHANCES FOR
CONVECTION WERE CONTINUED INTO WELL INTO FRI AND FRI NIGHT AS WAS IN
THE PREVIOUS FORECAST. THE ECMWF SOLUTION WOULD MEAN A DRIER END TO
THE WORK WEEK. AT THIS POINT...IT APPEARS THE BOUNDARY WILL HAVE
PASSED FAR ENOUGH SOUTH AND EAST AND THE UPPER LEVEL SYSTEM WILL HAVE
DEPARTED TO THE EAST ENOUGH FOR SAT TO BE DRY.

DIURNAL TEMPERATURE RANGES SHOULD GENERALLY BE SUPPRESSED FROM
MIDWEEK ON. HOWEVER...UNDER THE INFLUENCE OF THE DEPARTING RIDGE...
THE COMBINATION OF TEMPS IN THE UPPER 80S ON AVERAGE AND DEWPOINTS IN
THE LOW TO MID 60S SHOULD YIELD ABOUT AS WARM OF A HEAT INDEX AS HAS
BEEN EXPERIENCED SO FAR THIS SPRING. HOWEVER...THE WARMEST OF THESE
SHOULD CLIMB TO NO HIGHER THAN 90. RECORD HIGHS AT JKL AND LOZ WILL
LIKELY END UP APPROACHED AND POSSIBLY EXCEEDED. RECORD HIGHS FOR TUE
AT JKL AND LOZ ARE 85/1987 AND 88/1962 RESPECTIVELY. THE MAV MOS
NUMBERS APPEARED MUCH TOO WARM AND NUMBERS CLOSER TO THE MET/CONSALL
WERE MORE APPROPRIATE.
-- End Changed Discussion --

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 156 AM EDT SUN MAY 19 2013

FOG WILL BE THE FIRST CONCERN...AS SKIES ATTEMPT TO PARTIALLY CLEAR
ALONG AND WEST OF I-75. SME HAS ALREADY GONE DOWN TO 2 MILES. THE
LATEST IR SATELLITE TRENDS REVEAL SOME CLOUDS REGENERATING UPSTREAM.
AS SUCH...WILL KEEP SME IN THE IFR RANGE BEFORE IMPROVING TO MVFR
ASSUMING THE CLOUDS MAKE A RETURN. WILL MAINTAIN SOME MVFR
VISIBILITY RESTRICTIONS AT LOZ AND KEEP VFR AT JKL WHERE WINDS WILL
BE A TOUCH STRONGER. ONCE THE FOG BURNS OFF BY MID-
MORNING...SCATTERED CONVECTION WILL THREATEN DURING THE
AFTERNOON...BEFORE WINDING DOWN IN THE EARLY EVENING.


&&

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

$$

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