Area Forecast Discussion
Issued by NWS Jackson, KY

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000
FXUS63 KJKL 080106 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON KY
906 PM EDT TUE JUL 7 2015

.UPDATE...
ISSUED AT 906 PM EDT TUE JUL 7 2015

LINES OF SHOWERS AND THUNDERSTORMS CONTAINING STRONGER WINDS AT
TIMES...HAVE MADE THEIR WAY EAST INTO OUR AREA OVER THE PAST
FEW HOURS. HAVE FRESHENED UP THE POPS TO ACCOUNT FOR THE LATEST
RADAR TRENDS. INSTABILITY IS WANING IN THE FAR EAST..AND ANY
ISOLATED STORMS THAT HAVE TRIED TO INITIATE HAVE HAD A SHORT LIFE
SPAN. ALLOWED FOR SOME LOWER POPS EARLY THIS EVENING IN THE
SOUTHEAST...AND THEN RAMPED THEM UP LATER AS SEVERAL AREAS OF
CONVECTION KEEP TRACKING A BIT MORE TO THE EAST. THUS FAR...THE
CONVECTION HAS BEEN PROGRESSIVE ENOUGH TO KEEP THE THREAT OF FLASH
FLOODING LOW...HOWEVER AS LINES BECOME MORE PARALLEL WITH THE FLOW
WITH TIME...WILL HAVE TO WATCH FOR TRAINING CELLS. UPDATES HAVE
BEEN SENT.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 350 PM EDT TUE JUL 7 2015

AS OF MID AFTERNOON...A SHORTWAVE TROUGH WAS MOVING THROUGH THE
GREAT LAKES REGION SOUTH INTO THE LOWER OH VALLEY REGION WHILE
ANOTHER TROUGH WAS NEARING THE NORTHERN PLAINS. MEANWHILE...AN
UPPER LEVEL RIDGE EXTENDED FROM OFF THE SOUTHEAST US COAST INTO
THE SOUTHEASTERN CONUS. AT THE SFC...AN AREA OF LOW PRESSURE IS
TRACKING NORTHEAST FROM QUEBEC TOWARD THE CANADIAN MARITIMES WITH
A COLD FRONT TRAILING INTO THE EASTERN GREAT LAKES REGION TO THE
LOWER OH VALLEY AND INTO THE SOUTHERN PLAINS. ISOLATED TO
SCATTERED CONVECTION HAS MOVED ACROSS THE REGION ATTM. A RATHER
UNSTABLE AIRMASS IS IN PLACE ACROSS THE AREA WITH SBCAPE GENERALLY
IN THE 1500 TO 2000 J/KG RANGE.

THE SHORTWAVE TROUGH WILL CONTINUE TO MOVE EAST FROM ONTARIO INTO
QUEBEC AND THE NORTHEASTERN STATES TONIGHT. AT THE SAME
TIME...HEIGHTS WILL RISE RISE ACROSS THE SOUTHEAST. THIS WILL LEAD
TO THE COLD FRONT MOVING INTO THE OH VALLEY REGION SLOWING DOWN
AND NEARLY STALLING OUT. WHAT IS LEFT OF THE BOUNDARY WILL BE
NEARLY PARALLEL TO THE UPPER LEVEL FLOW WHILE WEAK DISTURBANCES IN
SW FLOW MOVE AROUND THE RIDGE AND ACROSS THE OH VALLEY REGION. PW
IS EXPECTED CLIMB TO GENERALLY FORM THE 1.3 TO 1.8 INCH RANGE TO
THE 2 TO 2.2 INCH RANGE OR ABOVE THE 75TH PERCENTILE OVERNIGHT INTO
EARLY ON WEDNESDAY. HEAVY RAIN RATES SHOULD BE REALIZED WITH THE
HEAVIER SHOWERS AND THUNDERSTORMS AND ANY LOCATIONS THE RECEIVE
REPEATED ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGH WEDNESDAY
WOULD RUN THE RISK OF FLASH FLOODING. WPC HAS PLACED NEARLY ALL OF
THE REGION IN THE DAY 1 EXCESSIVE RAINFALL OUTLOOK. THE FLASH
FLOOD WATCH WILL REMAIN IN EFFECT FOR THE ENTIRE REGION THROUGH 8
PM EDT ON WEDNESDAY. OTHERWISE...ANY STRONGER THUNDERSTORMS COULD
PRODUCE GUSTY WINDS AND SMALL HAIL.

THE MODEL CONSENSUS AND BEST DYNAMICS AS WELL AS CLOSER PROXIMITY
TO THE BOUNDARY LEADS TO THE BEST CHANCES FOR SHOWERS AND
THUNDERSTORMS THROUGH TONIGHT ACROSS THE NORTH AND NORTHWEST AND
LOWEST CHANCES NEAR THE VA BORDER. THE RISING HEIGHTS ACROSS THE
SOUTHEAST AND AN AREA OF LOW PRESSURE TRACKING FROM THE MS VALLEY
AND TO THE NW OF EAST KY SHOULD LEAD TO THE BOUNDARY RETREATING A
BIT FURTHER NORTH LATE IN THE DAY ON WEDNESDAY INTO WEDNESDAY
NIGHT. THIS SHOULD GENERALLY LEAD TO THE HIGHER CHANCES FOR
CONVECTION ON WED DURING THE FIRST HALF OF THE DAY AND ACROSS THE
NORTH AND EAST. CHANCES FOR CONVECTION SHOULD DIMINISH ON WED
NIGHT...ESPECIALLY ACROSS THE SOUTH. TEMPERATURES WILL REMAIN MILD
THROUGH THE PERIOD WITH LIMITED DIURNAL RANGES DUE TO THE MOIST
ENVIRONMENT AND EXPECTED CLOUD COVER.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 357 PM EDT TUE JUL 7 2015

MODELS CONTINUE TO BE IN DECENT AGREEMENT WITH OVERALL UPPER LEVEL
PATTERN IN THE LONG TERM PORTION OF THE PERIOD. THE PERIOD BEGINS
WITH UPPER LEVEL HIGH CONTINUING TO BUILD WEST ACROSS THE
SOUTHEASTERN CONUS. THE WESTERN CONUS WILL SEE A CLOSED LOW
CENTERED NEAR CENTRAL CALIFORNIA. ALTHOUGH A BIT MORE
INCONSISTENCY BEGINS TO BE MORE EVIDENT AS WE MOVE INTO THE
WEEKEND AND EARLY NEXT WEEK IN TERMS OF THE LOCATION OF THE UPPER
LEVEL HIGH. WHILE THERE IS SOME UNCERTAINTY ALL THE GUIDANCE DOES
SUGGEST THIS WILL BACK TO THE WEST AS WE MOVE THROUGH THE LONG
TERM PERIOD. OVERALL THIS WILL PRESENT GENERAL HEIGHT RISES IN THE
FIRST PORTION OF THE PERIOD AND HEIGHT FALLS EARLY NEXT WEEK.

OVERALL MODEL CONSISTENCY WITH SURFACE FEATURES REMAINS A BIT
MORE UNCERTAIN. MAIN ISSUE FOR THE LONG TERM IS WHERE DOES THE
FRONTAL BOUNDARY WAVIER THROUGH THE PERIOD. THIS ALONG WITH
SHORTWAVE ENERGY WITH WILL THE MAIN DRIVER FOR SHOWERS AND STORMS.
OTHERWISE MOST ACTIVITY WILL BE MORE DIURNALLY DRIVEN. MODELS DO
WANT TO BRING THE COLD FRONT EVER CLOSER BY THURSDAY...HOWEVER
BUILDING HEIGHTS WOULD SUGGEST THIS FRONT BECOME QUITE DIFFUSE AS
IT PROGRESSES INTO THE REGION. GIVEN THIS WILL KEEP BETTER CHANCES
ACROSS THE NORTH ON THURSDAY AND WANE CHANCES THROUGH THE EVENING
AND NIGHT. THE BOUNDARY LOOKS TO HANGUP ACROSS THE REGION SO WILL
KEEP CHANCE TO SLIGHT CHANCE POPS ACROSS THE AREA. THE UPPER HIGH
WILL SLOWLY PROGRESS WEST WHILE THE BOUNDARY LIFTS NORTH WHICH
WILL FOCUS POPS ACROSS THE EAST AND NORTHEAST. THEN AS HEIGHTS
BEGIN TO FALL EARLY NEXT WEEK INCREASING CHANCES OF POPS LOOK
REASONABLE PRETTY MUCH AREA WIDE...AS WE GET POSSIBLE LOW
PRESSURE SYSTEMS AND POTENTIAL FOR MCS/S TO DROP SOUTHEAST.

THERMAL RIDGE CONTINUES TO BUILD THROUGH THE PERIOD. THIS WILL
USHER IN GENERALLY NEAR TO ABOVE NORMAL TEMPERATURES THROUGH THE
PERIOD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 906 PM EDT TUE JUL 7 2015

SEVERAL LINES OF SHOWERS AND THUNDERSTORMS WILL THREATEN SYM...TO
JKL...TO LOZ...AND SME THROUGH 02 OR 03Z. ONCE THIS INITIAL
CONVECTION MAKES IT TO THE EAST...EXPECT ADDITIONAL CONVECTION TO
MOVE IN FROM THE WEST OVERNIGHT...ALTHOUGH WILL ONLY CONTINUE TO
CARRY VCTS FOR NOW...AS TIMING INDIVIDUAL ROUNDS WILL BE
DIFFICULT. CONDITIONS WILL LOWER TO AT LEAST MVFR THROUGH THE
OVERNIGHT...WITH IFR OR WORSE CONDITIONS POSSIBLE AT TIMES DURING
THE HEAVIER CONECTION. CEILINGS MAY IMPROVE BY LATE WEDNESDAY
AFTERNOON.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH WEDNESDAY EVENING FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.

&&

$$

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



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