Area Forecast Discussion
Issued by NWS Jackson, KY

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000
FXUS63 KJKL 061959
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
359 PM EDT MON JUL 6 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 350 PM EDT MON JUL 6 2015

THE MID AND UPPER LEVEL LOW PRESSURE SYSTEM CONTINUES TO DEPART TO
THE NORTHEAST OF THE REGION THIS AFTERNOON. A WEAK MID LEVEL RIDGE
IS BUILDING TOWARD THE REGION IN BETWEEN THIS DEPARTING SYSTEM AND
A TROUGH MOVING ACROSS THE PLAINS STATES AND APPROACHING THE GREAT
LAKES AND MS VALLEY. THERE HAVE BEEN A FEW SHOWERS ON THE OUTER
EDGE OF THE DEPARTING LOW...AND OVER THE CUMBERLAND PLATEAU...BUT
OVERALL MUCH LESS COVERAGE COMPARED TO 24 HOURS AGO.

A MID LEVEL RIDGE WILL BRIEFLY WORK EAST ACROSS THE COMMONWEALTH
THIS EVENING INTO THE OVERNIGHT...WITH THE AXIS OF THIS RIDGE
MOVING EAST BY DAWN. THIS WILL ALLOW FOR THE NEXT SHORTWAVE TO
BEGIN TO APPROACH THE REGION WITH THE CORRESPONDING COLD FRONT
ALSO ENTERING THE OH VALLEY REGION. THIS SYSTEM SHOULD BE A FOCUS
FOR CONVECTION MAINLY FROM TUE AFTERNOON INTO TUE EVENING AS
DAYTIME HEATING AND A MOIST AIRMASS WILL BE IN PLACE ALONG AND
AHEAD OF THE BOUNDARY. THE BEST DYNAMICS AND SHEAR HOWEVER SHOULD
RESIDE GENERALLY NORTH OF THE REGION...BUT WEAK SHORTWAVES IN SW
FLOW ALOFT WILL BRING A THREAT FOR CONVECTION THROUGH THE END OF
THE PERIOD.

COVERAGE OF CONVECTION SHOULD BE GREATEST ON TUE AFTERNOON AND TUE
EVENING. THE BEST COMBINATION OF THE SHEAR AND INSTABILITY SHOULD
BE ACROSS THE NW PART OF THE CWA...OR IN THE SPC MARGINAL CONVECTIVE
RISK FOR DAY 2. A COUPLE OF STORMS COULD PRODUCE STRONG WINDS
GUSTS. HOWEVER...GIVEN THE RECENT WET PERIOD...THE POTENTIAL FOR
THE FRONT TO STALL OR SLOW DOWN AND GENERALLY BE ALIGNED PARALLEL
TO THE UPPER LEVEL FLOW AND STORMS NOT EXPECTED TO MOVE ALL THAT
SWIFTLY...FLASH FLOODING COULD AGAIN BECOME A CONCERN BY THE END
OF THE PERIOD OR INTO THE LONG TERM PERIOD. PW IS NOT EXPECTED TO
BE SUSTAINED INORDINATELY HIGH...BUT THE POTENTIAL FOR TRAINING OR
REPEATED ROUNDS APPEARS TO BE THERE.

AFTER ANY LINGERING SHOWERS DISSIPATE BY EARLY EVENING...THE
DRIEST PART OF THE PERIOD WILL BE TONIGHT. MOST CONVECTION SHOULD
HOLD OFF UNTIL THE DAYTIME PERIOD LATE TONIGHT...BUT STRAY
CONVECTION CANNOT BE RULED OUT IN THE WARM SECTOR TOWARD DAWN.
OUTSIDE OF CONVECTION...VALLEY FOG...DENSE IS EXPECTED WITH THE
WET GROUND IN PLACE FORM RECENT RAINFALL. THE HIGHEST POPS WERE
USED IN THE NORTH...LIKELY WITH SCATTERED POPS IN THE SOUTH.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 340 PM EDT MON JUL 6 2015

MODELS ARE IN DECENT AGREEMENT WITH THE OVERALL UPPER LEVEL
PATTERN AS WE MOVE INTO THE LONG TERM PORTION OF THE FORECAST. THE
TROUGHING ACROSS THE EASTERN CONUS BREAKS DOWN AND LEADS TO
FAIRLY ZONAL FLOW ACROSS MUCH OF THE OHIO VALLEY INITIALLY...WHILE
TROUGH BUILDS ACROSS THE WESTERN CONUS. THROUGH THE PERIOD SUB
TROPICAL RIDGE BUILDS ACROSS THE SOUTHEASTERN CONUS SENDING MEAN
FLOW NORTH OF EASTERN KENTUCKY. THEN THIS UPPER LEVEL RIDGE BEGINS
TO SHIFT WEST AT THE END OF THE PERIOD AND WE GET BACK INTO A
STORMIER NW FLOW.

OVERALL SURFACE FEATURES LEAD TO A BIT LESS AGREEMENT FROM THE
GUIDANCE SUITES. THIS IS DUE TO THE SURFACE BOUNDARY ACROSS THE
OHIO VALLEY AND THE INTERACTION WITH BUILDING UPPER LEVEL RIDGE
ACROSS THE SOUTHEASTERN CONUS. MOST MODELS BESIDE THE OPERATIONAL
ECMWF KEEP THIS BOUNDARY NORTH OF EASTERN KENTUCKY GENERALLY
DRAPED ALONG THE OHIO RIVER REGION...WITH THE OUTLIER ECMWF
ALLOWING A BIT MORE SOUTHWARD PROGRESSION. GIVEN THE BUILDING
RIDGE THIS MORE SOUTHERN SOLUTION SEEMS TO BE LESS LIKELY BUT
WOULD TEND TO LEAN TOWARD A CONSENSUS BLEND APPROACH AT THIS
POINT. THIS WOULD LEAD TO BETTER CHANCES OF POPS ACROSS THE
NORTHERN PORTIONS OF EASTERN KENTUCKY...WHILE SLIGHT CHANCES WOULD
BE POSSIBLE ACROSS THE SOUTHERN HALF OF THE REGION. ONE THING TO
KEEP IN MIND IS OVERALL STEERING FLOW BECOMES QUIET WEAK ONCE THE
RIDGING BUILDS NORTH. THIS WILL LEAD TO POTENTIAL OF SLOW MOVING
STORMS AND LOCALLY HEAVY RAINFALL. THIS IS INDICATED WITH SOME
MODEL SOUNDING SUGGESTING PWATS NEAR THE 2.00 INCH MARK AND SLOWER
MEAN WINDS. WHILE TOWARD THE END OF THE LONG TERM THIS RIDGE
SHIFTS WEST ACROSS THE PLAINS LEADING TO BETTER CHANCES OF STORMS
IN THE EAST...WITH INCREASED POTENTIAL FOR SURFACE LOW/FRONTS AND
MCS/S MOVING SOUTHEAST INTO THE REGION.

GIVEN SUB TROPICAL/THERMAL RIDGE BUILDING ACROSS THE REGION EXPECT
OVERALL TEMPERATURES TO CLIMB TO NEAR AND ABOVE NORMAL THROUGH THE
PERIOD. THIS IS ALSO BACKED UP BY THE 6 TO 10 DAY FORECAST FROM
THE CPC.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 210 PM EDT MON JUL 6 2015

A FEW SHRA OR EVEN A STRAY TSRA MAY DEVELOP DURING THE FIRST 6
HOURS OF THE PERIOD...MAINLY IN THE FAR EAST AS A MID AND UPPER
LEVEL LOW DEPARTS. OTHERWISE...OUTSIDE OF ANY CONVECTION CIGS
SHOULD IMPROVE TO VFR IN ALL AREAS THROUGH 20Z. A BRIEF AREA OF
RIDGING WILL DOMINATE FOR MOST OF THE NIGHT AND FOG...DENSE IN
SOME AREAS...WILL DEVELOP IN VALLEYS BY 8Z AND THEN LIFT AND
DISSIPATE THROUGH 14Z. THE TAF SITES SHOULD BE AFFECTED...LOZ AND
SME FIRST AND THEN SJS...SYM AND JKL AS THE FOG LIFTS. AN
APPROACHING COLD FRONT SHOULD BRING ISOLATED TO SCATTERED
CONVECTION BY LATE IN THE PERIOD.


&&

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

$$

SHORT TERM...JP
LONG TERM...DJ
AVIATION...JP



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