Area Forecast Discussion
Issued by NWS Jackson, KY

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000
FXUS63 KJKL 210828
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
428 AM EDT MON JUL 21 2014

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 342 AM EDT MON JUL 21 2014

A VERY WARM...MOIST...AND UNSTABLE SHORT TERM PERIOD LOOKS TO BE THE
SCENARIO FOR EASTERN KENTUCKY. CONDITIONS ACROSS THE AREA AS OF 07Z
FEATURE SOME FOG DEVELOPMENT IN THE DEEPER VALLEYS. THIS IS MAINLY
WHERE SKIES HAVE CLEARED OUT FROM THE CLOUD COVER ASSOCIATED WITH
THE PREVIOUS EVENINGS CONVECTION. WHERE THIS HAS OCCURRED...MAY NEED
SOME HEADLINE ISSUED FRO THE DENSE FOG DEVELOPMENT. CLOUD COVER
SHOULD REMAIN PRETTY PERSISTENT INTO THE MORNING OVER THE EAST. LOWS
ONLY DROPPING INTO THE MID 60S THIS MORNING ALONG WITH MID 60
DEW POINTS WILL MAKE FOR A RATHER UNCOMFORTABLE MORNING. EVEN
NOW...WITH THIS JUICY AIR MASS...A FEW WEAK SHOWERS ARE STILL
DEVELOPING MAINLY OVER THE EAST.

THE DEVELOPMENT OF THIS SCENARIO LIES WITH A PINCHED OFF UPPER LOW
THAT WILL BECOME CUT OFF FROM THE UPPER LEVEL FLOW OVER THE NORTHERN
CONUS. THE MODELS CONTINUE TO SHOW THIS FEATURE ENHANCING CONVECTION
ACROSS THE SOUTHEAST BUT ALSO INTO THE APPALACHIAN REGION. THIS ALONG
WITH THE UPPER LEVEL RIDGE OVER THE SOUTHEAST SLIDING EAST INTO THE
BAHAMAS ALLOWS FOR AN INCREASED SOUTHERLY RETURN FLOW INTO THE
SOUTHEASTERN CONUS AND INTO THE APPALACHIANS. THIS PATTERN CONTINUES
TO LEAVE EASTERN KENTUCKY UNDER VERY WEAK FLOW.

THAT SAID...LOOKING AT THE LOWER LEVELS...BOTH THE GFS AND NAM AGREE
WITH QUITE A BIT OF INSTABILITY AVAILABLE WITH CAPE VALUES REACHING
2500 J/KG BOTH THIS AFTERNOON AND TUESDAY AFTERNOON...THIS WITH PWATS
IN THE 1.50 TO 1.75 INCH RANGE BOTH DAYS AND WEAK FLOW WILL LEAD TO
SOME CONCERNS WITH SLOW MOVING STORMS PRODUCING HEAVY RAIN. THE ONE
SAVING GRACE HERE IS THE UPPER DISTURBANCE IS STILL CENTERED OVER THE
GULF COAST STATES BUT SOME ENERGY FROM THE LOW ON THE NORTHERN FRINGE
LOOKS TO MAKE IT INTO THE CENTRAL APPALACHIAN CHAIN AND INTO SOUTHEASTERN
KENTUCKY. THIS UNCERTAINTY WITH A GOOD TRIGGER HERE KEEPS FROM GOING
LIKELY POPS BUT STILL WILL KEEP SLIGHT CHANCE TO CHANCE FROM WEST TO
EAST AND GOING WITH AERIAL COVERAGE BOTH DAYS AS WITH THE TYPE OF
MOIST AND UNSTABLE AIR MASS IN PLACE...NOT MUCH SUPPORT IS NEEDED FOR
STORM DEVELOPMENT. MAY NEED TO MENTION SOME THREAT OF SLOW MOVING
STORMS IN THE HWO...MAINLY FOR TUESDAY WITH THE BETTER SUPPORT MAKING IT
INTO THE AREA.

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 428 AM EDT MON JUL 21 2014

MODELS ARE IN GOOD AGREEMENT FOR THE PERIOD. ON TUESDAY EVENING SE KY
WILL BE ON THE FRINGE OF AN AREA OF DEEP MOISTURE OVER THE SE CONUS
ASSOCIATED WITH AN UPPER LOW/TROUGH. FEATURES WILL BE WEAK...AND ANY
CONVECTIVE PRECIP SHOULD BE POORLY ORGANIZED SHOULD SHOW A STRONG
DIURNAL TREND. HAVE CARRIED A SLIGHT CHANCE POP FOR ANY PRECIP WHICH
MAY LINGER INTO THE EVENING IN OUR SE COUNTIES.

ON WEDNESDAY...A LARGE MID/UPPER LEVEL TROUGH DROPPING INTO THE NE
CONUS WILL SEND ITS ASSOCIATED COLD FRONT SE INTO KY. THE FRONT WILL
SLOWLY TRANSITION ACROSS THE APPALACHIANS...EMERGING OVER VA AND THE
CAROLINAS FRIDAY. THERE WILL BE A PROLONGED ENHANCEMENT OF POPS FROM
WEDNESDAY THROUGH THURSDAY OVER THE JKL FORECAST AREA...BEFORE DRIER
AIR FINALLY MAKES IT WAY IN FROM THE NORTH BEHIND THE FRONT. DRY
WEATHER IS EXPECTED FROM LATE FRIDAY INTO SATURDAY AS HIGH PRESSURE
MOVES THROUGH THE OHIO VALLEY.

BY SUNDAY...LOW LEVEL FLOW SHOULD AGAIN CARRY A MORE HUMID AIR MASS
BACK INTO THE REGION. AT THE SAME TIME...WHAT WILL BECOME A
SIGNIFICANT UPPER LEVEL TROUGH WILL START TO DEEPEN OVER THE GREAT
LAKES AND OHIO VALLEY. THE COMBINATION WILL RESULT IN ANOTHER
POTENTIAL FOR SHOWERS AND THUNDERSTORMS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 138 AM EDT MON JUL 21 2014

WITH DECREASING CLOUD COVER AND COOLING TEMPS...FOG WILL BEGIN TO
DEVELOP TOWARDS DAWN...ESPECIALLY WHERE THE HEAVY RAINFALL HAS
PREVIOUSLY OCCURRED. WITH THIS...HAVE PUT SOME BELOW IFR VISIBILITY
AND CEILINGS AT THE TAF SITES TONIGHT. A FEW SPRINKLES WILL CONTINUE
ACROSS THE AREA INTO THE MORNING HOURS BUT SHOULD NOT BE A CONCERN TO
THE TAF SITES. HEADING INTO TOMORROW...FOG SHOULD LIFT BY 14 AND 15Z.
A WEAK DISTURBANCE OVERHEAD ALONG WITH SIGNIFICANT INSTABILITY WILL
ALLOW FOR SHOWERS AND THUNDERSTORMS TO DEVELOP AGAIN INTO THE
AFTERNOON AND INTO THE EVENING. COVERAGE AT THIS POINT APPEARS TO BE
IN QUESTION AND SHOWING SOME CONFIDENCE IN THUNDERSTORMS APPEARING AT
THE TAF SITES IS NOT POSSIBLE. WILL LEAVE THUNDERSTORMS OUT OF THE
TAFS BUT MENTION THE PRESENCE IN THE AFD. WINDS WILL BE LIGHT AND
VARIABLE THROUGH THE PERIOD.


&&

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

$$

SHORT TERM...SHALLENBERGER
LONG TERM...HAL
AVIATION...SHALLENBERGER






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