Area Forecast Discussion
Issued by NWS Jackson, KY

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FXUS63 KJKL 211042
AFDJKL

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

.UPDATE...
ISSUED AT 637 AM EDT MON JUL 21 2014

THE FEW SPRINKLES OVER THE AREA HAS DISSIPATED THIS MORNING SO HAVE
TAKEN THEM OUT AND ADJUSTED FOR THE CURRENT OBSERVATIONS. DENSE FOG
STILL APPEARS TO BE LINGERING IN SOME SPOTS SO WILL LEAVE IT IN THE
FORECAST THROUGH THE MID MORNING HOURS. HAVE LOADED THE LATEST OBS
AND UPDATED THE ZFP TO TAKE OUT SPRINKLES AND UPDATE THIS MORNINGS
LOWS.

&&

.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 FOR 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 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 637 AM EDT MON JUL 21 2014

EXPECT THE LINGERING FOG TO 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. FOG WILL DEVELOP AGAIN TONIGHT AND WILL BE DENSE IN SOME
AREAS...ESPECIALLY AREAS THAT RECEIVE RAINFALL. WILL NEED TO PUT
BELOW IFR VISIBILITY VALUES IN THE TAFS.

&&

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

$$

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






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