Area Forecast Discussion
Issued by NWS Jackson, KY

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FXUS63 KJKL 250307 AAB
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON KY
1107 PM EDT SUN AUG 24 2014

.UPDATE...
ISSUED AT 1015 PM EDT SUN AUG 24 2014

A FEW SHOWERS AND A STRAY THUNDERSTORM THAT MOVED ACROSS PARTS OF THE
REGION EARLIER IN THE EVENING DISSIPATED IN THE LAST HOUR TO HOUR
AND A HALF. THE HOURLY POPS GENERALLY HAD THIS TREND AND WERE LEFT
UNCHANGED OVERNIGHT...BUT A FRESH ZFP WAS ISSUED. HOURLY TEMPERATURES...
DEWPOINTS AND WINDS WERE ADJUSTED TO ACCOUNT FOR RECENT TRENDS.
DEWPOINTS LINGER NEAR 70 OR IN THE LOWER 70S IN THE FAR SOUTHEASTERN
VALLEYS BUT HAVE DROPPED INTO THE 60S ON ADJACENT RIDGETOPS. SOME OF
THE SOUTHEAST RIDGETOPS. HOWEVER...AT LEAST AREAS OF FOG REMAIN AS
SEVERAL VALLEYS WILL LIKELY REMAIN DECOUPLED.

UPDATE ISSUED AT 735 PM EDT SUN AUG 24 2014

THE GRIDS WERE UPDATED RECENTLY TO ACCOUNT FOR THE VERY ISOLATED
SHOWER ACTIVITY NEAR THE VA BORDER AND IN THE BIG SANDY REGION. POPS
WERE ALSO ADJUSTED IN THE LAKE CUMBERLAND REGION WHERE A COUPLE OF
SHOWERS AND A THUNDERSTORM WILL CONTINUE TO CLIP THE SOUTHWEST PART
OF THE AREA OVER THE NEXT HOUR TO HOUR AND A HALF. THE ACTIVITY
HAS DEVELOPED AS LOW LEVEL MOISTURE REMAINS...DESPITE A CAP DUE TO
WARM TEMPERATURES ALOFT ASSOCIATED WITH A BUILDING UPPER LEVEL RIDGE.
THE ACTIVITY SHOULD WANE BY 9 TO 10 PM...HOWEVER...WITH THE LOSS OF
DAYTIME HEATING. OTHERWISE...SEVERAL LOCATIONS...ESPECIALLY VALLEY
LOCATIONS THAT RECEIVED HEAVIER RAINFALL OVER THE PAST COUPLE OF DAYS
SHOULD EXPERIENCE AREAS OF FOG OVERNIGHT. SOME OF THIS MIGHT BECOME
DENSE IN A FEW LOCATIONS IN THE BIG SANDY REGION NEAR WHERE SOME OF
THE HEAVIEST RAIN FELL ON FRIDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 300 PM EDT SUN AUG 24 2014

A STRONG UPPER LEVEL RIDGE CONTINUES TO RESIDE OVER THE GULF
REGION...NORTHWARD INTO THE OHIO RIVER VALLEY. THIS RIDGE HAS
STRENGTHENED SINCE YESTERDAY WITH WARMER MID LEVEL TEMPERATURES. THIS
HAS ESSENTIALLY CREATED A CAP ACROSS THE AREA. WHILE INSTABILITY HAS
INCREASED ENOUGH...THIS CAP IS HOLDING MORE ROBUST DEVELOPMENT AT
BAY. A FEW WIDELY ISOLATED SHOWERS ARE ATTEMPTING TO POP UP ACROSS
FAR SOUTHEAST KENTUCKY...BUT WITH THE WARM MID LEVEL AIR...ARE HAVING
A TOUGH TIME SUSTAINING THEMSELVES. GIVEN THE TRENDS...HAVE OPTED TO
REMOVE THUNDER THROUGH THE REST OF THE DAY.

DEWPOINTS HAVE MIXED OUT A BIT BETTER THIS AFTERNOON WITH SOME MID TO
UPPER 60S SHOWING UP ACROSS THE AREA. THIS WILL ALLOW FOR A COOLER
NIGHT WITH LOWS WELL INTO THE 60S...ESPECIALLY IN THE VALLEYS...WHERE
A FEW LOWER 60 VALUES CANNOT BE DISCOUNTED.

THE RIDGE WILL HOLD ACROSS THE AREA THROUGH TOMORROW AND TOMORROW
NIGHT YIELDING MUCH OF THE SAME WITH ANOTHER SLIGHT CHANCE OF A ROGUE
SHOWER ACROSS SOUTH/SOUTHEAST KENTUCKY MONDAY AFTERNOON. DEWPOINTS
MAY MIX OUT A BIT BETTER TOMORROW AFTERNOON...AND COULD YIELD LOWS A
BIT COOLER FOR MONDAY NIGHT WITH THE COLDEST VALLEYS POSSIBLY
REACHING THE UPPER 50S.

TONIGHT AND MONDAY NIGHT WILL CONTINUE TO FEATURE PLENTY OF VALLEY
FOG...WHICH IS FAIRLY TYPICAL FOR THIS TIME OF YEAR.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 300 PM EDT SUN AUG 24 2014

THE MODELS START OUT IN FAIR AGREEMENT ALOFT FOR THE EXTENDED PART
OF THE FORECAST BEFORE THE SIMILARITIES IN THE FLOW BREAK DOWN LATE.
A LARGE RIDGE OVER MUCH OF THE NATION/S MIDSECTION WILL START TO
WEAKEN THROUGH THE WORK WEEK AS FAST FLOW RIPPLES WAVES OF ENERGY
OVER ITS NORTHERN EXTENT. THIS HAPPENS TO BE RIGHT THROUGH THE
SOUTHERN PORTION OF THE OHIO VALLEY. FOR THE WEEKEND...AN
APPROACHING TROUGH OVER THE PLAINS...MORE ROBUST IN THE ECMWF THAN
THE GFS...WILL START TO FILL AND SEND ADDITIONAL WAVES OF ENERGY
THROUGH THE REGION. THE ECMWF MAINTAINS THIS AS A DISTINCT FEATURE
INTO THE WEEKEND AS IT THROWS OFF ENERGY AND EASES INTO THE OHIO
VALLEY. THE GFS...IN CONTRAST...HAS MUCH HIGHER HEIGHTS FOR THE AREA
DURING THE WEEKEND AND JUST A HINT OF TROUGHINESS MOVING PAST TO THE
NORTH. FAVOR THE BLENDED SOLUTION THROUGH THE FIRST PART OF THE
EXTENDED BEFORE LEANING MORE TOWARD THE ECMWF/S SOLUTION OVER THE
WEEKEND.

SENSIBLE WEATHER WILL FEATURE A LIKELY DRY START TO THE EXTENDED
UNDER THE AEGIS OF THE STILL STRONG UPPER RIDGE AND SOUTHEAST SFC
HIGH. THE STORM TRACK WILL BE FOUND OVER THE NORTHERN OHIO VALLEY.
THE PROTECTION BREAKS DOWN BY WEDNESDAY AFTERNOON ALLOWING SHOWERS
AND THUNDERSTORMS TO RETURN TO THE AREA...BUOYED BY DIURNAL HEATING
AND INSTABILITY. THE CHANCES FOR CONVECTIVE ACTIVITY WILL CONTINUE
INTO THURSDAY THANKS TO THE ENERGY ALOFT AND ANOTHER WAVY FRONTAL
BOUNDARY LAID OUT FROM WEST TO EAST JUST NORTH OF THE CWA. A SFC LOW
SEEN BY THE ECMWF ASSOCIATED WITH THAT GREAT PLAINS TROUGH MAY PULL
THE FRONT SOUTHWEST THROUGH THIS PART OF THE STATE INTO THE DAY
FRIDAY EVENTUALLY LESSENING CHANCES OF SHOWERS AND STORMS BEFORE
RETURNING LATE IN THE DAY WITH RENEWED THREATS THAT WILL LAST INTO
THE WEEKEND GIVEN THE SFC LOW/S EXPECTED PROXIMITY AND ITS NEARBY
FRONTAL BOUNDARIES. THE NEW ECMWF IS SHOWING A SURGE OF BETTER
MOISTURE DURING THE DAY SUNDAY AS THE GULF IS TAPPED AND THAT MAY
BRING ABOUT CONCERNS FOR HEAVY RAIN BY THE END OF THE WEEKEND.
HOWEVER...FOR THE BULK OF THE EXTENDED PORTION OF THE FORECAST THE
MOISTURE SHOULD BE LOWER THAN WE HAVE EXPERIENCED OF LATE WHILE
TEMPERATURES ADHERE TO THEIR SEASONAL NORMS.

THE CR GRID LOAD PROVIDED A GOOD START TO THE FORECAST FOR THE
EXTENDED...THOUGH DID GIVE IT MORE OF A DIURNAL TREND IN THE HOURLY
GRIDS. ALSO...MADE THEM DRIER ON THURSDAY NIGHT AND A BIT WETTER
LATER FRIDAY. ALSO...ADJUSTED THE LOW TEMPERATURE GRIDS EACH NIGHT
TO BETTER REFLECT RIDGE AND VALLEY DIFFERENCES THAT WILL PROBABLY BE
MORE SIGNIFICANT ON TUESDAY NIGHT AND AGAIN FRIDAY NIGHT.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 743 PM EDT SUN AUG 24 2014

THE TAF LOCATIONS SHOULD EXPERIENCE VFR CONDITIONS ON AVERAGE TO
START THE PERIOD AND THE BULK OF THE NEXT 24 HOURS. THE ONLY
EXCEPTION TO THIS DURING THE FIRST HOUR OF THE PERIOD WOULD BE SOME
MVFR VIS OR CIGS WHERE ANY OF THE VERY ISOLATED SHOWERS OCCUR. CLEAR
OR CLEARING SKIES SHOULD STILL GIVE WAY TO SOME FOG IN THE VALLEYS
LATE TONIGHT. SOME OF THIS VALLEY FOG MAY LIFT INTO JKL AND
ESPECIALLY SJS. OVERALL...WE HAVE CONTINUED TO GO WITH SIMILAR
CONDITIONS TO LAST NIGHT WITH JKL...LOZ AND SME REACHING MVFR VIS IN
FOG FROM ABOUT 9Z TO 13Z. THE EXCEPTION REMAINS KSJS...WHERE VIS
DROPPED BELOW AIRPORT MINS LAST NIGHT AND MAY AGAIN TONIGHT BETWEEN
8Z AND 13Z.


&&

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

$$

UPDATE...JP
SHORT TERM...KAS
LONG TERM...GREIF
AVIATION...JP





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