Area Forecast Discussion
Issued by NWS Huntsville, AL

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000
FXUS64 KHUN 232103
AFDHUN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
403 PM CDT WED JUL 23 2014

.DISCUSSION...
A BROKEN LINE OF SHOWERS AND THUNDERSTORMS CONTINUE TO SLOWLY PUSH
SOUTH THROUGH CULLMAN...MARSHALL...AND DEKALB COUNTIES. ADDITIONAL
SCATTERED STRONG AND MARGINALLY SEVERE STORMS CONTINUE TO DEVELOP
OVER LAUDERDALE COUNTY AT THIS TIME AS WELL. IN BETWEEN ACTIVITY HAS
MOSTLY DISSIPATED AS THE ATMOSPHERE HAS BEEN WORKED OVER BY EARLIER
CONVECTION.

THIS ACTIVITY HAS FORMED ALONG A PREFONTAL TROUGH AXIS AHEAD OF THE
MAIN COLD FRONT WHICH CURRENTLY STRETCHES FROM SOUTHERN OHIO
SOUTHWEST INTO NORTHERN MISSOURI. EXPECT SCATTERED TO LIKELY SHOWERS
AND STORMS TO CONTINUE THIS EVENING...WITH LIKELY COVERAGE OVER
EXTREME NW ALABAMA.

RUC13 HAS HAD A GOOD HANDLE ON CONVECTION SO FAR. MODELS ALL SHOW THE
MAIN COLD FRONT APPROACHING SOUTHERN MIDDLE TENNESSEE AROUND
MIDNIGHT. BOTH GFS40 AND RUC13 SHOW A MORE CONCENTRATED AREA OF
SHOWERS AND THUNDERSTORMS REDEVELOPING AHEAD OF THIS FRONT BETWEEN 2
AM AND 7 AM...ALTHOUGH GFS40 DISSIPATES THIS ACTIVITY QUICKLY TOWARDS
DAYBREAK. RUC13 LOOKS MORE REASONABLE AND KEEPS THIS ACTIVITY GOING
WHILE SHIFTING IT SOUTHWARD TOWARD THE TENNESSEE RIVER DURING THE
MORNING HOURS ON THURSDAY. PWATS REMAIN BETWEEN 1.5 AND 1.8 INCHES
OVERNIGHT INTO TUESDAY MORNING AHEAD OF THE FRONT AND WITH CAPE
VALUES ALOFT REMAINING AROUND 1000 J/KG...THUS THE RUC13 POPS SEEM
MORE REASONABLE. LOCALLY HEAVY RAINFALL CAUSING SOME FLASH FLOODING
IS POSSIBLE...ESPECIALLY WITH WEAK FLOW EXPECTED UPSTREAM OF THE
FRONT AND POSSIBLE TRAINING OF STORMS.

DRIER AIR WILL PUSH INTO THE AREA FROM THE NORTHWEST TUESDAY
MORNING. THUS TAPERED POPS DOWN FROM SOUTHEAST TO NORTHWEST DURING
THE AFTERNOON HOURS...TAKING OUT POPS ENTIRELY FOR EXTREME NW
ALABAMA. KEPT A 60 POP MAINLY SOUTH OF THE TENNESSEE RIVER THURSDAY
MORNING INTO THE AFTERNOON HOURS...WITH LOWER ISOLATED TO SCATTERED
POP TO THE NORTHWEST. LOCALLY HEAVY RAINFALL CAUSING FLASH FLOODING
WILL REMAIN POSSIBLE THROUGH THE DAY ON THURSDAY...MAINLY SOUTH OF
THE TENNESSEE RIVER. CLOUDS AND PRECIPITATION SHOULD MAKE FOR A COOL
DAY ON THURSDAY WITH HIGHS ONLY CLIMBING INTO THE LOWER TO MID 80S.

EXPECT SHOWERS AND STORMS TO END BY LATE THURSDAY AFTERNOON...AS THE
FRONT SHIFTS SOUTH OF THE CULLMAN COUNTY. A FEW CLOUDS COULD LINGER
INTO THURSDAY NIGHT.

DESPITE THE FRONTAL PASSAGE...COOLER AIR DOES NOT PUSH INTO THE AREA
BEHIND THE FRONT. DRIER AIR WILL...BUT AN UPPER RIDGE BEHIND THE
FRONT SHOULD RAISE HIGH TEMPERATURES BACK INTO THE LOWER 90S QUICKLY
ON FRIDAY. MODELS CONTINUE TO BUILD THIS RIDGE IN FROM THE WEST
THROUGH SUNDAY...BEFORE ANOTHER COLD FRONT APPROACHES THE AREA
SATURDAY NIGHT INTO SUNDAY. SHOWER AND THUNDERSTORM CHANCES INCREASE
AHEAD OF THIS SYSTEM AGAIN SUNDAY NIGHT INTO MONDAY. STRONGER SHEAR
CONTINUES TO BE SHOWN BY MODELS AND THIS WILL LIKELY INCREASE THE
POSSIBILITY OF STRONGER TO SEVERE STORMS DEVELOPING.

VERY COOL AIR COULD MOVE INTO THE AREA BEHIND THIS SYSTEM EARLY NEXT
WEAK. LOWERED HIGH TEMPERATURES MONDAY AND TUESDAY TO REFLECT THIS.

KTW

&&

.AVIATION...
/ISSUED 1247 PM CDT WED JUL 23 2014/
FOR 18Z TAFS...COMBINATION OF WEAK SFC BOUNDARY AND UPPER LEVEL
TROUGH WILL MAINTAIN UNSETTLED WEATHER ACROSS THE REGION OVER THE
NEXT 48 HOURS. AT BOTH TAF SITES HAVE KEPT PREDOMINANT VFR CONDITIONS
WITH VICINITY SHOWERS THROUGH THE PERIOD TO ACCOUNT FOR UNCERTAINTY.
ALSO KEPT A WINDOW OF THUNDERSTORM POTENTIONAL WITH MVFR VSBYS
THROUGH MID AFTN AT KHSV BASED ON CURRENT RADAR AND MESOSCALE TRENDS.
MODEL GUIDANCE INDICATES A HIGH PROBABILITY OF CONVECTION LATE
TONIGHT/EARLY THURSDAY AND INCLUDED A WINDOW OF MVFR CONDITIONS DUE
TO THUNDERSTORMS DURING THAT PERIOD. OVERALL WIND FIELD SHOULD BE
LIGHT ASIDE FROM BRIEFLY TURBULENT WITHIN/NEAR THUNDERSTORMS.

15

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    72  83  65  91 /  60  60  10  10
SHOALS        72  84  64  92 /  60  30  10  10
VINEMONT      70  83  67  90 /  60  60  10  10
FAYETTEVILLE  70  81  64  89 /  60  30  10  10
ALBERTVILLE   73  83  66  91 /  60  60  10  10
FORT PAYNE    68  83  65  91 /  60  60  10  10

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

$$

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE
AT WEATHER.GOV/HUNTSVILLE.



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