Severe Thunderstorm Warning 91, NWS Huntsville, AL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
226 PM CDT TUE JUL 14 2015

.DISCUSSION...
THE 19Z SURFACE ANALYSIS AND IR/VISIBLE SATELLITE IMAGERY INDICATED
THAT A SHORT WAVE WAS MOVING INTO NORTHEAST ARKANSAS WITH A BOUNDARY
ANALYZED TO BE EXTENDING MORE WEST TO EAST ACROSS MIDDLE TENNESSEE. A
BROKEN LINE OF SHOWERS/STORMS WAS QUICKLY DEVELOPING IN THE UNSTABLE
ENVIRONMENT WITH DEWPOINTS POOLING INTO THE MID-UPPER 70S ALONG AND
SLIGHTLY AHEAD OF MIDDLE TENNESSEE INTO NORTHERN ALABAMA. EXPECT THAT
STORMS WILL CONTINUE TO DEVELOP AS THE BOUNDARY MOVES SOUTH-SOUTHEAST
TOWARD THE FORECAST AREA. FORECAST SOUNDINGS INDICATE A VERY
UNSTABLE ENVIRONMENT WITH CAPE VALUES APPROACHING 5000 J/KG ALONG
WITH LIFTED INDICES AT AROUND -10 THROUGH 00Z.

THE RUC/HRRR MODELS PUSH THE BROKEN LINE OF EXPECTED STRONG/SEVERE
STORMS THROUGH THE SEVERE THUNDERSTORM WATCH AREA IN SOUTHERN MIDDLE
TENNESSEE BY BETWEEN 22Z-23Z AND INTO NORTHERN ALABAMA. MONITORING
THE REST OF THE FORECAST AREA FOR EXPANDING THE SEVERE THUNDERSTORM
WATCH THAT IS IN EFFECT FOR SOUTHERN MIDDLE TENNESSEE NOW UNTIL 02Z
TONIGHT. THE SHORT TERM MODELS HAVE BEEN CONSISTENT THE PAST FEW
HOURS IN MOVING THE STORMS SOUTHEAST AND JUST ABOUT OUT OF THE
FORECAST AREA BY AROUND 05Z TONIGHT. WILL CONTINUE WITH THE SOLUTION
OF THE NAM MODEL INVOLVING DEVELOPMENT OF A SECONDARY AREA OF
SHRA/TSRA BY AROUND 09Z IN SOUTHERN MIDDLE TENNESSEE...WHICH SHOULD
ALSO DROP SOUTH-SOUTHEAST THROUGH THE FORECAST AREA BETWEEN THE 15Z-
18Z WEDNESDAY TIME FRAME. SUBSIDENCE AND LOW-MID LEVEL DRYING SHOULD
TAKE PLACE IN THE WAKE OF THIS WEAK BOUNDARY MOVING THROUGH THE
FORECAST AREA AFTER 18Z WEDNESDAY.

WILL CONTINUE WITH JUST ISOLATED SHRA/TSRA ON THURSDAY WITH LIMITED
MOISTURE/TRIGGER ACROSS THE FORECAST AREA. THE MODELS ARE SIMILAR IN
BUILDING BACK IN THE UPPER RIDGE MORE TOWARD THE FORECAST AREA BY
FRIDAY...WITH JUST ISOLATED/WIDELY SCATTERED SHRA/TSRA EXPECTED
THROUGH THE UPCOMING WEEKEND AND INTO EARLY NEXT WEEK. TEMPS WILL
CONTINUE TO BE HOT THROUGH THE EXTENDED FORECAST PERIOD...AND WILL GO
WITH A COMPROMISE BETWEEN THE GFS/ECMWF TEMP MODEL GUIDANCE.

TT

&&

.AVIATION...
/ISSUED 1248 PM CDT TUE JUL 14 2015/
FOR 18Z TAFS...
THUNDERSTORMS FORMING ALONG THE TN/KY BORDER THIS AFTERNOON ARE
FORECAST TO MOVE S/SE INTO NORTHERN ALABAMA AROUND 22Z. UPPER LEVEL
WINDS OUT OF THE N/NW...STORMS SHOULD PUSH SOUTH OF THE AREA BETWEEN
02-03Z. WIND GUSTS UPWARDS OF 60KTS...FREQUENT LIGHTNING AND HAIL UP
TO ONE INCH WILL BE POSSIBLE WITH ANY OF THESE STORMS. AN UPPER
LEVEL SYSTEM DROPPING S/SE OUT OF THE GREAT LAKES REGION COULD BRING
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS THROUGH THE AREA EARLY
WEDNESDAY MORNING. HOWEVER...CONFIDENCE ON THIS IS LOW AND HAVE LEFT
THE MENTION OF VCSH'S AROUND 10Z WEDNESDAY.

INCREASED SW WINDS ARE EXPECTED AT BOTH TERMINALS TODAY WITH SPEEDS
AROUND 12KTS AND GUSTS UP TO 20KTS POSSIBLE. WINDS SHOULD BEGIN TO
DECREASE TOWARDS THE END OF THE TAF PERIOD AS THE UPPER LEVEL SYSTEM
MOVES FURTHER EAST OF THE AREA.

STUMPF

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    75  97  72  96 /  50  30  10  20
SHOALS        75  97  72  96 /  50  30  10  10
VINEMONT      73  94  71  93 /  50  30  10  10
FAYETTEVILLE  72  92  70  91 /  50  30  10  10
ALBERTVILLE   73  93  71  92 /  50  30  10  10
FORT PAYNE    71  92  69  91 /  50  30  10  10

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ALZ001>007-016.

TN...NONE.
&&

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

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
258 PM CDT TUE JUL 14 2015

ALZ001>010-016-TNZ076-096-097-151000-
LAUDERDALE-COLBERT-FRANKLIN AL-LAWRENCE-LIMESTONE-MADISON-MORGAN-
MARSHALL-JACKSON-DEKALB-CULLMAN-MOORE-LINCOLN-FRANKLIN TN-
258 PM CDT TUE JUL 14 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH ALABAMA AND PORTIONS
OF SOUTHERN MIDDLE TENNESSEE.

.DAY ONE...TONIGHT...

A HEAT ADVISORY REMAINS IN EFFECT THROUGH 7 PM CDT TONIGHT FOR
PORTIONS OF NORTHWESTERN AND NORTH CENTRAL ALABAMA. HEAT INDICES ARE
LIKELY TO EXCEED 105 DEGREES THIS AFTERNOON ESPECIALLY WEST OF
INTERSTATE 65.

THUNDERSTORMS WILL CONTINUE TO DEVELOP THROUGH THE AFTERNOON AND
CONTINUE THROUGH THE EVENING. SOME STORMS COULD BE STRONG TO SEVERE
WITH DAMAGING WIND GUSTS AS THE MAIN SEVERE WEATHER THREAT. LOCALLY
VERY HEAVY RAINFALL WITH FLASH FLOODING AND HAIL UP TO THE SIZE
QUARTERS MAY ALSO BE POSSIBLE. THE SEVERE WEATHER THREAT WILL BEGIN
TO TAPER OFF AFTER MIDNIGHT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY...

A FEW THUNDERSTORMS WILL BE POSSIBLE ON WEDNESDAY MORNING AND
AFTERNOON BUT SEVERE WEATHER IS NOT EXPECTED. AFTER
WEDNESDAY...ISOLATED TO SCATTERED THUNDERSTORMS MAINLY DURING THE
AFTERNOON AND EVENING WILL CONTINUE THROUGH MONDAY. THE STRONGER
STORMS DURING THIS PERIOD WILL BE CAPABLE OF PRODUCING STRONG WIND
GUSTS BUT THE THREAT FOR WIDESPREAD SEVERE WEATHER WILL BE LOW.

OTHERWISE...TEMPERATURES WILL CONTINUE TO BE HOT THROUGH THE PERIOD
WITH HEAT INDICES GENERALLY AROUND 100 TO 105 DEGREES DURING THE
AFTERNOON EACH DAY. ADDITIONAL HEAT ADVISORIES MAY BE NECESSARY LATER
IN THE WEEK.

.SPOTTER CALL TO ACTION STATEMENT...

ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT PERSONNEL IS
EXPECTED THROUGH THIS AFTERNOON AND EVENING.

TT