Hail and Damaging Winds in Alabama, April 5, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
650 AM CDT THU APR 5 2012

.UPDATE...AVIATION DISCUSSION.

&&

.DISCUSSION...

CLOSED UPPER LEVEL LOW HAS PROGRESSED TOWARDS THE OKLAHOMA AND
ARKANSAS BORDER AS SEEN ON CURRENT WATER VAPOR IMAGERY. STORMS ARE
CURRENTLY FORMING NEAR THE MISSISSIPPI RIVER ALONG THE ARKANSAS AND
MISSISSIPPI BORDER. CURRENT OBS INDICATE SOME SURFACE CONVERGENCE
ALONG THIS BOUNDARY AIDING IN THE STORMS DEVELOPMENT COUPLED WITH A
60 KT MID LEVEL JET INDICATED BY PROFILERS IN THIS AREA.

EXPECT SHOWERS AND THUNDERSTORMS TO ENTER WESTERN ALABAMA EARLY THIS
MORNING SHORTLY AFTER SUNRISE. MODELS INDICATE THAT THE BEST LIFT
WILL BE OVER THE SOUTHERN HALF OF THE FORECAST AREA AS A SHORTWAVE
TROUGH ROTATES THROUGH THE UPPER LEVEL LOW. LARGE SCALE LIFT WILL BE
IN PLACE WITH DIVERGENT AND DIFFLUENT FLOW ALOFT AS A 50-60 KT MID
LEVEL JET AND 70-80 KT 300 MB JET NOSES INTO THE STATE DURING THE
EARLY MORNING HOURS. DEEP LAYER 0-6 KM BULK SHEAR VALUES WILL BE
NEAR 50 KTS WHICH WOULD SUPPORT ORGANIZED UPDRAFTS. THE WEAK SURFACE
BOUNDARY WILL ALSO HELP IN PROVIDING SOME SURFACE CONVERGENCE.
FORECAST MLCAPE VALUES OF 1000 TO 1500 J/KG SHOULD BE SUPPORTIVE FOR
STORMS TO INITIATE. MODELS SOUNDINGS INDICATE A UNIDIRECTIONAL SHEAR
PROFILE WITH WEAK BOUNDARY LAYER FLOW. THEREFORE...EXPECT THE
TORNADO THREAT TO REMAIN VERY LOW. THE MAIN THREATS WITH ANY STORMS
WILL BE LARGE HAIL AND DAMAGING WINDS.

AROUND 18Z THE UPPER LEVEL LOW WILL BE LOCATED NEAR MEMPHIS. THE LOW
WILL CONTINUE TO DIVE SOUTHEAST ACROSS THE FORECAST AREA DURING THE
AFTERNOON HOURS. LAPSE RATES WILL STEEPEN ALOFT THIS AFTERNOON AND
EVENING ACROSS THE FORECAST AREA WITH 500 MB TEMPERATURES OF -16 TO
-20 C AND MID LEVEL LAPSE RATES NEAR 7 C/KM. MODELS STILL VARY ON
THE AMOUNT OF MOISTURE AND INSTABILITY AVAILABLE AFTER THE MORNING
AND EARLY AFTERNOON CONVECTION. HOWEVER...CONTINUED CHANCES FOR
SHOWERS AND THUNDERSTORMS INTO THE EVENING WITH THE MAIN THREATS
BEING LARGE HAIL AND DAMAGING WINDS. SHOWERS AND THUNDERSTORMS
SHOULD COME TO AN END LATE THIS EVENING AS THE UPPER LEVEL LOW
CONTINUES TO PROGRESS TO THE SOUTH AND EAST.

NICE WEATHER WILL BE IN STORE FOR THE UPCOMING WEEKEND AS A RIDGE
BUILDS IN ACROSS THE SOUTHEAST. WITH NORTHWESTERLY FLOW ALOFT COOLER
AND DRY CONDITIONS WILL BE IN STORE WITH HIGHS IN THE 70S AND LOW IN
THE 40S AND 50S.

EARLY NEXT WEEK AN AMPLIFIED UPPER LEVEL TROUGH WILL DIVE OUT OF
SOUTHERN CANADA. AT THIS TIME EXPECT THE FRONT TO COME THROUGH
CENTRAL ALABAMA DRY. MUCH COLDER AIR WILL MOVE IN BEHIND THE FRONT
WITH FORECAST LOWS IN THE 40S AREA WIDE TUESDAY AND WEDNESDAY
MORNING. WILL HAVE TO CONTINUE TO MONITOR TEMPERATURES FOR THE
MIDDLE PART OF NEXT WEEK.

ANDERSON

&&

.AVIATION...
12Z TAF DISCUSSION.

LARGE UPPER LOW SPINNING OVER WESTERN ARKANSAS WILL TRIGGER NUMEROUS
SHOWERS AND TSTMS ACROSS CENTRAL ALABAMA AS IT TRACKS EASTWARD
TOWARDS ALABAMA.  THERE HAS BEEN SOME LCL IFR VSBYS DUE TO FOG...BUT
THIS SHOULD CLEAR BY 13Z.

FORECAST WILL BE DIFFICULT TODAY DUE TO THE TIMING OF THE CLUSTERS
OF CONVECTION DEVELOPING AHEAD OF UPPER LOW. THE MAJORITY OF THE
CONVECTION SHOULD BE AFFECT TAF SITES BETWEEN 15Z AND 21Z...AND
INCLUDED TEMPO TSRA DURING THIS TIME FRAME.  ANY OF THE STORMS THIS
AFTERNOON AND EVENING WILL HAVE THE CHANCE TO PRODUCE LARGE HAIL. AS
THE CENTER OF THE UPPER LOW PASSES ACROSS CENTRAL ALABAMA BETWEEN
00Z AND 06Z...THERE COULD BE ANOTHER ROUND OF STORMS PRODUCING LARGE
HAIL.  NORTHWEST WINDS OF 5-10 KNOTS AND DRIER AIR BEHIND EXITING
UPPER LOW SHOULD KEEP CIGS ABOVE 3000 FEET AGL AND VSBYS AOA 5 MILES
AFTER 06Z.

58/ROSE

&&

.PRELIMINARY POINT TEMPS/POPS...
GADSDEN     77  49  72  46  74 /  70  30  10   0   0
ANNISTON    78  52  72  47  74 /  70  40  10   0   0
BIRMINGHAM  78  51  73  50  74 /  70  30  10   0   0
TUSCALOOSA  80  52  75  49  76 /  70  20   0   0   0
CALERA      79  53  74  51  75 /  70  30  10   0   0
AUBURN      78  55  72  50  73 /  70  30  10   0   0
MONTGOMERY  80  55  76  52  76 /  70  30  10   0   0
TROY        78  54  76  49  74 /  80  30  10   0   0

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BIRMINGHAM AL
544 AM CDT THU APR 5 2012

ALZ011>015-017>050-061045-
AUTAUGA-BARBOUR-BIBB-BLOUNT-BULLOCK-CALHOUN-CHAMBERS-CHEROKEE-
CHILTON-CLAY-CLEBURNE-COOSA-DALLAS-ELMORE-ETOWAH-FAYETTE-GREENE-HALE-
JEFFERSON-LAMAR-LEE-LOWNDES-MACON-MARENGO-MARION-MONTGOMERY-PERRY-
PICKENS-PIKE-RANDOLPH-RUSSELL-SHELBY-ST CLAIR-SUMTER-TALLADEGA-
TALLAPOOSA-TUSCALOOSA-WALKER-WINSTON-
544 AM CDT THU APR 5 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE COUNTIES SERVED BY THE
NATIONAL WEATHER SERVICE OFFICE IN BIRMINGHAM.

.DAY ONE...TODAY AND TONIGHT.

SEVERE STORMS WILL BE POSSIBLE TODAY AND TONIGHT FOR ALL OF CENTRAL
ALABAMA. THE MAIN THREATS WILL BE LARGE HAIL...DAMAGING WINDS AND
LOCALLY HEAVY RAINFALL. THE THREAT OF TORNADOES IS VERY LOW AT
THIS TIME. THERE MAY BE MORE THAN ONE WAVE OF STORMS THAT MOVE
THROUGH CENTRAL ALABAMA THROUGHOUT THE DAY BETWEEN THE HOURS OF
10 AM AND 10 PM.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT MAY BE
NECESSARY THURSDAY.