Special Weather Statement, NWS Birmingham, AL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
312 PM CDT TUE APR 17 2012

.DISCUSSION...

SURFACE BOUNDARY DRAPED ACROSS THE MIDDLE OF CENTRAL ALABAMA HAS
SEEN SOME SHOWERS AND THUNDERSTORMS DEVELOP AS DAYTIME HEATING HAS
PEAKED. THE INCREASE IN INSTABILITY AND EXTRA LIFT FROM THE
SURFACE FRONT AND APPROACHING UPPER WAVE WILL ALLOW FOR SOME
STRONG TO ISOLATED SEVERE STORMS THIS AFTERNOON. EXPECT THIS LEVEL
OF ACTIVITY TO DIMINISH AFTER SUNSET.

MEANWHILE...HAVE BEEN WAITING FOR MOST OF THE DAY FOR THE MASS OF
SHOWERS OVER MISSISSIPPI TO BEGIN AN EASTWARD PUSH...ALTHOUGH LOCATIONS
IN THE NORTHWEST HAVE SEEN RAINFALL ALL DAY. EXPECT THIS WILL
HAPPEN SOON AND INTO THE OVERNIGHT WITH WIDESPREAD SHOWERS
COVERING ANY AREA FOR A FEW HOURS. THIS SYSTEM WILL EXIT WEDNESDAY
SO EXPECT MORNING SHOWERS OVER THE EASTERN COUNTIES THROUGH NOON
TOMORROW.

NICE WEATHER EXPECTED THURSDAY AND MOST OF FRIDAY AS THE NEXT
SYSTEM HAS SLOWED AND ITS AFFECTS ARE NOT EXPECTED TO ARRIVE
UNTIL LATER FRIDAY NIGHT BUT ESPECIALLY SATURDAY AND INTO SUNDAY.
THE DIGGING TROUGH BRINGING THE WET WEATHER THIS WEEKEND HAS TAKEN
ON A SPLIT FLOW CHARACTERISTIC OVER THE PAST COUPLE OF MODEL RUNS
PER THE GFS AND EURO. THIS DOES COMPLICATE THE FORECAST AS A SLOWER
MOVING AND UNUSUALLY DEEP UPPER LOW IS NOW FORECAST TO...MORE OR
LESS...MEANDER THROUGH THE DEEP SOUTH SATURDAY AND SUNDAY. THE CMC
HAS A COMPLETELY DIFFERENT EVOLUTION OF THIS SYSTEM BUT IS MORE IN
LINE WITH PREVIOUS RUNS. THUS...CONFIDENCE IN THE DETAILS OF THE
WEEKEND SYSTEM IS LOW...HOWEVER ABOVE AVERAGE IN THAT THERE WILL BE
RAINFALL AND POSSIBLY SOME LARGE HAIL DEPENDING ON THE TRACK OF
THE UPPER LOW. TEMPERATURES COULD BE A BIT OF A ROLLER COASTER
RIDE TOO. I STILL THINK THERE IS AN OPPORTUNITY TO BE MUCH COOLER
THAN OUR CURRENT TEMPERATURES BUT GUIDANCE NUMBERS ARE ALSO
STRUGGLING WITH CONSISTENCY.

&&

.AVIATION...

18Z TAF DISCUSSION

THE MAIN RAIN BAND REMAINS WEST OF THE TAF SITES...HOWEVER WE ARE
BEGINNING TO SEE ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPING
AHEAD OF THE LINE. EXPECT VC TS IN AFTER 19Z FOR MOST SITES. LOOK
FOR THE MAIN SHIELD TO WORK IN FOR THE AFTERNOON AND REMAIN THROUGH
THE EVENING. ONCE THE MAIN RAIN BAND LEAVES AFTER 6 TO 8Z FOR THE
NORTH LOW CLOUDS WILL BECOME THE MAIN PLAYER WITH IFR CIGS EXPECTED
ONCE AGAIN. MAY BE SOME DRIZZLE OR LIGHT RAIN AS WELL...BUT STUCK
WITH MIST AS THE QUALIFIER FOR NOW. MAY SEE CIGS RISE TO MVFR BY THE
END OF THE CYCLE BUT FOR TAF LENGTH CONTINUED WITH IFR THROUGH THE
END.

&&

.PRELIMINARY POINT TEMPS/POPS...
GADSDEN     74  51  74  49  79 /  90  80  30  10   0
ANNISTON    76  55  74  53  78 /  90  80  40  10   0
BIRMINGHAM  74  54  76  54  79 /  90  60  30  10   0
TUSCALOOSA  74  54  77  52  81 / 100  60  20  10   0
CALERA      77  55  76  55  78 /  90  60  30  10   0
AUBURN      82  59  75  56  78 /  50  80  50  10   0
MONTGOMERY  81  59  77  57  80 /  70  60  40  10   0
TROY        82  59  76  54  80 /  50  70  50  10   0

&&

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

&&

88/16

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BIRMINGHAM AL
305 PM CDT TUE APR 17 2012

ALZ011>015-017>050-182015-
MARION-LAMAR-FAYETTE-WINSTON-WALKER-BLOUNT-ETOWAH-CALHOUN-CHEROKEE-
CLEBURNE-PICKENS-TUSCALOOSA-JEFFERSON-SHELBY-ST. CLAIR-TALLADEGA-
CLAY-RANDOLPH-SUMTER-GREENE-HALE-PERRY-BIBB-CHILTON-COOSA-TALLAPOOSA-
CHAMBERS-MARENGO-DALLAS-AUTAUGA-LOWNDES-ELMORE-MONTGOMERY-MACON-
BULLOCK-LEE-RUSSELL-PIKE-BARBOUR-
305 PM CDT TUE APR 17 2012

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

.DAY ONE...THIS AFTERNOON AND TONIGHT.

SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS CENTRAL
ALABAMA THIS AFTERNOON AND EVENING HOURS. AN ISOLATED SEVERE
THUNDERSTORM WILL BE POSSIBLE THROUGH 8 PM FOR AREAS NORTH OF
INTERSTATE 85 AND EAST OF A DEMOPOLIS TO CORDOVA LINE. GUSTY WINDS
AND LARGE HAIL WILL BE THE THREATS FOR THE STRONGEST STORMS.

THE SEVERE POTENTIAL WILL DIMINISH FROM THE WEST AS THE LINE OF
MORE WIDESPREAD RAINS MOVE IN.

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

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT MAY BE
NEEDED THROUGH EARLY THIS EVENING.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
221 PM CDT TUE APR 17 2012

ALZ024-025-172000-
JEFFERSON AL-SHELBY AL-
221 PM CDT TUE APR 17 2012

...SIGNIFICANT WEATHER ADVISORY FOR WESTERN SHELBY AND CENTRAL
JEFFERSON COUNTIES UNTIL 300 PM CDT...

AT 221 PM CDT...THE NATIONAL WEATHER SERVICE WAS TRACKING A STRONG
THUNDERSTORM 6 MILES NORTHWEST OF MAYLENE...OR 7 MILES SOUTHWEST OF
HELENA...MOVING NORTH AT 25 MPH.

PEA SIZE HAIL AND WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THIS
STORM...ALONG WITH HEAVY RAIN AND FREQUENT DANGEROUS LIGHTNING.

LOCATIONS IN OR NEAR THE PATH OF THIS STORM INCLUDE...
  HELENA...
  BESSEMER...
  HOOVER...
  HUEYTOWN...
  VESTAVIA HILLS...
  HOMEWOOD...

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS... FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

TORRENTIAL RAIN...WHICH MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND
UNDERPASSES...IS ALSO LIKELY. DO NOT DRIVE YOUR VEHICLE ON A FLOODED
ROADWAY.

&&

LAT...LON 3354 8666 3316 8695 3318 8703 3321 8702
      3325 8703 3334 8703 3356 8702
TIME...MOT...LOC 1921Z 196DEG 22KT 3326 8695

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
228 PM CDT TUE APR 17 2012

ALZ027-036-172000-
COOSA AL-TALLADEGA AL-
228 PM CDT TUE APR 17 2012

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN TALLADEGA AND NORTHERN
COOSA COUNTIES UNTIL 300 PM CDT...

AT 224 PM CDT...THE NATIONAL WEATHER SERVICE WAS TRACKING A STRONG
THUNDERSTORM NEAR STRICKLAND CROSSROADS...OR NEAR WEOGUFKA...MOVING
NORTHEAST AT 15 MPH.

PEA SIZE HAIL AND WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THIS
STORM...ALONG WITH HEAVY RAIN AND FREQUENT DANGEROUS LIGHTNING.

LOCATIONS IN OR NEAR THE PATH OF THIS STORM INCLUDE...
  STEWARTVILLE...
  SYLACAUGA...
  WOODSTOCK...
  GANTTS QUARRY...
  SYLACAUGA MUNICIPAL AIRPORT...

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS... FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

TORRENTIAL RAIN...WHICH MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND
UNDERPASSES...IS ALSO LIKELY. DO NOT DRIVE YOUR VEHICLE ON A FLOODED
ROADWAY.

&&

LAT...LON 3319 8613 3319 8618 3311 8618 3304 8630
      3303 8638 3307 8643 3324 8635 3323 8611
TIME...MOT...LOC 1928Z 220DEG 15KT 3308 8636

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
256 PM CDT TUE APR 17 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0249 PM     HAIL             HOOVER                  33.38N 86.82W
04/17/2012  E0.50 INCH       JEFFERSON          AL   BROADCAST MEDIA

0250 PM     HAIL             SYLACAUGA               33.18N 86.26W
04/17/2012  E0.50 INCH       TALLADEGA          AL   BROADCAST MEDIA

0252 PM     HAIL             SYLACAUGA               33.18N 86.26W
04/17/2012  E1.00 INCH       TALLADEGA          AL   AMATEUR RADIO

0255 PM     HAIL             SYLACAUGA               33.18N 86.26W
04/17/2012  E1.75 INCH       TALLADEGA          AL   LAW ENFORCEMENT

&&

AG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
306 PM CDT TUE APR 17 2012

ALZ024>026-172045-
JEFFERSON AL-SHELBY AL-ST. CLAIR AL-
306 PM CDT TUE APR 17 2012

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN SHELBY...SOUTHWESTERN
ST. CLAIR AND EASTERN JEFFERSON COUNTIES UNTIL 345 PM CDT...

AT 306 PM CDT...THE NATIONAL WEATHER SERVICE WAS TRACKING A STRONG
THUNDERSTORM NEAR MEADOWBROOK...OR NEAR VESTAVIA HILLS...MOVING
NORTHEAST AT 20 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 40 MPH ARE
EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN.

LOCATIONS IN OR NEAR THE PATH OF THIS STORM INCLUDE...
  MOUNTAIN BROOK...
  IRONDALE...
  LEEDS...
  MOODY...
  TRUSSVILLE...

TORRENTIAL RAIN...WHICH MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND
UNDERPASSES...IS ALSO LIKELY. DO NOT DRIVE YOUR VEHICLE ON A FLOODED
ROADWAY.

&&

LAT...LON 3373 8660 3348 8631 3329 8677 3342 8688
TIME...MOT...LOC 2007Z 229DEG 19KT 3341 8672

19

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
317 PM CDT TUE APR 17 2012

ALZ028-172100-
CLAY AL-
317 PM CDT TUE APR 17 2012

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN CLAY COUNTY UNTIL
400 PM CDT...

AT 318 PM CDT...THE NATIONAL WEATHER SERVICE WAS TRACKING A STRONG
THUNDERSTORM NEAR ASHLAND...MOVING NORTHEAST AT 20 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 40 MPH ARE
EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN.

LOCATIONS IN OR NEAR THE PATH OF THIS STORM INCLUDE...
  LINEVILLE...
  BARFIELD...
  DELTA...
  GUNTHERTOWN...
  LAKE CHINNABEE...

TORRENTIAL RAIN...WHICH MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND
UNDERPASSES...IS ALSO LIKELY. DO NOT DRIVE YOUR VEHICLE ON A FLOODED
ROADWAY.

&&

LAT...LON 3324 8572 3325 8597 3338 8596 3340 8592
      3345 8592 3346 8590 3350 8590 3350 8585
      3347 8589 3347 8579 3350 8576 3349 8564
      3339 8564
TIME...MOT...LOC 2018Z 211DEG 19KT 3331 8587

19