Tornadoes and Flash Flooding in Alabama, March 8 to 9, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOBILE AL
845 PM CST TUE MAR 8 2011

.MESOSCALE UPDATE...00Z LIX SOUNDING WAS NEAR MOIST ADIABATIC AND
SATURATED FROM 400 MB TO THE SURFACE. THIS WOULD INDICATE HEAVY RAIN
WITH STRONG GUSTY WINDS. WE ARE NOTING NOW THAT THE WATER VAPOR
IMAGERY IS SHOWING A SMALL NARROW DRY AIR INTRUSION IN THE
MIDLEVELS. THE MIDLEVEL INTRUSION IS BOUNDED TO THE SOUTH OF A LINE
FROM PICAYUNE TO WIGGINS TO HATTIESBURG TO LUCEDALE MISSISSIPPI AND
THEN EAST TO NEAR BAY MINETTE ALABAMA. THIS INCLUDES A NOTCH NOSING
INTO THE HATTIESBURG AREA THAT WAS ASSOCIATED WITH THE EXPLOSIVE
CONVECTIVE GROWTH AND INCREASE IN LIGHTNING ACTIVITY AND LARGE HAIL.
WE OBSERVED EARLIER THAT 60 DBZ CORES WERE REACHING 40 KFT AND 70 TO
75 DBZ TO NEAR 26 KFT. CONTINUING TO CLOSELY MONITOR THE SITUATION.

.AVIATION [09/00Z ISSUANCE]...CURRENT MVFR/IFR CIGS EXPECTED TO
REMAIN THROUGH THE ENTIRE TAF CYCLE. SOUTHEAST WINDS WILL BE GUSTY
AT TIMES FROM 20 TO 25 KNOTS. VCTS AT ALL TAF SITES BY LATE
EVENING...WITH TEMPO GROUPS IN IFR/LIFR VISIBILITY CONDITIONS DUE TO
HEAVY RAIN BETWEEN 09/02Z AND 09/14Z AS A SQUALL LINE MOVES ACROSS
THE AREA. ANOTHER...LESS ORGANIZED LINE OF MAINLY SHRA AND ISOLATED
-TSRA WILL MOVE OVER THE AREA LATE IN THE MORNING AND AFTERNOON
HOURS. /22

**********************PREVIOUS********************

&&

.SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...A STRONG SHORTWAVE
SWEEPS FROM THE SOUTHERN PLAINS TOWARDS THE GREAT LAKES TONIGHT
WHILE A SECOND STRONG SHORTWAVE DIVES FROM THE NORTHWEST STATES INTO
THE CENTRAL PLAINS.  THE UPPER TROF AMPLIFIES SHARPLY IN RESPONSE TO
THESE TWO FEATURES...TAKING ON A SLIGHT NEGATIVE TILT AS IT MOVES
ACROSS THE SOUTHEAST STATES WEDNESDAY NIGHT. A SURFACE LOW MOVES FROM
NORTHEAST TEXAS TO THE MID MISSISSIPPI RIVER VALLEY OVERNIGHT THEN TO
NEAR THE GREAT LAKES WEDNESDAY INTO WEDNESDAY NIGHT...AND BRINGS A
STRONG COLD FRONT THROUGH THE FORECAST AREA. ANOTHER STRONG
SHORTWAVE IS SEEN IN CURRENT WATER VAPOR LOOP EXTENDING FROM NEAR
THE SABINE RIVER TO THE MISSISSIPPI BOOTHEEL AREA WITH STRONG
CONVECTION HAVING DEVELOPED OVER SOUTHWEST MISSISSIPPI AND SOUTHEAST
LOUISIANA MAINLY ALONG A WARM FRONTAL BOUNDARY IN THAT AREA. STRONG
ISENTROPIC UPGLIDE IS OCCURRING JUST WEST OF THE AREA AND WILL SHIFT
INTO MUCH OF THE FORECAST AREA OVERNIGHT WHILE THE WARM FRONT SHIFTS
NORTHEASTWARD THROUGH THE AREA. THE ENVIRONMENT BECOMES INCREASINGLY
MORE FAVORABLE FOR POTENTIAL STRONG TO SEVERE STORM
DEVELOPMENT...ESPECIALLY NEAR THE COAST AND OVER THE WESTERN PORTION
OF THE AREA OVERNIGHT...AND SPC HAS GENERALLY THIS PORTION OF THE
FORECAST AREA OUTLOOKED FOR A SLIGHT RISK.  BY 12Z WEDNESDAY...0-1
KM MLCAPES OVER THE WESTERN PORTION OF THE FORECAST AREA TO 500-700
J/KG NEAR THE COAST AND AROUND 200 J/KG WELL INLAND WHILE A 40-50
KNOT 850 JET PRODUCES HIGH 0-1 KM HELICITIES OF 200-325 M2/S2. WILL
HAVE THE MENTION OF POSSIBLE SEVERE STORMS IN THIS ENVIRONMENT
ROUGHLY OVER THE WESTERN HALF OF THE FORECAST AREA. A SQUALL LINE IS
ANTICIPATED TO BE NEARING THE WESTERN PORTION OF THE FORECAST AREA
NEAR 12Z WEDNESDAY THEN WILL MOVE QUICKLY ACROSS THE AREA AND EXIT
THE EASTERN PORTION DURING THE MID TO LATE AFTERNOON HOURS. THE
ENVIRONMENT CONTINUES TO BE SUPPORTIVE OF SEVERE STORM DEVELOPMENT
WITH 0-1 KM HELICITIES 200-300 M2/S2 AND 0-1 KM MLCAPES POTENTIALLY
AS HIGH AS AROUND 1000 J/KG OVER THE COASTAL COUNTIES DECREASING TO
300-500 J/KG WELL INLAND. SPC HAS ESSENTIALLY THE ENTIRE AREA
OUTLOOKED FOR A SLIGHT RISK AT THIS TIME FOR WEDNESDAY. DESPITE THE
FAIRLY FAST MOTION OF THE SQUALL LINE...ABUNDANT GULF MOISTURE WILL
BE IN PLACE WITH STRONG MOISTURE TRANSPORT DUE TO THE 40-50 KNOT 850
MB FLOW SUPPORTING HIGH RAINFALL RATES WITH THE STRONGER STORMS.
EXPECT QPF AMOUNTS WILL GENERALLY BE AROUND 3 INCHES WITH LOCALIZED
AMOUNTS WHERE STORMS TRAIN OVER THE SAME AREA POSSIBLY ATTAINING
AROUND 6 INCHES. A FLASH FLOOD WATCH CONTINUES IN EFFECT FOR THE
AREA WITH THE HIGHEST RISK OVER SOUTHEAST MISSISSIPPI AND WESTERN
SOUTHWEST ALABAMA WHERE HEAVY RAINS FELL ON SATURDAY. WILL HAVE A
WIND ADVISORY CONTINUING THROUGH WEDNESDAY DUE TO OCCASIONAL WIND
GUSTS BEING OBSERVED AROUND 30 KNOTS AND EXPECT THE GRADIENT WINDS
TO CONTINUE TO SUPPORT THIS AT LEAST THROUGH WEDNESDAY. ALONG A
SIMILAR VEIN...HAVE ISSUED A HEAVY SURF ADVISORY AND COASTAL FLOOD
ADVISORY FOR THE AREA GENERALLY WEST OF DESTIN.

WILL HAVE CHANCE POPS OVER THE EASTERN PORTION OF THE AREA WEDNESDAY
EVENING TAPERING OFF WESTWARD FOR CONVECTION ALONG THE FRONT AS IT
MOVES THROUGH...THEN SMALL POPS AFTER MIDNIGHT FOR THE EASTERNMOST
ZONES. DRY CONDITIONS FOLLOW FOR THURSDAY WITH COOLER AND DRIER AIR
FLOWING INTO THE REGION. AT THIS TIME...IT APPEARS THAT OVERNIGHT
LOWS THURSDAY NIGHT WILL REMAIN JUST ABOVE FREEZING OVER INLAND AREAS
BUT WILL NEED TO CONTINUE TO MONITOR. COOL CONDITIONS CONTINUE
THROUGH FRIDAY THEN TEMPERATURES RETURN TO AROUND SEASONABLE LEVELS
ON SATURDAY AS A SURFACE HIGH SHIFTS EAST OF THE AREA WITH A LIGHT
RETURN FLOW ENSUING. /29

.LONG TERM (SUNDAY THROUGH WEDNESDAY)...THE SURFACE HIGH CONTINUES
EAST OF THE AREA THROUGH THE WEEKEND AS A SYSTEM MOVING ACROSS THE
NORTHEAST STATES BRINGS A TRAILING FRONT DEEP INTO THE SOUTHEAST
STATES. WILL HAVE SMALL POPS FOR MONDAY AND MONDAY NIGHT THEN DRY FOR
TUESDAY. /29

&&

.MARINE...AN APPROACHING SYSTEM WILL CONTINUE TO CREATE A STRONG
SOUTHEASTERLY FLOW OVER THE COASTAL WATERS THROUGH WEDNESDAY. THERE
WILL BE AN INCREASING COVERAGE OF SHOWERS FROM THE WEST THIS
AFTERNOON INTO TONIGHT AS ISENTROPIC UPGLIDE SETS IN...WITH
THUNDERSTORMS BECOMING INCREASINGLY POSSIBLE TUESDAY NIGHT. A SQUALL
LINE WILL MOVE ACROSS THE COASTAL WATERS EARLY WEDNESDAY...ROUGHLY
STARTING AROUND 12Z WED AND EXIT EAST OF THE MARINE FA BY 20Z THURS.
VERY STRONG WINDS ARE LIKELY...WITH MARINE WARNINGS LIKELY
WEDNESDAY. AFTER THIS LINE MOVES EAST OF THE AREA...A LESS ORGANIZED
LINE OF MAINLY SHRA...WITH SOME TSRA WILL MOVE OVER THE AREA LATE
WEDNESDAY AFTERNOON INTO WEDNESDAY EVENING WITH THE FRONT.

STRONG OFFSHORE FLOW WILL FOLLOW THE FRONTAL PASSAGE...LASTING INTO
FRIDAY. SOME WEAKENING WILL OCCUR THURSDAY AS SURFACE HIGH PRESSURE
MOVES EAST...JUST NORTH OF THE NORTHERN GULF COAST...BUT WILL AGAIN
INCREASE THURSDAY EVENING AS THE COOLING OFFSHORE FLOW COMBINES WITH
THE SURFACE HIGH. THE SURFACE HIGH WILL TAKE A MORE ESE JOG...AS IT
MOVES OVER THE AREA...DROPPING THE WINDS QUICKLY LATE THURSDAY NIGHT
INTO FRIDAY.

FRIDAY NIGHT INTO SUNDAY...AS THE SURFACE HIGH NOODLES AROUND THE
AREA...LIGHT AND VARIABLE FLOW CAN BE EXPECTED FOR THE MARINE FA FOR
THE WEEKEND. /16

&&

.FIRE...A LOW PRESSURE SYSTEM OVER THE SOUTHERN PLAINS PASSES WELL
TO THE NORTH OF THE AREA ON WEDNESDAY AND BRINGS A STRONG COLD FRONT
THROUGH THE AREA. RAIN CHANCES INCREASE SHARPLY ACROSS THE AREA
TONIGHT WITH HIGH RAIN CHANCES ON WEDNESDAY...WITH RAIN ENDING
WEDNESDAY EVENING IN THE WAKE OF THE COLD FRONT. AFTERNOON RELATIVE
HUMIDITIES REMAIN VERY HIGH THIS AFTERNOON AND WEDNESDAY THEN DRIER
AND COOLER AIR FLOWS INTO THE REGION ON THURSDAY. AFTERNOON RELATIVE
HUMIDITIES WILL DROP SLIGHTLY BELOW CRITICAL LEVELS OVER THE
NORTHWEST FLORIDA PANHANDLE ON THURSDAY WITH BREEZY NORTHWEST WINDS
AROUND 15 MPH. /29

&&

.PRELIMINARY POINT TEMPS/POPS...
MOBILE      61  74  46  65 /  80 100  20  00
PENSACOLA   62  73  49  64 /  60 100  30  00
DESTIN      61  70  51  63 /  40 100  50  00
EVERGREEN   60  73  46  63 /  70 100  30  05
WAYNESBORO  60  77  41  63 / 100 100  05  00
CAMDEN      60  74  45  62 /  90 100  20  05
CRESTVIEW   60  74  48  66 /  50 100  40  00

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...WIND ADVISORY UNTIL 6 PM WEDNESDAY FOR THE FOLLOWING ZONES:
     BUTLER...CHOCTAW...CLARKE...CONECUH...COVINGTON...
     CRENSHAW...ESCAMBIA...LOWER BALDWIN...LOWER MOBILE...
     MONROE...UPPER BALDWIN...UPPER MOBILE...WASHINGTON...AND
     WILCOX.

     FLASH FLOOD WATCH FROM 6 AM WEDNESDAY TO 6 PM WEDNESDAY FOR THE
     FOLLOWING ZONES: BUTLER...CHOCTAW...CLARKE...CONECUH...
     COVINGTON...CRENSHAW...ESCAMBIA...LOWER BALDWIN...LOWER
     MOBILE...MONROE...UPPER BALDWIN...UPPER MOBILE...
     WASHINGTON...AND WILCOX.

FL...FIRE WEATHER WATCH FROM NOON THURSDAY TO 5 PM THURSDAY FOR THE
     FOLLOWING ZONES: COASTAL ESCAMBIA...COASTAL OKALOOSA...
     COASTAL SANTA ROSA...INLAND ESCAMBIA...INLAND OKALOOSA...
     AND INLAND SANTA ROSA.

     FLASH FLOOD WATCH FROM 6 AM WEDNESDAY TO 6 PM WEDNESDAY FOR THE
     FOLLOWING ZONES: COASTAL ESCAMBIA...COASTAL OKALOOSA...
     COASTAL SANTA ROSA...INLAND ESCAMBIA...INLAND OKALOOSA...
     AND INLAND SANTA ROSA.

     WIND ADVISORY UNTIL 6 PM WEDNESDAY FOR THE FOLLOWING ZONES:
     COASTAL ESCAMBIA...COASTAL OKALOOSA...COASTAL SANTA ROSA...
     INLAND ESCAMBIA...INLAND OKALOOSA...AND INLAND SANTA ROSA.

     HIGH SURF ADVISORY UNTIL 9 PM WEDNESDAY FOR THE FOLLOWING
ZONES:      COASTAL ESCAMBIA...COASTAL OKALOOSA...AND COASTAL
SANTA      ROSA.

MS...FLASH FLOOD WATCH FROM 6 AM WEDNESDAY TO 6 PM WEDNESDAY FOR THE
     FOLLOWING ZONES: GEORGE...GREENE...PERRY...STONE...AND
     WAYNE.

     WIND ADVISORY UNTIL 6 PM WEDNESDAY FOR THE FOLLOWING ZONES:
     GEORGE...GREENE...PERRY...STONE...AND WAYNE.

GM...SMALL CRAFT ADVISORY UNTIL NOON THURSDAY FOR THE FOLLOWING
     ZONES: COASTAL WATERS FROM DESTIN TO PENSACOLA FL OUT 20
     NM...COASTAL WATERS FROM PENSACOLA FL TO PASCAGOULA MS OUT
     20 NM...MOBILE BAY...WATERS FROM DESTIN TO PENSACOLA FL
     FROM 20 TO 60 NM...AND WATERS FROM PENSACOLA FL TO
     PASCAGOULA MS FROM 20 TO 60 NM.

&&

HAZARDOUS WEATHER OUTLOOK...UPDATE
NATIONAL WEATHER SERVICE MOBILE AL
300 PM CST TUE MAR 8 2011

ALZ051>064-FLZ001>006-GMZ630-650-655-670-675-MSZ067-075-076-078-
079-092100-
CHOCTAW-WASHINGTON-CLARKE-WILCOX-MONROE-CONECUH-BUTLER-CRENSHAW-
ESCAMBIA-COVINGTON-UPPER MOBILE-UPPER BALDWIN-LOWER MOBILE-
LOWER BALDWIN-INLAND ESCAMBIA-COASTAL ESCAMBIA-INLAND SANTA ROSA-
COASTAL SANTA ROSA-INLAND OKALOOSA-COASTAL OKALOOSA-MOBILE BAY-
COASTAL WATERS FROM PENSACOLA FL TO PASCAGOULA MS OUT 20 NM-
COASTAL WATERS FROM DESTIN TO PENSACOLA FL OUT 20 NM-
WATERS FROM PENSACOLA FL TO PASCAGOULA MS FROM 20 TO 60 NM-
WATERS FROM DESTIN TO PENSACOLA FL FROM 20 TO 60 NM-WAYNE-PERRY-
GREENE-STONE-GEORGE-
300 PM CST TUE MAR 8 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL
ALABAMA...SOUTHWEST ALABAMA...THE COASTAL WATERS OF ALABAMA AND
NORTHWEST FLORIDA...NORTHWEST FLORIDA AND SOUTHEAST MISSISSIPPI.

.DAY ONE...REST OF TODAY INTO WEDNESDAY AFTERNOON.

AS A STRONG UPPER SYSTEM APPROACHES FROM THE WEST...THERE WILL BE AN
INCREASE IN THE COVERAGE OF SHOWERS FROM THE WEST INTO THIS
EVENING...AND WITH AN INCREASE IN INSTABILITY OVER THE AREA TONIGHT
INTO WEDNESDAY...A CHANCE OF THUNDERSTORMS MIXING IN. THE
THUNDERSTORMS WILL BEGIN TO APPEAR IN THE LATE EVENING TO OVERNIGHT
HOURS...AND WITH AN INCREASE IN UPPER DYNAMICS STARTING TO APPROACH
THE AREA...
A FEW MAY BECOME STRONG TO SEVERE...MAINLY AFTER MIDNIGHT. WESTERN
SECTIONS OF THE AREA WILL SEE THE INITIAL INCREASE IN THE RISK OF
SEVERE WEATHER...WITH DAMAGING WINDS THE PRIMARY THREAT...BOTH FROM
SMALL CELLS MOVING NORTH-NORTHEAST OVER THE AREA AHEAD OF A SQUALL
LINE EXPECTED TO START MOVING OVER SOUTHEAST MISSISSIPPI AROUND
SUNRISE...AND THE SQUALL LINE ITSELF.

THE SQUALL LINE IS EXPECTED TO START MOVING ACROSS INLAND SOUTHEAST
MISSISSIPPI JUST BEFORE SUNRISE WEDNESDAY. WINDS GUSTING TO 60 MPH
ARE POSSIBLE WITH ANY STORM THAT MAY BECOME SEVERE. ISOLATED
TORNADOES CAN NOT BE RULED OUT WITH THE SEVERE CELLS.

WITH THE LIKELIHOOD THAT SOME LOCALITIES MAY SEE SEVERAL STRONG
THUNDERSTORMS CROSSING THEM...RAINFALL TOTALS FOR WEDNESDAY MAY
APPROACH 5 TO 7 INCHES...CREATING FLOODING PROBLEMS. A GENERAL 2 TO
3 INCHES OF RAIN IS EXPECTED OVER THE AREA.

A STRONG SOUTHEASTERLY WIND FLOW WILL MAKE HAZARDOUS CONDITIONS FOR
SMALL CRAFT THROUGH TONIGHT. THIS STRONG ONSHORE FLOW WILL ALSO
CREATE A HAZARDOUS SURF ALONG AREA BEACHES AHEAD OF THE FRONTAL
PASSAGE.

.DAYS TWO THROUGH SEVEN...REST OF WEDNESDAY THROUGH MONDAY

AS THE SURFACE FRONT STARTS MOVING OVER THE AREA MID MORNING ON...
ANOTHER ROUND OF MAINLY SHOWERS WITH A FEW THUNDERSTORMS WILL GET
PUSHED EAST OVER THE AREA WITH THE FRONT. THERE IS A MUCH SMALLER
RISK OF SEVERE WEATHER...THOUGH DAMAGING WINDS CAN NOT BE RULED OUT
IF A THUNDERSTORM BECOMES STRONG TO SEVERE.

THE STRONG ONSHORE FLOW WILL CONTINUE TO BE A HAZARD TO SMALL CRAFT
OVER AREA WATERS...ALONG WITH A ROUGH SURF ALONG AREA BEACHES.
BEHIND THE FRONT...STRONG OFFSHORE FLOW WILL FOLLOW...AGAIN CREATING
HAZARDOUS CONDITIONS FOR SMALL CRAFT. THIS STRONG OFFSHORE FLOW IS
EXPECTED TO LAST INT THURSDAY EVENING...THEN BEGIN TO SETTLE AS HIGH
PRESSURE MOVES TOWARDS THE AREA.

.SPOTTER INFORMATION STATEMENT...

THERE WILL BE AN INCREASING CHANCE FOR THE NEED OF SPOTTER AND EMA
ACTIVATION AFTER MIDNIGHT TONIGHT...STARTING WITH SOUTHEAST
MISSISSIPPI...AND LASTING THROUGH WEDNESDAY. STAY TUNED TO FURTHER
UPDATES ON THIS DEVELOPING WEATHER PATTERN.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOBILE AL
728 PM CST TUE MAR 08 2011

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

0718 PM     HAIL             CITRONELLE              31.09N 88.24W
03/08/2011  E1.00 INCH       MOBILE             AL   PUBLIC

            QUARTER SIZE HAIL REPORTED IN CITRONELLE, ALABAMA.

&&

JW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOBILE AL
758 PM CST TUE MAR 08 2011

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

0725 PM     HAIL             NEW AUGUSTA             31.20N 89.03W
03/08/2011  E1.00 INCH       PERRY              MS   LAW ENFORCEMENT

            PERRY COUNTY SHERIFFS OFFICE IN NEW AUGUSTA, MS REPORTED
            STRONG WINDS AND ONE INCH HAIL.

&&

JW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOBILE AL
816 PM CST TUE MAR 08 2011

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

0755 PM     HAIL             PIAVE                   31.40N 88.74W
03/08/2011  E0.50 INCH       GREENE             MS   EMERGENCY MNGR

            GREENE COUNTY EMERGENCY MANAGER REPORTED MARBLE SIZE HAIL
            ACROSS NORTHERN PORTIONS OF THE COUNTY.

&&

JW

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOBILE AL
832 PM CST TUE MAR 08 2011

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

0800 PM     HAIL             4 SW AVERA              31.26N 88.79W
03/08/2011  E1.00 INCH       GREENE             MS   PUBLIC

            PUBLIC REPORTED QUARTER SIZE HAIL 4 MILES SOUTHWEST OF
            AVERA NEAR THE INTERSECTION OF TUNG OIL AND NEELY-AVERA
            ROADS.

&&

JW