Areal Flood Warning 12, NWS Mobile, AL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOBILE AL
1244 PM CDT TUE SEP 4 2012

.PUBLIC UPDATE...MODERATE TO HEAVY RAIN IS ONGOING ACROSS MUCH OF
SOUTH CENTRAL ALABAMA EARLY THIS AFTERNOON AS THE REMNANTS OF ISAAC
VERY SLOWLY MOVE SOUTH. WILL MAINTAIN THE FLASH FLOOD WATCH FOR S CTL
AL AND THE W FL PANHANDLE AS ADDITIONAL DEVELOPMENT IS EXPECTED
FURTHER SOUTH THIS AFTERNOON AND TONIGHT. THERE IS THE POTENTIAL WE
MAY HAVE TO EXPAND THE WATCH A LITTLE FURTHER TO THE WEST...ESPECIALLY
FOR COASTAL AL...AS ALL GUIDANCE SHOWS CONTINUED REDEVELOPMENT OF
CONVECTION ALONG THE COAST TONIGHT THROUGH MIDDAY TOMORROW. WE WILL
CONTINUE TO EVALUATE THIS AND WILL PROVIDE MORE INFO IN THE AFTERNOON
FORECAST PACKAGE.

ONLY FORECAST CHANGE AT THIS POINT IS TO SIGNIFICANTLY REDUCE HIGHS
FOR THE EASTERN CWA DUE TO THE RAIN AND CLOUDS. 34/JFB

&&

.AVIATION (18Z ISSUANCE)...CONDITIONS SHOULD DETERIORATE AT THE
FORECAST TERMINALS THIS AFTERNOON THROUGH TONIGHT AS A LARGE COMPLEX
OF SHOWERS AND THUNDERSTORMS MOVES SOUTH TOWARD THE COAST. ADDITIONAL
DEVELOPMENT IS POSSIBLE OVERNIGHT THROUGH EARLY WEDNESDAY...SO WILL
MAINTAIN MVFR CONDITIONS...AND REFLECT THE POSSIBILITY OF IFR AT
TIMES. 34/JFB

&&

.PREV DISCUSSION... /ISSUED 425 AM CDT TUE SEP 4 2012/

SHORT TERM [TODAY AND TONIGHT]...RATHER IMPRESSIVE MCS MOVING INTO
NORTHERN SECTIONS OF THE CWFA THIS MORNING WILL CONTINUE TO PUSH
SOUTH TO SOUTHWEST TOWARDS THE COAST THIS MORNING RESULTING IN
LIKELY TO HIGH CHANCE POPS ACROSS MOST OF THE CWFA TODAY AND
TONIGHT. THIS PATTERN IS LIKELY A RESULT OF A REMNANT SFC LOW MOVING
SOUTHWARD FROM THE TN RIVER VALLEY TOWARDS THE NORTH CENTRAL GULF
COAST COMBINED WITH ENOUGH FORCING IN THE MID LEVELS TO ALLOW DECENT
COVERAGE OF SHOWERS AND THUNDERSTORMS TO REDEVELOP OR FORM OVER
INLAND AREAS OF THE CWFA THIS MORNING SHIFTING SOUTHWARDS TOWARDS
THE COAST AND OFFSHORE THIS AFTERNOON AND OVERNIGHT. BEST COVERAGE
WILL BEGIN OVER NORTHERN AND EASTERN SECTIONS OF THE CWFA THIS
MORNING SHIFTING SOUTHWARDS TOWARDS THE I-10 CORRIDOR LATE THIS
AFTERNOON AND ALONG THE IMMEDIATE COAST AND OFFSHORE OVERNIGHT. MOST
OF THE MODEL GUIDANCE DEPICTS ANOTHER MCS LIKE SYSTEM DEVELOPING
OVER THE FORECAST AREA TONIGHT SHIFTING SOUTH TOWARDS THE COAST AND
OFFSHORE POSSIBLE LEADING TO A FEW STRONG THUNDERSTORMS ALSO LATE
THIS AFTERNOON AND OVERNIGHT. LATEST MODEL SOUNDINGS CONTINUE TO
SHOW A RATHER MOIST COLUMN OF AIR ACROSS THE FORECAST AREA TODAY AND
TONIGHT WITH PRECIP WATER VALUES RANGING FROM 2.18 INCHES TO THE
WEST AND 2.37 OVER EASTERN SECTIONS SUGGESTING SOME AREAS COULD
EASILY RECEIVE 1.5 TO 2.0 INCHES OF ADDITIONAL RAINFALL TODAY AND
TONIGHT WITH LOCALLY HIGHER AMOUNTS. LAPSE RATES LOOK BETTER TO THE
WEST DUE SOME DRY AIR IN THE MID LEVELS WITH SOME CAPPING ALSO NOTED
IN THE LOWER LEVELS EARLY TODAY. LATEST ANALYSIS FROM SPC MESO PAGE
SHOWS MIXED LAYERED CAPES RANGING FROM 1500 TO 2500 ACROSS THE LOWER
HALF OF THE CWFA THIS MORNING WHICH HELPS SUPPORT THIS REASONING
LATER TODAY. CURRENT FORECAST POPS LOOK GOOD THIS MORNING THOUGH
MADE A FEW TWEAKS TO THE SOUTH SHIFTING THE HIGHER POPS FURTHER WEST
MOSTLY NEAR AND ALONG THE I-10 CORRIDOR AND SOUTHWARD THIS AFTERNOON
AND TONIGHT. AS FOR TEMPS WILL LEAN TOWARDS THE CURRENT MAV GUIDANCE
THROUGH TONIGHT GOING A TAD LOWER FOR MOST AREAS DUE TO CLOUDS AND
PRECIP. 32/EE

THE WET MICROBURST RISK TODAY IS MODERATE.

[WEDNESDAY THROUGH THURSDAY NIGHT]...STARTING OFF MID WEEK BETWEEN
UPPER HIGH PRESSURE CENTERED OVER WEST TEXAS...AND TWO SMALL CUTOFF
UPPER LOWS OVER OR NEAR FLORIDA. AN UPPER RIDGE EXTENDING EAST FROM
THE UPPER HIGH ACROSS THE NORTHERN PORTIONS OF MISSISSIPPI AND
ALABAMA WILL MIGRATE SLOWLY SOUTHWARD OVER THE FORECAST AREA AND
INTO THE NORTHERN GULF THROUGH THE REMAINDER OF THE SHORT
TERM...WHILE ONE UPPER LOW OFF THE EAST COAST OF FLORIDA LIFT
NORTHWEST AND THE OTHER OVER THE FLORIDA PANHANDLE DROPS SOUTH OVER
THE EASTERN GULF.

AT THE SURFACE...ESSENTIALLY ALL THE MODELS HAVE A NW-SE ORIENTATED
SURFACE TROUGH OR WEAK LOW LYING ACROSS THE FORECAST AREA WEDNESDAY
MORNING...THIS BEING THE RESULT OF A PASSING MCS. THE GFS KEEPS THE
TROUGH OR WEAK LOW OVER LAND...WHILE THE REMAINING MODELS DROP THE
LOW SOUTH OVER THE NORTHEAST GULF...WHICH APPEARS TO THE BEST
SOLUTION. STILL EXPECTING SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ACROSS THE AREA BOTH DAYS...BUT WITH HIGHEST POPS OVER
OUR SOUTHEAST ZONES CLOSER TO THE WEAK SURFACE LOW.

MOSTLY SUNNY SKIES OVER OUR NORTHWEST ZONES ON WEDNESDAY AND OVER
THE ENTIRE FORECAST AREA ON THURSDAY WILL ALLOW HIGH TEMPERATURES TO
WARM TO BETWEEN 93 AND 97 DEGREES...WITH UPPER 80S / LOWER 90S AT
THE BEACHES. LOWS EACH NIGHT WILL FALL INTO THE LOW TO MID 70S
INLAND AREAS...WITH UPPER 70S AT THE BEACHES. /22

LONG TERM [FRIDAY THROUGH TUESDAY]...A LONGWAVE TROF EVOLVES OVER
THE PLAINS FRIDAY AND ADVANCES INTO THE EASTERN STATES THROUGH EARLY
NEXT WEEK. A STRONG COLD FRONT WILL ADVANCE THROUGH THE CENTRAL
PLAINS ON FRIDAY...APPROACH THE REGION ON SATURDAY...AND THEN SWEEP
THROUGH THE AREA FORECAST SATURDAY NIGHT. WILL CONTINUE WITH 20-30
POPS FRIDAY FOR A COMBINATION OF A SERIES OF SHORTWAVES AND A WEAK
SURFACE TROF OVER THE AREA. 30-50 POPS FOLLOW FOR SATURDAY AND
SATURDAY NIGHT WITH THE APPROACH AND PASSAGE OF THE FRONT. A FEW
LINGERING SHOWERS MAY CONTINUE INTO SUNDAY MORNING DUE TO SLIGHT
ISENTROPIC LIFT IN THE WAKE OF THE FRONT. A DRY PERIOD WILL THEN
FOLLOW THROUGH THE REMAINDER OF THE FORECAST. TEMPERATURES WILL BE
ABOVE SEASONABLE LEVELS FRIDAY AND SATURDAY AHEAD OF THE FRONT...AND
THEN TREND TO BELOW SEASONABLE LEVELS EARLY NEXT WEEK BEHIND THE
FRONT. /22

MARINE...SURFACE RIDGE OF HIGH PRESSURE WILL CONTINUE TO BUILD OVER
THE NORTHERN GULF THROUGH THE WEEK COMBINED WITH REMNANT SURFACE LOW
MOVING SOUTHWARD OVER INTERIOR SECTIONS OF AL AND MS. THIS PATTERN
WILL CONTINUE TO GIVE WAY TO A MODERATE TO STRONG WEST TO SOUTHWEST
FLOW OVER THE MARINE AREA THROUGH WED THEN GRADUALLY DIMINISHING
FROM WEST TO EAST LATER IN THE WEEK. SOUTHERLY WINDS AND SEAS WILL
REBUILD LATE FRI INTO SAT AHEAD OF AN EARLY SEASON COLD FRONT WHICH
IS FORECAST TO MOVE SOUTH OVER THE MARINE AREA BY EARLY SUN. A
MODERATE TO STRONG OFFSHORE FLOW IS EXPECTED IN THE WAKE OF THE
FRONT SUN THROUGH EARLY MON...THEN GRADUALLY DIMINISHING THROUGH THE
MIDDLE OF THE WEEK. SEAS WILL RANGE FROM 2 TO 4 FEET THROUGH MOST OF
THE WEEK BUILDING TO 3 TO 5 FEET IN THE WAKE OF THE FRONT SUN
THROUGH MONDAY. EXPECTED SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS TO MOVE SOUTH TOWARDS THE COAST AND OFFSHORE LATE
TODAY AND OVERNIGHT AS REMNANT LOW/MCS CONTINUES TO DRIFT SOUTHWARD
TOWARDS THE COAST THROUGH TONIGHT. 32/EE

FIRE...A SURFACE RIDGE OF HIGH PRESSURE WILL REMAIN IN PLACE OVER
THE GULF OF MEXICO THROUGH TONIGHT AND WILL PROMOTE A LIGHT MOIST
SOUTHWESTERLY FLOW. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
WILL IMPACT THE REGION TODAY AND WEDNESDAY. RELATIVE HUMIDITY VALUES
ARE EXPECTED TO REMAIN WELL ABOVE CRITICAL LEVELS THROUGH THE MIDDLE
OF THE WEEK.

FOG POTENTIAL AND OTHER REMARKS...PATCHY LIGHT FOG DEVELOPMENT
REMAINS POSSIBLE DURING THE OVERNIGHT AND EARLY MORNING HOURS THROUGH
THURSDAY.

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...FLASH FLOOD WATCH FOR THE FOLLOWING ZONES: BUTLER...CLARKE...
     CONECUH...COVINGTON...CRENSHAW...ESCAMBIA...MONROE...
     WILCOX...

FL...FLASH FLOOD WATCH FOR THE FOLLOWING ZONES: COASTAL ESCAMBIA...
     COASTAL OKALOOSA...COASTAL SANTA ROSA...INLAND ESCAMBIA...
     INLAND OKALOOSA...INLAND SANTA ROSA...

MS...NONE.
GM...NONE.
&&

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MOBILE AL
800 AM CDT TUE SEP 4 2012

ALZ051>064-FLZ001>006-MSZ067-075-076-078-079-051300-
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-WAYNE-PERRY-
GREENE-STONE-GEORGE-
800 AM CDT TUE SEP 4 2012

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

.DAY ONE...TODAY AND TONIGHT

NUMEROUS SHOWERS AND THUNDERSTORMS WILL MOVE SOUTH TOWARDS THE COAST
THROUGH TONIGHT...WITH PERIODS OF TORRENTIAL LONG DURATION RAINFALL
LIKELY ACROSS SOUTH CENTRAL ALABAMA AND THE WESTERN FLORIDA
PANHANDLE. A FEW STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE
LATER TODAY AND TONIGHT...WITH GUSTY STRAIGHT LINE WINDS AND FREQUENT
CLOUD TO GROUND LIGHTNING BEING THE MAIN THREATS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS CAN BE EXPECTED EACH
DAY. A FEW STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE MOSTLY
DURING THE LATE AFTERNOON OR EVENING HOURS.

.SPOTTER INFORMATION STATEMENT...

ACTIVATION OF SKYWARN SEVERE STORM SPOTTER NETWORKS IS NOT
EXPECTED THROUGH MONDAY.

GMZ630-650-655-670-675-051300-
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-
800 AM CDT TUE SEP 4 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF THE COASTAL
WATERS OF ALABAMA AND NORTHWEST FLORIDA.

.DAY ONE...TODAY AND TONIGHT

A MODERATE TO STRONG WEST TO SOUTHWEST WIND FLOW OVER THE MARINE
AREA WILL CONTINUE TO GIVE WAY TO HAZARDOUS CONDITIONS FOR SMALL
CRAFT TODAY AND TONIGHT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

A MODERATE TO STRONG WEST TO SOUTHWEST WIND FLOW OVER THE MARINE
AREA WILL CONTINUE TO GIVE WAY TO HAZARDOUS CONDITIONS FOR SMALL
CRAFT ON WEDNESDAY. HAZARDOUS CONDITIONS FOR SMALL CRAFT CAN BE
EXPECTED LATE SATURDAY THROUGH EARLY MONDAY IN RESPONSE TO A
MODERATE TO STRONG COLD FRONT WHICH MOVES ACROSS THE MARINE AREA
SATURDAY NIGHT AND EARLY SUNDAY MORNING.

.SPOTTER INFORMATION STATEMENT...

ACTIVATION OF SKYWARN SEVERE STORM SPOTTER NETWORKS IS NOT
EXPECTED THROUGH MONDAY.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOBILE AL
927 AM CDT TUE SEP 04 2012

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

0900 AM     FLASH FLOOD      6 SW FORT DEPOSIT       31.93N 86.64W
09/04/2012                   BUTLER             AL   PUBLIC

            FLASH FLOODING REPORTED ON HIGHWAY 185 IN FAR NORTHERN
            BUTLER COUNTY.

0910 AM     FLASH FLOOD      ANDALUSIA               31.31N 86.48W
09/04/2012                   COVINGTON          AL   PUBLIC

            WATER COVERING THE ROAD AT THE INTERSECTION OF WOODRUFF
            STREET AND OPP AVENUE.

&&

CL

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOBILE AL
1039 AM CDT TUE SEP 04 2012

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

1000 AM     FLASH FLOOD      GREENVILLE              31.83N 86.63W
09/04/2012                   BUTLER             AL   EMERGENCY MNGR

            COUNTY ROAD 45 WAS CLOSED DUE TO FLASH FLOODING...NOW
            BACK OPEN. HIGHWAY 10 IS FLOODED IN GREENVILLE.

&&

MB

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOBILE AL
1148 AM CDT TUE SEP 04 2012

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

1100 AM     FLASH FLOOD      5 NNW RIDGEVILLE        32.00N 86.86W
09/04/2012                   WILCOX             AL   BROADCAST MEDIA

            STATE ROAD 21 CLOSED DUE TO WATER OVER THE ROAD.

&&

MB

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOBILE AL
1258 PM CDT TUE SEP 04 2012

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

1230 PM     FLASH FLOOD      4 E GREENVILLE          31.83N 86.56W
09/04/2012                   BUTLER             AL   EMERGENCY MNGR

            WATER OVER HIGHWAY 50 EAST OF HIGHWAY 10.

&&

MB