Flash Flooding in Alabama, May 16, 2008

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MOBILE AL
755 AM CDT FRI MAY 16 2008

.UPDATED...RADAR RETURNS HAVE FILLED IN QUITE IMPRESSIVELY OVER THE
LAST SEVERAL HOURS OVER THE GULF COAST. HAVE MADE SOME SLIGHT
ADJUSTMENTS TO COVERAGES AND TO A GREATER EXTENT GRIDDED
PRECIPITATION AMOUNTS GIVEN THE NEARLY SOLID LINE OF WEATHER MOVING
EASTWARD ACROSS THE MISSISSIPPI SOUND AND ACROSS THE COASTAL
SECTIONS. FORECASTERS ANTICIPATE TODAYS THUNDERSTORM COVERAGES TO BE
GREATEST ALONG THE GULF COAST WITH CATEGORICAL COVERAGES => 80%+
EXTENDING OUT INTO THE OPEN GULF. WINDS...WAVES AND SEAS WILL BE
HIGHER IN AND NEAR THUNDERSTORMS. VISIBILITIES COULD ALSO BE
RESTRICTED TO LESS THAN A MILE AT TIMES IN DOWNPOURS. /10

.....................PREVIOUS DISCUSSION......................

.SHORT TERM (TODAY AND TONIGHT)...A LARGE UPPER LEVEL TROF DIGGING
INTO NORTHERN MEXICO SENDS UPPER LEVEL ENERGY EAST NORTHEAST OUT OF
TEXAS AND ACROSS THE GULF COAST TODAY. AT THE SURFACE...A FRONTAL
BOUNDARY WAS POSITIONED FROM THE MID ATLANTIC DOWN INTO CENTRAL
MISSISSIPPI AND INTO EASTERN TEXAS. SOUTHEAST OF THE FRONT...A TROF
OF LOW PRESSURE WAS DRAPED FROM SOUTHERN ALABAMA TO OFF THE
LOUISIANA COAST. WITH THIS SYNOPTIC SCALE SETUP ALONG WITH
PRECIPITABLE WATERS FROM 1.75 TO 2 INCHES...ANOTHER ROUND OF
PRECIPITATION TODAY.

DUE TO CLOUD COVER WHICH WOULD ACT TO LIMIT DEGREE
INSTABILITY...SEVERE WEATHER RISK APPEARS LOW FOR THE TIME BEING.
HOWEVER...WITH THE FRONT TO THE WEST AND IF WE GET SOME BREAKS IN
THE OVERCAST ALLOWING SOME SOLAR INSOLATION...DESTABILIZATION MAY BE
ENOUGH FOR A FEW SEVERE STORMS. DAY SHIFT WILL BE MONITORING FOR
THIS. FOR TONIGHT...WE SEE A SOUTHWARD MOVEMENT OF THE FRONT...WHICH
WILL RESULT IN THE END OF THE PRECIPITATION THREAT OVER OUR AREA.
NIGHTTIME LOWS ABOUT 10 TO 15 DEGREES LOWER THAN RECENTLY...WITH
OFFICIAL NUMBERS FROM THE UPPER 50S INTERIOR AND IN THE LOWER/MID
60S CLOSE TO THE COAST. 10/GJM

&&

.LONG TERM (SATURDAY THROUGH NEXT THURSDAY)...WEAK HIGH PRESSURE
WILL GENERALLY BE IN COMMAND OF THE WEATHER OVER THE REGION SATURDAY
THROUGH TUESDAY WITH NO RAINFALL IN THE FCST MOST OF THAT TIME
PERIOD...BUT A WEAK TROF AND UPPER LEVEL SYSTEM WILL SWING DOWN FROM
THE NORTH SUNDAY AND SUNDAY NIGHT...BRINGING A BRIEF SLIGHT CHANCE
FOR RAIN TO PARTS OF THE FCST AREA...MAINLY NORTH. TOWARD THE END OF
THE LONG TERM PERIOD...ANOTHER TROF DROPS SOUTH...MAKING FOR A MORE
UNSETTLED WEATHER PATTERN WEDNESDAY AND THURSDAY...WITH A SLIGHT
CHANCE OF SHRA/TSRA BOTH DAYS. OVERALL...THOUGH...FAIRLY QUIET
WEATHER PATTERN SETTING UP FOR MUCH OF THE LONG TERM PERIOD. TEMPS
WILL INITIALLY BE JUST BELOW NORMAL FOR THIS TIME OF THE YEAR...BUT
RISING TO NORMAL OR JUST SLIGHTLY ABOVE BY MONDAY AND CONTINUING
THROUGH THURSDAY. 12/DS

&&

.MARINE...FRONT LOOKS TO COME THROUGH THE COASTAL WATERS THROUGH THE
AFTERNOON...BRINGING AN OFFSHORE FLOW IN ITS WAKE. EARLY ON
THOUGH...ALONG AND AHEAD OF THE FRONT...THUNDERSTORMS DAMPENING
MARINE PLANS. NORTHEAST WINDS SATURDAY TREND MORE WESTERLY LATE IN THE
WEEKEND AS NEXT TROUGH OF LOW PRESSURE/FRONT SINKS SOUTHWARD INTO
THE SOUTHERN STATES. THEN MORE OF A SOUTHWEST DIRECTION BY EARLY
NEXT WEEK AS SURFACE HIGH PRESSURE NOSES WEST ACROSS FLORIDA. 10 TO
15 KNOTS OF WIND ON AVERAGE MOST OF THE PERIOD WITH SEAS SUBSIDING
THIS WEEKEND. 10/GJM

&&

.FIRE WEATHER...A COLD FRONT WILL BE MOVING ACROSS THE FCST AREA
TODAY. AS A RESULT...EXPECT  SCATTERED SHOWERS AND THUNDERSTORMS
ACROSS THE REGION TODAY...POSSIBLY LINGERING ALONG COASTAL SECTIONS
INTO THIS EVENING. DRIER AIR WILL FILTER INTO THE AREA ON SATURDAY.
12/DS

&&

.PRELIMINARY POINT TEMPS/POPS...
MOBILE      79  58  81  59 /  80  10  10  10
PENSACOLA   80  61  81  64 /  80  10  10  10
DESTIN      78  64  79  67 /  80  20  10  10
EVERGREEN   77  57  82  55 /  50  05  10  10
WAYNESBORO  78  55  81  55 /  40  05  05  10
CAMDEN      77  56  82  56 /  40  05  10  10

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
FL...NONE.
MS...NONE.
GM...NONE.

&&

HAZARDOUS WEATHER OUTLOOK...UPDATED...
NATIONAL WEATHER SERVICE MOBILE AL
920 AM CDT FRI MAY 16 2008

ALZ051>064-FLZ001>006-GMZ630-650-655-670-675-MSZ067-075-076-078-
079-171200-
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-
920 AM CDT FRI MAY 16 2008

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...THIS MORNING THROUGH EARLY SATURDAY...

A SLOW MOVING LINE OF SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS
SOUTHERN ALABAMA AND THE WESTERN FLORIDA PANHANDLE THIS MORNING.
EXTENSIVE MODERATE TO HEAVY RAINFALL WILL CONTINUE DEVELOPING
BEHIND THE LINE AS IT MOVES EASTWARD.  THE GREATEST COVERAGE OF
STORMS WITH THE HEAVIEST OF RAINFALL WILL OCCUR MAINLY ALONG AND
SOUTH OF I-10.  FORECASTERS ARE EXPECTING CLOUDS TO KEEP THE
ATMOSPHERE FROM BECOMING UNSTABLE FOR SEVERE THUNDERSTORMS TODAY.

REGARDING FLOODING THIS MORNING AND EARLY AFTERNOON...A FLASH FLOOD
WATCH IS IN EFFECT UNTIL 4 PM CDT FOR SOUTHERN MOBILE AND BALDWIN
COUNTIES AND THE WESTERN FLORIDA PANHANDLE FOR UP TO FOUR INCHES OF
RAINFALL IN SOME LOCATIONS.  MOST AREAS WILL RECEIVE BETWEEN TWO AND
THREE INCHES OF ADDITIONAL RAINFALL WHEN COMPARED TO YESTERDAYS
EVENT. THE GREATEST THREAT WILL COME WHEN VERY HEAVY RAINFALL RATES
OCCUR OVER A SHORT TIME PERIOD...EVEN FOR ONLY A HALF HOUR.
UPSTREAM RAINFALL RATES OF 3 INCHES PER HOUR HAVE ALREADY BEEN
OBSERVED. A COLD FRONT IS FORECAST TO MOVE SOUTHWARD THROUGH THE
COURSE OF THE DAY...PUSHING THE THUNDERSTORM AND HEAVY RAINFALL
THREAT TO THE EAST OF THE AREA BY EARLY EVENING.

BY MIDNIGHT...DRY AIR WILL BE FLOWING INTO THE REGION FROM THE NORTH
AND A GOOD DRYING OUT WILL BE UNDERWAY.

.DAYS TWO THROUGH SEVEN...EARLY SATURDAY THROUGH THURSDAY.

NO HIGH IMPACT WEATHER IS FORECAST THROUGH THE PERIOD.

.SPOTTER INFORMATION STATEMENT...

ACTIVATION OF EMERGENCY MANAGEMENT OFFICIALS AND SEVERE WEATHER
SPOTTERS IS NOT ANTICIPATED TO BE REQUIRED THROUGH TONIGHT.