FXUS64 KMOB 302344
AFDMOB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOBILE AL
543 PM CST MON NOV 30 2009
.AVIATION (00Z ISSUANCE)...MVFR CEILINGS DUE TO LAYER LIFTED STRATUS
IN THE WAKE OF THE COLD FRONT SUCCUMBS TO DRIER AIR LATER THIS
EVENING WITH VFR CONDITIONS FOLLOWING AND CONTINUING THROUGH TUESDAY
MORNING. A CEILING NEAR 3.5 KFT FORMS LATER TUESDAY MORNING AS
OVERRUNNING STRENGTHENS DUE TO THE APPROACHING NORTHWESTERN GULF
SYSTEM...THEN MVFR CEILINGS FOLLOW BY THE EARLY AFTERNOON. WILL
INCLUDE A TEMPO GROUP FOR IFR CONDITIONS IN SHOWERS IN THE MID TO
LATE AFTERNOON. /29
&&
** PREVIOUS DISCUSSION **
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY) THE COLD FRONT CONTINUES TO
MAKE STEADY PROGRESS ACROSS THE AREA AND SHOULD BE CLEAR OF LAND
AREAS BY 00Z THIS EVENING...AND CLEARING THE COASTAL WATERS BY MID
EVENING BEFORE STALLING OVER THE NORTH CENTRAL GULF. NORTHERLY FLOW
BEHIND THE FRONT WILL USHER IN COOLER TEMPS TONIGHT WITH LOWS IN THE
UPPER 30S NORTH TO UPPER 40S ALONG THE IMMEDIATE COAST.
THE RESPITE FROM THE RAIN WILL BE SHORT LIVED AS THE WEATHER ALONG
THE NORTHERN GULF COAST WILL DETERIORATE RAPIDLY LATE TOMORROW
AFTERNOON INTO TOMORROW NIGHT. AS AN UPPER LEVEL LOW CURRENTLY OVER
NORTHERN MEXICO CONTINUES TO MOVE EAST...IT WILL INDUCE SURFACE
CYCLOGENESIS OVER THE WESTERN GULF ALONG THE STALLED FRONTAL ZONE BY
TOMORROW MORNING. THE LOW WILL BEGIN TO DEEPEN AND MOVE NORTHEAST
DURING THE DAY...ALLOWING THE STATIONARY FRONT OVER THE NORTH CENTRAL
GULF TO MOVE BACK TO THE NORTH AS A WARM FRONT. RAIN IS EXPECTED TO
QUICKLY DEVELOP OVER THE SOUTHWEST ZONES AND SPREAD INLAND TOMORROW
AFTERNOON AS 850 MB WINDS INCREASE TO NEAR 50 KT...AIDING IN STRONG
ISENTROPIC LIFT AND FRONTOGENESIS. USING A BLEND OF THE GFS AND
ECMWF...WHICH ONLY HAVE MINOR DIFFERENCES...PLACES A DEEPENING SUB
1000 MB LOW OVER SOUTHEAST LOUISIANA BY MIDNIGHT WEDNESDAY AND NEAR
THE SOUTHERN MS COAST BY DAYBREAK WEDNESDAY. THIS LOW TRACK IS
DISCONCERTING AS IT WILL ALLOW FOR A WIDE RANGE OF HAZARDS ACROSS THE
AREA.
HEAVY RAIN... DYNAMICS ARE VERY IMPRESSIVE WITH THIS SYSTEM BOTH IN
THE LOW AND UPPER LEVELS OF THE ATMOSPHERE. A STRENGTHENING 60-70 KT
850 MB LOW LEVEL JET WILL AID IN VERY STRONG LOW LEVEL CONVERGENCE IN
THE VICINITY OF THE WARM FRONT TUESDAY NIGHT. ALOFT...UPPER LEVEL
DIVERGENCE WILL BECOME MAXIMIZED AS A 100+ KT JETSTREAK ROUNDS THE
BASE OF THE UPPER LEVEL LOW. SUCH FORCING WILL ALLOW FOR A BAND OF
EXTREMELY HEAVY RAIN TO DEVELOP IN THE VICINITY OF THE FRONTAL
ZONE...WITH THE BEST LOCATION CURRENTLY SHAPING UP TO BE ALONG AND
SOUTHEAST OF THE INTERSTATE 65 CORRIDOR. BOTH THE GFS AND ECMWF
INDICATE VERY HIGH QPF AND A WIDESPREAD 2-4 INCHES APPEARS LIKELY
WITH A BAND OF 5-8 INCHES VERY POSSIBLE IN THE AFOREMENTIONED AREAS.
GIVEN THE POTENTIAL FOR SUCH HEAVY RAIN...HAVE ISSUED A FLASH FLOOD
WATCH FOR AREAS ALONG AND EAST OF I-65. TO THE NORTH AND WEST OF THIS
AREA...CURRENTLY EXPECTING RAINFALL OF 1 TO 3 INCHES.
SEVERE WEATHER...GIVEN THAT EASTERN PORTIONS OF THE FORECAST AREA ARE
EXPECTED TO BE IN THE WARM SECTOR...THERE WILL BE AN INCREASING
THREAT FOR SEVERE WEATHER TUESDAY NIGHT. INSTABILITY VALUES STILL
APPEAR MARGINAL WHICH WILL PREVENT THE THREAT FROM BEING EVEN HIGHER.
HOWEVER...MLCAPES OF AROUND 500 J/KG ARE EXPECTED TO SPREAD INLAND
ACROSS COASTAL ALABAMA AND THE FLORIDA PANHANDLE...POSSIBLY REACHING
AS FAR NORTH AS ESCAMBIA AND COVINGTON COUNTIES. WIND SHEAR PROFILES
WILL BE VERY SUPPORTIVE OF ROTATING STORMS. IF ENOUGH INSTABILITY
DEVELOPS...THEN WE WILL HAVE THE POSSIBILITY OF ISOLATED TORNADOES
AND SEVERE WIND GUSTS AS WINDS CLOSE TO 60 KT WILL BE PRESENT JUST
1000 FT ABOVE GROUND LEVEL.
COASTAL FLOODING AND WINDS... WINDS ARE FORECAST TO INCREASE TO 30 TO
40 KNOTS OFFSHORE TOMORROW NIGHT. ALONG THE COAST...GUSTS UP TO 40
MPH ARE POSSIBLE WITH BREEZY CONDITIONS OF 20-30 MPH FURTHER INLAND.
A WIND ADVISORY WILL LIKELY BECOME NECESSARY ALONG THE COASTAL
COUNTIES. WITH SUCH A STRONG ONSHORE FLOW AND TIDES CURRENTLY AT
THEIR HIGHEST RANGE IN THE SPRING TIDE CYCLE...COASTAL FLOODING WILL
BECOME A CONCERN STARTING TOMORROW EVENING. LATEST INDICATIONS SHOW
TOTAL TIDE HEIGHTS OF 3 TO 5 FEET...WHICH WILL CAUSE PROBLEMS IN THE
TYPICALLY PRONE COASTAL FLOODING LOCATIONS.
RAIN SHOULD BEGIN TO CLEAR FROM WEST TO EAST WEDNESDAY MORNING AS THE
LOW QUICKLY PULLS OFF TO THE NORTHEAST. EXPECT THE MAJORITY OF THE
RAIN TO HAVE ENDED BY 18Z WEDNESDAY. LOW LEVEL CYCLONIC FLOW PERSISTS
THROUGH THE DAY...SO WE WILL LIKELY KEEP LOW CLOUDS AROUND FOR MUCH
OF THE DAY.
STAYED CLOSE TO MAVMOS FOR TEMPERATURES. HIGHS IN THE MID 50S TO
AROUND 60 TOMORROW...NOT DROPPING MUCH TOMORROW NIGHT...AND IN FACT
LIKELY RISING OVER EASTERN SECTIONS OVER NIGHT. 60-65 FORECAST FOR
WEDNESDAY. 34/JFB
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) MUCH DRIER AND COLDER
WEATHER EXPECTED FOR THE LATTER HALF OF THE WEEK AS A LONGWAVE TROUGH
SETS UP OVER THE CENTRAL STATES...ALLOWING A FREE FLOW OF CONTINENTAL
POLAR AIR ALL THE WAY INTO THE DEEP SOUTH. HIGHS LOOK TO STRUGGLE TO
GET OUT OF THE 50S THURSDAY THROUGH SATURDAY...WITH FREEZING
OVERNIGHT LOWS EXPECTED FRIDAY AND SATURDAY MORNING. IN FACT...
SATURDAY MORNING IS LOOKING VERY COLD WITH TEMPS IN THE 20S VERY
POSSIBLE. TEMPS BEGIN TO MODERATE BY MONDAY AS THE HIGH SHIFTS EAST.
ONLY FORECAST CHANGE WAS TO REMOVE POPS OVER THE WEEKEND AS ALL
GUIDANCE IS IN AGREEMENT ON THE NEXT STORM SYSTEM NOT AFFECTING US
UNTIL LATE MONDAY AT THE EARLIEST. 34/JFB
&&
.AVIATION...(18Z ISSUANCE)...OVC010 THROUGH EARLY THIS EVENING
BECOMING BKN015 LATER THIS EVENING AND LIKELY THE REST OF TONIGHT
THEN SLOWLY DROPPING TO BELOW 010 LATER TUE MORNING AND LIKELY FOR
THE REST OF THE DAY ON TUE CONTINUING THROUGH TUE NIGHT. NORTHERLY
WINDS AT 10 TO 15 KTS WILL BUILD TO AROUND 15 KTS LATER TONIGHT
BECOMING NORTHEAST THEN EAST AND STEADILY BUILDING TO 20 TO 25 KNOTS
BY EARLY TUE AFTERNOON. SOUTHEAST TO SOUTHERLY WINDS GREATER THAN 25
KNOTS AT TIMES WILL BE LIKELY TUES NIGHT INTO WED MORNING WITH
GUSTS POSSIBLY AS HIGH AS 40 KNOTS WED MORNING. HEAVY RAIN IN
SHOWERS AND THUNDERSTORMS WILL FILL IN FROM THE SOUTHWEST TUE
AFTERNOON CONTINUING THROUGH MUCH OF THE DAY ON WED. /32
&&
.MARINE...A COLD FRONT WILL MOVE ACROSS THE NORTH CENTRAL GULF BY
LATE THIS AFTERNOON GIVING WAY TO A MODERATE TO STRONG OFFSHORE FLOW
EARLY THIS EVENING AND OVERNIGHT. AS A RESULT A SMALL CRAFT ADVISORY
IS IN EFFECT FOR THE COASTAL WATERS OF ALABAMA AND NORTHWEST FLORIDA
BEGINNING LATE TONIGHT AND EARLY WED. THE COLD FRONT WILL STALL OVER
THE NORTH CENTRAL GULF ON TUE...FOLLOWED BY A DEVELOPING AREA OF
LOW PRESSURE OVER THE WESTERN GULF MOVING EASTWARD ACROSS SOUTHERN
SECTIONS OF MISSISSIPPI AND ALABAMA LATE TUE THROUGH WED.
NORTHEASTERLY WINDS AROUND 20 KNOTS EARLY TUE WILL BECOME EAST
THEN SOUTHEAST 30 TO 40 KNOTS LATE IN THE DAY AND IN THE EVENING
THEN BECOMING SOUTH AFTER MIDNIGHT. AS A RESULT A GALE WATCH REMAINS
IN EFFECT FOR TUE AFTERNOON THROUGH WED AND WILL LIKELY BE UPGRADED
TO A GALE WARNING LATER TONIGHT. AS THE LOW MOVES INLAND ALONG THE
MS/AL COAST EARLY WED BOTH THE GFS AND ECMWF CONTINUE TO SHOW THE
SYSTEM DEEPENING POSSIBLY RESULTING IN WINDS SUSTAINED AT 40 KNOTS
OVER MUCH OF THE EASTERN HALF OF THE MARINE AREA WED MORNING AND
EARLY WED AFTERNOON. A WARM FRONT WILL LIKELY ACCOMPANY THIS SYSTEM
TO THE EAST MOVING NORTHWARD TOWARDS THE COAST EARLY WED RESULTING
SCATTERED THUNDERSTORMS MOST LIKELY STRONG TO SEVERE WITH ROTATING
CELLS DUE TO VERY IMPRESSIVE VERTICAL SHEAR IN THE LOWER LEVELS AND
DECENT INSTABILITY OFFSHORE AND POSSIBLY ALONG THE AL AND NWFL COAST
FROM ABOUT GULF SHORES TO DESTIN. STAY TUNED FOR FURTHER UPDATES
THROUGH WED AS THIS SYSTEM EVOLVES AND APPROACHES FROM THE
SOUTHWEST. /32
&&
.FIRE WEATHER...NO CONCERNS WITH A SOAKING RAIN EXPECTED TUESDAY
AFTERNOON THROUGH THE FIRST HALF OF WEDNESDAY.
&&
.HYDROLOGY...HEAVY RAINFALL IS EXPECTED OVER PORTIONS OF SOUTHEAST
MISSISSIPPI...SOUTHWEST/SOUTHCENTRAL ALABAMA...AND THE NORTHWEST
FLORIDA PANHANDLE OVER THE NEXT 48 HOURS. HOWEVER THE HEAVIEST
RAINFALL AMOUNTS APPEAR TO BE OVER SOUTHWEST/SOUTH CENTRAL ALABAMA
AND THE NORTHWEST FLORIDA PANHANDLE GENERALLY ALONG AND EAST OF THE
I-65 CORRIDOR. WIDESPREAD BASIN-AVERAGED RAINFALL AMOUNTS IN EXCESS
OF 3 INCHES WITH LOCALIZED AMOUNTS OF 5 TO 8 INCHES MAY CAUSE RIVERS
AND STREAMS TO RISE TO LEVELS THAT RESULT IN FLOODING.
MINOR FLOODING IS POSSIBLE ALONG THE STYX RIVER NEAR ELSANOR AND THE
FISH RIVER NEAR SILVERHILL BY WEDNESDAY EVENING. THESE TWO RIVERS
HAVE A HISTORY OF RISING QUICKLY DURING HEAVY RAIN EVENTS. HAVE
DECIDED TO KEEP THE SHOAL RIVER AT CRESTVIEW IN ACTION STAGE FOR THE
REST OF THE WEEK. THE SHOAL RIVER SHOULD REMAIN STEADY THROUGH EARLY
TUESDAY THEN THE RIVER WILL SLOWLY RISE AS HEAVY RAIN MOVES INTO THE
NORTHWEST FLORIDA PANHANDLE TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON. THE SHOAL RIVER IS EXPECTED TO CREST ON FRIDAY MORNING
NEAR 6.1 FEET. THE PERDIDO RIVER AT BARRINEAU PARK IS EXPECTED TO
RISE TO ACTION STAGE BY WEDNESDAY AFTERNOON. THESE RIVERS WILL NEED
TO BE WATCHED AS SIGNIFICANT CHANGES TO THE FORECAST ARE POSSIBLE
DEPENDING ON THE AMOUNT OF RAIN THAT DOES OCCUR.
FOR MORE SPECIFIC INFORMATION ON RIVER FLOODING...PLEASE REFER TO
THE LATEST HYDROLOGIC STATEMENTS...RIVER FLOOD WARNINGS...AND RIVER
FLOOD STATEMENTS ISSUED BY THE NATIONAL WEATHER SERVICE IN MOBILE.
04/KC
&&
.PRELIMINARY POINT TEMPS/POPS...
MOBILE 44 56 53 64 / 10 80 100 80
PENSACOLA 48 58 57 66 / 10 60 100 80
DESTIN 50 62 62 66 / 20 40 100 90
EVERGREEN 39 58 52 63 / 10 40 100 80
WAYNESBORO 40 55 50 59 / 10 60 90 70
CAMDEN 39 57 51 62 / 10 30 100 80
CRESTVIEW 43 60 55 64 / 20 30 100 90
&&
.MOB WATCHES/WARNINGS/ADVISORIES...
AL...FLASH FLOOD WATCH FROM 6 PM TUESDAY TO NOON WEDNESDAY FOR THE
FOLLOWING ZONES: BUTLER...CONECUH...COVINGTON...CRENSHAW...
ESCAMBIA...LOWER BALDWIN...LOWER MOBILE...MONROE...UPPER
BALDWIN...AND UPPER MOBILE.
COASTAL FLOOD WATCH FROM 6 PM TUESDAY TO 9 AM WEDNESDAY FOR THE
FOLLOWING ZONES: LOWER BALDWIN...AND LOWER MOBILE.
FL...FLASH FLOOD WATCH FROM 6 PM TUESDAY TO NOON WEDNESDAY FOR THE
FOLLOWING ZONES: COASTAL ESCAMBIA...COASTAL OKALOOSA...
COASTAL SANTA ROSA...INLAND ESCAMBIA...INLAND OKALOOSA...
AND INLAND SANTA ROSA.
COASTAL FLOOD WATCH FROM 6 PM TUESDAY TO 9 AM WEDNESDAY FOR THE
FOLLOWING ZONES: COASTAL ESCAMBIA...COASTAL OKALOOSA...AND
COASTAL SANTA ROSA.
MS...NONE.
GM...SMALL CRAFT ADVISORY FROM NOON TUESDAY TO 9 PM TUESDAY FOR THE
FOLLOWING ZONES: AND MOBILE BAY.
SMALL CRAFT ADVISORY FROM MIDNIGHT TUESDAY TO NOON TUESDAY 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...WATERS FROM DESTIN TO
PENSACOLA FL FROM 20 TO 60 NM...AND WATERS FROM PENSACOLA
FL TO PASCAGOULA MS FROM 20 TO 60 NM.
GALE WATCH FROM NOON CST TUESDAY TO MIDNIGHT CST THURSDAY FOR
COASTAL WATERS FROM DESTIN TO PASCAGOULA MS OUT 60 NM.
GALE WATCH FOR MOBILE BAY FROM 9 PM CST TUESDAY TO NOON CST
WEDNESDAY.
&&
$$
