FXUS64 KMOB 102321
AFDMOB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOBILE AL
520 PM CST THU DEC 10 2009
.AVIATION (00Z AND 06Z ISSUANCES)...VFR CONDITIONS CONTINUE FOR THE
NEXT 24-36 HOURS. BROKEN DECK OF HIGH AC/CIRRIFORM CLOUDS GRADUALLY
LOWER TO 6-8 KFT THROUGH THE PERIOD WITH WINDS GRADUALLY VEERING TO
THE NORTHEAST. /29
&&
.SHORT TERM [TONIGHT AND FRIDAY]...LATEST SURFACE MAP SHOWS FRONT
DEEP INTO THE SOUTHERN GULF WITH 10.18Z ANALYSIS INDICATING FRONTAL
WAVE IN THE FORMATIVE STAGES OVER THE SOUTHWEST GULF. NORTH OF THE
BOUNDARY EXISTS AN EXPANSIVE SURFACE HIGH PRESSURE SYSTEM POSITIONED
FROM THE SOUTHERN US...BACK ACROSS THE SOUTHERN PLAINS INTO THE
FRONT RANGE OF THE ROCKIES. THE FORECAST CALLS FOR THE SOUTHERN
STATES SURFACE HIGH TO EXPAND/MOVE EASTWARD OVER THE DEEP SOUTH IN
THE NEAR TERM WHILE GULF FRONT BEGINS TO EASE NORTHWARD TOWARD THE
COAST. THE HIGH LEVEL FLOW ATOP THE APPROACHING FRONT...WILL BE WEST
SOUTHWEST...CONTAINING MID LEVEL IMPULSES THAT MOVE EAST NORTHEAST
OVER THE NORTHERN GULF. LOW LEVEL ISENTROPIC LIFT BECOMES BETTER
ESTABLISHED OVER THE NORTHERN GULF DURING THE DAY FRIDAY WITH LIFT
LOOKING TO EXPAND NORTHWARD INTO THE REGION THROUGH THE AFTERNOON.
FORCING WILL OPERATE ON INCREASED LAYER MOISTURE FOR AN INCREASED POP
TREND FRIDAY. WITH THE REGION ON THE COOL AND MORE STABLE SIDE OF
THE FRONT...THE PREDOMINANT WEATHER CHARACTER LOOKS TO BE RAIN.
AS FOR TEMPERATURES...OVERNIGHT MINS LOOK TO DROP BELOW FREEZING
MAINLY NORTH OF THE COASTAL ZONE BREAKOUT =>MOBILE EASTWARD TO
CRESTVIEW. ALONG THE BEACHES...LOWS LOOK TO BE IN THE MID 30S.
FRIDAY'S MAX TEMPERATURES WILL BE ON THE COOL SIDE WITH READINGS
LOOKING TO STRUGGLE TO GET OUT OF THE 40S. A DREARY DAY AS THE CLOUDS
INCREASE AND THE RAINS MOVE IN FROM THE SOUTH. /10
&&
.LONG TERM [FRIDAY NIGHT THROUGH THURSDAY]...UPPER LEVEL DIVERGENCE
WILL BEGIN TO INCREASE ACROSS THE REGION TO BEGIN THE MEDIUM RANGE.
MEANWHILE...ISENTROPIC LIFT WILL ALSO CONTINUE TO INCREASE...WITH
LIFT NOTED IN THE 295-310K LAYER. RAIN IS EXPECTED TO INCREASE IN
COVERAGE FROM SOUTH TO NORTH THROUGH THE NIGHT. SATURDAY WET. FRONTAL
LOW PRESSURE STILL OVER THE WESTERN GULF BY 12Z SATURDAY...ITS
ATTENDANT FRONTAL BOUNDARY IS EXPECTED TO REMAIN OVER THE NORTHERN
GULF...KEEPING US FIRMLY IN THE COOL SECTOR. SO WE ARE EXPECTING A
VERY CHILLY RAIN OVERNIGHT WITH LOWS IN THE UPPER 30S INLAND TO LOWER
40S ALONG THE COAST. RAINS MAY BE LOCALLY HEAVY. NO WINTRY TYPE
PRECIP CONCERNS THOUGH ARE ANTICIPATED AS LAYER THICKNESSES WILL BE
TO WARM TO SUPPORT IT. GIVEN THE POSITION OF THE STRONG HIGH/WEDGE
INTO THE SOUTHEAST...CLOUDS AND RAIN EXPANDING NORTHWARD ACROSS THE
REGION ON SATURDAY...WE HAVE UNDERCUT THE MAVMOS GUIDANCE A FEW
DEGREES FOR HIGHS...LEANING CLOSER TO THE COOLER METMOS NUMBERS.
TRYING TO TIME WHEN SHALLOW COLD AIR WEDGE WILL WEAKEN IS ALWAYS
DIFFICULT AND NOT ALWAYS HANDLED WELL BY THE MODEL GUIDANCE.
THUS...WOULD NOT BE SURPRISED IF WE STAYED IN THE 40S ALL DAY ON
SATURDAY.
[SUNDAY THROUGH THURSDAY]...THE COOLER AIR WILL MODIFY AS THE SFC
HIGH OVER THE EASTERN SEABOARD CONTINUES TO WEAKEN AND RETREAT. THIS
ALLOWS THE RESIDUAL NORTHERN GULF WARM FRONT TO PUSH A LITTLE FURTHER
INLAND...ALTHOUGH IT BECOMES RATHER ILL DEFINED. GIVEN THIS BOUNDARY
IS PRESENT AND THE FACT THAT MODEL GUIDANCE BRINGS IN SOME
INSTABILITY DURING THE DAY...WILL KEEP A CHANCE POP GOING. RAIN
CHANCES SHOULD TAPER OFF SUNDAY NIGHT WITH LACK OF ANY DISCERNABLE
UPPER LEVEL FORCING AND A STABILIZING SFC LAYER. HIGHS APPROACH 70
CLOSE TO THE COAST SUNDAY WITH LOWER/MID 60S INLAND. LOWS WILL ONLY
BE IN THE 50S TO NEAR 60.
THE BREAK IN PRECIP WILL BE SHORT LIVED AS YET ANOTHER COLD FRONT
WILL BEGIN TO APPROACH LATE MONDAY AND CROSS THE AREA TUESDAY/TUESDAY
EVENING. MONDAY WILL BE WELL ABOVE NORMAL TEMP WISE WITH HIGHS IN THE
LOW TO MID 70S. COOLING DOWN AGAIN WEDNESDAY AND THURSDAY. /10
&&
.AVIATION (10/18Z AND 11/00Z ISSUANCES)...VFR CONDITIONS EXPECTED
THROUGH THE NEXT 24 HOURS...ALTHOUGH EXPECT CONSIDERABLE HIGH
CLOUDINESS TO CONTINUE. WILL CONTINUE WITH A NORTH TO NORTHEAST SFC
FLOW ACROSS THE REGION...STRONGER AND MORE GUSTY NEAR THE
COAST...ESPECIALLY DURING THE DAYTIME HOURS. 12/DS
&&
.MARINE...A WARM FRONT WILL MOVE NORTH TOWARD THE MARINE AREA THIS
WEEKEND AS AN AREA OF LOW PRESSURE DEVELOPS OVER THE NORTHWEST GULF.
A STRONG OFFSHORE FLOW TODAY AND TONIGHT WILL BECOME MOSTLY EAST
FRIDAY THROUGH EARLY SATURDAY AS THE AREA OF LOW PRESSURE APPROACHES
FROM THE WEST. A LIGHT TO MODERATE SOUTHERLY WIND FLOW WILL DEVELOP
BY EARLY SUNDAY AND CONTINUE THROUGH EARLY TUESDAY AS THE AREA OF LOW
PRESSURE WEAKENS AND LIFTS NORTH. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO BECOME NUMEROUS ESPECIALLY FRIDAY NIGHT AND SATURDAY. A
STRONG OFFSHORE FLOW IS EXPECTED IN THE WAKE OF A COLD FRONT BY THE
MIDDLE PART OF NEXT WEEK. 12/DS
&&
.FIRE WEATHER...STALLED FRONT OVER THE GULF TONIGHT BEGINS TO EASE
NORTHWARD ON FRIDAY AND STALL AGAIN...SHORT OF THE COAST ON SATURDAY
WITH STRONG HIGH PRESSURE CONTINUING TO DOMINATE THE SOUTHEASTERN
UNITED STATES. THE WEATHER BECOMES MORE UNSETTLED AS THE FRONT GETS
CLOSER TO THE COAST WITH A CHILLY RAIN IN THE FORECAST...ENTERING THE
WEEKEND. ALTHOUGH DAYTIME MIXED LAYERS LOOK TO BE SHALLOW UNDER COOL
CONDITIONS...MODERATE NORTHEAST TO EASTERLY TRANSPORT FLOW SHOULD
MAKE FOR FAIR TO AVERAGE DISPERSIONS MOST AREAS. /10
&&
.PRELIMINARY POINT TEMPS/POPS...
MOBILE 34 45 43 51 / 05 50 80 80
PENSACOLA 36 47 45 52 / 05 50 80 80
DESTIN 36 50 44 52 / 05 50 80 80
EVERGREEN 29 45 41 49 / 05 40 60 80
WAYNESBORO 30 45 39 47 / 05 20 70 80
CAMDEN 29 47 38 47 / 05 20 60 80
CRESTVIEW 31 45 41 50 / 05 50 80 80
&&
.MOB WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
FL...RED FLAG WARNING UNTIL 4 PM THURSDAY FOR THE FOLLOWING ZONES:
COASTAL ESCAMBIA...COASTAL OKALOOSA...COASTAL SANTA ROSA...
INLAND ESCAMBIA...INLAND OKALOOSA...AND INLAND SANTA ROSA.
MS...NONE.
GM...SMALL CRAFT ADVISORY UNTIL NOON FRIDAY FOR THE FOLLOWING ZONES:
AND MOBILE BAY.
SMALL CRAFT ADVISORY UNTIL NOON SATURDAY 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.
&&
$$
