FXUS64 KMOB 262141
AFDMOB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOBILE AL
341 PM CST THU NOV 26 2009
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)...A CHILLY NIGHT ON TAP
WITH WIDESPREAD SITES IN OUR INLAND COUNTIES EXPECTED TO SEE
OVERNIGHT LOWS NEAR 30 DEGREES. EXPECT THE NORTHERLY WINDS TO STAY
UP A LITTLE BIT TONIGHT ALONG AND NEAR THE COASTAL SO OVERNIGHT LOWS
WILL BE A LITTLE WARMER AROUND 40 TO MID 30S AT THESE SITES.
TEMPERATURES TOMORROW SHOULD WARM INTO THE LOWER 60S MOST SITES AS
THE UPPER LEVEL TROUGH SHIFTS EAST WITH RISING HEIGHTS AND WARM AIR
ADVECTION (WAA) ALOFT. THE SURFACE HIGH PRESSURE SYSTEM CENTERED OVER
THE SOUTHERN PLAINS WILL KEEP SURFACE WINDS NORTH TO WEST-
NORTHWESTERLY AS IT SHIFTS EASTWARD. SURFACE WINDS WILL BE LIGHTER
TOMORROW AS THE SURFACE GRADIENT WEAKENS AND WAA ALOFT SHUTS OFF
MOMENTUM MIXING FROM THE STRONGER WINDS ABOVE THE SURFACE. ANOTHER
COLD NIGHT EXPECTED FRIDAY NIGHT...HOWEVER...TEMPS AT MOST SITES
SHOULD REMAIN ABOVE FREEZING AS WARM TO NEUTRAL ADVECTION OCCURS IN
THE LOWER LEVELS AND RADIATIONAL COOLING IS HAMPERED BY HIGH LEVEL
CLOUDS INVADING FROM THE SOUTHWEST. CLOUD COVER COMES COURTESY OF THE
REMNANTS OF A CUT OFF LOW OVER BAJA CALIFORNIA BEING CAUGHT UP IN THE
SOUTHERN STREAM OF THE POLAR FRONT JET AND EJECTED EAST NORTH
EASTWARD ACROSS THE SOUTHEASTERN STATES. /08 JVW
.LONG TERM...(SATURDAY THROUGH THURSDAY)...BY SATURDAY THE SURFACE
HIGH SHIFTS EAST OF OUR AREA SIGNALING THE START OF A RETURN FLOW.
HENCE, TEMPERATURES WILL MODERATE AND HUMIDITIES WILL INCREASE AT
LEAST THROUGH EARLY MONDAY. THE GLOBAL SPECTRAL MODELS HAVE BEEN CONSISTENT
THE PAST SEVERAL DAY IN PROJECTING A FRONTAL SYSTEM INTO OUR REGION
DURING THE MONDAY TO MONDAY NIGHT TIME-FRAME. THE SOLUTIONS AMONG THE MODELS
AND THEIR ENSEMBLE MEMBERS AS TO THE TIMING AND THE STRUCTURE OF THIS
SYSTEM CONTINUES TO VARY CONSIDERABLY. LATEST GUIDANCE SUGGESTS THE
SHORTWAVE TROUGH NOW IMPACTING THE NORTHWEST PACIFIC COAST WILL
CONTINUE TO DEEPEN AS IT PROGRESSES EASTWARD. BY THE TIME IT PUSHES
EAST OF THE ROCKIES ON SUNDAY THE TROUGH HAS SPLIT WITH A DEEPENING
UPPER LEVEL LOW IN THE SOUTHERN STREAM OVER NORTHERN BAJA
CALIFORNIA...THE TROUGH CONTINUES TO PROPAGATE EASTWARD DRIVING A
SURFACE COLD FRONT ACROSS OUR REGION SOMETIME MONDAY...MAIN DYNAMICS
ARE SPLIT NORTH AND SOUTH OF OUR REGION...SO CHANCE OF STRONG TO
SEVERE STORMS LESSEN WITH THIS SOLUTION FOR MONDAY...MONDAY NIGHT.
BUT IS HEIGHTEN FOR SOMETIME TUESDAY NIGHT THROUGH
WEDNESDAY AS MODELS EJECT THE STRONG UPPER LEVEL LOW AND ASSOCIATED
SOUTHERN SHORTWAVE TROUGH NORTHEASTWARD STRENGTHENING THE REMNANTS OF
THE FRONTAL BOUNDARY PREVIOUSLY LEFT LINGERING ACROSS THE NORTHERN
AND WESTERN GULF. ECMWF AND GFS SUGGEST RAPID CYCLOGENESIS OF A
SURFACE LOW AS IT OCCLUDES AS IT MOVES ON SHORE SOMEWHERE BETWEEN SE
LA AND THE FL PANHANDLE. AMPLE FORCING AND SHEER WILL BE AVAILABLE IF
THE SYSTEM EVOLVES AS ADVERTISED FOR STRONG TO SEVERE
CONVECTION. DEPENDING ON THE TRACK...PARTS OF OUR REGION COULD END
UP IN THE WARM SECTOR. TOO MANY VARIABLES AND TOO MUCH INCONSISTENCY
IN MODEL RUNS TO FULLY BUY OFF ON A FULL SOLUTION RIGHT NOW...BUT
WE'LL HAVE TO CLOSELY MONITOR THE EVOLUTION OF THIS COMPLEX SYSTEM.
FOR NOW THOUGH...FEEL PRETTY CONFIDENT IN THE FORECAST OF INCREASING THE
CHANCE OF SHOWERS AND THUNDERSTORMS BEGINNING ON MONDAY. /08 JVW
&&
.AVIATION...(18Z ISSUANCE) LITTLE CHANGE TO PREVIOUS FORECAST. VFR
THROUGH TONIGHT WITH WINDS DROPPING OFF AFTER SUNSET AND INCREASING
A BIT AFTER SUNRISE.
&&
.MARINE...NORTHWEST WINDS WILL INCREASE AS COOL REINFORCEMENT
ARRIVES WITH A DEEP UPPER TROUGH. WINDS WILL DIMINISH FRIDAY
MORNING...REMAINING NORTH TO NORTHEAST INTO SATURDAY MORNING
BECOMING LIGHT AND VARIABLE AS THE SURFACE HIGH CENTER ARRIVES. WIND
WILL THEN VEER SOUTH SATURDAY NIGHT AS THE HIGH MOVES EAST OF THE
MARINE AREA. GUIDANCE MONDAY HAS THE OUTPUT OF THE ECMWF AND GFS AT
ODDS WITH EACH OTHER THEY BOTH ARE SHOWING A SURFACE LOW APPROACHING
FROM THE WEST CENTRAL GMEX OFF BROWNSVILLE BUT AT DIFFERENT TIMES
AND INTENSITY. LEFT THE WINDS ALONE TO KEEP THE BLEND WITH NEIGHBORS
ESPECIALLY WIND DIRECTION. THE EURO WAS WEAKER AND SLOWER BRINGING
THE LOW IN TO OUR WEST. WINDS INCREASING ONSHORE SUNDAY NIGHT
BECOMING NORTH MONDAY NIGHT. NEXT WINDOW FOR CONVECTION IS SUNDAY
NIGHT AS THE GULF OPENS UP AND WATER VAPOR RETURNS.
/77
&&
.FIRE WEATHER...THE POST FRONTAL DRY AIRMASS ENTRENCHED OVER THE
REGION ALONG WITH THE NORTHERLY SURFACE FLOW WILL CONTINUE THROUGH
FRIDAY. RELATIVE HUMIDITIES HAVE FALLEN BELOW CRITICAL LEVELS FOR
SEVERAL HOURS ACROSS THE WESTERN FLORIDA PANHANDLE TODAY AND ARE
EXPECTED TO DO SO AGAIN TOMORROW. THE AIRMASS OVER US WILL GRADUALLY
MODIFY SATURDAY AS SOUTHERLY SURFACE FLOW ESTABLISHES ITSELF OVER THE
REGION. /08 JVW
&&
.PRELIMINARY POINT TEMPS/POPS...
MOBILE 34 60 37 66 / 00 00 05 05
PENSACOLA 39 61 40 66 / 00 00 05 05
DESTIN 43 60 45 63 / 00 00 05 05
EVERGREEN 31 60 34 65 / 00 00 05 05
WAYNESBORO 29 59 33 66 / 00 00 05 05
CAMDEN 33 58 34 65 / 05 05 05 05
CRESTVIEW 32 61 35 66 / 00 00 05 05
&&
.MOB WATCHES/WARNINGS/ADVISORIES...
AL...FREEZE WARNING FROM 2 AM FRIDAY TO 7 AM FRIDAY FOR THE FOLLOWING
ZONES: BUTLER...CHOCTAW...CLARKE...CONECUH...COVINGTON...
CRENSHAW...ESCAMBIA...MONROE...UPPER BALDWIN...UPPER
MOBILE...WASHINGTON...AND WILCOX.
FL...FIRE WEATHER WATCH FROM 11 AM FRIDAY TO 4 PM FRIDAY FOR THE
FOLLOWING ZONES: COASTAL ESCAMBIA...COASTAL OKALOOSA...
COASTAL SANTA ROSA...INLAND ESCAMBIA...INLAND OKALOOSA...
AND INLAND SANTA ROSA.
FREEZE WARNING FROM 2 AM FRIDAY TO 7 AM FRIDAY FOR THE FOLLOWING
ZONES: INLAND ESCAMBIA...INLAND OKALOOSA...AND INLAND SANTA
ROSA.
RED FLAG WARNING UNTIL 6 PM THURSDAY FOR THE FOLLOWING ZONES:
COASTAL ESCAMBIA...COASTAL OKALOOSA...COASTAL SANTA ROSA...
INLAND ESCAMBIA...INLAND OKALOOSA...AND INLAND SANTA ROSA.
MS...FREEZE WARNING FROM 2 AM FRIDAY TO 7 AM FRIDAY FOR THE FOLLOWING
ZONES: GEORGE...GREENE...PERRY...STONE...AND WAYNE.
GM...SMALL CRAFT ADVISORY UNTIL 5 AM FRIDAY 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.
&&
$$
