FXUS64 KMOB 240548
AFDMOB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOBILE AL
1148 PM CST WED DEC 23 2009
.AVIATION (06Z ISSUANCE)...SIMILAR THINKING AS BEFORE WITH MVFR
CONDITIONS GENERALLY PREVAILING AHEAD OF THE SQUALL LINE WHICH IS
ANTICIPATED TO AFFECT MOB AND BFM BETWEEN 22-01Z AND PNS BETWEEN
23-03Z WITH IFR CONDITIONS...ALLOWING FOR TIMING UNCERTAINTIES. A
CLEAR PATCH HAS AFFECTED PNS AND HAVE KEPT TEMPO GROUPS IN THROUGH
10Z FOR THE TAF SITES TO HANDLE ALTERNATING SCATTERED/BROKEN CLOUDS
UNTIL LAYER LIFTED STRATIFORM CLOUDS PREVAIL. EAST WINDS GRADUALLY
VEER TO THE SOUTHEAST AND INCREASING TO 15-17 KNOTS THURSDAY
AFTERNOON...POSSIBLY HIGHER...AS THE SQUALL LINE ADVANCES FROM THE
WEST. LIGHT RAIN AND MVFR CEILINGS FOLLOW IN THE WAKE OF THE SQUALL
LINE. /29
&&
** PREVIOUS DISCUSSION **
.SHORT TERM (TONIGHT THROUGH CHRISTMAS NIGHT)...MODELS REMAIN IN
FAIRLY GOOD AGREEMENT IN BRINGING A COLD FRONT AND ASSOCIATED WEATHER
ACROSS THE FCST AREA ON CHRISTMAS EVE...THEN QUICKLY MOVING THE
WEATHER SYSTEM EAST OF THE REGION BY CHRISTMAS DAY. AS THE FRONT
APPROACHES FROM THE WEST TONIGHT...A GRADUALLY MOISTENING AIRMASS AND
WEAK LIFT WILL ALLOW FOR THE DEVELOPMENT OF SOME SHOWERS...AND
ISOLATED THUNDERSTORMS...ESPECIALLY COASTAL AND WESTERN ZONES
TONIGHT. THE ISOLATED THUNDERSTORM ACTIVITY SHOULD BE AFTER
MIDNIGHT...BUT SHOWERS ARE POSSIBLE ANYTIME OVERNIGHT. TONIGHTS LOW
TEMPERATURES GENERALLY RANGING FROM THE LOWER TO THE UPPER 50S ACROSS
THE AREA. ON CHRISTMAS EVE...A LINE OF THUNDERSTORMS IS EXPECTED TO
DEVELOP ALONG OR JUST AHEAD OF THE FRONT. THIS LINE OF STORMS IS
ANTICIPATED TO MOVE INTO OUR SOUTHEAST MISSISSIPPI COUNTIES BY LATE
AFTERNOON (3 OR 4 PM)...INTO SOUTHWEST ALABAMA AND PARTS OF THE
FLORIDA PANHANDLE BY AROUND 5 OR 6 PM...AND THEN EXITING STAGE RIGHT
BY AROUND MIDNIGHT. SUFFICIENT DYNAMICS AND SHEAR WILL EXIST FOR
STRONG TO SEVERE THUNDERSTORMS...BUT SUFFICIENT INSTABILITIES WILL
BE LIMITED TO NEAR THE COAST AND OVER THE GULF WATERS. CURRENT
THINKING IS THAT STRONG TO SEVERE THREAT WILL BE MOST LIKELY ALONG
THE COAST AND NOT SO MUCH OVER INTERIOR ZONES. BEST INSTABILITIES
WILL WORK INLAND RIGHT AHEAD OF THE FRONT...AND THAT IS WHERE THE
THREAT FOR STRONGER STORMS WILL BE. DAMAGING WINDS WOULD BE THE
PRIMARY THREAT.
AS THE FRONT APPROACHES...A WINDY SOUTHERLY FLOW WILL DEVELOP...AND
WE HAVE ISSUED A WIND ADVISORY FOR ALL OF OUR ZONES FROM 9AM THURSDAY
TILL 9PM THURSDAY. RIGHT NOW WE ARE EXPECTING SUSTAINED WINDS OF 15
TO 25 MPH...WITH FREQUENT GUSTS OF 30 TO 35 MPH. THE STRONGEST WINDS
WILL LIKELY BE ALONG THE COASTAL SECTIONS OF ALABAMA AND THE WESTERN
FLORIDA PANHANDLE.
MANY ARE RIVERS ACROSS THE REGION REMAIN IN MINOR AND MODERATE
FLOOD...BUT FOR NOW WE DON'T THINK ANY MAJOR ADDITIONAL PROBLEMS WILL
ARISE DUE TO THE EXPECTED FAST MOVEMENT OF THIS SYSTEM. ALSO DO NOT
SEE THE NEED FOR A DENSE FOG ADVISORY. STORM TOTAL QPF'S ARE EXPECTED
TO BE 2.00 TO 2.25 INCHES IN MOST LOCATIONS...BUT A FEW ISOLATED
TOTALS MAY RECEIVE A LITTLE MORE RAINFALL.
GENERALLY WENT WITH THE MAV MOS NUMBERS FOR TEMPERATURE FCST.
12/DS
&&
.LONG TERM (SATURDAY THROUGH WEDNESDAY)...NO CHANGES TO EXTENDED THIS
AFTERNOON. HIGH PRESSURE WILL BUILD INTO THE REGION IN THE WAKE OF
THE FRONT THAT MOVES THROUGH ON CHRISTMAS DAY...WITH COOLER
TEMPERATURES AND A DRIER AIRMASS WORKING INTO THE AREA. TEMPERATURES
ARE EXPECTED TO BE BELOW NORMAL ...WITH DAYTIME HIGHS IN THE 50S AND
NIGHTTIME LOWS RANGING FROM THE UPPER 20S TO THE MIDDLE 30S. 12/DS
&&
.AVIATION (18Z TAF CYCLE)...INCREASING WARM AIR ADVECTION IS
RESULTING IN THE DEVELOPMENT OF SCATTERED LIGHT SHOWERS AND MVFR
CIGS ACROSS THE AREA. EXPECT THESE CONDITIONS TO PERSIST FOR MUCH OF
THE NIGHT. EASTERLY TO SOUTHEASTERLY WINDS WILL BEGIN TO INCREASE
PRIOR TO DAYBREAK AND STRENGTHEN FURTHER THURSDAY MORNING. WIND
GUSTS OF 25-30 KT ARE LIKELY BY MIDDAY THURSDAY. THE CHANCE FOR
SHOWERS AND THUNDERSTORMS INCREASE FURTHER THURSDAY
MORNING...ESPECIALLY LATE MORNING AS A COLD FRONT BEGINS TO APPROACH
FROM THE WEST. MVFR CIGS SHOULD BE PREDOMINATE THROUGH 18Z...BUT MAY
OCCASIONALLY LOWER TO IFR. 34/JFB
&&
.MARINE...EAST TO SOUTHEAST WINDS WILL STRENGTHEN TO SMALL CRAFT
ADVISORY LEVELS TONIGHT AS THE PRESSURE GRADIENT TIGHTENS BETWEEN A
HIGH OVER THE EASTERN SEABOARD AND A DEVELOPING STORM SYSTEM IN THE
PLAINS. A COLD FRONT WILL BEGIN TO MOVE INTO THE MARINE AREA BY EARLY
THURSDAY EVENING AND EXIT BY MIDNIGHT FRIDAY. WINDS WILL GRADUALLY
VEER MORE TO THE SOUTH AHEAD OF THE FRONT DURING THE DAY THURSDAY...
WITH OCCASIONAL GUSTS REACHING CLOSE TO GALE FORCE. WE WILL HAVE TO
CAREFULLY MONITOR WINDS AHEAD OF THE FRONT FOR THE POTENTIAL OF A
SHORT DURATION GALE WARNING. SEAS WILL BUILD IN RESPONSE TO THE
STRENGTHENING WINDS...REACHING AS HIGH AS 7 TO 11 FEET. WIDESPREAD
SHOWERS AND THUNDERSTORMS ARE EXPECTED WITH THE FRONTAL PASSAGE...
WITH MUCH HIGHER WIND GUSTS POSSIBLE IN THE THUNDERSTORM ACTIVITY...
WHICH MAY NECESSITATE SPECIAL MARINE WARNINGS. WINDS WILL VEER TO
THE WEST BEHIND THE FRONT AND STAY STRONG THROUGH FRIDAY MORNING.
WINDS AND SEAS BEGIN TO DIMINISH BY LATE FRIDAY AS SURFACE HIGH
PRESSURE BEGINS TO BUILD IN. A NORTHWEST TO NORTHERLY FLOW IS
EXPECTED THROUGH THE WEEKEND...WITH WINDS STRONGER DURING THE
OVERNIGHT HOURS DUE TO COLD AIR DRAINAGE FROM LAND AREAS. 34/JFB
&&
.FIRE WEATHER...AS A COLD FRONT APPROACHES THE AREA TONIGHT AND
THURSDAY...AN INCREASING SOUTHERLY FLOW WILL KEEP RELATIVE HUMIDITY
LEVELS ABOVE CRITICAL VALUES THROUGH THURSDAY. WIDESPREAD SHOWERS
AND THUNDERSTORMS ARE EXPECTED TO MOVE ACROSS THE REGION OUT AHEAD
OF THE COLD FRONT TONIGHT THROUGH THURSDAY EVENING...WITH THE
STRONGEST AND MORE WIDESPREAD STORMS EXPECTED LATE THURSDAY
AFTERNOON AND INTO THURSDAY EVENING. BY FRIDAY...DRIER AND COOLER AIR
WILL BE MOVING INTO THE REGION IN THE WAKE OF THE COLD FRONT. 12/DS
&&
.PRELIMINARY POINT TEMPS/POPS...
MOBILE 58 69 41 53 / 50 90 70 10
PENSACOLA 57 67 46 54 / 30 90 100 10
DESTIN 56 67 49 56 / 20 90 100 10
EVERGREEN 50 65 42 55 / 30 90 100 10
WAYNESBORO 53 68 36 50 / 60 100 60 10
CAMDEN 49 65 42 52 / 30 90 100 10
CRESTVIEW 53 66 47 55 / 20 90 100 10
&&
.MOB WATCHES/WARNINGS/ADVISORIES...
AL...WIND ADVISORY FROM 9 AM THURSDAY TO 9 PM THURSDAY FOR THE
FOLLOWING ZONES: BUTLER...CHOCTAW...CLARKE...CONECUH...
COVINGTON...CRENSHAW...ESCAMBIA...LOWER BALDWIN...LOWER
MOBILE...MONROE...UPPER BALDWIN...UPPER MOBILE...
WASHINGTON...AND WILCOX.
FL...WIND ADVISORY FROM 9 AM THURSDAY TO 9 PM THURSDAY FOR THE
FOLLOWING ZONES: COASTAL ESCAMBIA...COASTAL OKALOOSA...
COASTAL SANTA ROSA...INLAND ESCAMBIA...INLAND OKALOOSA...
AND INLAND SANTA ROSA.
MS...WIND ADVISORY FROM 9 AM THURSDAY TO 9 PM THURSDAY FOR THE
FOLLOWING ZONES: GEORGE...GREENE...PERRY...STONE...AND
WAYNE.
GM...SMALL CRAFT ADVISORY UNTIL 9 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...MOBILE BAY...WATERS FROM DESTIN TO PENSACOLA FL FROM
20 TO 60 NM...AND WATERS FROM PENSACOLA FL TO PASCAGOULA MS
FROM 20 TO 60 NM.
&&
$$
