FXUS64 KMOB 090000 AAA
AFDMOB
AREA FORECAST DISCUSSION...AVIATION UPDATE
NATIONAL WEATHER SERVICE MOBILE AL
550 PM CST TUE DEC 8 2009
.AVIATION UPDATE FOR 09/00Z...MOST REPORTING LOCATIONS AROUND THE
AREA ALREADY IFR IN LOW CEILING AND FOG. EXPECT THESE CONDITIONS TO
CONTINUE OVER NIGHT WITH SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS. BEST CHANCES FOR STRONG OR SEVERE STORMS BEFORE
MIDNIGHT LOOK TO BE ACROSS THE NORTHERN SECTIONS. COLD FRONT CROSSES
INTERSTATE 65 SHORTLY AFTER SUNRISE AND BEGINS THE CLEARING OUT
PROCESS WITH SUNNY SKIES AREAWIDE BY AFTERNOON. /11
************************PREVIOUS*****************************
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)TAKING A LOOK AT THE
CURRENT ANALYSIS OVER THE CONUS AND SURROUNDING AREAS...THE SMALL
SHORTWAVE WHICH FIRED OFF LAST NIGHT INTO THIS MORNING'S ROUND OF
RAIN IS LOCATED OVER MS/AL...TAKING A NORTHEAST PATH AS THE MAIN
UPPER SYSTEM MOVES OVER EAST OVER THE CENTRAL PLAINS. AS THE LOWER
MISS RIVER VALLEY HAS COME UNDER THE INCREASING SOUTHERLY FLOW FROM
THIS MAIN SYSTEM...A WARM FRONT HAS ORGANIZED ALONG THE GULF
COAST...WITH ITS POSITION AT 1 PM RUNNING FROM SOUTH OF KDTS TO SOUTH
OF KHBG.
FOR TONIGHT INTO WEDNESDAY...AS THE ENERGY OVER THE ROCKIES MOVES
EAST...PASSING OVER THE MID MISS RIVER VALLEY TONIGHT...THEN
TAKING A NORTHEAST TREK. A COLD FRONT ASSOCIATED WITH THIS SYSTEM
WILL START MOVING ACROSS THE AREA LATE TONIGHT INTO EARLY WEDNESDAY.
WITH INLAND PROGRESSION OF THE WARM FRONT COMES AN INCREASED RISK OF
DESTABILIZATION OF THE ATMOSPHERE...AND THE BETTER CHANCE FOR
THUNDERSTORMS TO BECOME STRONG TO SEVERE. GUIDANCE IS EASING THE
0-3KM HELICITY AHEAD OF THE BEST INSTABILITY MOVING OVER THE
FA...BUT LOOKING AT THE MODEL SOUNDINGS...ENOUGH WILL BE PRESENT FOR
SOME OF THE STORMS TO BEGIN TO ROTATE. GUIDANCE IS ADVERTISING THE
MAIN SQUALL LINE MOVING OVER THE FA IN THE EVENING AND EXITING EAST
OF THE FA BY SUNRISE. THERE EXISTS SOME TIMING DIFFERENCES AMONGST
THE GUIDANCE...BUT ALL GENERALLY AGREE TO THIS TIME FRAME.
FOR LATER WEDNESDAY ON...AS THE FRONT MOVES OVER THE FA
WEDNESDAY...EXITING SOUTH OF THE MARINE AREA BY EARLY AFTERNOON.
GUIDANCE THEN STALLS THE FRONT OVER THE CENTRAL GULF BY WEDNESDAY
NIGHT. GUIDANCE IS ADVERTISING A SHORTWAVE PASSING OVER THE NORTHERN
GULF COAST...PROVIDING A CHANCE FOR ISENTROPIC UPGLIDE SHOWERS OVER
MAINLY THE MARINE FA.
.LONG TERM...(FRIDAY ON)BY FRIDAY...ANOTHER SYSTEM IS STARTING
ACROSS THE PLAINS...ALBEIT THE SOUTHERN ONES...FORMING A SURFACE LOW
OVER THE WESTERN GULF AND TAKING IT NORTHEAST TOWARDS THE FA. THIS
SURFACE LOW BECOME MORE DISORGANIZED AS IT DUE TO DISORGANIZED UPPER
ENERGY...BUT PROVIDING THE NEXT CHANCE FOR RAIN FRIDAY INTO SATURDAY.
YET ANOTHER ROUND OF ENERGY BRING A THIRD ROUND OF PRECIP TO THE
AREA IN THE MONDAY...TUESDAY TIME FRAME.
&&
.AVIATION...(18Z ISSUANCE)DIFFICULT CEILING FORECAST FOR TAFS.
WARM FRONT CURRENTLY IN THE PROCESS OF MOVING INLAND THROUGH THE
COASTAL COUNTIES BUT CEILINGS HAVE BEEN SLOW TO RISE. HAVE GONE
WITH PREVAILING MVFR CONDITIONS THROUGH MUCH OF THE PERIOD WITH
TEMPO GROUPS FOR SHOWERS GRADUALLY TRANSITIONING TO IFR CONDITIONS
IN THUNDERSTORMS FROM ABOUT 6-10Z AS A WEAKENING SQUALL LINE IS
EXPECTED TO MOVE THROUGH THE AREA. VFR CONDITIONS FOLLOW IN THE
WAKE A COLD FRONT WHICH MOVES THROUGH AROUND 14-16Z WEDNESDAY.
/29
&&
.MARINE...SOUTHERLY WINDS WILL INCREASE THROUGH TONIGHT AS A COLD
FRONT ADVANCES FROM THE SOUTHERN PLAINS. THE COLD FRONT MOVES
THROUGH THE MARINE AREA ON WEDNESDAY WITH A MODERATE NORTHERLY WIND
FOLLOWING IN THE WAKE OF THE FRONT. HAVE TRIMMED THE SMALL CRAFT
ADVISORY ENDING TIME TO 12Z FOR MOBILE BAY ALTHOUGH THIS IS
STRETCHING IT AS WINDS WILL HAVE SUBSIDED TO 15 KNOTS BY THEN...AND
WILL LEAVE THE ENDING TIME AS IS FOR THE REMAINDER OF THE AREA AS
ALTHOUGH WINDS WILL HAVE SUBSIDED WELL BELOW ADVISORY LEVELS BY
THEN...SEAS WILL BE A BIT SLOWER TO SUBSIDE. THE OFFSHORE FLOW
INCREASES WEDNESDAY NIGHT AS STRONG HIGH PRESSURE BUILDS INTO THE
REGION AND BECOMES EASTERLY BY FRIDAY AS HIGH PRESSURE MOVES ACROSS
THE SOUTHEAST STATES. A MODERATE TO STRONG ONSHORE FLOW DEVELOPS
FRIDAY NIGHT AS A LOW PRESSURE SYSTEM APPROACHES FROM THE NORTHWEST
GULF...THEN SWITCHES TO THE NORTHWEST BY SATURDAY EVENING AS THE LOW
PRESSURE SYSTEM MOVES ACROSS THE NORTHERN GULF AND EAST OF THE
MARINE AREA. /29
&&
.FIRE WEATHER...AFTER THE LAST ROUND OF RAIN WITH THE CURRENT SYSTEM
MOVES EAST OF THE AREA WEDNESDAY MORNING AND ITS ASSOCIATED FRONT
STALLS OVER THE NORTHERN GULF OF MEXICO...A COOLER...DRIER AIRMASS
WILL MOVE OVER THE AREA...WITH DAYTIME RELATIVE HUMIDITY VALUES
THURSDAY DROPPING GENERALLY INTO THE 30 TO 35 PERCENT RANGE. A WEAK
UPPER SYSTEM WILL PASS OVER THE AREA LATE WEDNESDAY NIGHT INTO
THURSDAY ...BRINGING A SLIGHT CHANCE FOR RAIN...MAINLY TO NEAR
COASTAL COUNTIES. THIS WILL ALSO HELP TO LIMIT THE DAYTIME RELATIVE
HUMIDITY DROP THURSDAY. A STRONGER UPPER SYSTEM WILL APPROACH THE
AREA FRIDAY INTO SATURDAY...WITH MORE RAIN EXPECTED AHEAD OF A
FRONTAL PASSAGE SATURDAY NIGHT. ANOTHER ROUND OF RAIN IS EXPECTED
LATE MONDAY INTO TUESDAY IN THE COMING WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
MOBILE 61 69 36 55 39 / 80 10 20 20 10
PENSACOLA 62 72 42 56 40 / 80 20 20 30 10
DESTIN 64 72 43 56 41 / 70 30 30 30 10
EVERGREEN 58 67 35 54 34 / 90 10 10 10 05
WAYNESBORO 54 58 29 53 29 / 90 10 10 05 10
CAMDEN 57 62 32 52 31 / 90 05 10 10 10
CRESTVIEW 63 73 40 56 36 / 80 20 20 30 10
&&
.MOB WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
FL...NONE.
MS...NONE.
GM...SMALL CRAFT ADVISORY UNTIL NOON WEDNESDAY 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.
SMALL CRAFT ADVISORY UNTIL NOON WEDNESDAY FOR THE FOLLOWING
ZONES: AND MOBILE BAY.
&&
$$
29/16
