FXUS64 KMOB 261738 AAA
AFDMOB
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MOBILE AL
1138 AM CST SAT DEC 26 2009
.AVIATION...
18Z TAF CYCLE.
VFR CONDITIONS EXPECTED THROUGH EARLY SUNDAY MORNING WITH ONLY MID
AND HIGH LEVEL CLOUDS STREAMING ACROSS THE AREA DUE TO STRONG
SOUTHWESTERLY UPPER LEVEL FLOW. A WEAK TROUGH WILL MOVE ACROSS THE
AREA SUNDAY MORNING...AND THERE WILL BE A CHANCE FOR MVFR CIGS
THROUGH 18Z...ALTHOUGH RAIN CHANCES APPEAR VERY SMALL. A LIGHT EAST
TO SOUTHEAST WIND TODAY BECOMES LIGHT AND VARIABLE TONIGHT WITH SFC
RIDGING PERSISTING. WINDS BECOME NORTHWEST NEAR 18Z TOMORROW AS THE
SFC TROUGH MOVES THROUGH. 34/JFB
&&
/PREVIOUS DISCUSSION ISSUED 400 AM CST SAT DEC 26 2009/
.SHORT TERM (TODAY AND TONIGHT)...LATEST SFC MAP SHOWS WEAK SFC
RIDGE CENTERED MOSTLY OVER SOUTHERN LA PROGGED TO DRIFT EAST AND
WEAKEN OVER THE SW AL AND NWFL COASTAL AREAS THROUGH 12Z
SUN...GENERALLY IN RESPONSE TO MAIN UPPER LOW OVER THE UPPER MS
RIVER MEANDERING OR DRIFTING SLIGHTLY NORTHWARD THROUGH TONIGHT. TO
THE SOUTH AND SOUTHWEST BETTER MID TO HIGH CLOUDINESS IS NOTED BY
IR/WV LOOPS THIS MORNING MOSTLY IN RESPONSE TO FAVORABLE SIDE OF
SOUTHERN BRANCH OF UPPER JET STREAK LOCATED ACROSS THE NW AND N
CENTRAL GULF...COMBINED WITH A WEAK INVERTED SFC TROF REFLECTING IN
THE LOWER LEVELS...PROGGED TO SHIFT ENE ACROSS THE NORTH CENTRAL
GULF THROUGH TONIGHT. WITH THIS PATTERN MAIN CONCERN ACROSS THE CWFA
TODAY CONTINUES TO BE PERSISTENT HIGH CLOUDINESS FROM THE
SW...GIVING WAY TO MORE COOL DAMP CONDITIONS ACROSS THE REGION
THROUGH TONIGHT. AS RESULT HAVE LEANED TOWARDS COOLER MET GUIDANCE
FOR TEMPS THIS AFTERNOON AND THE WARMER MAV NUMBERS FOR TONIGHT DUE
TO THE PERSISTENT CLOUDINESS FROM THE SW AND CONSISTENCY W/
SURROUNDING OFFICES. AS FOR POPS FOR LATE TONIGHT AND INTO EARLY SUN
HAVE TRIMMED BACK THE COVERAGE OF LIGHT RA JUST A TAD...MOSTLY OVER
LAND...WHICH IS BASICALLY A REFLECTION OF THE SLOWER ECMWF
SOLUTION...32/EE
SUNDAY INTO MONDAY NIGHT...ENHANCED UPPER LEVEL DIVERGENCE OVER THE
CENTRAL GULF COAST AREA IN A COUPLED UPPER POLAR/SOUTHERN STREAM JET
PATTERN WEAKENS AS SOUTHERN STREAM SHORTWAVES MOVE AWAY FROM THE
REGION BUT STILL LEAVES THE CENTRAL GULF COAST REGION UNDER THE
INFLUENCE OF THE RIGHT ENTRANCE REGION OF A 130+ UPPER POLAR JET. A
SURFACE LOW...INITIALLY BETTER DEFINED SUNDAY MORNING...MOVES FROM
THE NORTHWESTERN GULF EASTWARD AND WEAKENS WITH THE WEAKENING UPPER
LEVEL SUPPORT. WITH THE WEAKENING TREND...WILL STAY CLOSE TO THE
CURRENT PACKAGE WHICH HAS SMALL POPS OVER THE COASTAL COUNTIES ON
SUNDAY THEN DRY SUNDAY NIGHT THROUGH MONDAY NIGHT AS RIDGING BUILDS
IN FROM THE PLAINS. AS NOTED BY THE DAY SHIFT...THE 1000-850 MB
THICKNESSES ARE NEAR 1320 METERS OVER THE NORTHERN MOST COUNTIES
WHICH SUGGESTS A FEW SLEET PELLETS WOULD BE MIXED IN WITH PRECIP IN
THIS AREA...BUT THIS IS MOOT AS AM LIKEWISE KEEPING POPS POPS SOUTH
OF THE THIS COLDER AIR WITH THIS ISSUANCE. TEMPERATURES WILL TREND
COOLER DURING THE PERIOD AS A DEEP LAYER NORTHERLY FLOW STRENGTHENS
WITH THE RIDGING BUILDING IN FROM THE WEST. /29
.LONG TERM (TUESDAY INTO FRIDAY)...CHALLENGING FORECAST FOR THE LONG
TERM. PER COORDINATION WITH AREA OFFICES HAVE GONE WITH THE SLOWER
BUT MORE CONSISTENT ECMWF SOLUTION FOR A SURFACE LOW DEVELOPING OVER
THE NORTHWESTERN GULF ON TUESDAY WHICH TRACKS EASTWARD AND ACROSS
THE CENTRAL GULF COAST REGION WEDNESDAY NIGHT THROUGH THURSDAY. THE
SUPERIOR PERFORMANCE OF THE ECMWF THIS SEASON WITH THESE GULF LOWS
PLAYED HEAVILY IN THE SELECTION OF THIS MODEL...AND THE TENDENCY FOR
RIDGING OVER THE SOUTHEASTERN STATES TO SLOW DOWN THE EASTWARD
ADVANCE OF GULF SYSTEMS WHICH ALSO FAVORS THE SLOWER ECMWF
SOLUTION. WILL INTRODUCE SLIGHT CHANCE POPS OVER THE EASTERN
SECTION WITH CHANCE POPS OVER THE WESTERN HALF OF THE FORECAST AREA
TUESDAY NIGHT THEN LIKELY POPS ACROSS MUCH OF THE AREA WEDNESDAY AND
WEDNESDAY NIGHT AS THE SURFACE LOW ADVANCES TO COASTAL MISSISSIPPI.
HAVE STAYED WITH GOOD CHANCE POPS ON THURSDAY TO BETTER BLEND WITH
NEIGHBORS AS THE SURFACE LOW IS EXPECTED TO TRACK ACROSS THE
FORECAST AREA. LIKELY POPS WOULD BE SUPPORTED BUT THIS IS TEMPERED
BY UNCERTAINTIES WITH THE PATTERN. POPS TAPER OFF THURSDAY NIGHT
INTO FRIDAY AS THE SYSTEM EXITS TO THE NORTHEAST AND MAY EVOLVE INTO
A POWERHOUSE SYSTEM AFFECTING THE NEW ENGLAND AREA. TEMPERATURES
REMAIN BELOW SEASONABLE LEVELS THROUGH THE PERIOD. /29
.MARINE...HIGH PRESSURE CENTERED OVER THE LOWER MS RIVER AND NORTH
CENTRAL GULF WILL MOVE EAST AND WEAKEN THROUGH SUN AS A WEAK
INVERTED SFC TROF OF LOW PRESSURE MOVES EAST AND DAMPENS ACROSS THE
CENTRAL AND NORTHERN GULF THROUGH SUN NIGHT. AS A RESULT A MODERATE
NORTHERLY WIND FLOW OVER THE MARINE AREA THIS MORNING WILL WEAKEN
AND BECOME MOSTLY EAST BY LATE THIS AFTERNOON...REMAINING MOSTLY
EAST THROUGH MIDDAY SUN THEN BACKING FROM THE NORTH AS COOLER AIR
ADVECTS SOUTH IN THE WAKE OF MAIN UPPER TROF AXIS SLOWLY SHIFTING
EAST OF THE CENTRAL GULF COAST REGION. AS THIS SYSTEM EXITS TO THE
EAST INCREASED RIDGING ALOFT IS NOTED FOR THE FIRST PART OF NEXT
WEEK GIVING WAY TO ANOTHER SFC HIGH OVER MUCH OF THE LOWER MS RIVER
AND SE CONUS MONDAY THROUGH TUE. BY WED NEXT DEEPENING UPPER TROF
MOVES ACROSS THE CENTRAL CONUS WITH A DEVELOPING SFC LOW AND
ATTENDANT COLD FRONT DEVELOPING OVER EAST TX MOVING EASTWARD ACROSS
THE NORTHERN GULF WED THROUGH EARLY THU. NORTHERN WINDS AND SEAS
WILL BUILD IN THE WAKE OF THE THIS SYSTEM THOUGH NOT UNTIL OVER THE
WEEKEND AS MAIN TROF AXIS SHIFTS EAST OF THE REGION. 32/EE
.FIRE WEATHER...RELATIVE HUMIDITIES WILL DROP BELOW CRITICAL LEVELS
THIS AFTERNOON OVER MOST OF THE NORTHWEST FLORIDA PANHANDLE EXCEPT
FOR CLOSE TO THE COAST. HAVE GONE AHEAD WITH A RED FLAG WARNING FOR
THE ENTIRE NORTHWEST FLORIDA PANHANDLE. RELATIVE HUMIDITIES
OTHERWISE REMAIN JUST ABOVE CRITICAL LEVELS SUNDAY AND MONDAY. /29
&&
.PRELIMINARY POINT TEMPS/POPS...
MOBILE 54 35 57 34 / 00 20 20 10
PENSACOLA 55 38 59 37 / 00 20 20 10
DESTIN 54 42 56 41 / 00 20 20 10
EVERGREEN 53 31 55 29 / 00 10 10 10
WAYNESBORO 53 31 55 29 / 00 10 10 10
CAMDEN 52 30 54 29 / 00 10 10 10
CRESTVIEW 55 32 58 30 / 00 20 20 10
&&
.MOB WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
FL...RED FLAG WARNING FROM 11 AM SATURDAY TO 5 PM SATURDAY FOR THE
FOLLOWING ZONES: COASTAL ESCAMBIA...COASTAL OKALOOSA...
COASTAL SANTA ROSA...INLAND ESCAMBIA...INLAND OKALOOSA...
AND INLAND SANTA ROSA.
MS...NONE.
GM...NONE.
&&
$$
