Area Forecast Discussion
Issued by NWS Mobile, AL

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FXUS64 KMOB 312049
AFDMOB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOBILE AL
349 PM CDT FRI OCT 31 2014

.SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...WEATHER MAPS SHOW
STRONG CANADIAN FRONT...THE LEADING EDGE OF A MUCH COLDER
AIRMASS...ADVANCING SOUTHEAST ACROSS THE MIDSOUTH. THERE IS A FEW
SPOTTY SHOWERS IN FRONTAL CLOUDS NOTED OVER THE DEEP SOUTH. WILL
CARRY ISOLATED SHOWERS OVER THE INTERIOR NORTHEAST FOR THE REMAINDER
OF THE AFTERNOON. ANY MEASURABLE RAINS LOOK VERY LIGHT. HIGH
RESOLUTION GUIDANCE INDICATE POTENTIAL OF SPOTTY RAINS THIS
EVENING...GENERALLY OVER THE SAME AREAS. CONSIDERING THIS AND GIVEN
SATELLITE/RADAR TRENDS...WILL ADD 10% OR LESS POPS IN FOR THE
EVENING. AT THIS TIME...MEASURABLE RAIN LOOKS LIMITED AT BEST GIVEN
LIMITED DEEP MOISTURE.

THE STRENGTH OF THE HIGH/INCREASED PRESSURE GRADIENT MAGNITUDE IN THE
WAKE OF THE PASSING COLD FRONT AND EXPECTED NORTHWEST TO NORTHERLY
FLOW...SUGGESTS THAT CRITERIA FOR A WIND ADVISORY WILL BE MET OVER
THE GULF COAST TONIGHT. LATEST GRIDDED WIND SPEEDS CALL FOR NORTHWEST
TO NORTH WINDS INCREASING TO 20 TO 25 MPH WITH FREQUENT HIGHER GUSTS
BETWEEN 30 AND 35 MPH ALONG THE COASTAL COUNTIES TONIGHT. THE
STRONGER OF THESE WINDS LOOK TO BE FOCUSED ALONG THE LAND AND SEA
INTERFACE AT THE BEACHES. COLD AIR ADVECTION PROCESSES WILL ALSO BE
UNDERWAY TONIGHT AS A DEEP NORTH TO NORTHWEST FLOW WITHIN A LARGE
ATMOSPHERIC COLUMN SPREADS OVER THE AREA IN THE WAKE OF THE FRONTAL
PASSAGE. TEMPERATURES DROPPING OFF INTO THE MID 30S OVER THE INTERIOR
TO LOWER HALF OF THE 40S OVER THE COAST. THESE NUMBERS WILL BE SOME
10 TO 15 DEGREES BELOW CLIMATOLOGY.

FOR SATURDAY...AN ANOMALOUSLY DEEP UPPER LEVEL TROF DIGS ACROSS THE
SOUTHEAST SATURDAY MORNING...MOVING OFF THE MID ATLANTIC COAST BY
EVENING. THE ENSEMBLES INDICATE THAT THE MID LEVEL HEIGHT FIELDS
WITHIN THIS TROF ARE ~ 5 STANDARD DEVIATIONS BELOW THE MEAN FOR
NOVEMBER 1ST. FORECAST 24 HOUR 1000-850 MILLIBAR THICKNESS CHANGE
ENDING SATURDAY AFTERNOON IS AROUND 40 METERS LOWER THAN TODAY. THIS
RESULTS IN A MUCH COLDER DAY FOR SATURDAY WITH HIGHS LOOKING TO NOT
GET OUT OF THE 50S OVER THE INTERIOR. CLOSER TO THE COAST...MAY GET
TO 60...BUT COULD BE DIFFICULT TO REACH THERE...GIVEN THE DEEP TROF
TO THE EAST AND COLD AIR ADVECTION PROCESSES PUSHING ACROSS THE DEEP
SOUTH. BREEZY DAY CONTINUES AS HIGH PRESSURE BUILDS IN FROM THE
WEST. /10

A LARGE DOME OF CANADIAN HIGH PRESSURE WILL SETTLE OVER THE OH/TN
VALLEYS SATURDAY NIGHT WITH RIDGING EXTENDING SOUTH INTO OUR REGION.
SINCE THE HIGH IS NOT DIRECTLY CENTERED OVER THE AREA...A LIGHT WIND
IS LIKELY TO PERSIST THROUGH MUCH OF THE NIGHT. EVEN WITH THE LIGHT
WIND...GUIDANCE IS IN STRONG AGREEMENT ON THE FIRST LIGHT FREEZE OF
THE YEAR FOR ALMOST ALL INLAND LOCATIONS. THEREFORE...HAVE EXPANDED
THE FREEZE WATCH FURTHER SOUTH...BUT IT DOES NOT INCLUDE COASTAL
ZONES. IN FACT...THE LOCAL HI RES WRF AND NCEP HI RES WRF BOTH SHOW
EVEN COLDER LOW TEMPS THAN WHAT MOS IS SHOWING EVEN WITH A PERSISTENT
LIGHT WIND. THIS BOLSTERS CONFIDENCE ON THE POTENTIAL FREEZE...WITH
SOME FAR INLAND LOCATIONS WILL LIKELY DROP INTO THE UPPER 20S. SUNDAY
MORNING RECORD LOWS AT MOBILE AND PENSACOLA (30 AND 31 RESPECTIVELY
SET IN 1966) APPEAR SAFE FOR NOW. 34/JFB

.LONG TERM (SUNDAY THROUGH FRIDAY)...THE DEEP MID TO UPPER LEVEL
TROUGH WILL QUICKLY LIFT NORTHEAST INTO THE NORTHWEST ATLANTIC ON
SUNDAY WHILE RIDGING BUILDS IN FROM THE WEST. THE LARGE SURFACE HIGH
WILL STILL BE PRESENT ACROSS THE REGION AND THIS WILL MAINTAIN
ANOTHER 24 HOURS OF BELOW NORMAL TEMPERATURES. HIGHS SUNDAY WILL ONLY
CLIMB INTO THE LOW TO MID 60S WITH LOWS SUNDAY NIGHT IN THE MID TO
UPPER 30S EXCEPT FOR LOWER 40S ALONG THE IMMEDIATE COAST. PATCHY
FROST IS POSSIBLE OVER WELL INLAND LOCATIONS.

A CONTINUED MODERATION TOWARD SEASONAL TEMPERATURES IS EXPECTED EARLY
NEXT WEEK AS THE SFC HIGH WEAKENS AND MOVES EAST INTO THE WESTERN
ATLANTIC WHILE MID TO UPPER LEVEL RIDGING PERSISTS ACROSS OUR AREA.

UNCERTAINTY INCREASES FOR THE MID TO LATE WEEK AS GUIDANCE DISAGREES
ON HOW TO HANDLE THE INCOMING TROUGH INTO THE WESTERN STATES. THE
ECMWF CONTINUES TO SPLIT OFF A PIECE OF ENERGY AND CUT IT OFF OVER
FAR NW MEXICO WED-THU. THE ECMWF FINALLY EJECTS THE ENERGY EAST AS IT
PHASES WITH A NORTHERN STREAM SHORTWAVE ON SATURDAY . THE GFS IS MUCH
MORE PROGRESSIVE WITH THIS SOUTHERN STREAM ENERGY...SHOWING THE BEST
RAIN CHANCES THU-EARLY FRI COMPARED TO THE ECMWF WHICH KEEPS MAINLY
DRY WEATHER IN PLACE THROUGH FRI. DID NOT MAKE ANY CHANGES TO THE
EXTENDED AT THIS TIME...CAPPING RAIN CHANCES AT 20% WED-FRI AND
WARMING TEMPERATURES TO SLIGHTLY ABOVE NORMAL LEVELS. A LOOK AT THE
GFS ENSEMBLES AND THE NAEFS DO NOT BOLSTER CONFIDENCE IN ANY ONE
SOLUTION AT THIS TIME. WE WILL HAVE TO WAIT FOR A BETTER SIGNAL FROM
THE ENSEMBLES BEFORE WE CAN SIGNIFICANTLY INCREASE RAIN CHANCES FOR
ANY ONE OR TWO DAYS MID TO LATE NEXT WEEK. 34/JFB

&&

.AVIATION...
31.18Z TAF ISSUANCE...A COLD FRONTAL PASSAGE WILL BRING POTENTIAL OF
CLOUDS WITH BASES 3 TO 5 KFT LATE THIS AFTERNOON AND EVENING. NO RAIN
ANTICIPATED. SKIES CLEARING LATE TONIGHT. VSBY OK. FOLLOWING THE
FRONTAL PASSAGE...INCREASING NORTHWEST TO NORTHERLY WINDS FOLLOW
BEGINNING BY AND AFTER 21Z. WINDS INCREASE 15 TO 20 KNOTS WITH
FREQUENT GUSTS POSSIBLY BETWEEN 25 AND 35 KNOTS TONIGHT...ESPECIALLY
CLOSER TO THE BEACH AREAS. THE INCREASE IN WINDS WILL BE THE MAIN
HAZARD TO APPROACHES AND DEPARTURES. /10

&&

.MARINE...GIVEN THE STRENGTH ON THE PRESSURE GRADIENT...COLDER AIR
ADVECTION ATOP WARMER SEA SURFACE TEMPERATURES AND RESULTANT WIND
FIELD...UNUSUALLY STEEP LAPSE RATES IN THE MARINE BOUNDARY LAYER WILL
SUPPORT TRANSFER OF HIGHER MOMENTUM WINDS FROM ALOFT TO THE WATER
SURFACE TONIGHT. CONSIDERING THIS...THE LATEST HIGH RESOLUTION SHORT
RANGE WEATHER MODELS ARE ALSO IN SUPPORT OF THIS SCENARIO...INDICATING
THAT GALE FORCE WIND GUSTS ARE LIKELY OVER ALL MARINE WATERS TONIGHT
THROUGH MID MORNING SATURDAY. AS HIGH PRESSURE MOVES EAST OF THE
AREA...A LIGHT TO MODERATE EASTERLY WIND FLOW IS FORECAST FOR THE
FIRST HALF OF THE UPCOMING WEEK. SEAS SHOW A SUBSIDING TREND LATE
SUNDAY THEN REBUILD NEXT WEEK DUE TO A MODERATE...PERSISTENT EASTERLY
FETCH. /10

&&

.FIRE WEATHER...A STRONG REINFORCING SURGE OF COLD AND DRY AIR WILL
MOVE INTO THE REGION LATER THIS EVENING AND PERSIST THROUGH THE
WEEKEND. GUSTY WINDS CAN BE EXPECTED TONIGHT INTO SATURDAY. IN
ADDITION...RELATIVE HUMIDITY VALUES WILL DROP INTO THE MID 20
TO LOWER 30 PERCENT RANGE SATURDAY AFTERNOON. THIS WILL RESULT IN
CONDITIONS NEAR RED FLAG CRITERIA ACROSS SOUTHEAST MISSISSIPPI.
AFTER COORDINATION WITH THE STATE OF MISSISSIPPI...A FIRE WEATHER
WATCH WILL NOT BE ISSUED AT THIS TIME. ALABAMA AND FLORIDA LOCATIONS
WILL STAY JUST SHORT OF CRITERIA. VERY DRY WEATHER WILL PERSIST INTO
SUNDAY...BUT WINDS WILL BE MUCH LOWER AND CONDITIONS ARE NOT EXPECTED
TO MEET RED FLAG CRITERIA. 34/JFB

&&

.PRELIMINARY POINT TEMPS/POPS...
MOBILE      37  58  34  63  39 /  05  00  00  00  00
PENSACOLA   42  60  37  64  45 /  05  00  00  00  00
DESTIN      44  61  40  63  47 /  05  00  00  00  00
EVERGREEN   36  57  30  61  34 /  10  00  00  00  00
WAYNESBORO  35  58  29  62  36 /  10  00  00  00  00
CAMDEN      35  57  30  60  34 /  10  00  00  00  00
CRESTVIEW   38  60  31  64  35 /  05  00  00  00  00

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...WIND ADVISORY FROM 10 PM FRIDAY TO 1 PM SATURDAY FOR THE
     FOLLOWING ZONES: LOWER BALDWIN...LOWER MOBILE...UPPER
     BALDWIN...UPPER MOBILE...

     FREEZE WATCH FROM 1 AM SUNDAY TO 8 AM SUNDAY FOR THE FOLLOWING
     ZONES: BUTLER...CHOCTAW...CLARKE...CONECUH...COVINGTON...
     CRENSHAW...ESCAMBIA...MONROE...UPPER BALDWIN...UPPER
     MOBILE...WASHINGTON...WILCOX...

FL...FREEZE WATCH FROM 1 AM SUNDAY TO 8 AM SUNDAY FOR THE FOLLOWING
     ZONES: INLAND ESCAMBIA...INLAND OKALOOSA...INLAND SANTA
     ROSA...

     WIND ADVISORY FROM 10 PM FRIDAY TO 1 PM SATURDAY FOR THE
     FOLLOWING ZONES: COASTAL ESCAMBIA...COASTAL OKALOOSA...
     COASTAL SANTA ROSA...INLAND ESCAMBIA...INLAND OKALOOSA...
     INLAND SANTA ROSA...

MS...FREEZE WATCH FROM 1 AM SUNDAY TO 8 AM SUNDAY FOR THE FOLLOWING
     ZONES: GEORGE...GREENE...PERRY...STONE...WAYNE...

GM...GALE WARNING FROM 10 PM FRIDAY TO 10 AM SATURDAY FOR THE
     FOLLOWING ZONES: CHOCTAWHATCHEE BAY...COASTAL WATERS FROM
     DESTIN TO PENSACOLA FL OUT 20 NM...COASTAL WATERS FROM
     PENSACOLA FL TO PASCAGOULA MS OUT 20 NM...MISSISSIPPI
     SOUND...NORTHERN MOBILE BAY...PENSACOLA BAY SYSTEM...
     PERDIDO BAY...SOUTHERN MOBILE BAY...WATERS FROM DESTIN TO
     PENSACOLA FL FROM 20 TO 60 NM...WATERS FROM PENSACOLA FL TO
     PASCAGOULA MS FROM 20 TO 60 NM...

     SMALL CRAFT ADVISORY UNTIL 10 PM FRIDAY FOR THE FOLLOWING ZONES:
     CHOCTAWHATCHEE BAY...COASTAL WATERS FROM DESTIN TO
     PENSACOLA FL OUT 20 NM...COASTAL WATERS FROM PENSACOLA FL
     TO PASCAGOULA MS OUT 20 NM...MISSISSIPPI SOUND...NORTHERN
     MOBILE BAY...PENSACOLA BAY SYSTEM...PERDIDO BAY...SOUTHERN
     MOBILE BAY...WATERS FROM DESTIN TO PENSACOLA FL FROM 20 TO
     60 NM...WATERS FROM PENSACOLA FL TO PASCAGOULA MS FROM 20
     TO 60 NM...

     SMALL CRAFT ADVISORY FROM 10 AM SATURDAY TO 6 AM SUNDAY FOR THE
     FOLLOWING ZONES: CHOCTAWHATCHEE BAY...COASTAL WATERS FROM
     DESTIN TO PENSACOLA FL OUT 20 NM...COASTAL WATERS FROM
     PENSACOLA FL TO PASCAGOULA MS OUT 20 NM...MISSISSIPPI
     SOUND...NORTHERN MOBILE BAY...PENSACOLA BAY SYSTEM...
     PERDIDO BAY...SOUTHERN MOBILE BAY...WATERS FROM DESTIN TO
     PENSACOLA FL FROM 20 TO 60 NM...WATERS FROM PENSACOLA FL TO
     PASCAGOULA MS FROM 20 TO 60 NM...

&&

$$








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