Area Forecast Discussion
Issued by NWS Mobile, AL

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000
FXUS64 KMOB 111740 AAC
AFDMOB

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MOBILE AL
1140 AM CST THU FEB 11 2016

.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

&&

.AVIATION...
VFR FLIGHT CATEGORIES SHOULD CONTINUE ACROSS THE REGION THROUGH THE
AFTERNOON...WITH OCCASIONALLY GUSTY SW WINDS 10-15 KTS. INCREASING
LOW- LEVEL MOISTURE AND DIMISHING WIND SPEEDS WILL AID IN THE
DEVELOPMENT OF BR AND LOW ST OVERNIGHT...MAINLY AT COASTAL TERMINALS.
REDUCED VSBYS AND CIGS WILL LIKELY RESULT IN FLIGHT CATEGORIES
BECOMING MVFR BETWEEN 12/0600-0900 UTC. PROBABILISTIC GUIDANCE
INDICATES SOME POTENTIAL FOR LOWER FLIGHT CATEGORIES TOWARD SUNRISE.
VSBYS/CIGS SHOULD IMPROVE BY MID-MORNING FRIDAY. /BUTTS/

&&

.PREV DISCUSSION... /ISSUED 1036 AM CST THU FEB 11 2016/

DISCUSSION...SEE UPDATED INFORMATION FOR LAND AREAS BELOW.

UPDATE...

LATEST SUBJECTIVE ANALYSIS SHOWS A TROUGH OF LOW PRESSURE EXTENDING
ACROSS CENTRAL ALABAMA FROM A SURFACE TROUGH OF LOW PRESSURE IN THE
ARKLAMISS. IT STILL LOOKS LIKE THIS TROUGH WILL SAG SOUTHWARD INTO
THE NORTHERN PARTS OF OUR FORECAST AREA THIS EVENING.  A
SOUTHWESTERLY FLOW CONTINUES THROUGH THE BOUNDARY LAYER LATE THIS
MORNING...WITH DEWPOINTS MUCH HIGHER THAN WHAT WE WERE SEEING THIS
TIME YESTERDAY.

AVAILABLE OBSERVATIONAL DATA INDICATES TEMPERATURES ARE WARMING MORE
QUICKLY THAN CURRENTLY FORECAST.  BASED ON THIS...AND THE FLOW
THROUGH THE BOUNDARY LAYER...TEMPERATURE GRIDS HAVE BEEN ADJUSTED
UPWARD. IT NOW LOOKS LIKE HIGHS COULD EASILY REACH THE MIDDLE 70S
THIS AFTERNOON ACROSS SOUTHEAST MISSISSIPPI...AND INTERIOR PORTIONS
OF SOUTHWEST ALABAMA BETWEEN US-84 AND IH-65.

ISC GRIDS HAVE BEEN SENT AND SHOULD BE POSTED TO THE INTERNET.
UPDATED TEXT PRODUCTS WILL BE FORTHCOMING.  /BUTTS/


PREV DISCUSSION... /ISSUED 528 AM CST THU FEB 11 2016/

DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

AVIATION...
12Z ISSUANCE...VFR CONDITIONS WILL PREVAIL THROUGH MUCH OF THE PERIOD
FOLLOWED BY MVFR CONDITIONS IN FOG DEVELOPING LATE TONIGHT. THERE IS
SOME POTENTIAL FOR IFR OR LIFR CONDITIONS IN FOG LATE TONIGHT AS
WELL...BUT NOT SUFFICIENT TO INCLUDE IN THE TAF FORECAST AT THIS
TIME AND WILL CONTINUE TO MONITOR. CALM TO LIGHT SOUTHWEST WINDS
BECOME SOUTHWEST AROUND 10 KNOTS AROUND MID MORNING THEN SUBSIDE
TONIGHT. /29

PREV DISCUSSION... /ISSUED 407 AM CST THU FEB 11 2016/

NEAR TERM /NOW THROUGH THURSDAY NIGHT/...THE AXIS OF A LONGWAVE TROF
REMAINS NEAR THE EAST COAST THROUGH THE PERIOD WHILE A SURFACE LOW
NEAR THE ARKLATEX ADVANCES EASTWARD ACROSS THE GULF COAST STATES AND
EVOLVES INTO MORE OF AN EAST-WEST ORIENTED SURFACE TROF IN THE
PROCESS.  A SOUTHWESTERLY SURFACE FLOW PREVAILS OVER THE AREA
THROUGH THE PERIOD WITH SURFACE DEWPOINTS INCREASING TO NEAR 50 OVER
COASTAL COUNTIES TO THE MID 40S INLAND.  DESPITE THE PRESENCE OF THE
SURFACE TROF OVER THE AREA TONIGHT...SKIES WILL BE MOSTLY CLEAR AND
EXPECT PATCHY FOG TO DEVELOP LATE TONIGHT ACROSS THE ENTIRE AREA.
THERE ARE SOME INDICATIONS THAT THE FOG MAY BECOME DENSE AS WELL AT
LEAST IN SOME LOCATIONS.  DRY CONDITIONS WILL OTHERWISE CONTINUE
OVER THE AREA WITH MUCH WARMER DAYTIME HIGHS TODAY IN THE LOWER 70S
FOR MUCH OF THE AREA...EXCEPT FOR MID TO UPPER 60S NEAR THE
IMMEDIATE COAST.  LOWS TONIGHT WILL BE LIKEWISE MUCH WARMER IN
COMPARISON TO THE COLD TEMPERATURES OF LATE AND RANGE FROM THE LOWER
50S NEAR THE COAST TO AROUND 40 WELL INLAND. /29

SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...FRIDAY THROUGH FRIDAY
NIGHT...AN UPPER LOW SOUTH OF HUDSON BAY SHIFTS SOUTH...CLOSER TO THE
GREAT LAKES. THIS PUSHES SOUTH A WEDGE OF COOLER AIR OVER THE EASTERN
CONUS. FOR THE SOUTHEASTERN STATES...THIS MEANS A COOLING OFF THIS
PERIOD OF THE FORECAST AS A RE-ENFORCING FRONT IS PUSHED SOUTH
ACROSS THE AREA...TO OVER THE NORTHERN GULF OF MEXICO. UNTIL
THEN...TEMPS ABOVE SEASONAL EXPECTED FOR FRIDAY...WITH HIGHS IN THE
LOW 70S...THEN COOLER FRIDAY NIGHT AS OPPOSED TO TONIGHT...WITH LOWS
FRIDAY NIGHT IN THE UPPER 30S TO LOW 40S.

SATURDAY THROUGH SATURDAY NIGHT...A SHORTWAVE SYSTEM MOVING ACROSS
THE NORTHERN US ROCKIES AND NORTHERN PLAINS PUSHES THE GREAT LAKES
SYSTEM EAST...MOVING SURFACE HIGH PRESSURE FROM OVER THE NORTHERN PLAINS
TO OVER THE EASTERN GREAT LAKES/OHIO RIVER VALLEY. THIS SHIFTS THE
LOW LEVEL FLOW FROM NORTHERLY TO EASTERLY BY SATURDAY MORNING...BUT
NOT LONG ENOUGH TO SEE ANY ATLANTIC MOISTURE WORKING ITS WAY OVER THE
FA. TEMPS BELOW SEASONAL CONTINUES...WITH HIGHS SATURDAY IN THE UPPER
40S NORTH TO MID 50S CLOSER TO THE COAST. LOWS GENERALLY IN THE UPPER
20S TO LOW 30S EXPECTED SATURDAY NIGHT.

/16

LONG TERM /SUNDAY THROUGH WEDNESDAY/...SUNDAY INTO SUNDAY
NIGHT...THE NORTHERN PLAINS ENERGY IS FOLLOWED BY MORE ENERGY MOVING
OVER THE PLAINS. THE MORE SOUTHERN SHORTWAVE ENERGY BEGINS TO FORM A
SURFACE LOW OVER THE SOUTHERN PLAINS ALONG THE WESTERN EDGE OF THE
COOL AIR-MASS OVER THE EASTERN CONUS. THE INCREASING SOUTHERLY FLOW
ON THE EAST SIDE OF THE SURFACE LOW BRINGS BACK ISENTROPIC UPGLIDE
SHOWERS TO THE SOUTHERN PLAINS AND LOWER MISSISSIPPI RIVER VALLEY.
FOR THE FA...THIS MEANS WESTERN PORTIONS OF THE FA MAY START TO SEE
SOME SHOWERS AFTER MIDNIGHT SUNDAY NIGHT. TEMPS SUNDAY RAND FROM LOW
50S NORTHEAST TO UPPER 50S SOUTHWEST. LOWS SUNDAY NIGHT ARE EXPECTED
TO RANGE FROM UPPER 30S NORTHEAST TO MID 40S SOUTHWEST.

MONDAY THROUGH MONDAY NIGHT...THE MEDIUM RANGE GUIDANCE BEGINS TO
DIVERGE...WITH THE ECMWF ADVERTISING WEAKER SHORTWAVE ENERGY MOVING
OVER THE SOUTHERN PLAINS AND LOWER MISSISSIPPI RIVER VALLEY TO THE
SOUTHEASTERN STATES THAN THE GFS. THIS RESULTS IN A MORE
ORGANIZED...DEEPENING SURFACE LOW MOVING OVER THE SOUTHEASTERN
STATES. BOTH MODELS HAVE BEEN CONSISTENT IN THEIR STRENGTH...WITH
THE GFS BEING CONSISTENTLY THE STRONGER ONE. WITH EITHER
SOLUTION...HAVE WENT IN THE MIDDLE...WITH A WEAK SURFACE LOW MOVING
OVER CENTRAL/NORTHERN MISSISSIPPI/ALABAMA/GEORGIA MONDAY INTO MONDAY
NIGHT. ENOUGH INSTABILITY LOOKS TO BE PRESENT FOR THUNDER TO BE
INCLUDED...BUT DO NOT FEEL ENOUGH FOR ANY STRONG TO SEVERE STORMS TO
BE MIXED IN...AT THIS POINT. HIGHS MONDAY IN THE 60S...LOWS MONDAY
NIGHT RANGING FROM AROUND 40 NORTHWEST TO UPPER 40S SOUTHEAST AS
POST SYSTEM COOLER AIR BEGINS TO MOVE OVER THE FA. ALSO...BEST CHANCE
FOR RAIN WILL BE OVER THE NORTHERN THIRD OF THE FA...ALONG AND NORTH
OF A VERY WEAKLY ORGANIZED WARM FRONT STRETCHING ALONG AND NORTH OF
HIGHWAY 84.

TUESDAY THROUGH WEDNESDAY...THE EASTERN ENERGY MOVES OFF...AS MORE
SHORTWAVE ENERGY MOVES TOWARDS THE WEST COAST. THIS DEVELOPS AN UPPER RIDGE
OVER THE WESTERN CONUS...MOVING EAST TO NEAR THE ROCKIES. THIS RIDGE
MOVES SURFACE HIGH PRESSURE FROM OVER THE SOUTHERN PLAINS OVER THE
NORTHERN GULF COAST TO OVER THE NORTHEASTERN GULF COAST. FOR THE
FA...THIS SHIFTS NORTHERLY FLOW TO SOUTHERLY...WARMING THE FA IN THE
PROCESS. HIGHS TUESDAY IN THE UPPER 50S TO LOW 60S...AROUND 70S
WEDNESDAY. LOWS TUESDAY NIGHT GENERALLY IN THE LOWER TO MID 40S.

/16

MARINE...MODERATE WEST TO SOUTHWEST WINDS...STRONGER MAINLY OVER
THE OPEN GULF WATERS...WILL PERSIST OVER THE MARINE AREA THROUGH
FRIDAY AHEAD OF A COLD FRONT APPROACHING FROM THE NORTH...THEN
SWITCH TO A NORTHERLY FLOW FRIDAY NIGHT AS THE FRONT MOVES THROUGH
THE MARINE AREA.  WINDS WILL BE NEARLY AT SMALL CRAFT ADVISORY
CONDITIONS TODAY AND TONIGHT...BUT HAVE OPTED FOR SMALL CRAFT
EXERCISE CAUTION AT THIS TIME DUE TO UNCERTAINTIES.  A MODERATE
OFFSHORE FLOW ON SATURDAY GRADUALLY SWITCHES TO AN ONSHORE FLOW BY
MONDAY AS ANOTHER COLD FRONT APPROACHES FROM THE WEST.  THE FRONT
MOVES ACROSS THE AREA MONDAY NIGHT WITH A STRONG OFFSHORE FLOW IN
THE WAKE OF THE FRONT. /29

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
FL...NONE.
MS...NONE.
GM...NONE.
&&

$$

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