000
FXUS64 KMOB 180854
AFDMOB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOBILE AL
354 AM CDT TUE JUN 18 2013

.SHORT TERM [TODAY THROUGH WEDNESDAY NIGHT]...ISOLATED SHOWERS HAVE
DEVELOPED ALONG COASTAL AL/MS VERY EARLY THIS MORNING AS A PERSISTENT
SW/S FLOW HAS HELPED TO MAINTAIN MLCAPES OF 500-1000 J/KG ALONG THE
COAST. THIS INSTABILITY COMBINED WITH PRECIP WATERS NEAR 1.8 INCHES
HAS RESULTED IN THIS NOCTURNAL COASTAL DEVELOPMENT. TYPICALLY IN THIS
ENVIRONMENT WE CAN EXPECT A CONTINUED INCREASE IN COVERAGE THROUGH
THE EARLY MORNING...HOWEVER GUIDANCE SHOWS SLIGHTLY LOWER PW AIR
(AROUND 1.5 INCHES) MOVING INTO THE AREA BY 12Z...WHICH MAY SERVE TO
CUT DOWN ON THE COVERAGE.

OTHERWISE...SHORTWAVE ENERGY MOVING INTO THE LOWER MS VALLEY IS
RESULTING IN SCATTERED THUNDERSTORM DEVELOPMENT FROM CENTRAL AL WEST
TO NORTHERN LOUISIANA. SOME OF THESE STORMS COULD AFFECT FAR
NORTHERN PORTIONS OF THE FORECAST AREA THIS MORNING. WHILE THIS
INITIAL SHORTWAVE ENERGY WILL MOVE OFF TO OUR NORTH AND EAST THIS
MORNING...A BROAD UPPER LEVEL TROUGH WILL REMAIN IN PLACE THROUGHOUT
THE DAY. A WELL DEFINED 700 MB TROUGH AXIS IS FORECAST TO MOVE INTO
CENTRAL AL/MS THIS AFTERNOON WITH PRECIP WATERS INCREASING BACK TO
NEAR 2 INCHES OVER THE FORECAST AREA. IN ADDITION...A WEAK COLD FRONT
(MORE LIKE A PRESSURE TROUGH) WILL MOVE INTO THE FAR INLAND ZONES
THIS AFTERNOON. THIS WILL SET THE STAGE FOR NUMEROUS SHOWERS AND
THUNDERSTORMS ACROSS FAR INLAND SW AL/SE MS WITH SCATTERED COVERAGE
EXPECTED ELSEWHERE GIVEN THE ABUNDANT DEEP LAYER MOISTURE AND MLCAPES
AVERAGING AROUND 2000 J/KG. FREQUENT LIGHTING...GUSTY WINDS...AND
TORRENTIAL DOWNPOURS ARE THE MAIN STORM THREATS. THE WET MICROBURST
RISK IS MODERATE TODAY...WHICH SUGGESTS AN ISOLATED PULSE SEVERE
STORM CANNOT BE RULED OUT.

THE SFC-850 MB TROUGH SLOWLY MOVES SOUTH TOWARD THE COAST BY EARLY
WEDNESDAY MORNING WHILE THE 700 MB TROUGH JUST BEGINS TO MOVE INTO
THE NORTHERN CWA. THIS WILL LIKELY RESULT IN SCATTERED CONVECTION
ACROSS MUCH OF THE REGION THIS EVENING...WITH CONVECTION BECOMING
FOCUSED ACROSS THE SOUTHERN ZONES AFTER MIDNIGHT. IN FACT...WITH
PRECIP WATERS OF 2 INCHES...COMBINED WITH THE MODEST LOW LEVEL
CONVERGENCE...ANOTHER INCREASE IN CONVECTION IS POSSIBLE ALONG THE
I-10 CORRIDOR AFTER MIDNIGHT. FOCUSED 50% CHANCES ACROSS THIS AREA
FOR THE LATE NIGHT HOURS...BUT SUBSEQUENT FORECASTS MAY NEED TO
RAISE THIS FURTHER. STAYED CLOSE TO MAV GUIDANCE FOR HIGHS WHICH ARE
FAIRLY SEASONABLE IN THE UPPER 80S TO LOWER 90S. WENT A DEGREES OR
TWO ABOVE GUIDANCE FOR LOWS CONSIDERING THE AMOUNT OF CLOUD COVER
EXPECTED. 34/JFB

SURFACE PRESSURE TROF/WEAK SURFACE FRONT DROPS DOWN TOWARD THE
CENTRAL GULF COAST ON WEDNESDAY AND WILL ACT AS A FOCUS FOR UNSETTLED
WEATHER WITHIN A DEEP LAYER MOIST AIRMASS (PRECIPITABLE WATERS ~ 2
INCHES) ALIGNED EAST TO WEST ALONG THE TROF AXIS. CONSIDERING THE
EASTWARD PASSAGE OF WELL DEFINED MID LEVEL DISTURBANCES AT THE BASE
OF AN APPROACHING MID LEVEL TROF...THE COMBINED LIFT FROM THE SURFACE
AND UPPER AIR FEATURES SETS THE STAGE FOR SCATTERED/NUMEROUS SHOWERS
AND STORMS. STRONGER STORMS WILL BE EFFICIENT IN DROPPING SOME
LOCALLY HEAVY RAINS AT TIMES. THE HIGHER CHANCES OF SHOWERS/STORMS
LOOK TO SHIFT/DEVELOP SOUTHWARD OFF THE COAST INTO WEDNESDAY NIGHT
WITH THE POSITION OF THE SURFACE TROF/FRONT. DAILY HIGHS LOOK TO
RANGE FROM THE UPPER 80S COAST AND LOWER 90S INTERIOR. IT MUST BE
SAID THAT IF A WELL DEFINED RAIN SHIELD MOVES ACROSS THROUGH THE
DAY...THEN HIGH TEMPERATURES WILL LIKELY NEED TO BE ADJUSTED SEVERAL
DEGREES LOWER. OVERNIGHT LOWS WEDNESDAY NIGHT GENERALLY IN THE LOWER
70S INTERIOR TO MID/UPPER 70S COAST. /10

.LONG TERM [THURSDAY THROUGH MONDAY]...THE FORECAST AREA LOOKS TO
REMAIN IN A GENERAL MID LEVEL WEAKNESS THROUGH MUCH OF THE MEDIUM
RANGE WITH A SUBTLE...WEAK SURFACE PRESSURE TROF HANGING AROUND.
THUS...WILL EXPECT TO SEE ISOLATED TO SCATTERED SHOWERS/STORMS
REMAINING IN THE OUTLOOK. SLIGHTLY BETTER COVERAGE ANTICIPATED
DURING THE DAYTIME HOURS WHEN BETTER INSTABILITY IS REALIZED. HIGHS
TO RANGE FROM THE UPPER 80S/LOWER 90S. LOWS NEAR 70 INTERIOR TO MID
70S COAST. /10

&&

.AVIATION...(12Z ISSUANCE)...THE PERIOD WILL START OFF WITH SCATTERED
MVFR STRATUS WITH ISOLATED TO SCATTERED TROPICAL SHOWERS AND A FEW
STORMS EXPECTED NEAR THE FORECAST TERMINALS. CIGS WILL LIKELY LIFT
TO VFR LEVELS BY MID TO LATE MORNING...BUT ADDITIONAL SCATTERED
SHOWERS AND STORMS ARE EXPECTED THIS AFTERNOON AND CONTINUE THROUGH
THE NIGHT. PERIODS OF IFR/MVFR CONDITIONS CAN BE EXPECTED IN THE
TSTM ACTIVITY. 34/JFB

&&

.MARINE...GULF BUOYS AND MOBILE BAY OBS INDICATE SOUTHWEST WINDS HAVE
INCREASED TO 15-20 KT EARLY THIS MORNING AS THE GRADIENT TIGHTENS
BETWEEN A LOW MOVING ACROSS THE TN VALLEY AND SFC HIGH PRESSURE OVER
THE NORTH CENTRAL GULF. WINDS MAY DECREASE SLIGHTLY AFTER
DAYBREAK...BUT THE COMBINATION OF A SFC TROUGH APPROACHING FROM THE
NORTH COMBINED WITH SEABREEZE EFFECTS WILL RESULT IN SW WINDS
INCREASING AGAIN BY LATE AFTERNOON AND CONTINUING INTO THE EVENING.
SMALL CRAFT WILL NEED TO EXERCISE CAUTION. WINDS DECREASE WED-THU
OUT OF SW-NW AS THE SFC TROUGH LINGERS OVER THE AREA. A PREDOMINATE
EAST TO SOUTHEAST FLOW DEVELOPS BY THE END OF THE WEEK INTO THE
WEEKEND AS THE SURFACE TROUGH DISSIPATES AND HIGH PRESSURE BUILDS
ACROSS THE SOUTHEASTERN STATES.

WINDS AND SEAS WILL BE LOCALLY HIGHER NEAR ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS TODAY...WITH COVERAGE POTENTIALLY BECOMING
NUMEROUS ACROSS AREA BAYS AND NEAR SHORE GULF WATERS EARLY WEDNESDAY
MORNING. A CHANCE FOR STORMS WILL CONTINUE THURSDAY THROUGH
SATURDAY...WITH THE BEST CHANCES OCCURRING DURING THE EARLY MORNING
HOURS. 34/JFB

&&

.PRELIMINARY POINT TEMPS/POPS...
MOBILE      90  73  89  72  91 /  40  40  60  20  20
PENSACOLA   90  77  89  73  90 /  30  50  60  30  30
DESTIN      88  78  87  75  87 /  20  50  60  30  30
EVERGREEN   91  71  92  66  93 /  50  40  50  20  30
WAYNESBORO  89  70  91  67  93 /  60  40  40  20  20
CAMDEN      89  69  92  66  93 /  60  40  40  20  20
CRESTVIEW   92  72  92  69  92 /  30  40  60  30  30

&&

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

$$