000
FXUS64 KMOB 190447 AAC
AFDMOB

AREA FORECAST DISCUSSION...AVIATION UPDATE
NATIONAL WEATHER SERVICE MOBILE AL
1145 PM CDT TUE JUN 18 2013

.AVIATION UPDATE...CHANCES OF SHOWERS AND THUNDERSTORMS WILL
CONTINUE OVERNIGHT DUE TO AN APPROACHING UPPER LEVEL DISTURBANCE AND
A COLD FRONT MOVING SLOWLY SOUTHWARD TOWARD THE AREA. CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL INCREASE AGAIN WITH DAYTIME HEATING
ON WEDNESDAY WITH IFR/MVFR CIGS AND VISBYS POSSIBLE IN AND AROUND
SCATTERED TO LOCALLY NUMEROUS SHOWERS AND THUNDERSTORMS. COVERAGES
WILL DECREASE AFTER SUNSET ON WEDNESDAY. /13


&&

.PREV DISCUSSION...

SHORT TERM [TONIGHT THROUGH WEDNESDAY]...WATER VAPOR IMAGERY AND RUC
500 MB ANALYSIS INDICATE A MOIST WESTERLY FLOW REGIME IS PERSISTING
ACROSS MUCH OF THE SOUTHEASTERN U.S. THIS AFTERNOON. SURFACE LOW
PRESSURE IS MEANWHILE CENTERED IN THE VICINITY OF NORTH
CAROLINA/VIRGINIA...WHILE AN ASSOCIATED WEAK FRONTAL BOUNDARY REMAINS
DRAPED SOUTHWESTWARD FROM THIS FEATURE ACROSS NORTHERN
GEORGIA...ALABAMA AND MISSISSIPPI. MLCAPES ARE GENERALLY RANGING
BETWEEN 1000-1500 J/KG ACROSS OUR FORECAST AREA THIS
AFTERNOON...WHILE PRECIPITABLE WATER VALUES ARE MOSTLY AVERAGING
BETWEEN 1.5 AND 2 INCHES. THIS MOIST AND UNSTABLE
ENVIRONMENT...COMBINED WITH A WEAK EMBEDDED SHORTWAVE IMPULSE IN THE
WESTERLY FLOW ALOFT HAS AIDED IN THE DEVELOPMENT OF SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS INTERIOR PORTIONS OF
SOUTHEAST MISSISSIPPI AND SOUTHWEST ALABAMA EARLY THIS AFTERNOON.
THE WET MICROBURST RISK REMAINS IN THE MODERATE CATEGORY...SO A FEW
STRONG PULSE STORMS WILL BE POSSIBLE THROUGH THE EARLY EVENING HOURS.

THE MOIST WESTERLY FLOW PATTERN WILL PERSIST ACROSS OUR FORECAST
AREA THROUGH WEDNESDAY. THE AFOREMENTIONED WEAK BOUNDARY WILL
CONTINUE TO SAG SOUTHWARD AND WILL BECOME ORIENTED NEAR COASTAL
PORTIONS OF THE FORECAST AREA BY EARLY WEDNESDAY MORNING. THE DEEP
LAYER MOISTURE AXIS WILL ALSO CONTINUE TO EDGE SOUTHWARD TO NEAR THE
COAST BY WEDNESDAY AFTERNOON. WE THEREFORE EXPECT SCATTERED SHOWERS
AND THUNDERSTORMS TO CONTINUE TO DEVELOP ALONG AND AHEAD OF THE
BOUNDARY THROUGH WEDNESDAY. PRECIPITATION CHANCES WILL BE MAINTAINED
IN THE 40-50 PERCENT RANGE ACROSS MOST LOCATIONS TONIGHT INTO
WEDNESDAY. FREQUENT LIGHTNING...GUSTY WINDS...AND VERY HEAVY RAIN
WILL BE POSSIBLE AT TIMES WITH THE STRONGER STORMS THAT DEVELOP.
LITTLE CHANGE WAS MADE TO THE TEMPERATURE FORECAST. LOWS TONIGHT
SHOULD RANGE FROM NEAR 70 OVER THE INTERIOR TO THE MID 70S NEAR THE
COAST. HIGHS WEDNESDAY LOOK TO MOSTLY RANGE FROM THE UPPER 80S TO
AROUND 90. /21

SHORT TERM [WEDNESDAY NIGHT THROUGH THURSDAY NIGHT]...SURFACE
TROUGH WILL MOVE TOWARD THE CENTRAL GULF COAST ON WEDNESDAY EVENING
AND OFFSHORE OVERNIGHT. IT WILL SERVE AS A FOCAL POINT FOR CONVECTION
WITHIN A HIGH HUMIDITY BAND OF AIR...WHERE PRECIPITABLE WATER IS
ABOUT 2 INCHES...ALIGNING ITSELF EAST TO WEST ALONG THE TROUGH AXIS.
EASTWARD PASSAGE OF WELL DEFINED MID LEVEL DISTURBANCES AT THE BASE
OF THE APPROACHING FEATURE WILL COMBINE WITH THERMODYNAMIC LIFTING
FROM THE SURFACE AND DYNAMIC LIFTING BY THOSE UPPER VORTLOBES
MENTIONED. THESE TWO TERMS WOULD BRING SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS. SOME WILL BRING HEAVY RAIN AND STRONG
GUSTY WINDS.  AFTER SUNSET BEFORE MIDNIGHT THE CONVECTION WILL DIE
DOWN AND THE ATMOSPHERE WILL STABILIZE WHILE IT IS RECYCLING FALLEN
RAINWATER INTO WATER VAPOR. SHOWERS AND THUNDERSTORMS WOULD INCREASE
SOUTHWARD OFF THE COAST AFTER MIDNIGHT WEDNESDAY NIGHT TOWARD
SUNRISE THURSDAY MORNING WITH THE AFOREMENTIONED SURFACE FEATURE
BEING OFFSHORE AND THE LAND BREEZE SPINNING UP WHICH WE BELIEVE
WOULD BOTH BRING A GREATER CHANCE OF RAIN THAN AFTER SUNSET. THE
TROUGH ALOFT SHOULD MIGRATE EAST THURSDAY AND GIVE US A LESSER CHANCE
FOR RAIN. /77

LONG TERM [FRIDAY THROUGH MONDAY]...NO CHANGES. THE FORECAST AREA
WILL REMAIN IN A GENERALLY HUMID MID LEVEL ZONAL FLOW THROUGH MUCH
OF THE MEDIUM RANGE WITH A WEAK SURFACE TROUGH PRESENT TO THE EAST.
THAT FEATURE SHOULD BE GONE BY SATURDAY EXPECT TO SEE ISOLATED TO
SCATTERED SHOWERS/STORMS REMAINING IN THE OUTLOOK WITH SLIGHTLY MORE
COVERAGE DURING THE DAYTIME WHEN HUMIDITY WILL BE HIGH
HORIZONTALLY AND VERTICALLY...AND THERMODYNAMIC INSTABILITY
INCREASES. DYNAMIC FORCES ALOFT APPEAR TO BE MUCH LESS THAN THEY ARE
CURRENTLY SINCE A RIDGE ALOFT WILL BE BUILDING OVER THE REGION LATE
THIS WEEK. /77

MARINE...SURFACE LOW PRESSURE WILL CONTINUE TO MOVE EASTWARD TO
NEAR THE EASTERN SEABOARD TONIGHT...WHILE HIGH PRESSURE STRETCHES
ACROSS SOUTHERN FLORIDA INTO THE NORTHERN GULF OF MEXICO. THE
GRADIENT BETWEEN THESE TWO FEATURES WILL RESULT IN A MODERATE
SOUTHWESTERLY WIND FLOW OVER THE MARINE AREA THROUGH TONIGHT. A
LIGHT TO MODERATE SOUTHWEST TO NORTHWEST WIND IS EXPECTED
WEDNESDAY-THURSDAY AS A WEAK COLD FRONT/PRESSURE TROUGH APPROACHES
THE GULF COAST REGION. A LIGHT TO OCCASIONALLY MODERATE
SOUTHEASTERLY TO SOUTHERLY FLOW PATTERN SHOULD DEVELOP BY THE END OF
THE WEEK INTO THE WEEKEND AS HIGH PRESSURE BUILDS ACROSS THE
SOUTHEASTERN STATES. WINDS AND SEAS WILL BE LOCALLY HIGHER NEAR
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. /21

&&

.PRELIMINARY POINT TEMPS/POPS...
MOBILE      73  89  70  89  70 /  60  50  20  30  20
PENSACOLA   74  90  74  90  73 /  60  50  20  30  30
DESTIN      77  88  76  87  75 /  50  50  20  40  30
EVERGREEN   70  88  68  91  67 /  60  50  20  30  30
WAYNESBORO  70  88  65  90  65 /  50  40  20  20  20
CAMDEN      70  88  66  91  66 /  40  30  20  20  20
CRESTVIEW   71  91  69  92  67 /  60  50  20  40  30

&&

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

$$