Area Forecast Discussion
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FXUS64 KMOB 252047
AFDMOB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOBILE AL
347 PM CDT MON MAY 25 2015

.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)...FOR TONIGHT THROUGH
TUESDAY...A SHARP LONGWAVE RIDGE ORIENTED
ALONG THE EAST COAST SHIFTS SLOWLY EASTWARD INTO THE WESTERN
ATLANTIC WHILE A SERIES OF SHORTWAVES MOVE ACROSS THE PLAINS AND
EASTERN STATES.  A PROMINENT SHORTWAVE CURRENTLY ASSOCIATED WITH
CONVECTION OVER THE FORECAST AREA WILL SHIFT SLOWLY EAST OF THE AREA
THIS EVENING...AND WHILE SUBSIDENCE IN THE WAKE OF THIS FEATURE WILL
RESULT IN LIMITED CONVECTIVE POTENTIAL THIS EVENING...WEAKER
ADDITIONAL SHORTWAVES WILL MOVE INTO THE AREA OVERNIGHT.  HAVE GONE
WITH CHANCE POPS ACROSS THE AREA THIS EVENING...THEN TAPERING TO
SLIGHT CHANCE POPS FOR MUCH OF THE EASTERN PORTION OVERNIGHT WHILE
CHANCE POPS CONTINUE FOR THE REMAINING PORTION.  A STRONG SERIES OF
SHORTWAVES WILL MEANWHILE ADVANCE ACROSS THE SOUTHERN AND CENTRAL
PLAINS...AND EJECT NORTH OF THE AREA ON TUESDAY.  DESPITE THESE
FEATURES PASSING NORTH OF THE AREA WHICH WILL SUPPORT BOTH THE MOST
CONVECTION AND ALSO CONTAIN THE STRONGEST DYNAMICS...THERE ARE TWO
INGREDIENTS WHICH WILL AID IN CONVECTIVE DEVELOPMENT SOUTH OF THIS
PREFERRED AREA AND AFFECT THE FORECAST AREA ON TUESDAY.

FIRST OF ALL...A BROAD 850MB THETA-E AXIS WILL BE LOCATED WEST OF
THE AREA TONIGHT THEN SHIFTS EASTWARD MAINLY INTO THE WESTERN
PORTION OF FORECAST AREA ON TUESDAY.  SECONDLY...AS THIS OCCURS THE
850-300 MB THICKNESS PATTERN SHOWS DIFLUENCE ADVANCING EASTWARD AS
WELL...AND MOVING INTO THE FORECAST AREA DURING THE DAY.  EXPECT
CONVECTION TO DEVELOP WEST OF THE FORECAST AREA OVERNIGHT...POSSIBLY
EVOLVING INTO A MESOSCALE CONVECTIVE SYSTEM...MCS...AND ADVANCE
ALONG THE BROAD THETA-E AXIS AND INTO THE FORECAST AREA DURING THE
DAY ON TUESDAY.  HAVE GONE WITH LIKELY POPS WEST OF I-65 FOR THE
MORNING HOURS WITH CHANCE TO GOOD CHANCE POPS FURTHER EAST...THEN
FOR THE AFTERNOON HOURS WILL HAVE LIKELY POPS ACROSS THE AREA EXCEPT
FOR CATEGORICAL POPS OVER INTERIOR SOUTHEAST MISSISSIPPI AND
INTERIOR SOUTHWEST ALABAMA.

AS FAR AS STRONG TO SEVERE STORM POTENTIAL...MODEL SOUNDINGS SHOW
SOME DRIER MID LEVEL AIR NEAR 12Z TUESDAY...BUT THIS IS WIPED OUT BY
MIDDAY TUESDAY LEAVING A MOIST SOUNDING WITH A MINIMUM RH OF ABOUT
65 PERCENT THROUGH 500 MB. WITH LITTLE IF ANY DRY MID LEVEL AIR
PRESENT WHEN THE BETTER DEEP LAYER LIFT OCCURS MIDDAY TUESDAY INTO
TUESDAY AFTERNOON...THIS WILL MAKE DOWNDRAFT ACCELERATION RATHER
DIFFICULT EXCEPT FOR VIA PRECIPITATION LOADING.  GOING BY THE
SYNOPTIC SCALE PATTERN...VIRTUALLY ALL OF THE FAVORABLE DYNAMICS
WILL BE LOCATED NORTH OF THE FORECAST AREA THROUGH THE PERIOD WITH
850 MB WINDS NEAR 25 KNOTS...RATHER MEAGER FOR ANY SEVERE WEATHER
POTENTIAL.  THIS RESULTS IN 0-1 AND 0-3 KM HELICITY VALUES OF 40-80
M2/S2 OVER THE AREA...AND AT BEST 100 M2/S2 OVER THE
NORTHWESTERN-MOST PORTION OF THE FORECAST AREA. THE WILDCARD IN THIS
SCENARIO IS THE POTENTIAL MCS DEVELOPMENT AND HOW THIS MAY INCREASE
SHEAR OVER THE AREA.

AS FAIRLY HIGH INSTABILITY WILL BE PRESENT WITH SBCAPES OF 2500-3000
J/KG...EXPECT AT LEAST STRONG STORMS TO BE A RISK WITH THE PRIMARY
MECHANISM BEING PRECIPITATION LOADING LEADING TO STRONG GUSTY WINDS.
BASED ON THE BEST SHEAR WITHIN THIS ENVIRONMENT...IT LOOKS LIKE THE
EXTREME NORTHWESTERN PORTION OF THE AREA...ROUGHLY FROM WAYNESBORO
TO CAMDEN...IS WHERE THERE IS A SLIGHT RISK FOR SEVERE STORM
DEVELOPMENT WITH WIND GUSTS AROUND 60 MPH POSSIBLE. THIS RISK AREA
COULD EXPAND CHANGE BASED ON HOW AND IF THE MCS DEVELOPS...BUT THERE
IS LOW CONFIDENCE ON THE TIMING AND EVOLUTION OF THIS POSSIBLE
FEATURE AT THIS TIME...MAINLY DUE TO THE BEST DYNAMICS EJECTING
NORTH OF THE AREA...AND WILL HAVE TO BE CLOSELY MONITORED.

LOWS TONIGHT WILL RANGE FROM THE UPPER 60S INLAND TO LOWER 70S NEAR
THE COAST.  HIGHS ON TUESDAY WILL BE IN THE LOWER TO MID 80S. /29

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...ENERGY FROM THE DISSOLVING
UPPER SYSTEM OVER THE SOUTHWESTERN CONUS CONTINUES TO MOVE NORTHEAST
OVER THE LOWER/MID MISS/TENN RIVER VALLEYS. THE UPPER RIDGE OVER THE
EASTERN CONUS HAS SHIFTED OFF THE EAST COAST...BUT THE SURFACE RIDGE
STRETCHING WEST OVER THE SOUTHEASTERN STATES REMAINS PRETTY MUCH
INTACT. THE GRADIENT EASES...WEAKENING THE ONSHORE FLOW AND MOISTURE
INFLUX...BUT WITH PRECIP H20 VALUES REMAINING AT OR ABOVE 1.75" FOR
MOST OF THIS PART OF THE FORECAST...THE CHANCE OF RAIN REMAINS ON THE
HIGH SIDE....ESPECIALLY INLAND.

WITH THE UPPER RIDGE IN MORE EASTWARD LOCATION...THE UPPER ENERGY IS
EXPECTED TO MOVE MORE OVER THE FA. LOOKING AT THE MODEL SOUNDINGS...
INSTABILITY FOR WEDNESDAY RANGED FROM AROUND 1000J/KG(NAM) TO OVER
3000L/KG(GFS)...WITH THE NAM ADVERTISING A MORE SATURATED AIRMASS.
EITHER WAY...ENOUGH INSTABILITY IS AVAILABLE FOR SOME THUNDERSTORMS
TO BECOME STRONG OR SEVERE. WINDSHEAR CONTINUES TO BE LIMITED AND
UNIDIRECTIONAL...HELPING TO LIMIT THE DEVELOPMENT OF SPINNERS. AT
THIS TIME...WITH THE CURRENT MOIST AIRMASS AND LIMITED ROTATION
POSSIBILITIES...WIND DAMAGE AND HAIL APPEAR TO BE THE PRIMARY
THREATS.

.LONG TERM...(THURSDAY ON)...THURSDAY INTO FRIDAY...THE PASSING UPPER
ENERGY EASES...WITH THE CHANCE OF RAIN DECREASING. TEMPS REMAIN
AROUND SEASONAL...THOUGH...WITH THE UPPER RIDGE SHIFTED WELL EAST OF
THE FA.

FRIDAY NIGHT THROUGH MONDAY...MORE UPPER ENERGY THAT HAS MOVED OVER
THE WESTERN CONUS MOVES EAST OVER THE PLAINS AND MID MISS RIVER
VALLEY. BY THE END OF THE DAY MONDAY...GUIDANCE IS ADVERTISING AN
UPPER TROUGH OVER THE MISS RIVER VALLEY. FOR THE FA...MOISTURE LEVELS
REMAIN HIGH AND WITH THE APPROACHING UPPER TROUGH...THE CHANCE OF
RAIN INCREASES EACH DAY THROUGH THE LATTER PART OF THE FORECAST.
TEMPS REMAIN AT OR A BIT ABOVE SEASONAL LEVELS.


&&

.MARINE...A RIDGE OF HIGH PRESSURE OVER THE SOUTHEAST STATES WILL
MAINTAIN A SOUTHEASTERLY FLOW WHICH GRADUALLY DIMINISHES THROUGH
SATURDAY.  WINDS AND SEAS WILL BE HIGHER NEAR SCATTERED TO
OCCASIONALLY NUMEROUS STORMS THROUGH FRIDAY. /29


&&

.PRELIMINARY POINT TEMPS/POPS...
MOBILE      71  83  70  86  69 /  40  70  40  60  30
PENSACOLA   73  83  72  86  72 /  40  70  40  60  30
DESTIN      75  83  72  85  73 /  40  50  40  60  30
EVERGREEN   68  85  68  86  66 /  30  70  30  60  40
WAYNESBORO  69  84  67  85  66 /  40  80  40  60  30
CAMDEN      68  85  67  86  67 /  30  80  60  60  40
CRESTVIEW   69  86  70  90  67 /  30  70  30  60  30

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...HIGH RIP CURRENT RISK THROUGH TUESDAY AFTERNOON FOR LOWER
     BALDWIN-LOWER MOBILE.

FL...HIGH RIP CURRENT RISK THROUGH TUESDAY AFTERNOON FOR COASTAL
     ESCAMBIA-COASTAL OKALOOSA-COASTAL SANTA ROSA.

MS...NONE.
GM...NONE.
&&

$$


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