Areal Flood Advisory 13, NWS Mobile, AL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOBILE AL
538 AM CDT SUN MAR 16 2014

.SHORT TERM (TODAY AND TONIGHT)...A TORNADO WATCH IS NOW IN EFFECT
FOR ALL AREAS THROUGH NOON. A VIGOROUS MID TO UPPER TROF OF LOW
PRESSURE MOVING EAST OF THE CENTRAL PLAINS STATES THIS MORNING WILL
CONTINUE TO DIG SOUTHWARD OVER THE LOWER MS RIVER VALLEY AND CENTRAL
GULF STATES TODAY AND TONIGHT WITH A STRONG SFC LOW OUT AHEAD OF THE
TROF TRACKING EASTWARD OVER CENTRAL PARTS OF MS AND AL. IN THE LOWER
LEVELS OF THE ATMOSPHERE ALL THE MODEL GUIDANCE CONTINUES TO DEPICT
A 45 TO 55 KNOT H8 JET FORMING OVER LOWER MS SHIFTING EAST INTO
WESTERN AND NORTHERN SECTIONS OF THE CWFA EARLY THIS MORNING THEN
EASTWARD OVER REMAINING AREAS THROUGH EARLY THIS AFTERNOON. LATEST
BULK SHEAR VALUES FROM THE LATEST RAP HAVE CLIMBED TO AROUND 70
ALONG THE MS/AL COAST WITH SLIGHTLY LOWER VALUES EXTENDING UP INTO
SE MS AND PARTS OF SW AL. SURFACE DEWPTS HAVE CLIMBED TO THE MID 60S
OVER MUCH OF THE WESTERN HALF OF THE CWFA ALSO THIS MORNING PROGGED
TO SPREAD EAST OVER THE REST OF THE FORECAST AREA LATER THIS MORNING
AND THIS AFTERNOON. EFFECTIVE CAPES OF 500 J/KG OR HIGHER HAVE NOSED
ONSHORE OVER SOUTHERN MS THIS MORNING AND WILL LIKELY SHIFT NORTH
AND EAST AND INCREASE THROUGH MID AFTERNOON DUE TO SFC HEATING AND
INCREASED MOISTURE TRANSPORT IN THE LOWER LEVELS. FOR LATE TODAY AND
TONIGHT MAIN UPPER TROF CONTINUES TO DIG OVER THE WESTERN GULF AND
SHIFT EAST WITH DEEP MOISTURE STILL IN PLACE RESULTING IN MORE
CONVECTION FOR MOST AREAS OVERNIGHT WITH THE BETTER COVERAGE OVER
THE EASTERN HALF OF THE CWFA. LATEST MODEL SOUNDINGS DEPICT THE
DEEPER MOISTURE TO THE EAST WITH WETBULB VALUES LOWERING TO AROUND
9K FT THIS EVENING AND OVERNIGHT. WHAT THIS MEANS AS MAIN UPPER TROF
BEGINS TO LIFT OUT TO THE NORTHEAST OVERNIGHT AND EARLY MON ANY
THUNDERSTORMS THAT DO DEVELOP WILL HAVE TO BE WATCHED CLOSELY FOR
HAIL. WILL LEAN TOWARDS THE COOLER MET GUIDANCE FOR HIGHS TODAY DUE
TO CLOUDS AND RAIN AND THE WARMER MAV GUIDANCE OVERNIGHT DUE TO MORE
CLOUDS AND POSSIBLE RAIN. 32/EE

FOR MONDAY THROUGH TUESDAY NIGHT...AN UPPER TROF MOVES ACROSS THE
REGION THROUGH MONDAY NIGHT WHILE A LONG WAVE SYSTEM ADVANCES INTO
THE PLAINS.  A SURFACE RIDGE BUILDS SLOWLY INTO THE REGION MONDAY
INTO MONDAY NIGHT IN THE WAKE OF THE SURFACE LOW/COLD
FRONT...EVENTUALLY MOVING ACROSS THE FORECAST AREA ON TUESDAY.  WILL
HAVE LIKELY POPS EAST OF I-65 MONDAY MORNING TAPERING TO SLIGHT
CHANCE POPS FURTHER WEST...WITH POPS GRADUALLY TAPERING OFF TO DRY
CONDITIONS BY TUESDAY MORNING.  THE PLAINS UPPER TROF TAKES ON A
NEGATIVE TILT WHILE MOVING TOWARDS THE GREAT LAKES REGION...WITH AN
ASSOCIATED SURFACE LOW BRINGING A TRAILING COLD FRONT TO NEAR THE
LOWER/MID MISSISSIPPI RIVER VALLEY LATE TUESDAY NIGHT.  DRY
CONDITIONS CONTINUE THROUGH TUESDAY NIGHT DUE TO LOW DEEP LAYER
MOISTURE.  TEMPERATURES ON MONDAY WILL BE AROUND TEN DEGREES BELOW
NORMAL FOR MUCH OF THE AREA AND SEVERAL DEGREES BELOW NORMAL MONDAY
NIGHT.  TEMPERATURES WARM TO SLIGHTLY BELOW SEASONABLE VALUES ON
TUESDAY. /29

.LONG TERM (WEDNESDAY THROUGH SATURDAY)...THE UPPER TROF CONTINUES
ACROSS THE GREAT LAKES REGION AND ACROSS THE NORTHEAST STATES
THROUGH THURSDAY WITH THE UPPER FLOW BECOMING FAIRLY ZONAL OVER THE
FORECAST AREA.  THE TRAILING COLD FRONT CONTINUES EASTWARD AND
WEAKENS...BUT THERE IS CONTINUING UNCERTAINTY WHETHER THE FRONT
MOVES THROUGH THE FORECAST AREA WEDNESDAY OR LATER TOWARDS THURSDAY
MORNING.  DESPITE THESE DIFFERENCES...MODEL SOUNDINGS REMAIN TOO DRY
TO SUPPORT A MENTION OF PRECIP AND HAVE CONTINUED WITH A DRY
FORECAST THROUGH FRIDAY.  A FAIRLY ZONAL FLOW CONTINUES THROUGH
FRIDAY WITH UNCERTAINTY FOR SATURDAY AS TO WHETHER SUBTLE RIDGING OR
AN UPPER TROF WILL ADVANCES INTO THE EASTERN STATES.  A SURFACE
RIDGE BUILDS ACROSS THE AREA IN THE WAKE OF THE COLD FRONT AND
ESTABLISHES A RETURN FLOW BY FRIDAY.  ANOTHER COLD FRONT APPROACHES
THE AREA ON FRIDAY AND MOVES TO NEAR OR THROUGH THE FORECAST AREA ON
SATURDAY.  DEEP LAYER MOISTURE INCREASES WITH THE RETURN FLOW AND
WILL RETURN CHANCE POPS TO THE REGION BY SATURDAY.  TEMPERATURES
WILL BE A FEW DEGREES ABOVE NORMAL THROUGH THE PERIOD. /29

&&

.AVIATION (12Z ISSUANCE)...IFR TO MVFR CONDITIONS THROUGH 17.12Z.
LOW CLOUDS IN HEAVY SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH
MIDDAY TODAY GRADUALLY TAPERING OFF THIS AFTERNOON AND EARLY THIS
EVENING THEN REFORMING AGAIN OVERNIGHT AND EARLY MON AS MAIN UPPER
TROF OF LOW PRESSURE PUSHES EAST OF THE AREA LATE TONIGHT AND EARLY
MON. WINDS WILL BE SOUTH AT 15 TO 20 KNOTS WITH HIGHER GUSTS IN
THUNDERSTORMS SHIFTING SOUTHWEST AND DIMINISHING TO 10 TO 15 KNOTS
LATE TODAY THEN WEST TO NORTHWEST AT 5 TO 10 KNOTS THIS EVENING AND
OVERNIGHT. A FEW STORMS MAY BE SEVERE WITH POSSIBLE TORNADOES AND
DAMAGING WINDS ALONG WITH HEAVY RAIN AND FREQUENT LIGHTNING. 32/EE

&&

.MARINE...A TORNADO WATCH IS IN EFFECT FOR THE NORTHERN END OF
MOBILE BAY UNTIL NOON. STRONG THUNDERSTORMS WILL BE AFFECTING ALL
MARINE AREAS THIS MORNING AND THIS AFTERNOON REFORMING AGAIN
OVERNIGHT AND EARLY MON. A STRONG SOUTHERLY WIND FLOW WILL CONTINUE
OVER THE MARINE AREA THIS MORNING THEN SHIFT SOUTHWEST TO WEST AND
GRADUALLY DIMINISH LATE TODAY AND TONIGHT AS A DEEP AREA OF LOW
PRESSURE TO THE NORTH SHIFTS EAST. SEAS UP TO 7 FEET FROM 0 TO 60 NM
OUT CAN BE EXPECTED. NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED
THROUGH THIS EVENING WITH SOME STORMS BECOMING STRONG AT TIMES. A
LIGHT OFFSHORE FLOW WILL DEVELOP IN THE WAKE OF THE LOW EARLY MONDAY
THEN SHIFT SOUTH LATER IN THE DAY AS WEAK HIGH PRESSURE DEVELOPS
OVER THE NORTH CENTRAL GULF. A LIGHT TO MODERATE ONSHORE FLOW WILL
CONTINUE THROUGH THE WEEK...MOSTLY DURING THE AFTERNOON AND EVENING
HOURS...AS HIGH PRESSURE SHIFTS EAST AND REMAINS STATIONARY ALONG
THE EASTERN SEABOARD. 32/EE

&&

.PRELIMINARY POINT TEMPS/POPS...
MOBILE      72  52  62  42  68 / 100  70  40  10  05
PENSACOLA   72  57  64  47  66 / 100  80  70  30  05
DESTIN      66  59  66  52  65 / 100  90  70  30  05
EVERGREEN   71  54  62  43  69 / 100  70  60  20  05
WAYNESBORO  73  49  57  37  68 / 100  60  20  10  05
CAMDEN      73  51  60  41  68 / 100  70  40  20  05
CRESTVIEW   70  57  65  43  70 / 100  80  70  30  05

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...HIGH RIP CURRENT RISK UNTIL 7 PM SUNDAY FOR THE FOLLOWING ZONES:
     LOWER BALDWIN...LOWER MOBILE...

     FLASH FLOOD WATCH UNTIL 7 PM SUNDAY FOR THE FOLLOWING ZONES:
     BUTLER...CHOCTAW...CLARKE...CONECUH...COVINGTON...
     CRENSHAW...ESCAMBIA...LOWER BALDWIN...LOWER MOBILE...
     MONROE...UPPER BALDWIN...UPPER MOBILE...WASHINGTON...
     WILCOX...

FL...FLASH FLOOD WATCH UNTIL 7 PM SUNDAY FOR THE FOLLOWING ZONES:
     COASTAL ESCAMBIA...COASTAL OKALOOSA...COASTAL SANTA ROSA...
     INLAND ESCAMBIA...INLAND OKALOOSA...INLAND SANTA ROSA...

     HIGH RIP CURRENT RISK UNTIL 7 PM SUNDAY FOR THE FOLLOWING ZONES:
     COASTAL ESCAMBIA...COASTAL OKALOOSA...COASTAL SANTA ROSA...

MS...FLASH FLOOD WATCH UNTIL 7 PM SUNDAY FOR THE FOLLOWING ZONES:
     GEORGE...GREENE...PERRY...STONE...WAYNE...

GM...SMALL CRAFT ADVISORY UNTIL 4 PM SUNDAY FOR THE FOLLOWING ZONES:
     COASTAL WATERS FROM DESTIN TO PENSACOLA FL OUT 20 NM...
     COASTAL WATERS FROM PENSACOLA FL TO PASCAGOULA MS OUT 20
     NM...MISSISSIPPI SOUND...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...

&&