Special Weather Statement, NWS Mobile, AL

Area Forecast Discussion
National Weather Service Mobile AL
627 PM CDT WED MAY 18 2016

.DISCUSSION...Updated for latest aviation discussion below.

&&

.AVIATION...
00Z issuance...Generally VFR conditions prevail across the region
except for in and around spotty thunderstorm and shower activity over
Southern Alabama and the Western Florida Panhandle. Convection should
wane early this evening with VFR prevailing throughout most of the
night. Areas of low stratus and fog will develop after midnight
creating areas of IFR/MVFR fog and stratus that will burn off by mid
morning giving way to VFR conditions. /08

&&

.PREV DISCUSSION... /issued 346 PM CDT WED MAY 18 2016/

NEAR TERM /Now Through Thursday/...A weak front will slowly sink
southward toward the coast through tonight. The combination of the
boundary along with plenty of deep layer moisture and boundary layer
heating will continue to lead to the development of scattered
showers and isolated thunderstorms through early evening. Showers
and thunderstorms will end this evening as the boundary layer cools.
Lows tonight will fall into the low and mid 60s inland to low 70s
along the coast. The front will remain near the coast or just
offshore with some slightly drier air moving into the northern part
of the area on Thursday. Scattered showers and storms will remain
possible mainly along and southeast of interstate 65 during the day
on Thursday during peak heating. Highs will climb into the low to
mid 80s in most areas. Lower 80s can be expected right along the
coast. /13

SHORT TERM /Thursday night Through Saturday night/...An upper trof
over the Plains Thursday night advances into the eastern states
through Friday night. A quasi-stationary frontal boundary will be
oriented East-West across the forecast area Thursday evening, and
shifts northward overnight as a surface low develops near coastal
Texas. The frontal boundary continues to advance northward through
Friday as the surface low advances to near northern Alabama,
meanwhile bringing a trailing cold front into southern Mississippi. A
shortwave trof moves across the Great Lakes region Friday night and into
the eastern states trof on Saturday, with the upper trof
strengthening through Saturday night. The surface low deepens in
response while shifting into the east central states Friday night,
then continues northeast and off the New England coast Saturday
night. This system is expected to bring the cold front through the
forecast area Friday night into early Saturday morning, although the
front may stall near the coast on Saturday before continuing further
into the Gulf.

The forecast area is expected to be in the warm sector on Friday with
mixed layer capes near 1000 J/kg, possibly near 1500 j/kg in some
locations. With an 850 mb flow near 25-30 knots, 0-1 km helicity
values will be typically around 100-150 m2/s2. For Friday, convection
will be driven initially by a strong shortwave which moves across
the forecast area in addition to a second weaker shortwave advancing
into the area. This second shortwave moves across the eastern half of
the area Friday evening, with the cold front moving through most of
the area through the night.  Pops increase Thursday night with the
approach of the stronger shortwave, increasing to likely over the
westernmost portion of the area tapering to slight chance further to
the east. Have gone with categorical pops for most of the area for
Friday as deep layer forcing associated with the shortwave moves
across the area followed by moderate forcing with the second
shortwave.  Chance to likely pops follow for Friday evening as the
front moves into the area, with the higher pops over the eastern
portion where forcing from the second shortwave will be present. Slight
chance to chance pops follow overnight as the front continues to
near the coast along with drier air moving into the area.

One forecast uncertainty for Friday is that both the GFS and NAM are
showing shallow but significant subsidence developing in the wake of
the first stronger shortwave on Friday which would limit convective
strength with the second shortwave.  This appears to favor the
potential for strong storm development more during the morning hours,
but there is too much uncertainty with the timing and phasing of the
shortwaves to make this determination at this point.  Have opted to
stay with the current wording in the Hazardous Weather Outlook for
the potential for some strong storms on Friday. Other than slight
chance pops for the eastern portion of the area Saturday morning, dry
conditions follow for the remainder of the period. Lows Thursday
night will range from the mid/upper 60s inland to the lower 70s
closer to the coast, then trend cooler by Saturday night to the lower
60s inland and mid/upper 60s at the coast. Highs on Friday will be
mostly in the lower 80s, with lower to mid 80s for Saturday. /29

LONG TERM /Sunday Through Wednesday/...A sharp upper trof over the
eastern states moves off into the western Atlantic Sunday night with
longwave ridging building into the Eastern states through the
remainder of the period. A large surface high builds into the Eastern
states through Monday, then evolves into a surface ridge over the
northern Gulf by Wednesday. Dry conditions are expected through the
period. Highs will be in the lower 80s on Sunday then trend to mid to
upper 80s by Wednesday. Lows Sunday night will range from around 60
inland to the mid 60s near the coast, then trend warmer for Tuesday
night to the mid 60s inland and near 70 at the coast. /29

MARINE...A weak cold front will stall near the coast late tonight
into Thursday with a generally light and variable wind flow. A light
to moderate southerly flow then persists late Thursday through
Friday. A light to moderate northerly flow develops Saturday and over
the weekend in the wake of a cold front that moves offshore Saturday
morning. Scattered to numerous showers and thunderstorms are expected
ahead of the front Friday into Friday night. /13

&&

.MOB Watches/Warnings/Advisories...
AL...None.
FL...None.
MS...None.
GM...None.
&&

This product is also available on the web at:
http://weather.gov/mob

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MOBILE AL
544 AM CDT WED MAY 18 2016

ALZ051>060-261>266-FLZ201>206-MSZ067-075-076-078-079-191045-
CHOCTAW-WASHINGTON-CLARKE-WILCOX-MONROE-CONECUH-BUTLER-CRENSHAW-
ESCAMBIA-COVINGTON-MOBILE INLAND-BALDWIN INLAND-MOBILE CENTRAL-
BALDWIN CENTRAL-MOBILE COASTAL-BALDWIN COASTAL-ESCAMBIA INLAND-
ESCAMBIA COASTAL-SANTA ROSA INLAND-SANTA ROSA COASTAL-
OKALOOSA INLAND-OKALOOSA COASTAL-WAYNE-PERRY-GREENE-STONE-GEORGE-
544 AM CDT WED MAY 18 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL
ALABAMA...SOUTHWEST ALABAMA...NORTHWEST FLORIDA AND SOUTHEAST
MISSISSIPPI.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

A FEW STRONG THUNDERSTORMS WILL POSSIBLE ON FRIDAY WITH GUSTY
WINDS...FREQUENT LIGHTNING AND HEAVY RAIN. SOME MINOR FLOODING WILL
ALSO BE POSSIBLE MAINLY IN AREAS OF POOR DRAINAGE.

.SPOTTER INFORMATION STATEMENT...

ACTIVATION OF SKYWARN SEVERE STORM SPOTTER NETWORKS IS NOT
EXPECTED THROUGH TUESDAY.

GMZ630>635-650-655-670-675-191045-
NORTHERN MOBILE BAY-SOUTHERN MOBILE BAY-MISSISSIPPI SOUND-
PERDIDO BAY-PENSACOLA BAY SYSTEM-CHOCTAWHATCHEE BAY-
COASTAL WATERS FROM PENSACOLA FL TO PASCAGOULA MS OUT 20 NM-
COASTAL WATERS FROM DESTIN TO PENSACOLA FL OUT 20 NM-
WATERS FROM PENSACOLA FL TO PASCAGOULA MS FROM 20 TO 60 NM-
WATERS FROM DESTIN TO PENSACOLA FL FROM 20 TO 60 NM-
544 AM CDT WED MAY 18 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF THE COASTAL
WATERS OF ALABAMA AND NORTHWEST FLORIDA AND THE COASTAL WATERS OF
ALABAMA AND NORTHWEST FLORIDA.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

A FEW STRONG THUNDERSTORMS WILL BE POSSIBLE OVER THE MARINE AREA ON
FRIDAY. GUSTY WINDS AND FREQUENT LIGHTNING WILL BE THE MAIN
THREATS.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOBILE AL
646 PM CDT WED MAY 18 2016

ALZ060-FLZ205-190030-
COVINGTON AL-OKALOOSA INLAND FL-
646 PM CDT WED MAY 18 2016

...A STRONG THUNDERSTORM WILL AFFECT THE FOLLOWING COUNTIES...
SOUTHWESTERN COVINGTON AND NORTHEASTERN OKALOOSA COUNTIES UNTIL 730
PM CDT...

AT 645 PM CDT...THE STRONG THUNDERSTORM WAS LOCATED 7 MILES NORTHWEST
OF LAUREL HILL...OR 13 MILES WEST OF FLORALA...MOVING EAST AT 15 MPH.

DIME SIZE HAIL AND WINDS IN EXCESS OF 30 MPH WILL BE POSSIBLE WITH
THIS STORM.

LOCATIONS IMPACTED INCLUDE...
LAUREL HILL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO LOCALIZED FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 10 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

&&

LAT...LON 3100 8663 3112 8662 3115 8640 3094 8641
TIME...MOT...LOC 2345Z 272DEG 11KT 3105 8654