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Area forecast discussion...updated 
National Weather Service Mobile Alabama
1108 am CDT Thursday Sep 18 2014

Update...did a quick update to the current zone forecast mainly to
add better cloud cover for most areas in southeast MS and parts of
southwest Alabama generally west of a line stretching from Mobile to
Butler in Alabama. Otherwise...latest precipitation/temperature forecast for today
looks close to the current 12z model guidance. 32/ee

&&

Aviation...[18.18z issuance]...mostly VFR conditions through 19.18z
with brief periods of MVFR to IFR conditions in isolated showers and
thunderstorms occurring mainly in the late afternoon or early evening
hours. Winds will be east shifting south at 5 to 8 knots through this
afternoon becoming variable less then 5 knots overnight and early
Friday morning...then becoming mostly east at 5 to 7 knots through
19.18z. 32/ee

&&

Marine...adjusted forecast for the rest of today mostly to reflect
current conditions a little better this morning. A light easterly
flow is still expected through late this morning or early this
afternoon shifting mostly south at 8 to 11 knots later this
afternoon and early this evening. 32/ee

&&

Previous discussion... /issued 428 am CDT Thursday Sep 18 2014/

Short term...(today through saturday)...for today through tonight...
the weak front as defined by the surface Theta-E boundary is roughly
along the Highway 84 corridor as of 3am. Expect the boundary to push a
little further south through daybreak due to diurnal cooling. The
front will retreat back to the north a little by this afternoon is
response to daytime heating...with the boundary likely to extend
roughly from Waynesboro to Pensacola. To the south of the boundary
dewpoints will stay in the upper 60s to around 70...while dewpoints
will mix out into upper 50s/lower 60s across portions of south
central Alabama. In the upper levels...a weak shortwave currently over the
Texas Panhandle will quickly move west today...moving into western
portions of the forecast area by this afternoon which will slightly
moisten the middle levels of the atmosphere and provide for some modest
forcing. Therefore...will maintain a 20-30% chance of thunderstorms
to the south of the boundary this afternoon and evening. A dry day is
expected elsewhere as precipitable waters drop to around 1.25 inches
across far eastern and northern portions of the forecast area. Stayed
close to guidance for highs...which will average out to around 90
degrees...lower 90s well inland and upper 80s along the beaches.

Any lingering isolated storms are expected to dissipate overnight
with the front pushing back to the south due to diurnal effects.
Lows will range from the middle 60s far inland to around 70 along and
south of I-10. 34/jfb

Friday through Saturday...several pieces of upper energy organize
into a closed low centered over NE-eastern Florida. With the organizing of the
upper low over Florida...a surface low organizes off the Florida Atlantic coast
Friday night through Saturday...then begins to head north along the
eastern Seaboard.

With the shortwave energy mainly over the southeastern half of the
forecast area...have went with or a bit above guidance with respect to
probability of precipitation...dry over the northwestern half for Friday. As the energy
shifts east-southeast and organizes into the upper low...the land portion of the
forecast area generally dries out. Temperatures cool off a scooch into the
weekend...but still remain above seasonal.

Long term...(saturday night on)...Saturday night through Sunday
night...the upper low over Florida opens and gets drawn NE ahead of a
strong shortwave digging southeast over the eastern Continental U.S.. this dance
of the upper dynamics sends the surface low off the Florida coast NE along
the East Coast ahead of a surface front getting pushed southeast over the
lower miss River Valley and southeast-eastern Continental U.S.. by Monday morning...
guidance is advertising the wind-shift portion of the front moving to
near/just south of the northern Gulf Coast. The colder portion of the
airmass remains north of the forecast area. With no significant airmass exchange
over the forecast area to this point...temperatures remain above seasonal. Probability of precipitation
continue to remain below seasonal...with any upper support by the
upper trough over the eastern Continental U.S. Being to DAR east of the forecast area.

Monday through Monday night...the shortwave energy moves through the
eastern trough...pulling the trough eastward a bit. More importantly
for the forecast area is the front moving across the forecast area and over the northern
Gulf. With the upper dynamics working against any increase in probability of precipitation
with the frontal passage...around seasonal probability of precipitation expected Monday into Monday
night.

Tuesday through Thursday...shortwave energy moving over the northwest-eastern
Continental U.S. Works with some energy from the eastern trough to cut-off the
upper ridge that has moved over the plains...then rebuild it over the
eastern Continental U.S.. through all this...surface high pressure that moved
over the eastern Continental U.S. Remains in place...keeping the forecast area under cooler
northeasterly flow. Temperature drop to below seasonal levels through middle
week. The only wild card is how any shortwave energy interacts with
the surface boundary over the northern Gulf. The GFS is advertising
some upglide showers moving inland over S-eastern Alabama/GA/NW-ern Florida. The
European model (ecmwf) keeps the activity more over the Gulf. Have went with a blended
solutions...with rain showers/thunderstorms and rain generally affecting near coastal portions
of the forecast area.

Aviation...
12z issuance...any lingering patchy fog will quickly dissipate after
sunrise with predominate VFR conditions expected through the next 24
hours. Isolated to scattered storms possible this afternoon/early
evening roughly south and west of a Waynesboro to Pensacola line.
Patchy MVFR fog possible after 06z Friday...especially across the
coastal counties of Alabama/northwest Florida. 34/jfb

Marine...light winds will persist over the marine area through
early Friday as a weak front lingers across the region. Winds will
be offshore during the late night/morning hours...becoming onshore
(especially close to the coast) during the afternoon/early evening.
A moderate to strong easterly flow becomes established by Friday
night as high pressure builds across the eastern Seaboard into the
southeast states. Winds will be close to exercise caution levels
(15-20 kt) over the open Gulf waters Friday night and Saturday. East
to northeast winds diminish sun-Monday as the high weakens. A cold
front approaches the marine area by Monday night...but confidence is
low on how far south the boundary will push. Little change in seas
through Friday morning...building Friday night into Saturday...
possibly as high as 5 feet well offshore. Seas subside Sunday into
Monday. 34/jfb

&&

Preliminary point temps/pops...
Mobile 90 69 89 69 88 / 20 20 20 10 10
Pensacola 90 71 88 72 86 / 10 10 30 10 10
Destin 85 75 87 72 86 / 05 10 30 10 10
Evergreen 92 65 90 66 87 / 05 05 20 10 10
Waynesboro 90 66 90 66 89 / 20 20 10 10 10
Camden 90 64 90 66 87 / 05 05 10 10 10
Crestview 92 65 90 66 86 / 05 10 30 10 10

&&

Mob watches/warnings/advisories...
Alabama...none.
Florida...none.
MS...none.
GM...none.
&&

$$

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