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Area forecast discussion 
National Weather Service Mobile Alabama
455 am CDT Thursday Oct 2 2014

Short term...(today through saturday)...for today through tonight...
surface high pressure along the Atlantic Seaboard continues to ridge
into the local forecast area from the northeast this morning...but will
be weakening this afternoon and tonight as a cold front move toward
the region from the west. Both the GFS and European model (ecmwf) remain very similar
in the timing of the approaching front through late tonight...with
the frontal position prognosticated to be just east of the Mississippi River
by around 12z Friday. A weak upper level disturbance will be ejected
from the developing upper trough over the plains states today...moving
northeast across the local forecast area today. Precipitable waters increase to around
2.15 inches by this afternoon...and with the weak upper forcing
expect scattered showers and thunderstorms to develop this
afternoon...especially over the western half of the forecast area. Upper
dynamics weaken somewhat early this evening and along with loss of
daytime heating will likely see a brief decrease during the evening
hours of any convective coverage that develops this afternoon. After
midnight though...upper level dynamics begin to drastically increase
and along with low level forcing from the approaching cold front and
increased deep layer moisture...expect rain chances to increase again
overnight. A chance for scattered showers and storms today and this
evening will increase to good chance and likely showers and storms
after midnight tonight especially along and west of I-65. Both maximum
and min temperatures will continue to be above normal for this time of the
year during the short term period...with highs today generally in the
middle 80s (although there will be some upper 80s in a few locations
over interior zones and lower 80s at some locations along the
immediate coast). Lows tonight generally ranging from the lower 70s
over much of the interior to the middle 70s at the coast 12/ds

Friday through Friday night...a shortwave embedded in an upper trough
over the eastern Continental U.S. Gets pushed quickly eastward by more energy
diving into the upper trough (and organizing into a closed low over
the western Great Lakes in the process). This pushes a surface front
quickly east over the eastern Continental U.S....especially over tenn/SC and
points north. For our neck of the Woods...this means that the front
will cross the area Friday afternoon/evening. Witht he strongest push
(read better dynamics) being well north of the forecast area...am not expecting
any added support to the thunderstorms ahead/with the front. Enough
instability is expected to be present for a few thunderstorms that do
develop to become strong to severe...but with limited wind shear...am
not expecting an organized severe event. Another day of temperatures above
seasonal expected Friday. A significantly cooler airmass moves over
the area Friday night...with temperatures sell below seasonal expected by
Saturday morning.

Saturday...as the energy in the Great Lakes closed low is joined by
more energy swirling around near it...the northerly push brings more
of the cooler airmass over the forecast area. This keeps temperatures for the day well
below seasonal levels.

Long term...(saturday night on)...Saturday night through
Sunday...the more lobes of energy swirl around the upper low now
swirling around just north of the Great Lakes...another piece of
energy moves south over the plains...pushing surface high pressure
associated with the cool airmass over...then east of the forecast area. Am
expecting temperatures to drop even further below seasonal levels...with most
of the forecast area seeing temperatures in the 40s. At this point...temperatures dipping to
near record levels are expected overnight Saturday night.

Record:

Mobile 44 (2010)
Pensacola 49 (1987)

Sunday night through Tuesday...more energy swirls into the eastern
Continental U.S. Upper trough. With the surface high east of the forecast area...onshore
flow returns to the forecast area. As this piece of energy moves over the plains
towards the forecast area...guidance is advertising a quick round of rain showers
moving over the forecast area. The European model (ecmwf) is a bit farther south with the
dynamics...developing a surface low over the lower miss River Valley
and taking it northeast...whilst the GFS is advertising more of an
isentropic upglide showers event. This is the first run that the
European model (ecmwf) has advertised this surface low developing...so am tending to
discount it for now and lean towards the GFS for the forecast this
part of the forecast. Temperatures moderate upward...to a bit above seasonal
levels by Tuesday...with a chance of rain also a bit above seasonal.

Tuesday night through Thursday...the southern end of the axis of the
eastern trough swings east of the forecast area...allowing upper level high
pressure to build north from over the Gulf of mex. This allow surface
high pressure to settle over the southeastern Continental U.S. And keep the forecast area
under easterly low level flow. Temperatures a bit above seasonal with little
chance for rains expected through middle week.

&&

Aviation...
02/12z issuance...will maintain VFR conditions in the near term but
will monitor for amendments if needed due to lower ceilings/fog through
about 13z this morning. Light southeast wind forecast through
tonight. Some rain showers/few thunderstorms and rain activity this afternoon and
tonight...becoming a little more noticeable overnight. 12/ds

&&

Marine...a ridge of surface high pressure north and east of the
marine area today will drift east off the US Atlantic coast through
early Friday as a cold front approaches the marine area from the
west. The cold front will move across the coastal waters late Friday
afternoon and evening...with strong high pressure building in its
wake. Current light flow becomes moderate southwest to west wind by
Friday night as the front moves across the marine area...then strong
offshore (northwest to north) expected in the wake of the front. The
increased winds on Friday night and through Saturday will be
accompanied with building seas. Showers and thunderstorms expected
today and Friday as the front approaches and passes across the
marine area. 12/ds

&&

Preliminary point temps/pops...
Mobile 85 73 85 56 73 / 50 50 70 20 00
Pensacola 85 75 86 60 74 / 40 50 70 40 00
Destin 82 76 85 65 74 / 30 40 70 50 00
Evergreen 87 71 85 52 71 / 40 50 70 20 00
Waynesboro 88 71 85 49 71 / 50 60 70 10 00
Camden 88 71 85 49 70 / 40 60 70 20 00
Crestview 87 72 85 57 73 / 30 50 70 40 00

&&

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

$$

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