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Area forecast discussion 
National Weather Service Mobile Alabama
700 am CDT sun Aug 2 2015

Aviation update...1200z issuance...VFR conditions expected to
prevail throughout the period except in and around afternoon thunderstorms.
Expect less convection today then we have seen the past couple of
days. Expecting little more than isolated coverage except over the
Florida Panhandle where low end scattered coverage is possible.
Confidence was not high enough to bring then on site at any of our
taf locations. /08


Previous discussion... /issued 508 am CDT sun Aug 2 2015/

Short term...(today through tuesday)...for today through tonight...
convection continues to develop along the frontal boundary over the
northern Gulf. The front has sagged well south and east of the
forecast area. A broad east to west surface trough aided by
afternoon heating and associated with a closed low to middle-level
wave...apparent in the 850 to 700 mb geopotential heat fields which
has become detached from the main westerly flow aloft...will develop
over the forecast area this afternoon. Airmass has dried
considerably since yesterday as layer precipitable water amounts have fallen from
a little over 2 inches to a maximum of around 1.7 inches near the
coast and to as low as an inch in our more northern Alabama and MS
counties. Our southeast MS and SW Alabama counties lie along the eastern
periphery of a broad upper level ridge extending eastward from its
center in western Texas. Large scale forcing in the global spectral
models project increasing subsidence today...especially over our
western zones so have kept the forecast dry except along the coastal
zones of Mobile and Baldwin counties where the sea breeze front
might provide enough lift to tap into afternoon sb convective available potential energy...but
confidence is pretty low. Went with isolated afternoon thunderstorms as well
over our Alabama counties east of I-65 whose weather may be influenced by
the broad upper trough aloft (500 mb and above)...associated with
the closed lows at the 700 and 850 mb levels...due to their
susceptibility to minor shortwaves propagating southeastward in the
northwesterly flow aloft...both the GFS and European model (ecmwf) project just such
a feature brushing the area this afternoon. Expect scattered thunderstorms
over the Florida Panhandle due to a combination of the sea breeze
front and the broad low pressure aloft. Little change in temperature
trends as daytime highs continue to climb into the middle to upper 90s
in the interior and low to middle 90s near the coast. Heat indices
generally climb to near 100...with isolated locations peaking around
105. Overnight lows middle to upper 70s along and near the coast then
upper 60s to low 70s inland. /08 jw

This afternoon's wet microburst risk is moderate long the coast. a vorticity lobe sweeps around an upper lower near Hudson pushes several weak shortwaves over the NE Florida out of the
eastern Continental U.S. Trough along with their associated surface low. More
shortwave energy tops the western Continental U.S. Ridge and starts to move
southeast over the plains. Over the forecast area and surrounding areas...a
surface trough is left north of the Gulf Coast. For the
forecast...with weak onshore flow developing over coastal
areas...some moisture moves inland...enough for a few thunderstorms and rain along the
coast. The drier airmass over the northern two thirds of the forecast area
remains a bit longer...allowing daytime temperatures to rise into the upper

Monday night through Tuesday...shortwave energy flatters the western
ridge more...with some eastward squeezing of the upper ridge over
the Southern Plains as it de-amplifies. Temperatures cool a bit from Monday
as a result....and with that temperatures a bit cooler than Monday result. A
Gulf Breeze organizes and moves inland again Tuesday...bringing more
Gulf moisture further inland. Even so...with less upper
support...probability of precipitation still remain confined to the coast and on the isolated

Long term...(tuesday night on)...Tuesday night through
Wednesday...some of the energy that topped the western ridge in the
short term moves into and deepens the East Coast upper trough and
re-building the western ridge. The surface ridge stretching west
over the Gulf of mex re-organizes...providing a more organized
onshore flow...and increases moisture levels inland from the coast.
Increased rain chances spread inland...and with the increasing cloud
cover...temperatures a bit cooler than the short term...but still a bit
above seasonal...result.

Wednesday night through upper low moving south along the
West Coast works with several rounds of shortwave energy moving into
the eastern trough to build and sharpen the western ridge...along
with shifting it eastward a bit. The Gulf of mex surface ridge sees
some shifting and dimpling...but generally remains intact...keeping a
general south to southwest flow off the Gulf over the lower miss
River Valley and southeastern states. This brings the chance of rain
back to seasonal levels (scattered mainly afternoon thunderstorms
lasting into the evening)...with temperatures easing downward towards
seasonal levels.

Friday night through Sunday...some of the shortwave energy that moves
into the eastern trough brings a weak surface boundary across the
tenn River Valley to along the northern Gulf Coast by Sunday. This
brings in cool air for the last day of the forecast and dries the forecast area
out for Sunday into the following week. Do not see a significant
drop in temperatures...though...with around seasonal temperatures continuing.

Marine...a light offshore flow will continue through the morning but
will gradually turn southerly and strengthen during the afternoon as
a broad area of surface low pressure develops inland near the coast.
A moderate southwesterly wind flow will persist through the early
evening and then gradually diminish overnight. An onshore flow should
then prevail through the work week as high pressure builds over the
Gulf. /08 jw


Preliminary point temps/pops...
Mobile 95 73 96 74 94 / 20 05 20 10 20
Pensacola 93 75 93 77 92 / 30 10 20 10 20
Destin 93 78 91 79 89 / 30 10 20 10 20
Evergreen 98 68 97 71 97 / 10 05 05 05 10
Waynesboro 96 70 98 71 97 / 10 05 05 05 05
Camden 98 67 97 70 99 / 10 05 05 00 05
Crestview 96 71 98 72 95 / 30 10 10 10 20


Mob watches/warnings/advisories...


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