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Area forecast discussion...updated 
National Weather Service Mobile Alabama
1152 PM CDT Thursday Oct 8 2015

Discussion...updated for latest aviation discussion below.


06z issuance...VFR ceiling conditions will prevail under a 25000
foot broken cirrus cloud canopy overnight. Localized MVFR
visibilities due to light fog is expected late kept a
tempo group from 09-13z ranging from 3sm for kmob...4sm for kbfm and
5sm for kpns. A few low clouds (3500 to 5000 feet) will develop
throughout the day Friday...mainly along the immediate coast as a
weak seabreeze tries to develop. Nearly calm or light north winds
are expected overnight. Winds at kmob will become north around 5
knots during the day Friday. Winds at kbfm and kbfm will become east
around 6 knots by late morning due to their close proximity to the
coast...and then turn to the southeast by late afternoon as the weak
seabreeze tries to push inland. /22


Previous discussion... /issued 852 PM CDT Thursday Oct 8 2015/

Discussion...see updated information for land areas below.

Update...infrared satellite imagery showing a cirrus cloud canopy
spreading east across the forecast area from an Upper Cutoff low
pressure area over northwest Mexico. Skies will remain mostly clear
to partly cloudy through the remainder of the night. Will keep patchy
fog across the entire forecast area after midnight as near term
models are still developing some reductions in visibility...
especially across extreme southwest Alabama and southeast
Mississippi. Hourly temperatures are trending within a degree or no updates needed at this time. /22

Previous discussion... /issued 349 PM CDT Thursday Oct 8 2015/

Near term /tonight through Friday/...weak ridging both surface and aloft
over the region through late tonight...breaking down somewhat on Friday
as a front approaches the region from the northwest. The surface ridge
axis is just inland over the southeast the light low
level wind flow has become more easterly today as expected. For
tonight and Friday...expect a typical diurnal onshore (afternoon and
evening)/offshore (overnight and early morning)light wind flow
pattern. With the more easterly component...low level moisture is
gradually increasing over the some patchy light
overnight fog will be possible in some locations tonight. As the
front approaches late Friday...could see an isolated shower or two
over far northwestern zones...but with lack of any real forcing we
think the chances for this will be low enough to not include any low
end rain chances at this time. Lows tonight ranging from the lower
60s well inland to the middle 60s near the coast. Highs Friday
afternoon in the middle 80s most locations...except for some lower 80s
near the coast. 12/ds

Short term /Friday night through Sunday night/...Friday night
through Saturday...a shortwave moves southeast across the southeastern
quarter of the Continental U.S....pushing a weak front that had started south
across the forecast area south of the forecast area and over the central Gulf of mex.
Guidance is still very conservative in any precipitation with the front
(best dynamics passing well northeast of the forecast area and general lack of
instability ahead/with). Looking at thickness values...with the west-northwest-
east-southeast passage of the upper dynamics...the greatest drop in values (read
cooler airmass moving in) is over northeastern-most portions of the
forecast area and northeast of the forecast area. This is mostly realized
Saturday...with these areas of the forecast area seeing the closes drop to near
seasonal temperatures for Saturday.

Saturday night through Sunday night...the shortwave moves to over the
Florida/GA/SC Atlantic coast...stalls and forms an upper low. This leaves
the forecast area under general northerly flow...with eastern-most portions of
the forecast area seeing the possibility of some wrap-around stratus limiting
heating. The European model (ecmwf) is the strongest in bringing the stratus in (due
to its positioning the upper low farthest west and advertising a
deeper low. Have tried to go between the two solutions for temperatures.

Long term /Monday through Thursday/...another upper shortwave dives
southeast across the eastern Continental U.S....pushing a bit stronger front
across the forecast area late Monday night through Tuesday. With the dynamics a
bit closer and a bit more instability to work with...did add rumbles
to the low chance of rain Monday night through Tuesday. This front
brings more dry air in over the forecast area...with the diurnal temperature range
opening up...then temperatures warming back to above seasonal levels by the
end of the week.

Marine...expect a general light diurnal wind flow late this evening
through most of Friday with a general southeasterly flow this
evening becoming more northeasterly overnight. On Friday the light
offshore flow will become more onshore again during the early
afternoon hours...but will gradually shift to more predominately
offshore late in the day and especially Friday night into early
Saturday as a cold front approaches and slowly moves across the
marine area. By late Saturday through Sunday...a light to occasionally
moderate offshore flow will develop as a front moves well south of
the marine area and a ridge of high pressure is reinforced from the
north. Winds become more lighter and more variable early next week
before increasing and becoming more westerly during the middle part
of the week as another front is expected to approach the marine
area. Seas generally around 2 feet (or less) early in the period...
building to 2 to 4 feet well offshore over the weekend with the
slightly stronger offshore flow...then subsiding slightly early next
week as high pressure builds in. With the second front expected to
be approaching the marine area by the middle part of next
week...seas likely to increase slightly. 12/ds


Mob watches/warnings/advisories...


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