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Area forecast discussion...updated 
National Weather Service Mobile Alabama
813 PM CDT Friday Aug 29 2014

Update...deep layer moisture continues to spread northward across
our forecast area this evening between a middle level ridge of high
pressure centered over the southeastern states and a middle level trough
approaching the Mississippi River valley region from the plains
states. The latest radar trends continue to show occasional
development of a few showers and thunderstorms within the deeply
moist airmass over inland portions of our forecast area...with
better convective coverage noted over western portions of our
offshore marine zones. With precipitable water values expected to
range between 2 and 2.25 inches across our region overnight...we will
maintain a low chance of convection across the County warning forecast area through the
night...with slightly better coverage indicated near the coast.

Increased southeasterly winds and elevated surf heights will support
a moderate risk of rip currents along the beaches of southwest
Alabama and the northwest Florida Panhandle through the weekend. An
updated surf zone forecast has been issued to reflect the moderate
risk through Sunday. /21

&&

Aviation [30.00z terminal forecast discussion]...VFR conditions are
generally expected through the forecast period with broken to
overcast middle and high level cloud cover spreading across the region.
The general trend through the evening/overnight will be lower
convective coverage over inland areas...with a better chance of
rain showers/thunderstorms and rain near coastal areas as convection over the northern Gulf of
Mexico slowly moves northward. For now confidence only remains high
enough to just keep thunderstorms in the vicinity mention in at kmob...kbfm and kpns...but
will continue to monitor northward moving convection over the water
and make amendments if necessary. MVFR to localized IFR conditions
will be possible in and near showers and storms. /21

&&

Previous discussion... /issued 405 PM CDT Friday Aug 29 2014/

Short term (tonight through Monday night)...for tonight and
Saturday...microburst risk remains moderate this afternoon. Deep
layer humidity in the face of decreasing stability and modest rise
of cape ahead of convection moving in from the south. This feature
will reach along a line from near Atmore Alabama to Waynesboro
Mississippi by 29... Thomasville to Butler Alabama by
30... was close to NAM...Euro...and GFS calculations. It
will weaken later this evening and into Saturday. Precipitable
water is rising to 2.4 inches by early this evening with cape a
relatively modest 1500 j/kg. Cape should reach 2500 to 3000 j/kg on
Saturday. Li expected -2 to -4 degree c. This evening and-5 to -6
Saturday. Rather limited forcing...Omega about 1 to 3
microbars/sec...so the bands of rain would yield only about 0.75
inches over the next 24 hours. Other inhibitions include a bit of
drying out overnight before we Jump Up to likely mostly west of
I-65. 77/blowing dust

For Saturday night through Monday night...a well defined shortwave
trough located from the lower Mississippi River valley to Great Lakes
region ejects off to the northeast through Monday allowing for an
extreme southeast states upper ridge to build westward into the
south central states. A weak surface trough previously over the
northern Gulf is expected to have dissipated by Saturday evening
with a surface ridge otherwise remaining in place over the northern
Gulf coastal area through Monday night and maintaining a southerly
flow. While abundant Gulf moisture will be in place at 00z Sunday
with precipitable water values around 2.0 inches...somewhat drier
deep layer air currently entering the eastern Gulf in the GOES
precipitable water loop is eventually drawn into the forecast area.
At this time...expect a gradual decrease in precipitable water values
to near 1.4-1.7 inches by Sunday morning...then a likewise gradual
recovery to around 2.0 inches by Monday as more abundant Gulf
moisture moves back into the area. Overall am expecting a more
typical diurnal convective pattern through the period. Will have
slight chance to chance probability of precipitation Saturday evening...with the
better coverage over the western portion closer to the ejecting
upper trough. Chance probability of precipitation follow for most of the area Sunday and
Monday with mostly dry conditions each night. Daytime highs will be
about a few degrees above normal with overnight lows a few degrees
above normal over interior areas...and up to several degrees above
normal closer to the coast. /29

Long term (tuesday through friday)...an upper ridge gradually
expands across the southeastern states during the period while a
surface ridge remains over the northern Gulf coastal area...although
there is the potential for a surface low well to the north to bring
a weak trailing front or surface trough into the area Thursday night
into Friday. A combination of the latter feature and an otherwise
typical diurnal pattern of daytime heating leading to convective
development will support chance probability of precipitation each day. Highs and lows will
be about a few degrees above normal through Thursday then closer to
seasonable values by Friday. /29

Aviation (18z issuance)...increasing deep layer humidity in the
face of convection moving in from the south. Expecting VFR to MVFR
until arrival of the leading edge of a band of showers now crossing
the beach. This feature should reach along a line from near Atmore
Alabama to Waynesboro Mississippi by 29... Thomasville to
Butler Alabama by 30.0100z. Ceilings about 2500 to 3500 feet except
1000 to 1500 or less in heavy rain. Visibility generally 3 to 5
miles in rain showers and 1 to 3 miles in more intense cells. 77/blowing dust

Marine...a weak high pressure ridge extends from the western
Atlantic Ocean to the north central Gulf of Mexico bringing a light
to moderate southeasterly wind through Tuesday. Bands of showers and
thunderstorms will spread northward across the area today through
much of the weekend over the marine area. Visibility down to a
mile...and gusty winds possible...in more intense cells. Seas 2 to 3
feet. 77/blowing dust

&&

Preliminary point temps/pops...
Mobile 76 90 76 92 75 / 40 60 30 30 10
Pensacola 78 91 78 92 77 / 40 50 20 30 20
Destin 79 90 79 90 79 / 30 40 20 30 20
Evergreen 72 93 73 94 72 / 20 60 20 30 20
Waynesboro 74 90 72 92 71 / 30 70 30 30 10
Camden 72 92 72 94 73 / 20 60 30 30 20
Crestview 73 93 73 94 72 / 30 40 20 30 20

&&

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

$$

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