Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion...updated 
National Weather Service Mobile Alabama
1150 PM CDT Monday Sep 22 2014

Aviation...
06z issuance
VFR conditions will prevail through the next 24 hours. /13

&&

Update...a cooler and drier airmass continues to move into the area
in the wake of a cold front that has moved well into the marine area.
The current forecast remains on track and no changes are needed at
this time. /13



&&

Previous discussion... /issued 635 PM CDT Monday Sep 22 2014/

Short term (tonight through Thursday night)...for tonight...as an
upper low over the southeastern Continental U.S. Slowly shifts east to over the
Carolina coast...surface high pressure over the Ohio River and middle
miss river valleys shifts east...to over the middle Atlantic Seaboard.
The surface front this system pushed south across the forecast area today has
reached the coast at 20z and continues steadily south over the Gulf
of mex. With the upper dynamics showing little eastward movement the
first 24 hours of the forecast...the greatest push will be over the
lower miss River Valley to Sabine River. For the forecast area...this means
that the area will dry out tonight...with the area seeing temperatures
dropping into the middle 50s inland to upper 60s closer to the coast.

For Tuesday...guidance is advertising moisture returning quickly
over eastern-most sections of the forecast area as the flow becomes northeast
toe easterly...bringing Atlantic moisture over the area. Feel that
guidance is a bit overdone in this respect...so have cutback the
moisture return over eastern-most sections of the forecast area. /16

For Tuesday night through Thursday night...an upper low over the
extreme southeast states slowly drifts northward while a fairly
strong surface ridge over the region weakens gradually. Dry
conditions continue through the period. Lows Tuesday night and
Wednesday night will be in the middle sixties close to the coast with
upper fifties further inland...then trending warmer to middle sixties
across the area Thursday night. Highs on Wednesday and Thursday
will be mostly in the lower to middle eighties. /29

Long term (friday through monday)...a Rex block was expected to
form over the eastern states but now looks to struggle to organize
as an upper low over the east central states moves slowly off to the
east allowing for weak upper ridging to remain over the area. An
upper trough advances into the plains meanwhile and later into the
southeast states Sunday into Monday. A fairly tight surface ridge
remains over the southeast states through at least Saturday...but
there continues to be the potential for a surface low to develop
over the northeastern or north central Gulf and bring increased rain
chances to the area. Guidance has been struggling with the handling
and development of this feature unfortunately which degrades
confidence...but a general trend of increasing rain chances through
the period still looks good. Will start with slight chance probability of precipitation
gradually returning to the area and increasing to chance probability of precipitation Friday
into Saturday with chance to good chance probability of precipitation for Sunday and Monday.
Highs will remain near normal through the period while overnight
lows trend from several degrees above normal to about 7-8 degrees
above normal by Sunday night. /29

Marine...an upper low over the southeastern Continental U.S. Moves to the
Carolina coast before opening and getting pushed off by Moe energy
moving over the northern miss River Valley. This movement in the
upper troposphere pushes surface high pressure over the middle miss
river/Ohio River valleys eastward to the middle Atlantic
Seaboard...where it gets absorbed by by another surface high moving
rapidly east north of the US/California border. For our neck of the
Woods...this means a tight pressure gradient setting up over the
northern Gulf Coast...and moderate to strong northeasterly flow
lasting through the week. The gradient eases during the weekend as
it becomes more easterly...with the surface ridge over the eastern
Continental U.S. Weakening and a weak surface low forming over the Yucatan
Peninsula. /16

&&

Preliminary point temps/pops...
Mobile 61 85 64 84 64 / 05 00 05 05 10
Pensacola 65 85 67 84 67 / 05 00 05 10 10
Destin 68 84 68 84 68 / 05 00 10 10 10
Evergreen 55 84 58 84 59 / 05 00 05 05 05
Waynesboro 53 84 57 84 57 / 05 00 00 05 05
Camden 53 85 57 83 58 / 05 00 00 05 05
Crestview 60 84 61 84 61 / 05 00 05 10 10

&&

Mob watches/warnings/advisories...
Alabama...none.
Florida...none.
MS...none.
GM...Small Craft Advisory until 7 PM Wednesday for the following
zones: Choctawhatchee Bay...coastal waters from Destin to
Pensacola Florida out 20 nm...coastal waters from Pensacola Florida
to Pascagoula MS out 20 nm...Mississippi Sound...northern
Mobile Bay...Pensacola Bay system...Perdido Bay...southern
Mobile Bay...waters from Destin to Pensacola Florida from 20 to
60 nm...waters from Pensacola Florida to Pascagoula MS from 20
to 60 nm...

&&

$$

National Weather Service Glossary of Abbreviations