-- Discussion containing changed information from previous version are highlighted. --
816
FXUS64 KMOB 242117
AFDMOB

Area Forecast Discussion
National Weather Service Mobile AL
417 PM CDT Tue Sep 24 2024

...New NEAR TERM, SHORT TERM, LONG TERM, MARINE...

.NEAR TERM...
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(Now through Wednesday)
Issued at 417 PM CDT Tue Sep 24 2024

Current water vapor imagery reveals a digging longwave trough over
the central US with an upper ridge positioned over portions of the
Florida Panhandle and western Atlantic. The upper level trough will
continue to amplify through Wednesday as it sinks southward over the
Mississippi Valley and eventually breaks off from the northern jet
stream. Down in the lower levels, a surface front is currently
draped across northern Mississippi and Louisiana and this feature
will continue to move southeast and approach the local area through
the evening hours. At the same time, a surface ridge which is
currently positioned along the northern Gulf coast weakens and
begins to retreat from the area tonight as the front approaches.
Conditions will remain mostly dry through the rest of the afternoon
given this surface ridging and the lack of substantial deep layer
moisture. Better moisture will begin to usher into these
northwestern zones ahead of the surface front tonight with PWATs
rising to around 1.6 to 1.8 inches. This moisture combined with the
lingering surface boundary will result in the development of
isolated to scattered showers and storms across southeast
Mississippi and southwest Alabama late this evening and into early
Wednesday morning. Additional showers and storms are expected to
develop as some peripheral response of Tropical Storm Helene
entering into the southern Gulf of Mexico Wednesday morning. This
activity will likely develop over the eastern Gulf Waters and
gradually spread into the adjacent coastal areas of northwest
Florida and south central Alabama through Wednesday morning. Rain
chances will remain elevated through the day Wednesday as the front
will moves further into the local area and deep layer moisture
increases. This moisture combined with plenty of forcing due to
strong diffluence aloft and convergence along the front will result
in numerous to widespread showers and storms across the area. If
this activity is able to remain more scattered in the morning and
early afternoon hours, then we could see a localized severe threat
develop over portions of south central Alabama and the Florida
Panhandle where decent destabilization would overlap with ample deep
layer shear. The main concern if this were to pan out would be gusty
wind or a brief tornado. However, if this activity becomes more
widespread, then poor lapse rates should keep storms sub-severe
across the majority of the area. SPC has outlooked south central
Alabama and the Florida Panhandle in a marginal risk for this severe
potential. Rain chances should begin to taper off over far western
portions of the area by Wednesday evening as the front stalls across
the area and slightly drier air moves in behind the boundary. Rain
chances will remain elevated over the eastern half of the area
through Wednesday evening.

Low temperatures tonight will fall into the upper 60s and lower 70s
for interior portions of the region with middle 70s at the beaches.
High temperatures on Wednesday afternoon will range from the middle
to upper 80s. A low risk of rip currents continues tonight, but will
increase to a moderate risk on Wednesday. /14
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&&

.SHORT TERM...
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(Wednesday night through Friday night)
Issued at 417 PM CDT Tue Sep 24 2024

An upper level low will remain across the lower Mississippi River
valley. An associated frontal boundary will stall along the I-65
corridor Wednesday night into Thursday, maintaining elevated rain
chances along and east of I-65 through Thursday. As likely major
Hurricane Helene makes landfall some along the big bend area of
Florida, some drier air will be pulled south into the area
resulting in decreasing rain chances Thursday night and dry
conditions on Friday. Hazardous marine conditions(due to strong
winds and high waves) can be expected with high surf (breakers
greater than 10 feet) along with a high risk of rip currents.
Rainfall amounts continue to decrease with only 2 to 4 inches
possible mainly across far eastern areas. /13
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&&

.LONG TERM...
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(Saturday through Tuesday)
Issued at 417 PM CDT Tue Sep 24 2024

The upper level low gradually weakens and lifts northeast into the
Ohio Valley by early next week. A dry airmass remains through much
of the area with only very isolated showers possible over the
weekend. A reinforcing shot of drier air is possible late in the
period. /13
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&&

.MARINE...
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Issued at 417 PM CDT Tue Sep 24 2024

Tropical Storm Helene is expected to strengthen to near
hurricane strength when it reaches the northwestern Caribbean
Wednesday morning. Further intensification is expected and this
system is likely to become a major hurricane before approaching the
northeastern Gulf Coast Thursday evening. Significantly higher seas
and strengthening winds are expected over the marine area as a
result. A Tropical Storm Watch has been issued for the Florida 0-60
nm Gulf waters. We may need to include a Small Craft Advisory for
the remainder of the marine area beginning late Wednesday night
which continues until seas subside Friday morning. Please see the
National Hurricane Center for additional information. Winds and seas
are expected to gradually subside Friday into Friday night with a
moderate westerly to southwesterly flow prevailing through the
weekend. /14
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&&

.PRELIMINARY POINT TEMPS/POPS...
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Mobile      71  89  69  82  66  84  66  86 /  10  60  60  40  20   0   0  10
Pensacola   75  86  72  80  69  82  71  85 /  20  70  90  70  30  10   0  10
Destin      76  86  72  81  71  83  72  85 /  30  80  90  80  50  10   0  10
Evergreen   69  87  68  80  66  83  62  86 /  20  80  80  70  50  10   0  10
Waynesboro  69  85  64  80  63  82  61  85 /  30  60  40  30  20  10   0  10
Camden      68  84  66  77  64  80  62  83 /  20  80  70  70  50  10   0  10
Crestview   71  87  69  79  66  84  63  86 /  30  80  90  90  50  10   0  10
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&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...None.
FL...None.
MS...None.
GM...None.
&&

$$

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