478
FXUS64 KMOB 250854
AFDMOB

Area Forecast Discussion
National Weather Service Mobile AL
354 AM CDT Wed Sep 25 2024

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

.NEAR TERM...
(Now through Thursday night)
Issued at 354 AM CDT Wed Sep 25 2024

An upper level longwave trough, currently located over the
central US is continuing to dig southeastward this morning. Within
the next few hours, it will begin to break off from the northern
just stream, resulting in an anomalously large upper low that
parks itself over the Mississippi River Valley. This low is
responsible for two things: 1) helping to send a frontal boundary
into the region from the west, and more importantly 2) keeping the
core of soon-to-be Hurricane Helene to our east.

For today, the front, which is currently located over central
Mississippi, will begin moving into our local area. Plenty of
forcing due to strong diffluence aloft and convergence along the
front, in addition to ample moisture (PWATs around 1.6 to 1.9
inches), will result in scattered to numerous showers and storms
across the area, especially in the afternoon. The front should stall
somewhere near the I-65 corridor by Wednesday evening, allowing for
high rain chances to continue (especially along and east of it)
through Wednesday night. Although lapse rates are rather poor,
daytime heating should allow for some destabilization to occur.
This, paired with favorable deep layer shear due to the close
proximity of the upper low could result in the organization of a few
strong to marginally severe storms. Gusty to damaging winds seem to
the primary threat. Not really anticipating a tornado threat due to
very weak low-level shear values and straight-lined hodographs.

For Thursday, all eyes point to the Gulf as Helene rapidly
strengthens into a major hurricane and sprints toward the Florida
Big Bend area. Thankfully for our local area, the core is far enough
away for us to be spared from the hurricane force winds and storm
surge effects. However, as this system quickly lifts northward, it
is expected to grow in size considerably and therefore we will still
see some impacts. Hazardous marine conditions (due to strong winds
and high waves), dangerously high surf (breakers greater than 10
feet), and life threatening rip currents are expected, especially as
we get into the Thursday afternoon through Thursday night timeframe.
We will also be monitoring for the potential of, at least, minor
coastal flooding along the coastal interface going into Thursday
night. As far as rainfall, we are currently anticipating a general 2
to 4 inches (locally higher possible) over south central Alabama and
the western Florida Panhandle through this entire period, with lower
amounts for southwest Alabama and southeast Mississippi. This
rainfall could lead to isolated to scattered instances of flash
flooding, especially over urban and poor drainage areas, and some
minor river flooding cannot be ruled out. And lastly, wind gusts of
around 25 to 35 mph are anticipated across the area (highest near
the coast) starting as early as Thursday morning. An occasional gust
to near tropical storm force cannot be ruled out. We will continue
to monitor the progress of Helene closely, as any shifts to the west
will likely bring stronger impacts than what was listed above. /96

&&

.SHORT AND EXTENDED TERM...
(Friday through Tuesday)
Issued at 354 AM CDT Wed Sep 25 2024

Per the latest track for Helene from the National Hurricane Center,
the system is expected to have weakened to a depression over
northern Georgia by Friday morning. The system becomes absorbed
into a rather unusual large upper low which slowly moves from over
the lower Mississippi River valley to become centered near the
Mississippi/Ohio River confluence by Saturday. The upper low later
breaks down leaving an upper trof over the eastern states by
Monday. Am anticipating predominately dry conditions for our area
on Friday, with dry conditions prevailing through Sunday. There
appears to be a small chance for rain over the eastern half of the
area on Monday although confidence is low, then dry conditions
prevail on Tuesday except for a possible small chance for rain
over Okaloosa county Florida. A high risk of rip currents will
continue through Friday night, then a moderate risk is expected on
Saturday with a low risk for Sunday. A high surf advisory will
probably be necessary for Friday, but surf conditions will have
subsided by Friday night. /29

&&

.MARINE...
Issued at 354 AM CDT Wed Sep 25 2024

Based on the latest track for Helene from the National Hurricane
Center and the associated wind field (and probabilities of 34+
knots), have added the 20-60 nm portion of the Alabama coastal
waters to the Tropical Storm Warning currently in effect for the
western Florida Gulf waters. Have also issued a Small Craft Advisory
for the remainder of the marine area which will be in effect from 4
am Thursday to 1 pm Friday, by which time both winds and seas will
have subsided sufficiently. Winds and seas will be higher near
storms. /29

&&

.PRELIMINARY POINT TEMPS/POPS...
Mobile      89  69  81  64  83  66  86  66 /  40  50  40  20  10   0   0   0
Pensacola   87  73  80  68  82  72  85  72 /  60  80  70  30  10   0   0   0
Destin      86  74  81  71  82  73  85  73 /  80  80  80  50  10   0   0  10
Evergreen   87  70  78  64  83  62  86  64 /  70  70  70  50  10   0   0   0
Waynesboro  85  65  82  62  81  62  84  61 /  50  30  30  20  10   0   0   0
Camden      86  68  77  63  80  62  83  62 /  60  60  60  50  10   0   0   0
Crestview   87  72  79  66  83  64  86  66 /  90  80  80  50  10   0  10   0

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...High Rip Current Risk from this evening through late Friday
     night for ALZ265-266.

FL...High Rip Current Risk from this evening through late Friday
     night for FLZ202-204-206.

MS...None.
GM...Small Craft Advisory from 4 AM Thursday to 1 PM CDT Friday for
     GMZ630>636-650.

     Tropical Storm Warning for GMZ655-670-675.

&&

$$

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