151
FXUS64 KMOB 121107
AFDMOB

Area Forecast Discussion
National Weather Service Mobile AL
607 AM CDT Wed Mar 12 2025

...New AVIATION...

.AVIATION...
(12Z TAFS)
Issued at 606 AM CDT Wed Mar 12 2025

VFR conditions expected through the forecast. Winds will increase
to southerly around 10 knots today, then ease to around 5 knots
this evening. Rainshowers will begin to approach inland southeast
Mississippi areas towards sunrise Thursday.
/16
&&

.PREV DISCUSSION... /issued 344 AM CDT Wed Mar 12 2025/

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

NEAR TERM...
(Now through Thursday night)
Issued at 341 AM CDT Wed Mar 12 2025

An upper level ridge builds today ahead of a developing upper
system moving over the Plains. This closed system will move over
the Mississippi River late tonight, and bring a quick round of
rain showers and thunderstorms to the forecast area Thursday. An
upper ridge builds over the Southeast Thursday night as the upper
system moves quickly off. With southerly low level flow re-
established over the forecast area and nearby, a very dry airmass
currently over the forecast area (around 0.2" of precipitable h20)
rises to around 1.1" Thursday. Looking at the possibility of
rowdy storms, SBCapes rise to around 1000J/kg, and a modest Bulk
wind shear (around 40kts) is present over land areas of the
forecast area (higher over and south of the coast, though). With
the center of the upper system passing over Tennessee, upper
support is modest at best over the forecast area. Enough for a few
storms to bring strong to marginally severe winds. Not to forget,
model soundings are advertising mid level lapse rates around 7.5C
or a bit higher, leading to a possiblity of hail development. SPC
has placed most of the forecast area in a Marginal Risk.

The upper ridging ahead of the coming upper low combined with the
dry airmass to allow high temperatures today to rise to a bit above
seasonal norms, mid to upper 70s north of I-10, low 70s south to the
coast. A higher chance of rain over eastern portions of the forecast
area Thursday will help to limit heating over these portions of the
forecast a bit more, leading to a west to east gradient in high
temperatures for Thursday (mid 70s along the eastern border of the
forecast area to low 80s over inland southeast Mississippi). Low
temperatures are a bit more stable, with increasing moisture levels
and cloud cover helping to temper radiational cooling. Mid to upper
50s expected over most of the forecast area tonight and upper 50s to
low 60s Thursday night.

A rip risk of Rip Currents is expected through Thursday night.
/16

SHORT THROUGH LONG TERM...
(Friday through Tuesday)
Issued at 341 AM CDT Wed Mar 12 2025

Friday is a transition day in between the storm systems as weak
shortwave ridging quickly builds into and then out of the area
through the day. The morning and afternoon hours on Friday will be
dry.

All eyes then turn to the weekend storm system that will impact our
area. We will state up front that many of the details will not be
ironed out for a few more days...we will continue to refine the
forecast as we draw closer to the day/night of the event. So what is
the setup? A potent shortwave rounds the base of a trough as it
swings across the Plains on Friday and pivots toward the Great Lakes
region by mid-day Saturday. As the lead shortwave ejects north, the
base of the main trough amplifies (with another more subtle shortwave
rounding through the base) and the trough eventually swings toward
the region Saturday night into Sunday. An anomalously deep surface
low is still expected to develop over the Central Plains on Friday
in response to the lead shortwave and it will follow a similar path
as it also pivots toward the Upper Midwest over the weekend (turning
into a stacked low). Looking way further south and closer to the
local area, guidance still indicates that a wave of low pressure may
attempt to develop along the north central Gulf Coast (Louisiana) by
Saturday morning. This would lead to a warm front attempting to lift
out of the Gulf and eventually surge north through our area early on
Saturday. Deep onshore flow develops ahead of this system as rich
Gulf moisture funnels into the area. PWATs quickly recover by Friday
afternoon and evening and begin to surge to 1.8+ inches by Saturday
afternoon. In addition to increasing moisture, it will be breezy
ahead of this system as the pressure gradient increases as the area
remains sandwiched between the deep surface low sliding across the
Plains and a surface high parked over the western Atlantic. Winds
will start picking up by Friday afternoon and not let up until
Sunday. Can`t rule out some isolated showers on Friday afternoon
given the increasing southerly flow and moisture moving into the
area, but, by and large, the area remains dry through the day.
Showers and storms will start to become more scattered and
potentially widespread overnight Friday into Saturday.

What We Know - This looks like it might be a long duration event.
What We Don`t Know (Yet) - The exact timing (or even general timing
at this point) or the severity of the event. Looking at Friday night
into the pre-dawn hours on Saturday, there is certainly enough
instability and some shear overnight to see some strong to severe
storms, but the more favorable environment for severe storms comes
into play on Saturday. We will likely go from not much of anything
on radar at sunset on Friday to a few strong to marginally severe
storms on radar by midnight and then begin to transition to the
potential for severe storms with all hazards on the table before pre-
dawn on Saturday. That`s just the pre-event as the main event will
be during the day on Saturday. The best dynamics move into the Deep
South and Southeast as we roll through Saturday. Could the worst of
the weather be elsewhere in the Deep South and not in our area,
yes...could it be in our area, also yes...we just don`t have those
specifics yet. That said, it is becoming increasingly likely that we
see two rounds of potentially high-impact weather on Saturday with
supercells forming in the warm sector and a potent squall line
swinging through the area Saturday night.

Again, it is still too far out in time to nail down the specifics,
extent, severity, and timing of this event...especially considering
the differences in the guidance this far ahead of the potential
event. Once we get closer in time, we will have a better handle on
how the mesoscale details evolve for the event. Continue to check
back over the next few days as we iron out all the details for the
upcoming weekend. Storms should push east of the area through the
morning on Sunday (along with the passage of a cold front) with a
dry forecast for Monday and Tuesday.

Beach Forecast - The rip current risk jumps to a HIGH RISK over the
weekend. Surf quickly increases as we head into the weekend with the
potential for 5-7 foot breakers possible at the beaches on Saturday
and Sunday before the surf begins to subside. 07/mb

MARINE...
Issued at 341 AM CDT Wed Mar 12 2025

AFD: Light to a times moderate onshore flow lasts into Friday,
Winds will become moderate to strong Friday night into the coming
weekend as a stronger upper system passes. A Small Craft Advisory
Friday night into the weekend will likely be needed.
/16

&&

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

$$

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