Area Forecast Discussion
Issued by NWS Mobile, AL

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FXUS64 KMOB 252352
AFDMOB

Area Forecast Discussion
National Weather Service Mobile AL
652 PM CDT Mon Mar 25 2024

...New AVIATION...

.AVIATION...
(00Z TAFS)
Issued at 652 PM CDT Mon Mar 25 2024

MVFR conditions prevail this evening across the forecast area as
brisk southeasterly winds persist. Expect southeasterly winds to
remain sustained around 20 to 25 knots this evening with gusts
periodically approaching 30 to 40 knots, gradually shifting to
southerly by late this evening. A line of strong to severe storms
will approach the forecast area from the west late this evening,
and move through the area shortly after midnight through noon
Tuesday, bringing with it potential for damaging wind gusts and
tornadoes. Expect IFR ceilings to become established during the
overnight period as well, lingering into the day Tuesday.
Underneath any storms, LIFR to VLIFR ceilings and visibility can
be expected. There is also the potential for low level wind shear
out of the south at 35 to 40kts beginning this evening and
lasting into the morning Tuesday. /22

&&

.PREV DISCUSSION... /issued 411 PM CDT Mon Mar 25 2024/

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

NEAR TERM...
(Now through Tuesday)
Issued at 411 PM CDT Mon Mar 25 2024

A rather potent system has begun to affect the forecast area as
strong, gusty gradient winds are already being experienced.
Conditions will continue to deteriorate throughout the rest of
today into tonight. Gusty winds up to 45 mph, life threatening
beach conditions, and the potential for a line of strong to severe
storms capable of producing damaging winds up to 70 mph and a
couple tornadoes(can`t rule out a strong tornado or two) may
affect the forecast area during the period.

Synopsis...A deep upper trough continues to transit the central
US today, ejecting into the upper midwest tonight. At the surface,
a rather impressive surface pressure gradient has set up across
the deep south resulting in strong southerly flow which is quickly
transporting moisture northward. Despite a rather short return
time between the last front and this one, strong low and deep
layer flow should be enough to push moisture well inland. This is
already being noticed as dewpoints have climbed into the lower to
middle 60s near the coast already. A cold front and associated
pre- frontal trough will push into Mississippi by early this
evening. A line of storms will quickly progress eastward overnight
entering the area around sometime around midnight. This line of
storms will then move eastward through Tuesday morning, slowly
weakening across our area as the best upper diffluence associated
with the main trough quickly lifts north of the area. Skies will
rapidly clear in the wake of the front as drier northwesterly flow
moves in. This system will bring the usual gambit of hazards we
see during the spring. MM/25 BB/03

Severe thunderstorms...Confidence across southeastern Mississippi
has continued to increase this morning into early afternoon, with
increasing uncertainty further east. The upper jet associated with
the aforementioned trough will nose into southeastern Mississippi
around midnight through 6 am. Strong upper level difluence and
ample height falls are expected during this period, primarily
across our southeastern Mississippi counties, perhaps skirting
into our interior southwestern Alabama counties. This type of
setup typically yields a glancing blow for severe weather
affecting our interior MS into interior southwest AL counties.
Given the deep layer wind fields, shear will not be an issue with
rather large curved hodographs supportive of organized storms
likely in the form of a squall line (QLCS). At this time it is not
anticipated for any discrete supercells to develop ahead of the
line. Limited instability around 500 to 1,000j/kg owing to the
short return period from our last system and cooler midlevels
removed to the west in conjunction with the lack of height falls
ahead of the line should preclude much if any warm sector
development. Not to say it can`t happen, but anything that tries
to develop will likely struggle ahead of the line. Typically in
these high shear/ low CAPE (instability) setups, we heavily rely
on strong upper level support and lift which will likely remain
confined nearer the front and QLCS over southeastern MS into
interior southwestern AL. If a supercell does form and mature
ahead of the line, things get a little more interesting and the
potential for a strong (EF-2+) tornado goes up significantly.

High shear low cape environments generally rely heavily on
intense jet dynamics to support storms. As the line enters our
area from the west, there appears to be a small window of
opportunity as the QLCS progresses across southeastern Mississippi
into southwestern Alabama where upper level forcing will be
sufficient to support a severe threat. Damaging winds will likely
be the primary threat given the strong low level flow nearing 50
to 60 knots at 925mb. It will not take much for damaging winds to
reach the surface with that kind of low level flow and the
potential for some more significant winds in excess of 70 mph
certainly exists. Large, curved hodographs with 0-3km bulk shear
vectors of 50+ knots largely perpendicular to the QLCS orientation
will support a tornado threat through QLCS mesovortex development
with best odds of this across southeastern Mississippi into
interior southwestern Alabama. Impressive low level streamwise
vorticity is exhibited by modeled hodographs across the risk area
with 0-1km SRH values approaching 400 to 500 m2/s2. Given the
magnitude of this, a couple strong QLCS tornadoes (EF-2+) can not
be ruled out. Our greatest concern appears to be across interior
portions of southeastern Mississippi including Wayne, Perry and
Greene counties up into Washington and Choctaw counties in
Alabama.

Confidence in the QLCS continuing eastward past the aforementioned
area quickly drops off further east as storms cross into Alabama.
Low level shear will continue to be strong; however, as mentioned
the upper support will lift out, resulting in a quick weakening of
storms as they hit the eastern extent of what limited instability
was available. The strong low level flow may be enough to support
a localized damaging wind threat with any stronger storms but a
more widespread severe risk seems unlikely once getting within the
vicinity of the I-65 corridor and points east. Trends may need to
be monitored as any uptick in instability/lift would then support
the severe threat extending further eastward. MM/25 BB/03

Wind....The pressure gradient continues to tighten across the
forecast area this evening with strong wind gusts already
occurring across the area this afternoon. So far the highest wind
gust that has been measured has been around 45mph at several
locations. The tightening gradient will allow for rather strong
low level flow to develop across the area, increasing as we head
into the overnight. 925 mb winds will intensify to nearly 50 knots
just a few thousand feet off the surface, with some interior
spots approaching 60kts during the overnight period. This low
level jet coupled with some level of surface instability despite
being the overnight hours will allow for strong wind gusts to mix
down to the surface. As a result, wind gusts up to 45 mph will be
possible late Monday afternoon into Monday night. Winds will not
be as strong on Tuesday as the better low level wind field lifts
north and the gradient weakens. A wind advisory remains in effect
for the entire area through Tuesday morning as strong winds can
result in downed trees and hazardous driving conditions on area
bridges. BB/03

Coastal Hazards...The best way to sum this section up is if you
are here on spring break, vacation, just passing through, STAY
OUT OF THE DANG WATER!

With the strong southerly flow and Gale candidness offshore, wave
heights will rapidly increase late Sunday night into Tuesday.
Expect surf heights to climb to 7 to 9 feet. We have issued a high
surf warning for all area beaches. On top of the high surf, life
threatening rip currents will be likely across all area beaches
through Wednesday as seas take a few days to subside. Currently,
we are heading into a neap tide meaning that tidal ranges are
rather small across the area. However, given the strong low level
flow will need to be closely monitored across northern Mobile Bay
for some coastal flooding. Right now guidance is just below
criteria which makes sense given the neap tide but if winds trend
any stronger then we might get close to seeing some minor coastal
flooding. Nonetheless, some overwash may be possible in our prone
barrier islands such as Ft. Pickens, Dauphin Island, Santa Rosa
Island. MM/25 BB/03

Heavy Rainfall...Despite recent rains the last few weeks, this
system appears to be too quick hitting to be overly concerned
about heavy rainfall. Local flash flood guidance ranges from 2 to
3 inches per hour inland with areas of 3 to 5 inches per hour
required along the coast. Given the rather quick progression
across the area and the fact that instability and lift decrease
the further east we move; heavy rainfall and flooding outside of
local nuisance flooding seems rather unlikely at this point. Can`t
rule out a localized spot seeing some nuisance flash flooding,
but confidence in a more widespread threat is rather low at this
time. MM/25 BB/03

SHORT TERM...
(Tuesday night through Thursday night)
Issued at 411 PM CDT Mon Mar 25 2024

A drier airmass will move into the area Tuesday night as rain
moves east out of the area. Dry conditions prevail through the
short term as the upper trough slowly moves east. A northwest
upper flow develops on Thursday as the upper trough moves east
with high pressure building across the southeast. Highs on
Wednesday will be in the low to mid 70s and upper 60s and low 70s
on Thursday. Lows Tuesday night will range from the upper 40s and
low 50s inland to mid and upper 50s along the coast. Lows continue
to cool each night with upper 30s and low 40s inland to low 50s
along the coast Thursday night. /13

LONG TERM...
(Friday through Monday)
Issued at 411 PM CDT Mon Mar 25 2024

Northwest flow aloft with
sfc high pressure and resulting dry conditions will prevail into
the weekend. The upper flow becomes more zonal with increasing
moisture levels late in the period. However, no precip is expected
through the period. Highs will gradually warm through the period
with low to mid 70s on Friday warming into the upper 70s and low
80s for the weekend into early next week. /13

MARINE...
Issued at 411 PM CDT Mon Mar 25 2024

Strong onshore flow has developed and will persist through Tuesday
ahead of the next approaching system. Frequent gusts to gale force
are likely, particularly late Monday afternoon into early Tuesday
for the marine waters and a Gale warning remains in effect. Seas
continue to build considerably through the rest of tonight. A line
of strong to possibly severe storms will move across the marine
zones on Tuesday bringing gusty winds and potential for
waterspouts. Winds will become light to moderate out of the north
on Wednesday as the cold front moves offshore. BB/03

&&

.PRELIMINARY POINT TEMPS/POPS...
Mobile      65  78  53  76  49  73  45  74 /  90  90  10   0  10   0   0   0
Pensacola   66  75  57  76  52  72  48  72 /  40  90  10  10  10   0   0   0
Destin      66  74  60  75  55  72  51  71 /  20  90  30  20  10   0   0   0
Evergreen   64  76  50  76  46  72  41  76 /  40  90  10  10  10   0   0   0
Waynesboro  61  78  49  71  45  70  40  74 / 100  40   0   0  10   0   0   0
Camden      62  75  50  71  46  68  39  73 /  70  90  10   0  10   0   0   0
Crestview   65  75  53  78  48  73  42  76 /  20  90  30  20  10   0   0   0

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...Wind Advisory until 7 AM CDT Tuesday for ALZ051>060-261>266.

     High Rip Current Risk through late Wednesday night for ALZ265-
     266.

     High Surf Warning until 10 AM CDT Tuesday for ALZ265-266.

     High Surf Advisory from 10 AM Tuesday to 10 AM CDT Wednesday for
     ALZ265-266.

FL...Wind Advisory until 7 AM CDT Tuesday for FLZ201>206.

     High Rip Current Risk through late Wednesday night for FLZ202-
     204-206.

     High Surf Warning until 10 AM CDT Tuesday for FLZ202-204-206.

     High Surf Advisory from 10 AM Tuesday to 10 AM CDT Wednesday for
     FLZ202-204-206.

MS...Wind Advisory until 7 AM CDT Tuesday for MSZ067-075-076-078-079.

GM...Gale Warning until 7 AM CDT Tuesday for GMZ630>636-650-655-670-
     675.

     Small Craft Advisory from 7 AM Tuesday to 1 AM CDT Wednesday for
     GMZ650-655-670-675.

&&

$$

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