658
FXUS64 KBMX 121134
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
534 AM CST Wed Feb 12 2025

...New AVIATION...

.KEY MESSAGES...
Issued at 1229 AM CST TUE WED 12 2025

 - Periods of moderate to heavy rainfall will continue through
   Thursday, resulting in 2 to 4 inches of additional rainfall
   accumulation with some risk for flooding.

 - There is a slight risk for severe weather across the majority
   of Central Alabama for this afternoon through tonight. Threats
   include damaging 60 mph wind gusts and a few tornadoes.

 - There is a low-medium chance for severe storms Saturday night
   as another trough and cold front move through the area.

&&

.SHORT TERM...
(Today through Thursday)
Issued at 1226 AM CST WED FEB 12 2025

I would like to describe this short-term forecast as complicated,
but in reality the driving factor is simple: the location of the
warm front. The severe weather threat, the flooding threat, etc,
they are all dependent upon how far north the stalled warm front
retreats this afternoon. Much of the high-res guidance this
morning suggests that the stratiform rainfall north of I-20 will
aid in suppressing the movement of the front, keeping everything
to the south. As such, a lot of the forecast has shifted that way
as well. From a rainfall standpoint, the warm front remaining
south keeps some of the heaviest rainfall amounts south of I-20. A
lot of this rainfall will be the result of convective training,
as storm fire and ride the front to the NE. In turn, more
locations could see anywhere from 2-3 inches of rainfall through
tomorrow AM. With heavier convection, 4+ inches in some locations
will certainly not be out of the question as well.

From a severe weather standpoint, we coordinated with the SPC, and
had the slight risk trimmed slightly back to the south. There is a
ton of question marks regarding the northern extend of severe
weather today. Here, damaging winds and a QLCS tornado or two will
be the main weather hazards. However, farther south (I-85 corridor)
a more complicated scenario is developing. Its possible that these
areas will remain relatively rain and cloud free this afternoon,
allowing for better destabilization. Given the timing of the main
line, isolated storms could develop ahead of it, resulting in a
narrow corridor for higher tornado probabilities. The SPC
considered an upgrade to an ENH risk in these areas, but there are
still quite a few question marks regarding this. As such, the SPC
stayed with the Slight Risk, but will be reevaluating as the
latest guidance begins to rolls in.

/44/

&&

.LONG TERM...
(Thursday night through next Tuesday)
Issued at 251 AM CST WED FEB 12 2025

Northwest flow will develop across the area Thursday night in the
wake of the departing cold front. For a brief moment we will get a
taste of winter again as temperatures fall into the mid 20s north to
mid 30s south. A ridge will build across the Eastern CONUS on Friday
with sunny skies expected across Central Alabama.

Meanwhile, to our west a potent upper-level trough will be deepening
over the Four Corners Friday night. We begin to shift back into
active weather by the weekend with the development of a surface low
over the ArkLaTex Saturday afternoon. In response, a warm front will
rapidly lift northward through the area as strong warm air advection
redevelops with temperatures warming into the 70s. Destabilization
across the area will be aided by a ~50kt south-southwesterly LLJ
with southwesterly mid-level flow increasing to around 70-80 kts.
Strong height falls will precede a line of showers and storms which
currently look to reach the AL/MS state line late Saturday night as
the surface low lifts towards the Ohio Valley. Temperatures aloft
are slightly on the warmer side, but nonetheless a broad warm sector
characterized by MLCAPE ~500-800 J/kg is expected to be in place
across our west with eff. bulk shear values as high as 60 kts,
providing support for severe storms. Forecast hodographs exhibit
ideal low-level curvature, so QLCS tornadoes will be a concern in
addition to damaging straight line wind gusts. The cold front will
be moving at a quick pace, so the severe window looks to be no more
than 10-12 hours at most with the risk potentially decreasing with
eastward extent as instability wanes through the overnight hours.
Still have plenty of time to workout the specifics. In terms of
flooding, an additional 1 to 2 inches of rain does not look too
troublesome for now given the day or two of dry weather beforehand.

Cooler air filters back in behind the system at the start of next
week. We will have a couple nights with lows in the 20/30s then
cooler during the daytime. In fact, some of our northern locations
will stay in the 40s on Monday. A unique split flow pattern may
develop by the middle of next week with global models suggesting a
shortwave, suppressed to the south over the northern Gulf, could
bring additional rain to the area Tuesday night.

86/Martin

&&

.AVIATION...
(12Z TAFS)
Issued at 526 AM CST WED FEB 12 2025

IFR and LIFR CIGS will continue to hover across the region today,
with -RA and RA falling off and on. A line of thunderstorms will
move across the region closer to 13/02z, with quick drops in VIS
possible during the heaviest rain. As the rain moves out, IFR CIGS
will likely linger for the remainder of the TAF period.

/44/

&&

.FIRE WEATHER...

Widespread showers will continue through tonight, ending by early
tomorrow morning as a cold front passes through the area. 20ft
winds will be from the south today, breezy at times at 8 to 15 mph
with gusts up to 20 to 25 mph. Winds shift to the northwest
tomorrow morning, remaining around 5 to 8 mph. Dry air will filter
back into the area for a couple of days with min RH in the 35-40%
range on Friday. Moisture increases well above critical thresholds again
on Saturday with winds shifting back to the south in advance of
another cold front which will bring more rain to the area. Winds
shift back to the northwest on Sunday with a few days of dry
weather developing for the first part of next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     63  44  56  26 / 100 100   0   0
Anniston    67  49  59  29 / 100 100  10   0
Birmingham  67  46  56  30 / 100  90   0   0
Tuscaloosa  69  45  56  30 / 100  90   0   0
Calera      70  49  58  32 /  90 100   0   0
Auburn      75  58  66  35 /  90  90  40   0
Montgomery  79  55  66  36 /  80  90  20   0
Troy        78  57  68  38 /  60  90  50   0

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
Flood Watch through late tonight for the following counties:
Bibb-Blount-Calhoun-Chambers-Cherokee-Chilton-Clay-Cleburne-
Coosa-Etowah-Fayette-Greene-Hale-Jefferson-Lamar-Perry-Pickens-
Randolph-Shelby-St. Clair-Sumter-Talladega-Tallapoosa-Tuscaloosa-
Walker.

&&

$$

SHORT TERM...44
LONG TERM....86
AVIATION.../44/