575
FXUS64 KBMX 130034
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
734 PM CDT Sun May 12 2024

...New AVIATION...

.SHORT TERM...
(This evening through Monday)
Issued at 1230 PM CDT SUN MAY 12 2024

High pressure will continue to weaken today and move towards the
east coast. Chaotic winds in the mid and low levels will turn to
the south and southwest this evening as a developing low moves
through the MS River Valley towards AL. A warm front is expected
to move into the southern half of the state. High res models
differ on how far north to take this front, with several recent
runs trending farther south, in the southern most counties of
Central Alabama. This system will bring plenty of upper level
divergence, and combined with a mid level jet, scattered to
widespread showers and thunderstorms are expected through Monday
afternoon.

The initial area of scattered showers are expected overnight
tonight, moving into the southwestern counties shortly before
midnight. These showers will move to the northeast through the
early morning, increasing in coverage. A rumble of thunder could
be heard in this activity, but accumulations are expected to be on
the lighter side as moisture continues to advect into the state
with that southwesterly flow.

By early morning, sometime between 3 and 5 am, another area of
showers and thunderstorms is expected to move into west Alabama.
Models are trying to keep this area focused along the front and
in the southern half of the area, so will highlight the southern
half of the state for now to have the highest chances for stronger
storms with this second wave. CAMs have been fairly consistent in
showing a wake low type feature in the far southwest of Central
Alabama. If this maintains consistency, will need to keep an eye
on how far south this area of storms moves. Winds will be strong
with this feature, and damaging winds are possible. Instabilities
are weak, though 01 km shear is around 35-40 kts and 0-6 km shear
around 60-70 kts in the far southwest. PW values will easily be in
the 90th percentile or above for this time of year. Heavy
accumulations are expected with strong showers and any
thunderstorms.

This activity is expected to move east and southeast through mid
morning. There could be a break in the activity through the early
afternoon, though models diverge on how long of a break and how
much of a coverage of storms would develop later. Right now, have
included chances for scattered afternoon showers and
thunderstorms with instabilities rebounding slightly into the 500
j/kg range, and shear remaining strong around 40-50 kts.
Confidence is lower on timing and details of the afternoon storms,
so will need to keep an eye on what the overnight and early
morning system does, as well as how far north the morning feature
moves.

24

&&

.LONG TERM...
(Monday night through next Saturday)
Issued at 223 PM CDT SUN MAY 12 2024

A convective system will track across south Alabama Monday night
and into Tuesday morning. Models differ on track of this impulse
as the rain event on Monday will likely determine northward extent
of heavy rainfall Monday night/Tuesday. The NAM/GFS has the
higher rainfall amounts on Monday between I-85 and I-65, so any
residual instability will likely stay south of I-85 Monday night
and Tuesday. The models this season have consistently had a biased
northward extent of the warm front, so not buying any severe
threat north of I-65, with low end severe threat along and south
of the I-85 corridor. Heavy rain may be the higher threat Monday
and Tuesday. There will likely be a corridor of 3-4 inches with
locally higher amounts somewhere close to the I-85 corridor. Will
hold off on any flood watch at this time as the rainfall amounts
on Monday will help with confidence for flood threat. There will
be a lull in the rain Wednesday and Thursday, with the next upper
impulse arriving Thursday night and Friday.

58/rose

&&

.AVIATION...
(00Z TAFS)
Issued at 730 PM CDT SUN MAY 12 2024

VFR conditions expected for the next several hours, with
increasing clouds. Rain begins to move in across the area,
generally after 10-12z with prob30 TSRA at all sites during the
day tomorrow. CIGs begin to drop steadily during the day tomorrow
and will likely be IFR as the precip moves in. There could be
moments of LIFR during any thunderstorm activity with both VIS and
CIGs dropping. Conditions could improve slightly towards the end
of the TAF period, but will likely occur just after the end of
this period.

25/Owen

&&

.FIRE WEATHER...

Rain with embedded thunderstorms will overspread Central Alabama
tonight. 20ft winds will be east-southeast at 3-5 mph and southeast
7-10 mph on Monday. Max RH values tonight above 90 percent and
Min RH on Monday 70-75 percent. Rain, heavy at times, will
continue Monday night and into Tuesday morning.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     57  72  61  80 /  30  80  80  70
Anniston    59  73  63  79 /  40  80  80  70
Birmingham  61  72  65  80 /  50  80  80  50
Tuscaloosa  62  75  65  82 /  60  90  80  40
Calera      61  73  65  80 /  60  90  80  60
Auburn      63  74  65  77 /  50  90  90  90
Montgomery  63  76  65  82 /  50  90  90  80
Troy        63  77  65  82 /  50  90  90  90

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...24
LONG TERM....58
AVIATION...25/Owen