200
FXUS64 KBMX 252104
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
404 PM CDT Sat May 25 2024

...New LONG TERM...

.SHORT TERM...
(This evening through Sunday)
Issued at 125 PM CDT SAT MAY 25 2024

Strong to severe storms have developed late this morning and into
the early afternoon associated with a synoptic upper level
shortwave impulse and mesoscale boundary triggers at the surface.
There`s no doubt we`ve got plenty of instability to work with, as
the 12z KBMX sounding this morning measured almost 3000 J/kg of
SBCAPE before sunrise. With daytime heating, sufficient effective
bulk shear values between 30 and 40 knots, and DCAPE values
between 700 and 1000 J/kg, isolated severe wind gusts along with
large hail will be possible across the far southeast counties
through this afternoon.

For the remainder of the area, the forecast remains quite
uncertain in terms of overall coverage of storms. Westerly to
northwesterly flow aloft will continue, with upper level shortwave
impulses expected to move across Central Alabama. At the very
least through the remainder of the afternoon and evening, isolated
to scattered showers and storms are expected to develop along and
south of the I-20 corridor. These storms are expected to also be
on the strong side, with isolated severe storms also not out of
the question. Hail and gusty winds will be the main hazards. At
this point, we aren`t anticipating any widespread development in
the form of an MCS, but mesoscale trends will continue to be
monitored through the evening and overnight hours. I`ve adjusted
highs a degree or two more this afternoon based on current trends,
with most of the western and southwestern locations hitting the 90
degree mark or just above.

For now, barring any further development the overnight forecast is
fairly quiet with a lingering slight chance of a storm through
midnight. Patchy fog development is also possible overnight as
low-level clouds eventually clear out with light winds. Sunday
appears to be a calmer day, as upper level heights will actually
increase as a 594 decameter ridge builds over the central Gulf of
Mexico. That will help winds aloft become more westerly to west-
southwesterly by Sunday afternoon. If we get any convective
activity during the day on Sunday, it should remain across the far
northern counties. Rain chances will then increase across the
northwest counties in response to the upper trough axis moving
eastward over the plains states and approaching surface front in
Arkansas. Hot and humid conditions are expected due to the lack of
showers and storms with highs in the lower 90s in most locations.
Heat indices will approach the 100 degree mark during the peak
heating of the day.

56/GDG

&&

.LONG TERM...
(Sunday night through next Friday)
Issued at 346 PM CDT SAT MAY 25 2024

The main story in the extended continues to be late Sunday night
into Monday as the main upper system is expected to move through
with some strong to severe storms possible. A second additional
wave of convection may occur during the afternoon hours with
heating before the surface system is through. After that, milder/
rain free conditions are expected for the second half of the week
as ridging takes hold for Tuesday through Friday.

08

Previous long-term discussion:
(Sunday night through next Friday)
Issued at 327 AM CDT SAT MAY 25 2024

The main upper level trough is expected to slide through the region
late Sunday night through the overnight hours into Monday. This
upper wave will provide the forcing for showers and thunderstorms
across Central AL. There will be enough instability in place, along
with modest deep layer shear to support a few strong to severe
storms overnight Sunday night into Monday. After the initial upper
wave moves through, guidance suggests the surface boundary could
trigger additional convection during the afternoon/evening hours on
Monday as it moves through.

Drier conditions expected Tuesday through Friday as the main trough
remains to our east and broad ridging sets up to our west. Some
guidance tries to bring a few waves down in this northwesterly flow,
but this hasn`t been consistent. Most guidance shows the ridging
winning out leading to mostly dry conditions for much of the
upcoming week.

25/Owen

&&

.AVIATION...
(18Z TAFS)
Issued at 125 PM CDT SAT MAY 25 2024

The best chances for TSRA this afternoon will be across the SE TAFs
at MGM/TOI closest to a complex of storms that has developed.
Elsewhere to the N and W activity will be more scattered and
confidence is not as high to include any TS in TAFs ATTM. Have some
SH mentioned at times late this afternoon for all but TCL. MVFR and
some IFR stratus (possible S...TOI) is possible to develop later
tonight after 9/10z until about 15/16z with low level moisture. Only
confident with enough moisture to also include MVFR patchy fog at
TOI for now. Will be looking at future guidance to see if it is
needed to be added elsewhere in next/later issuances.

08

&&

.FIRE WEATHER...

Scattered showers and thunderstorms will continue into this
evening. Another round of convection is expected again late
Sunday night through Monday. 20 foot winds will be from the south
to southwest at less than 5 mph this afternoon, increasing to
6 to 12 mph on Sunday. Patchy fog is possible across the eastern
portions of the area as well. Min RH values will be near or above
45 percent through Monday, with overnight recoveries near 100%.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     67  89  68  88 /  20  10  60  60
Anniston    69  89  70  87 /  20  10  50  60
Birmingham  71  91  71  89 /  20  10  60  50
Tuscaloosa  72  92  72  90 /  20  10  60  40
Calera      70  90  72  89 /  20  10  50  50
Auburn      70  88  71  86 /  20  10  20  60
Montgomery  71  92  73  90 /  30  10  20  60
Troy        70  91  72  89 /  30  10  10  50

&&

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

$$

SHORT TERM...56/GDG
LONG TERM....08/25/Owen
AVIATION...08