231
FXUS64 KBMX 221809
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
109 PM CDT Wed May 22 2024

...New SHORT TERM, AVIATION...

.SHORT TERM...
(This afternoon through Thursday)
Issued at 107 PM CDT WED MAY 22 2024

A couple rounds of thunderstorms will pass within close proximity to
the northwestern portions of Central Alabama over the next 24 hours
as a northeast to southwest oriented cold front slowly drifts
towards the Mid-South region. The mid-level ridge axis has shifted
east of the area allowing low-level flow to take on more of a south
to southwesterly heading. Deeper moisture still resides to our west,
so our dewpoints will mix down into the lower to mid 60s this
afternoon and again tomorrow while lower 70s dewpoints are forecast
over northern Mississippi and the Tennessee Valley. The first wave
of thunderstorms will likely follow the more favorable instability
gradient as it moves along the frontal zone, staying north of the
forecast area and moving from Mississippi into northern Alabama this
afternoon.

A second wave will have improved upper-level support overnight as a
shortwave begins to pass across the area. Some weakening
thunderstorms will move in across the northwest around midnight, but
QPF amounts look minimal. Same story on Thursday as the front
remains well to our north. Most of the activity will remain north of
Central Alabama during the day, and any isolated shower or storm is
not expected to be strong as a result of limited forcing and
instability. Expect mostly sunny conditions with highs in the mid to
upper 80s.

86/Martin

&&

.LONG TERM...
(Thursday night through next Tuesday)
Issued at 315 AM CDT WED MAY 22 2024

A southern stream shortwave remains forecast to move across the
Tennessee Valley Friday morning. This will likely be accompanied
by a weakening thunderstorm complex to our north, so chances for
showers/storms remain in the forecast for our northern half. The
perturbation is progged to advance into the Appalachians mid to
late morning. Thus, convective coverage during the afternoon may
not be too high considering the background effects of the low-
amplitude ridge in the region.

Latest guidance suggests the ridge sill strengthen a bit on
Saturday, though both moisture & instability values climb ahead of
a stalling cold front laying over to our north. Forecast
soundings from the GFS/ECMWF both show modest mid-level lapse
rates with ~30 kts eff. bulk shear. MLCAPE of 2,000-3,000 J/kg is
progged with dewpoints in the low 70s. Thus, any convective
development during the afternoon could be strong, and we`ll need
to keep an eye out for severe weather once mesoscale details can
be sorted out.
rebound
Subsequent disturbances will impacts regions to our northwest on
Sunday, with a notable system moving from the Plains toward the
Midwest. Meanwhile, we`ll remain hot/humid with at least a
scattering of showers/storms across the northern half of Central
Alabama. There`s disagreement on timing, but medium-range guidance
depicts stormy weather associated with a frontal passage in our
area Monday/Tuesday. Cooler, more stable weather would follow.

40/Sizemore

&&

.AVIATION...
(18Z TAFS)
Issued at 107 PM CDT WED MAY 22 2024

A scattering of low-level cu have developed again this afternoon,
but another period of VFR conditions is expected. High pressure
extends along the East Coast into the northeastern Gulf of
Mexico, so surface winds are out of the south around 5 to 10 kts.
Winds will go calm tonight, and high-level cloud cover will
increase across the area.

86/Martin

&&

.FIRE WEATHER...

High pressure will be in control through Thursday. Min RH values
this afternoon and Thursday 45 to 50 percent. 20 foot winds will
be generally 4 to 6 mph from the south. Max RH levels tonight will
be above 90 percent. Next chance for wetting rain Thursday night
across the northwest, with chances for rain across the northern
counties on Friday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     66  88  65  87 /  10  20  20  40
Anniston    67  88  67  87 /  10  10  10  30
Birmingham  70  89  70  88 /  10  10  10  30
Tuscaloosa  69  89  70  90 /  10  20  10  20
Calera      69  88  68  88 /  10  10  10  20
Auburn      68  87  68  86 /   0   0   0  10
Montgomery  68  89  69  91 /   0   0   0  10
Troy        66  89  68  90 /   0   0   0  10

&&

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

$$

SHORT TERM...86/Martin
LONG TERM....40
AVIATION...86/Martin