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000
FXUS64 KBMX 181758
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
1258 PM CDT Thu Apr 18 2024

...New SHORT TERM, AVIATION...

.SHORT TERM...
(This afternoon through Friday)
Issued at 1247 PM CDT THU APR 18 2024

A broad area of low-level ridging is centered over the Central and
Eastern Gulf of Mexico while lower amplitude mid-level ridging is
also present over the Eastern CONUS, producing westerly flow aloft.
Warm conditions are expected this afternoon with a mix of sun and
clouds. Highs will reach the mid 80s. There will be an opportunity
for some storms late today and into the evening hours as an embedded
shortwave moves from the Midsouth region and across the Tennessee
Valley. Some thunderstorms associated with this feature are already
ongoing near the Mississippi River, but that activity has really
struggled to maintain intensity with eastward extent as we still
have residual dry air in the mid-levels. Some deeper moisture is
confined near the shortwave, so expect the thunderstorms to
eventually move into western portions of the area early this evening
as the shortwave moves east, but instability will be on the decline
by that point. Any strong storms moving through Mississippi should
be on a weakening trend as they reach Central Alabama, so expect
the activity to be sub-severe.

Meanwhile, a surface low is forecast to moves towards the Ohio
Valley tonight dragging a cold front across the Lower MS River
Valley. Convection along the southern sections of the front will
really struggle as it moves further into an unfavorable environment
dominated by the Gulf ridge and lacking in deep moisture. As such,
expect another round of decaying showers and a few storms to affect
primarily the far northern portions of the area after midnight
before diminishing by sunrise. Patchy fog appears likely tomorrow
morning, especially in the south. Will monitor trends to see if a
Dense Fog Advisory is needed. The frontal boundary will be near the
I-20 corridor by tomorrow afternoon. As temperatures warm into the
lower to mid 80s, some isolated to scattered thunderstorms will
develop. Despite MUCAPE ranging from 2000-3000 J/kg along the
surface boundary, thunderstorm growth is expected to struggle
through the dry air, limiting coverage, intensity, and longevity,
but gusty thunderstorm winds will be possible in a few instances.

86/Martin

&&

.LONG TERM...
(Friday night through next Wednesday)
Issued at 208 AM CDT THU APR 18 2024

The boundary will continue to shift southward through the night
Friday, stalling somewhere between I20 and I85 in the southern
half of the area. Low level flow south of the boundary will be
out of the south and southwest, while flow north of the boundary
will be from the northwest. This boundary will allow for an axis
of convergence for storms to develop Saturday afternoon, and
through much of the day on Sunday.

Saturday afternoon, the greatest shear will be in areas along and
north of I20, with the greatest instability along and south of
the boundary, along with PW values just shy of the 90th percentile
for this time of year. Scattered showers and thunderstorms are
possible Saturday afternoon through the early night. Wind
profiles are fairly weak through the midlevels, so a few strong
storms are expected. Any activity should weaken through the
evening Saturday, with scattered showers and thunderstorms
expected Sunday, increasing in coverage and intensity through the
morning. The entire area could see rain, but the higher chances
will be around this same boundary. Shear will be much higher
Sunday afternoon, though instabilities are expected to be less
than Saturday.

High temperatures will be near normal in areas north of the
boundary, while areas south of the boundary see temperatures a
couple of degrees above normal. With cloud cover anticipated the
entire weekend, areas north of the boundary could be up to 10
degrees or more below normal on Sunday, with areas south of the
boundary a few degrees below normal.

By Sunday evening, a high pressure developing over the western MS
River Valley will move east, and the weakening front will move
east ahead of that high. Winds will be predominately from the west
Monday through Wednesday bringing moisture to the mid and upper
levels and warm air to the state. The area should remain dry with
the next chance for rain in the general timeframe of Thursday
when a low pressure system is expected to move across Alabama.

Temperatures are expected to rebound quickly, reaching near normal
temperatures by Tuesday, and above normal temperatures in the low
to mid 80s by Wednesday.

24

&&

.AVIATION...
(18Z TAFS)
Issued at 1247 PM CDT THU APR 18 2024

A brief period of VFR conditions is expected for the first half of
this TAF period, but some convection is forecast to move into the
area this evening associated with a mid-level shortwave. Coverage
is expected to decrease with time. With most of the activity
ending by 06Z, IFR ceilings are then expected to develop with some
patchy fog possible, mainly at MGM/TOI. Ceilings will be very
slow to rise tomorrow morning.

86/Martin

&&

.FIRE WEATHER...

Isolated to scattered showers/storms are possible in the northern
half of the area this afternoon, with the best chances north of
the I-20 corridor. Increasing rain chances late tonight for areas
north of I-20. Min RH values 40-55% this afternoon and Friday
afternoon, with 20 foot winds should be light and variable
this morning becoming south 5-7 mph by the afternoon. winds will
be shifting to a more westerly direction on Friday but remain less
than 7 mph. Max RH values tonight will be again right around
100%. Rain chances remain in the forecast through Sunday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     63  81  57  76 /  50  50  10  30
Anniston    64  82  60  77 /  50  40  10  30
Birmingham  66  81  61  76 /  50  40  10  40
Tuscaloosa  65  82  61  75 /  60  40  10  40
Calera      66  81  61  76 /  50  40  10  40
Auburn      66  82  65  81 /  20  20  10  40
Montgomery  65  85  64  83 /  20  20  10  40
Troy        64  85  64  86 /  10  20   0  40

&&

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

$$

SHORT TERM...86/Martin
LONG TERM....24
AVIATION...86/Martin