379
FXUS64 KBMX 131924
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
224 PM CDT Tue Aug 13 2024

...New LONG TERM...

.SHORT TERM...
(This evening through Wednesday)
Issued at 1250 PM CDT TUE AUG 13 2024

This afternoon.

Elongated ridging is positioned from over North Texas and
Southern Oklahoma southeast over much of Louisiana and over much
of the Northern Gulf of Mexico southeast to over Southern Florida.
Sprawling surface high pressure extended from across much of
Minnesota southeast to over Western Pennsylvania while a
stationary front extended from Northern Louisiana southeast across
South Mississippi into SOuthwest Alabama to across the Western
FLorida Panhandle. A shortwave in the northwest flow pattern aloft
was supporting showers and storms across Southern Missouri and
Northern Arkansas.

Expect partly cloudy skies today as low and mid level moisture
values begin to increase across the area, but the coastal boundary
will remain to the south of the area, resulting in dry conditions
areawide. Winds will be from the north to northwest at 5-10 mph.
High temperatures will range from the lower 90s in the higher
elevations east and northeast to the upper 90s south, generally
near and south of the U.S. Highway 80 corridor. Humidity values
with these temperatures will result in heat index values from 99
to 101 degrees across portions of the southwest third of the area
this afternoon.

Tonight.

Mid-level ridging will contract overnight, extending from over
Central Oklahoma and extending southeast to over the Northern Gulf
Coast while residual troughing over the Mid Atlantic States and
the Carolinas remains in place. A shortwave disturbance will move
southeast with time, moving over Central Tennessee tonight.
Expansive surface high pressure will extend its reach from across
much of Minnesota eastward into New York State and southward into
the Carolinas and Tennessee Valley. The coastal boundary to our
south will lift northward a bit, extending from near Monroe, LA
east to south of Meridian MS and extending east to south of
Columbus, GA.

Partly cloudy skies will persist across the northwest half of the
area with mostly clear skies over the rest of the area. Winds
will be light from the north to northeast at 3-6 mph. Low
temperatures will range from the mid 60s in the higher terrain
east and northeast to the low 70s south and west.

Wednesday.

Amplified ridging will persist over the Southern Plains to our
west while troughing will become centered just offshore of the Mid
Atlantic Coast. The shortwave over Tennessee will move southeast
over North Georgia before sunrise. The first disturbance will be
just to the east of the area toward midday as some modeling
depicts another disturbance to our northwest that will approach
the area later in the day. Surface high pressure will consolidate
with time over much of the Great Lakes and East- Central Ohio
River Valley Region while the front to our south will extend from
Central Arkansas southeast into Southwest Alabama.

Expect partly cloudy skies northwest with fair skies southeast to
start the day followed by scattered clouds areawide by late
morning. Isolated showers with some thunderstorms are forecast
across the far northwest portion of the area toward mid to late
morning and will gradually expand south and east, affecting the
northwest portion of the forecast area toward mid afternoon. This
activity looks to decrease as it encounters a persistently dry and
more stable airmass over the southeast portion of the area so
PoPs will be greatest near and northwest of the Interstate 59
corridor. Winds will be from the north to northeast at 5-10 mph.
High temperatures will range from around 90 far north to the upper
90s south. Higher humidity values with these forecast
temperatures will support heat index values from 100-103 degrees
across the southern third of the forecast area Wednesday
afternoon.

05

&&

.LONG TERM...
(Wednesday night through next Monday)
Issued at 214 PM CDT TUE AUG 13 2024

Model trends show heights increasing slightly on Thursday as the
ridge expands across the southeast, and will trim low rain chances
back and increase temps by a degree or two. Otherwise, forecast is
on track. As moisture increases for the end of the week, heat
advisories will be possible, as heat indices will be back above
105F for portions of the area Friday and Saturday.

14

Previous long-term discussion:
(Wednesday night through Monday)
Issued at 350 AM CDT TUE AUG 13 2024

A 500 mb ridge will shift eastward over Alabama on Thursday, and
anticyclonic flow suggests convection should be limited by
subsidence and less than ideal moisture quality. Slight chance
PoPs will be maintained in case convection is able to develop
upstream within the northwesterly flow pattern. The ridge may
start to relent on Friday as deep-layer flow transitions from
anticyclonic to neutral or cyclonic. If this occurs in conjunction
with weak height falls, thunderstorms could become quite numerous
Friday afternoon. Continued height falls are expected through the
weekend, potentially leading to one or two MCS events between
Saturday and Monday. Timing and location of this potential
activity remains unclear due to the low-predictability nature of
northwesterly flow.

87/Grantham

&&

.AVIATION...
(18Z TAFS)
Issued at 1157 AM CDT TUE AUG 13 2024

VFR conditions will prevail through early Wednesday across the
entire area. Scattered cumulus is expected across much of the area
this afternoon with dry conditions persisting over much of the
area. Low-level winds will be from the northwest to north at 4-8
kts. Skies will range from scattered north and west to few south
and east overnight with bases remaining in the high to mid levels.
Low-level winds will be light from the north to northeast at 3-6
kts. Increasing clouds from the northwest are forecast through the
day Wednesday with chances for isolated showers and a few storms
west and northwest of the northwest terminal locations through the
end of this cycle. VFR conditions will persist further east and
southeast through later in the day on Tuesday.

05

&&

.FIRE WEATHER...

A slow increase in moisture will begin Wednesday, with minimum RH
values ranging from 35 to 50 percent, and northerly 20ft winds at
5-8mph. Low rain chances return Wednesday and for western areas on
Thursday. For Thursday, minimum RH values will be above 40
percent, with light easterly to southeasterly 20 foot winds.
Slightly higher rain chances are expected for the end of the week.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     67  92  70  92 /   0  20   0  10
Anniston    68  93  71  92 /   0  20   0  10
Birmingham  71  92  73  93 /   0  20   0  10
Tuscaloosa  72  95  73  95 /   0  30  10  10
Calera      69  93  73  93 /   0  20   0  10
Auburn      71  94  72  91 /   0  10   0  10
Montgomery  71  97  75  95 /   0  10   0  10
Troy        71  96  73  93 /   0  10   0  10

&&

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

$$

SHORT TERM...05
LONG TERM....14
AVIATION...05