Birmingham, Alabama 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

151
FXUS64 KBMX 200518
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
1218 AM CDT Thu Aug 20 2026

...New AVIATION...

.KEY MESSAGES...
Issued at 1216 AM CDT THU AUG 20 2026

- Heat: Major HeatRisk is expected to persist through the end of
  the workweek, with heat indices are forecast between 103 to 108
  degrees. A Heat Advisory is in effect for portions of central
  Alabama through Thursday and may be needed for Friday.

- Thunderstorms: Isolated to scattered afternoon to evening
  thunderstorms will remain in the forecast through Saturday. Rain
  chances will increase this weekend.

- Severe: Isolated severe thunderstorms are possible this
  afternoon and early evening with damaging wind the main threat.

&&

.DISCUSSION...
(Thursday through next Wednesday)
Issued at 1157 PM CDT WED AUG 19 2026

A low pressure over the Great Lakes shifts northeast, dragging a
cold front southward through the TN Valley and into northern
Alabama by the afternoon. Enough instability will support
scattered showers and thunderstorms late afternoon through at
least Midnight, tapering off overnight. While thermodynamic
parameters remain similar, greater boundary convergence should
result in higher convective coverage. High CAPE, dry mid-level
air, and fairly high DCAPE suggest damaging downbursts remain the
primary threat with collapsing storms. The Heat Advisory
continues through 9 PM and will likely need to be extended again
through Friday as high moisture and lows in the 70s provide
little relief.

By Friday, an amplifying trough east of the MS River will shift
local flow to the northwest and eventually west. The
aforementioned boundary will continue its southward push,
focusing diurnal convection generally between the I-20 and I-
85 corridors. A continued risk for downburst winds exists given
the persistent airmass. Temperatures may trend a few degrees
lower, but high humidity will maintain heat indices in the triple
digits.

Model uncertainty persists regarding the southern progress of the
boundary on Saturday. While some guidance suggests widespread
convection, recent runs favor the trough axis moving through with
prevailing northwest flow. A weak mid-level jet could increase
surface winds across the north, with gusts of 20-25 mph possible.
Rain chances remain in the forecast pending better model
consistency. Northwest flow and modest cold air advection will
drop temperatures for the weekend; heat indices should finally
fall below 105 degrees, though they will remain in the 100-
104 range.

Brief high pressure gives way to another developing low moving
across the Tennessee Valley region toward the end of the period,
bringing an increase in rain chances. Timing differences
regarding the trough exit and low progression remain; will adjust
the forecast as trends emerge.

16

&&

.AVIATION...
(06Z TAFS)
Issued at 1216 AM CDT THU AUG 20 2026

VFR conditions will prevail overnight and through the morning
hours on Thursday. Expect cumulus development by midday and
increasing through the afternoon and into the evening with chances
for showers and thunderstorms high enough to include PROB30 at
all sites, potentially developing earlier in time west and later
in time east during the afternoon and into the evening hours.

Note: AMD NOT SKED for AUO due to a weather observation outage.

05

&&

.FIRE WEATHER...

MinRH values will generally range between 35 and 45% the next few
days, before slowly climbing into the weekend ahead of increasing
rain chances. Winds will remain light the next few days, before
increasing into the weekend as well. Fire weather concerns are
currently low, but they will start to increase by Monday no
meaningful rainfall occurs with this weekend`s system.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     98  72  94  70 /  30  50  30  10
Anniston    96  72  92  70 /  30  50  50  20
Birmingham  97  73  92  71 /  30  50  40  10
Tuscaloosa 100  74  96  72 /  30  40  30  10
Calera      96  73  93  71 /  30  50  50  20
Auburn      94  74  91  73 /  20  40  60  30
Montgomery  98  74  96  73 /  30  40  60  30
Troy        97  72  94  71 /  30  40  70  30

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 9 PM CDT this evening for the following
counties: Autauga-Barbour-Bibb-Bullock-Chilton-Coosa-Dallas-
Elmore-Fayette-Greene-Hale-Jefferson-Lamar-Lowndes-Macon-Marengo-
Marion-Montgomery-Perry-Pickens-Pike-Shelby-Sumter-Tuscaloosa-
Walker.

&&

$$

DISCUSSION...16
AVIATION...05