Area Forecast Discussion
Issued by NWS Birmingham, AL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46
000
FXUS64 KBMX 250021
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
721 PM CDT Sun Mar 24 2024

...New AVIATION...

.SHORT TERM...
(This evening through Monday)
Issued at 1254 PM CDT SUN MAR 24 2024

Breezy conditions will continue this afternoon and into tomorrow.
Southwesterly winds are gusting up to 20 mph today and temperatures
reside in the 60s across the area. Many areas will likely reach the
low to mid 70s for highs this afternoon. Temps will drop down in the
40s to low 50s tonight, although winds will remain elevated at 10-15
mph overnight.

We should warm up back to the upper 60s to mid 70s Monday afternoon,
although increased cloud cover, especially in western areas, may
hold down temps by a couple degrees. Wind gusts will increase by
tomorrow afternoon, with gusts of 30-40 mph possible by the evening
and continuing into the overnight in advance of a cold front. A Wind
Advisory will be in effect for most of Central Alabama from Monday
afternoon until Tuesday morning.

12

&&

.LONG TERM...
(Monday night through next Saturday)
Issued at 208 PM CDT SUN MAR 24 2024

Key Messages:

- A line of showers and thunderstorms is forecast to move into
Central Alabama Monday night. Locally heavy rainfall is possible
which could pose a threat for localized flooding, mainly for areas
west of I-65, where 2-3" of rain is currently forecast.

- Severe weather threats have increased from the previous forecast
  as the line is expected a few hours earlier and could still be
  on the stronger side as it enters the area. The biggest threats
  still remain in the southwest counties overnight, then tapering
  off across our far southern counties throughout Tuesday morning.
  Strong to marginally severe storms will remain possible at least
  to the I-65 corridor through a few hours after sunrise.

- Strong non-thunderstorm (gradient) wind gusts of 35-45 mph are
  forecast Monday night into Tuesday morning. A Wind Advisory is in
  effect.

With the faster scenario now showing up and the possibility if it
even being a few hours faster than currently forecast, there is a
slight chance that stronger storms may be ongoing as the line
moves into Central Alabama. We still will see the system begin to
decay as it moves across the area, but the severe threat can`t be
ruled out, so it has been included in the forecast. We still
expect the pinching of the system as it moves east, but we could
see some low 60 dewpoints work into the southwest just ahead of
the line. After the line moves through we should be dry through
the end of the week. We do potentially have one more chilly night
with a frost potential across the northern half of the area, as
well locally cooler spots in the southwest.

16

Previous long-term discussion:
(Monday night through next Saturday)
Issued at 412 AM CDT SUN MAR 24 2024

A strong area of (mainly linear) convection is forecast to move
into Alabama Monday night into early Tuesday morning, ahead of a
SSW to NNW oriented cold front. This MCS is associated with a
shortwave perturbation rotating through a broad trough across the
central CONUS. While an occluded low pressure will be situated
near Iowa at this time, a stout low-level jet (LLJ) is progged
across the Southeast/Gulf Coast with 850 mb winds of 60-70 kts,
and 925 mb winds of 40-50 kts. This will coincide with a 8-10 mb
pressure gradient across Central Alabama, ahead of the MCS. As
such, surface wind gusts of 35-45 mph are forecast Monday night
into Tuesday morning, a continuation of gusty winds from Monday
afternoon. An expanded Wind Advisory will be issued for this.

The main impact from convection is locally heavy rainfall. Latest
QPF situates 2-3" of rain generally west of I-65. Localized flooding
is possible in low-lying or poor drainage areas, particularly if
some storm-scale bands/higher rainfall rates can orient more
parallel to deep-layer flow. The weakening nature of the MCS Tuesday
morning has led to a decreasing confidence for flooding across the
remainder of Central Alabama. Furthermore, the system is forecast to
remain displaced from favorable surface-based instability to support
a meaningful wind or tornado threat early Tuesday morning. Most
guidance continues to depict the warm sector pinching/tapering off
by the early morning, and it certainly appears this will be a system
dominated by kinematics. It`s not uncommon to see gradient wind
gusts being the dominant hazard in a scenario like this.

The decaying MCS will progress eastward Tuesday morning and should
be exiting our forecast area during the afternoon. A cooler, drier
airmass will move in thereafter along with clearing skies.

A broad mid- to upper-level trough is forecast to position across
the central CONUS Wednesday morning with southwesterly flow aloft
nearing the East Coast. This trough will eventually exit the eastern
CONUS on Friday as high pressure centers near the Southeast by then.
As such, stable conditions are forecast Wednesday through the end of
the period with developing ridge and noticeable warming trend
in the region Friday through Sunday.

40/Sizemore

&&

.AVIATION...
(00Z TAFS)
Issued at 715 PM CDT SUN MAR 24 2024

East to southeast winds 5-10kts early this evening will increase
overnight as the atmosphere does not look like it decouples. There
may even be gusts around 20kts as the winds above the surface
increase. Winds around 2k ft will be southeast around 40kts which
puts us just into LLWS criteria. Will add this mention at all
sites overnight. Otherwise, just mid and high cloudiness drifting
by. On a side note, a few of the model solutions due mention some
lower ceilings late tonight but still remaining VFR. Will watch
for this potential development. On Monday, winds continue gusty
east southeast 10-15kts with gusts to around 25kts or so. Ceilings
will lower by afternoon but remain VFR. Rain and thunder chances
hold off until after periods end.

75

&&

.FIRE WEATHER...

A frontal boundary will begin to move closer to the area on Monday
and we will begin to see an increase in moisture levels from west
to east. Winds will be increasing during the afternoon from west
to east as the front moves closer. 20 foot winds will generally
be 13 to 17 mph with higher gust from the south/southeast. With
the moisture increase, RH values will be in the 40s and 50s though
during the afternoon. Wetting rains are forecast for Monday night
through Tuesday afternoon. Drier air moves back into the area
Tuesday night/Wednesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     44  68  54  69 /   0   0  80 100
Anniston    45  68  57  69 /   0   0  70 100
Birmingham  48  69  58  71 /   0   0  90  90
Tuscaloosa  50  71  58  74 /   0  10 100  70
Calera      48  69  58  71 /   0  10  80  90
Auburn      45  68  58  68 /   0   0  30  90
Montgomery  49  73  61  71 /   0   0  50 100
Troy        49  75  62  70 /   0   0  30  90

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 1 PM Monday to 7 AM CDT Tuesday for the
following counties: Fayette-Greene-Hale-Lamar-Marengo-Marion-
Pickens-Sumter-Tuscaloosa-Walker-Winston.

Wind Advisory from 7 PM Monday to 7 AM CDT Tuesday for the
following counties: Autauga-Bibb-Blount-Calhoun-Cherokee-Chilton-
Clay-Cleburne-Coosa-Dallas-Elmore-Etowah-Jefferson-Lowndes-
Montgomery-Perry-Randolph-Shelby-St. Clair-Talladega-Tallapoosa.

&&

$$

SHORT TERM...12
LONG TERM....16
AVIATION...75


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.