Special Weather Statement, NWS Birmingham, AL

Area Forecast Discussion
National Weather Service Birmingham AL
350 AM CDT Wed Mar 31 2021

.SHORT TERM...
/Updated at 0350 AM CDT Wed Mar 31 2021/

Through this Afternoon.

Thunderstorms developing upstream across northern Mississippi
will follow in the footsteps of ongoing activity through the mid
to late morning. This activity may have the ability to produce
isolated damaging winds, but rain-cooled air and a lack of daytime
heating should limit this potential. For the afternoon, pressure
falls will take place ahead of the approaching cold front as a
strong vort max pivots through the base of a larger trough. With
dewpoints in the mid to upper 60s, SBCAPE of 1500-2000 J/kg will
develop in the warm sector as temperatures rise into the 70s to
lower 80s south of I-20. This should result in an upward trend in
thunderstorm intensity in the presence of 40-50 kt deep layer
shear. Quarter size hail will be possible with the strongest and
most isolated updrafts, but the main threat should come from
damaging winds as storms grow upscale into a line with bowing
segments. Due to a lack of storm-relative inflow, the tornado
threat appears to be very low.

87/Grantham

Tonight.

Once the rain clears on out by Midnight, we will see strong CAA
move into the area. This CAA will bring in near freezing
temperatures as early as Thursday morning for the far northern
counties. Winds should remain up overnight so widespread frost is
not anticipated, however, a few isolated areas could see some
patchy frost if well protected from the wind. We will also need to
monitor for a strong winds with the gradient winds that will set
up early tonight. Right now the winds should remain below wind
advisory criteria, but breezy conditions can be expected.

16

.LONG TERM...
/Updated at 0345 AM CDT Wed Mar 31 2021/

The big story for the extended will be the well below freezing
temperatures for Friday morning and now looks like Saturday
morning as well. Look for an area wide freeze on Friday morning
with temperatures ranging from the mid 20s in the protected
valleys in the northeast to 32 in the far south. With the
pending weather today will hold off on a freeze watch for this
issuance but may need to with the afternoon update. Or we may just
go ahead and go with a freeze warning as the conditions appear
very likely. While we warm up into the 50s/60s on Friday we will
drop back down into the 20s and low 30s Friday night/Saturday
morning. Both nights will see very little winds, so areas of frost
will be likely. Beyond Saturday we remain dry for the rest of the
period as the active weather settles down over the region.
Daytime temperatures will moderate through the extended with
ample sunshine.

16

&&

.AVIATION...
06Z TAF Discussion.

A warm front has just about cleared the area as of this writing.
Majority of the convection will be generally north of all sites.
Ceilings will begin to drop and fluctuate between IFR and MVFR
through 12z.

By 12z, scattered showers and some thunderstorms will be present
near all the northern terminals. A cold front will move into the
area around 15 to 18z spreading showers and thunderstorm chances
to all terminals. Northern terminals may experience a brief rise
in ceilings, then back down. Southern terminals will jump to VFR
and back down as front approaches. The best chance for any fog
will be near TOI. Winds shift to the north northwest around 10kts
and gusts to near 20-25kts after 19z starting in the north.

16

&&

.FIRE WEATHER...

Showers and thunderstorms through the early hours tonight as a
front moves through the region. Much cooler and drier weather is
expected behind a cold front with afternoon RH values of 25 to 30
percent on Thursday through Sunday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     68  33  52  26  55 / 100  50   0   0   0
Anniston    69  35  53  28  56 / 100  60   0   0   0
Birmingham  69  36  53  30  56 / 100  30   0   0   0
Tuscaloosa  70  37  56  30  58 / 100  20   0   0   0
Calera      69  36  54  30  56 / 100  30   0   0   0
Auburn      75  39  54  31  56 / 100  90   0   0   0
Montgomery  80  40  58  32  60 / 100  70   0   0   0
Troy        81  40  58  31  59 / 100 100   0   0   0

&&

.BMX WATCHES/WARNINGS/ADVISORIES/...
Flash Flood Watch through this evening for the following
counties: Blount...Calhoun...Cherokee...Cleburne...Etowah...
Fayette...Jefferson...Lamar...Marion...St. Clair...Walker...
Winston.

&&

Hazardous Weather Outlook
National Weather Service Birmingham AL
459 AM CDT Wed Mar 31 2021

ALZ011>015-017>050-011300-
Marion-Lamar-Fayette-Winston-Walker-Blount-Etowah-Calhoun-Cherokee-
Cleburne-Pickens-Tuscaloosa-Jefferson-Shelby-St. Clair-Talladega-
Clay-Randolph-Sumter-Greene-Hale-Perry-Bibb-Chilton-Coosa-Tallapoosa-
Chambers-Marengo-Dallas-Autauga-Lowndes-Elmore-Montgomery-Macon-
Bullock-Lee-Russell-Pike-Barbour-
459 AM CDT Wed Mar 31 2021

This Hazardous Weather Outlook is for the counties served by the
National Weather Service office in Birmingham.

.DAY ONE...Outlook through Tonight.

A cold front will move through Central Alabama today. Damaging winds
and large hail will be possible through 7 PM until the front passes
the southeast for all of Central Alabama. The threat will end from
northwest to southeast as the front clears. Heavy rains will also be
possible across the north and flash flooding may be possible through
the afternoon.

Minor flooding will occur along portions of the Tombigbee,
Coosa, and Black Warrior River Basins.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Additional minor flooding may develop across the area and may
persist through the weekend along portions of the Tombigbee, Coosa,
and Black Warrior River Basins.

A brief freeze is possible in the far north on Thursday morning.  A
more widespread freeze is likely Friday morning for most of Central
Alabama. Saturday morning will also see a potential of freezing
temperatures for much of the northern half of the area. The longest
duration of freezing temperatures will be north of Interstate 85
Friday morning.

.SPOTTER INFORMATION STATEMENT...

Activation of storm spotters and emergency management may be needed
through 7 PM this evening.

Special Weather Statement
National Weather Service Birmingham AL
556 AM CDT Wed Mar 31 2021

ALZ011>013-311200-
Fayette AL-Marion AL-Lamar AL-
556 AM CDT Wed Mar 31 2021

...SIGNIFICANT WEATHER ADVISORY FOR MARION...FAYETTE AND LAMAR
COUNTIES UNTIL 700 AM CDT...

At 555 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Fairview to near Aberdeen. Movement was
east at 40 mph.

Winds in excess of 40 mph will be possible with these storms.

Locations impacted include...
Hamilton, Winfield, Fayette, Haleyville, Vernon, Sulligent, Guin,
Hackleburg, Brilliant, Glen Allen, Kennedy, Detroit, Belk, Beaverton,
Gu-Win, Bluff, Blooming Grove, Brinn, Lake Buttahatchee and Weston.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3432 8817 3431 8763 3387 8764 3387 8759
      3352 8779 3352 8793 3366 8826
TIME...MOT...LOC 1055Z 289DEG 35KT 3442 8826 3387 8857

87/GRANTHAM