Special Weather Statement, NWS Birmingham, AL

Area Forecast Discussion
National Weather Service Birmingham AL
256 AM CDT Sun Mar 28 2021

.SHORT TERM...
/Updated at 0211 AM CDT Sun Mar 28 2021/

Through this Morning.

Strong warm advection is holding temperatures in the 70s with
dewpoints currently in the mid/upper 60s across Central AL. A
complex of intense thunderstorms are ongoing from western
Tennessee southwest into eastern Arkansas along a cold front which
is situated over the Mississippi River. Based on current storm
motions and hi- res guidance, expect the line to reach our
northwestern counties by 3 AM or perhaps an hour earlier where
strong eff. bulk shear of 50- 60 kts and MLCAPE ~1000-1500 J/kg
will support a continued risk of damaging winds within organized
bowing structures as the primary threat. Current sfc obs in our
northwest indicate southerly to south- southwesterly surface winds
with progged 850mb winds out of the southwest to west-southwest.
This slight low- level clockwise turning with height will yield a
low- end threat for embedded tornadoes within the line. We expect
surface winds to veer and instability to slowly decrease after the
line moves into northwestern Central AL with the overall tornado
threat decreasing with time as the line nears the I-20/59
corridor.

Through Monday Night.

With ample instability ahead of the approaching cold front and
strong forcing aloft, thunderstorms will continue to be possible,
with the strongest activity just to our north. With that said,
there will be scattered pockets of severe winds and isolated
pockets of hail possible across all of Central Alabama from early
this morning in the northwest to mid afternoon in the southeast.

Wind profiles will be sufficient for a few tornadoes northwest
and north early through late this morning, generally across the
northern portion of the forecast area. These dynamics and
favorable shear environment will be departing to the east as we
progress through the day. Does look like the tornado probabilities
will begin to decrease as the morning progresses, however, there
will still be a non zero threat down to I-85. So with the morning
HWO will include the counties to I-85 in as TOR and the areas
south of I-85 as severe.

After noon, strong surface destabilization is expected across the
south and southeast, which will result in storm intensification
with time as we proceed through the afternoon. The concern for
damaging winds and large hail will grow with time across the
southeast due to the further increasing instability through the
day on Sunday. While a brief tornado southeast can not be fully
ruled out, the potential is low compared to across the northwest
and northern counties this morning. As the cold front moves
through, a few lingering showers are expected, but the atmosphere
will stabilize quickly as cold air advection ensues.

Any remaining showers should be exiting the southeast counties
early tonight. Much cooler and drier air will overspread the area
by Monday morning with lows in the mid 30s north to 40s elsewhere.
Did add in patchy frost across the far northern counties. Not sure
if the winds will die completely off but the more sheltered
locations should at least see some patchy frost. Not enough
coverage to issue a Frost Advisory, but worth watching. Highs on
Monday will be pleasant with readings in the 60s. A warm front
will lift northward Monday night with a chance of showers across
the southern counties.

86/16

.LONG TERM...
/Updated at 0211 AM CDT Sun Mar 28 2021/

With the advancing warm front, look for mostly cloudy skies on
Tuesday with scattered showers and thunderstorms, with better
chances of rain south of I-20. Increasing rain chances Tuesday
night across north Alabama as low level southerly flow increases
ahead of an approaching short wave. Looks like the best coverage
here will be in the north. Behind it, a strong cold front will
push through Central Alabama on Wednesday producing widespread
showers and thunderstorms. There is small window across the
southern counties Wednesday afternoon when surface based
instability may be high enough for a low end severe threat, with
wind and hail the biggest concerns. SPC has issued a day 3
marginal just to our west, so confidence is increasing that we
will see a chance on Wednesday. Will go ahead and include a low
end confidence for severe storms on Wednesday in the HWO. A much
colder air mass will overspread the area Thursday and Friday. In
fact we could see some upper 20s in the north on Friday morning.
A Freeze Watch may be issued in the next few days if the trend
continues.

16

&&

.AVIATION...
06Z TAF Discussion.

Conditions should deteriorate to MVFR in the 7-9z time frame
ahead of our TSRA that will be moving in ahead of and along a
front. Gusty winds will be possible outside of storms. A few
storms could be strong to severe with the frontal passage. Threat
time for storms will be best in the morning for TCL/BHM, morning
to midday for EET/ASN/ANB and midday to afternoon for MGM/TOI. May
return to VFR conditions again by 18z TCL to 23z TOI.

16

&&

.FIRE WEATHER...

A band of showers and thunderstorms will track southeast across
the area today. Some of the storms may be severe. Cooler with no
rain after 10 PM tonight through Monday. Increasing rain chances
Tuesday and Tuesday night as a warm front lifts northward. Showers
likely and a chance of storms on Wednesday. No fire weather
concerns due to moist ground fuels and high RH values.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     68  36  66  42  71 / 100   0   0   0  30
Anniston    72  39  69  46  73 / 100   0   0  10  30
Birmingham  67  40  67  47  73 / 100   0   0  10  30
Tuscaloosa  69  40  68  46  73 /  90  10   0   0  40
Calera      68  40  67  48  73 / 100  10   0  10  40
Auburn      75  42  68  51  70 / 100  20   0  20  50
Montgomery  77  44  71  51  75 / 100  20   0  10  50
Troy        81  46  71  52  76 / 100  20   0  20  50

&&

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

&&

Hazardous Weather Outlook
National Weather Service Birmingham AL
309 AM CDT Sun Mar 28 2021

ALZ011>015-017>050-291115-
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-
309 AM CDT Sun Mar 28 2021

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

.DAY ONE...Outlook through Tonight.

Severe storms will move across the northwestern portions of Central
Alabama while digging southward. There is a low end threat for
tornadoes, while hail and damaging wind will be the primary threats
along with localized flooding with any training that may develop.

The tornado threat decreases the further south you go, but will
remain a non zero threat until the Interstate 85 corridor. South of
the Interstate 85, an increase in activity this afternoon may
increase the threat for damaging winds and large hail through 4 PM.

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

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Minor flooding will continue along portions of the Tombigbee,
Cahaba, Coosa, Locust Fork, and Black Warrior River Basins through
this week.

A cold front will move through on Wednesday. At this time there is a
low end threat for strong winds and large hail with the passage of
the front.

A freeze is possible Friday morning for the northern half of Central
Alabama.

.SPOTTER INFORMATION STATEMENT...

Activation of storm spotters and emergency management may be needed
through this afternoon and again on Wednesday.

Special Weather Statement
National Weather Service Birmingham AL
325 AM CDT Sun Mar 28 2021

ALZ011-014-280900-
Winston AL-Marion AL-
325 AM CDT Sun Mar 28 2021

...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL MARION AND
NORTHWESTERN WINSTON COUNTIES UNTIL 400 AM CDT...

At 325 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Moulton to near Brinn. Movement was east
at 70 mph.

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

Locations impacted include...
Haleyville, Brushy Lake, Needmore, Brinn, Bear Creek, Posey Field
Airport, Sipsey River Rec Area, Grayson, Pebble and Upper Bear Creek
Reservoir.

LAT...LON 3430 8723 3428 8726 3416 8781 3431 8764
TIME...MOT...LOC 0825Z 251DEG 64KT 3451 8736 3420 8786

86/Martin