Special Weather Statement, NWS Birmingham, AL

Area Forecast Discussion
National Weather Service Birmingham AL
244 AM CDT Fri Aug 4 2023

...New SHORT TERM, LONG TERM...

.SHORT TERM...
(Today through Saturday)
Issued at 240 AM CDT FRI AUG 4 2023

Biggest weather feature within the short term is the next inbound
MCS and the heat to the south and west. With regards to the MCS, it
is currently located over Tennessee and is quickly diving southward.
A boundary currently located over the north-central Alabama is also
helping surface convergence and fire off storms through the early
morning hours. During the day, some strengthening of the line is
possible as daytime instability may help to "fuel" these storms.
Heat is also expected to play a role in southern and western areas
as well. With southerly flow from the Gulf, this should allow for
higher temperatures and dewpoints. This should help to increase heat
indices in those areas.

16/Serre

&&

.LONG TERM...
(Saturday through Thursday)
Issued at 240 AM CDT FRI AUG 4 2023

Mid- to upper-level ridging will continue to remain prominent in the
Southern Plains and Southwest through early next week. This will
continue to foster excessive heat in those areas, with influence of
these conditions nudged eastward into portions of the Deep South.
Afternoon highs across Central Alabama will be in the low to mid 90s
on Sunday and Monday, with dewpoints in the low to mid 70s. Heat
indices up to 109 degrees will be possible at times, particularly
for areas south and west. I'll maintain HWO mentioning as a result,
but confidence is somewhat wavered by the prospect for afternoon
convection, which appears to be somewhat enhanced on Sunday
afternoon as a perturbation dips into the Tennessee Valley (main
disturbance north). I've kept PoPs <50% until mesoscale details
become more clear, but there's a decent signal in latest guidance
for convection that afternoon with PWs in the 1.9" to 2.3" range.

Meanwhile, the disturbance to our north will continue east from the
Ohio Valley toward the Northeast, though presence of a longwave
trough will settle across the eastern CONUS as the overall pattern
becomes less amplified. This will lead to an increase in mid- to
upper-level flow across Central Alabama with 500 mb winds of 20-40
kts by Monday afternoon. With enhanced flow aloft focused from the
Central Plains toward the Southern Appalachians, perturbations will
follow a trajectory into our region, and this could be the case on
Tuesday with most guidance progging a shortwave moving into the
Tennessee Valley. This could lead to organized thunderstorm
potential with 3,000-4,000 J/kg SBCAPE and 30-40 kts eff. bulk shear
established across Alabama. We'll continue to monitor severe
potential for Tuesday.

Quasi-zonal flow on Tuesday will begin to transition to a more
northwesterly flow again on Wednesday with subsequent disturbances
aloft moving across the mid Mississippi Valley toward the
Appalachians. These disturbances will help influence convective
coverage each day given rich boundary layer moisture remains in
place across the Deep South with afternoon heat and instability.
Thus, the pattern seems to remain fairly active toward the end of
next week with 30-50% chances for showers and thunderstorms each
day. I generally stayed near normal values for forecast temperatures.

40/Sizemore

&&

.AVIATION...
(06Z TAFS)
Issued at 1238 AM CDT FRI AUG 4 2023

VFR conditions expected through the early morning at all terminals.
Another MCS round looks to be incoming to Central Alabama today. The
predominate motion looks to generally be from Northeast to
Southwest, though slowly. ANB, ASN, and BHM seem to be in the
morning, then TCL and EET by the early afternoon, then MGM and TOI
in the later afternoon and early evening. Some storms may be
locally heavy, with reduced visibilities and ceilings.

16/Serre

&&

.FIRE WEATHER...

Scattered to numerous showers and thunderstorms will continue
across Central Alabama beginning this morning through the
afternoon. Minimum RH values will be 55-70%. Outside
thunderstorms, 20 ft winds will be light and variable. Humid
conditions will continue over the next several days with a chance
for showers and thunderstorms maximizing each afternoon.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     85  69  90  71 /  90  20  50  20
Anniston    85  72  91  73 /  90  20  40  20
Birmingham  86  73  91  75 /  90  20  40  20
Tuscaloosa  90  74  91  74 /  80  20  50  20
Calera      87  74  90  74 /  80  20  40  20
Auburn      86  73  90  74 /  80  20  50  20
Montgomery  91  74  93  75 /  70  20  40  30
Troy        92  74  93  74 /  70  20  50  30

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
Flood Watch through this afternoon for the following counties:
Blount-Calhoun-Cherokee-Clay-Cleburne-Etowah-Jefferson-Randolph-
Shelby-St. Clair-Talladega-Walker-Winston.

Heat Advisory until 9 PM CDT this evening for the following
counties: Dallas-Greene-Hale-Lowndes-Marengo-Perry-Pickens-
Sumter.

&&

SHORT TERM...16/Serre
LONG TERM....40/Sizemore
AVIATION...16/Serre

Hazardous Weather Outlook
National Weather Service Birmingham AL
255 AM CDT Fri Aug 4 2023

ALZ011>015-017>050-051100-
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-
255 AM CDT Fri Aug 4 2023

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

.DAY ONE...Outlook through Tonight.

Isolated flash flooding will be possible through early this
afternoon as the showers and storms move over the same areas in the
northern and eastern portions of Central Alabama.

Severe thunderstorms are possible between 9 AM and 6 PM, across a
good portion of Central Alabama. Damaging winds up to 60 mph will be
possible.

Heat indices will range from 105 to 108 degrees across southwestern
portions of Central Alabama late this morning through early afternoon
ahead of any thunderstorms.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Heat indices will reach or exceed 105 degrees at times across much
of Central Alabama Saturday through Monday. At this time, the highest
heat indices are forecast Sunday and Monday.

.SPOTTER INFORMATION STATEMENT...

Activation of storm spotters and emergency management may be needed
through late this afternoon.

Preliminary Local Storm Report
National Weather Service Birmingham AL
419 AM CDT Fri Aug 4 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0400 AM     Flash Flood      5 NNE Blountsville      34.14N 86.55W
08/04/2023                   Blount             AL   Trained Spotter

            Hackney Rd has around 6 inches of flowing
            water over it.

&&

AS

Preliminary Local Storm Report
National Weather Service Birmingham AL
420 AM CDT Fri Aug 4 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0402 AM     Flash Flood      Oneonta                 33.95N 86.47W
08/04/2023                   Blount             AL   Emergency Mngr

            Numerous streets in Oneonta are underwater.

&&

AS

Special Weather Statement
National Weather Service Birmingham AL
505 AM CDT Fri Aug 4 2023

ALZ025>027-041045-
Shelby AL-Talladega AL-St. Clair AL-
505 AM CDT Fri Aug 4 2023

...Strong thunderstorms will impact portions of northwestern
Talladega, northeastern Shelby and central St. Clair Counties through
545 AM CDT...

At 505 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Springville to Harrisburg. Movement was
south at 25 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Pell City, Leeds, Moody, Springville, Odenville, Margaret, Argo,
Alpine Bay Resort, Bald Rock, Alpine, Logan Martin Lake, Coosa
Island, Harrisburg, Branchville, Logan Martin Dam, Country Club
Estates, St. Clair County Airport, St. Clair Springs, Wattsville and
Chula Vista.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3373 8621 3333 8621 3351 8656 3353 8652
      3355 8652 3356 8655 3362 8655 3363 8653
      3371 8653 3383 8645 3382 8643 3386 8638
TIME...MOT...LOC 1005Z 339DEG 21KT 3382 8641 3360 8628

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

40/Sizemore