Special Weather Statement, NWS Birmingham, AL

Area Forecast Discussion
National Weather Service Birmingham AL
259 PM CDT Wed Jul 28 2021

.SHORT TERM...
/Updated at 0127 PM CDT Wed Jul 28 2021/

Through Thursday.

The center of a deep ridge over the Central CONUS is building
towards the Ozarks and encouraging hot conditions across the
forecast area. Above 850mb, a much drier airmass is advecting
southward with better rain chances focused along the Gulf Coast
and our far southern counties for this afternoon. Due to the dry
air aloft, any thunderstorms that do develop will be watched very
closely for microbursts and gusty winds, but this potential is
greatest across the north where no to minimal develop is expected.

While the northern half is forecast to stay rain-free, the saturated
soil conditions are resulting in dewpoints in the mid to upper 70s,
and as air temperatures rise into the mid 90s, this combination will
cause high heat indices ranging from 102-107F. Hot conditions will
develop again tomorrow afternoon as small height rises cause
temperatures to reach the upper 90s in some locations. Therefore,
the Heat Advisory will continue for all of Central AL, and has also
been extended into Friday (Friday's forecast will be detailed in the
long term discussion below).

1000-500mb RH drops to around 30% tomorrow and, for the first time
since earlier this month, there is a decent chance that the forecast
area will be rain-free. Will maintain a 15-20% chance across the far
south, but most of the convection will be related to sea breeze
activity along the coast where it should make very little inland
progress.

86

.LONG TERM...
/Updated at 0228 PM CDT Wed Jul 28 2021/

Friday through Tuesday.

Central Alabama will transition from a hot/humid air mass to a
cooler air mass by early next week as a fairly strong upper trof
develops east of the MS river. Expect highs on Friday/Saturday to
reach the middle and upper 90s. Friday should be rain free due to
a strong upper ridge over the area. Small rain chances return on
Saturday as a sea-breeze induced boundary moves inland over south
Alabama. By Sunday the first wave of convection ahead of the short
wave trof will impact Central Alabama. Some stronger storms
possible Sunday if the air mass has time to destabilize ahead of
the rain cooled outflow boundary. Numerous showers and storms on
Monday, although cloud cover and cooler temperatures will limit
any instability. Models differ on position of upper trof axis on
Tuesday, but some drying likely across north Alabama.

58/rose

Previous long-term discussion:
/Updated at 0318 AM CDT Wed Jul 28 2021/

Friday through Tuesday.

A strong mid-level ridge will extend from Wyoming to northern
Florida on Friday. PWATs do creep up a bit from Thursday, so there
is a non-zero potential for a very isolated shower with strong
heating, but the ridge will keep coverage 10 percent or less.
Otherwise, strong heating and high low-level thicknesses will result
in widespread upper 90s for highs. A few spots may hit 100F. Dew
points will mix out a little in the afternoon, but probably not
enough to keep heat indices below 105 especially with recent wet
conditions. The ridge axis slides slightly southwestward on
Saturday, with some height falls in northeast AL. A weak cold front
will also begin to approach North Alabama. Highs will be in the mid
to upper 90s, near 100 in the southeast, and pooling dew points
ahead of the front will result in high heat indices. Increasing
PWATs and weakening of the ridge will result in the potential for
isolated to widely scattered thunderstorms.

The ridge will retrograde westward by Sunday and become more
amplified across the western CONUS, with associated downstream
amplification of a trough over the eastern CONUS. Some models hint
at an MCS developing off to our northwest Saturday night which could
track southeastward along the cold front, resulting in an increase
in rain chances late Saturday night into Sunday morning. Showers and
storms become numerous on Sunday with height falls and PWATs around
2 inches, but there could be some continued heat concerns across the
southern half of the area depending on timing of convection. The
trough will result in high temperatures becoming below normal Monday
and Tuesday, with an end to heat concerns, and some guidance brings
some drier air in by Tuesday.

32/Davis

&&

.AVIATION...
18Z TAF Discussion.

VFR conditions will continue at most TAF sites through this forecast
period with a mid-level ridge further establishing over the region.
Much drier air is entering the area through northerly mid-level flow
on the eastern side of the ridge. This will suppress rain chances to
the far south with best chances for a passing thunderstorm near TOI.
No impacts expected at the northern terminals, but some patchy fog
may develop briefly tomorrow morning due to lingering moisture on
the ground and calm, clear conditions.

86

&&

.FIRE WEATHER...

A warm and moist airmass will persist across Central Alabama
through Saturday. A strong upper ridge will build over the area
and suppress rain chances. The upper ridge will also result in
light surface and transport winds. Better rain chances return
Sunday and Monday as an upper trof pushes in from the north.
Highs Thursday through Saturday will be in the middle to upper
90s.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     71  97  73  97  74 /   0   0   0  10   0
Anniston    71  96  73  97  75 /   0  10   0  10   0
Birmingham  74  97  75  98  77 /   0  10   0  10   0
Tuscaloosa  75  97  76  99  77 /  10  10   0  10   0
Calera      73  95  75  98  76 /  10  10   0  10   0
Auburn      74  95  75  96  76 /  20  10   0  10   0
Montgomery  75  97  75  99  77 /  30  20   0  10   0
Troy        74  96  76  98  77 /  40  20   0  10   0

&&

.BMX WATCHES/WARNINGS/ADVISORIES/...
Heat Advisory until 7 PM CDT Friday for the following counties:
Autauga...Barbour...Bibb...Blount...Bullock...Calhoun...
Chambers...Cherokee...Chilton...Clay...Cleburne...Coosa...
Dallas...Elmore...Etowah...Fayette...Greene...Hale...Jefferson...
Lamar...Lee...Lowndes...Macon...Marengo...Marion...Montgomery...
Perry...Pickens...Pike...Randolph...Russell...Shelby...St.
Clair...Sumter...Talladega...Tallapoosa...Tuscaloosa...Walker...
Winston.

&&

Hazardous Weather Outlook
National Weather Service Birmingham AL
813 AM CDT Wed Jul 28 2021

ALZ011>015-017>050-291615-
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-
813 AM CDT Wed Jul 28 2021

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

.DAY ONE...Outlook through Tonight.

Hot temperatures along with high humidity values will lead to heat
indices reaching or exceeding 105 degrees over much of Central
Alabama this afternoon.

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

Heat indices will continue to be oppressive Thursday though the
weekend with values reaching or exceeding 105 degrees.

.SPOTTER INFORMATION STATEMENT...

Activation of storm spotters and emergency management is not
expected at this time.

Special Weather Statement
National Weather Service Birmingham AL
635 PM CDT Wed Jul 28 2021

ALZ048-050-290000-
Russell AL-Barbour AL-
635 PM CDT Wed Jul 28 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN BARBOUR AND SOUTH
CENTRAL RUSSELL COUNTIES UNTIL 700 PM CDT...

At 635 PM CDT, Doppler radar was tracking a strong thunderstorm 9
miles north of Lakepoint Resort State Park, or 16 miles north of
Georgetown, moving southwest at 10 mph.

Winds in excess of 40 mph will be possible with this storm.

Locations impacted include...
Lakepoint Resort State Park, Hawkinsville and Twin Springs.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3213 8506 3209 8505 3206 8506 3203 8506
      3202 8505 3200 8507 3198 8507 3193 8511
      3210 8530 3222 8510 3216 8503
TIME...MOT...LOC 2335Z 047DEG 10KT 3212 8509