Special Weather Statement, NWS Birmingham, AL

Area Forecast Discussion
National Weather Service Birmingham AL
356 PM CDT Wed Aug 18 2021

.SHORT TERM...
/Updated at 123 PM CDT Wed Aug 18 2021/
Through Tomorrow.

The western Atlantic ridge is drifting southward and becoming
elongated across the Gulf of Mexico. Slight height rises will
support warm afternoon temperatures with highs in the 90s and
suppressed rain coverage, especially across the south. On the other
hand, the upper-level trough over the Upper Midwest, which extends
southwest through the Ozarks, will begin to eject eastward this
afternoon through tomorrow. The base of the trough will move across
the Tennessee Valley and will be accompanied by a greater presence
of showers and storms, mainly affecting our northwest late this
afternoon. Any activity that lingers beyond dark this evening will
diminish before midnight with mostly pleasant conditions overnight
and temperatures in the lower to mid 70s.

Afternoon convection will become more expansive along and north of I-
20 during the day tomorrow associated with increased PVA and high
PWAT values of 2-2.1 inches. As such, Likely PoPs have been
maintained for areas north of the I-85 corridor for tomorrow
afternoon where cold pool interactions are likely to result in a
broad coverage of storms. Areas south of I-85 will be further away
from forcing and under a greater influence from the ridge, so only
routine summertime PoPs are expected.

86

.LONG TERM...
/Updated at 355 PM CDT Wed Aug 18 2021/
Thursday night through Tuesday.

No major changes were made in the extended forecast. The best
rain chance day in the extended still appears to be on Friday
with the upper low pressure system and shortwave activity that
will be in place across Eastern Conus. This will likely continue
into Saturday but with a NE to SW gradient. This will be due to
the system moving off into the Atlantic as well as a large upper
ridge building over much of the SRN and Central US moving into
Sunday. For the remainder of the extended, rain chances become
more diurnally influenced. Will continue to mention heat in the
HWO with the lower rain chances, hot/humid conditions, and heat
indices approaching 105 each of those afternoons starting Sunday.

08

Previous long-term discussion:
/Updated at 340 AM CDT Wed Aug 18 2021/
Thursday night through Tuesday.

A short wave trof will develop over the Ohio Valley Region and
evolve into a cut-off low by the weekend. This will place Alabama in
an active northwest flow pattern that will result in above normal
rain chances thru Saturday. The cut-off low will eject northeast by
early next week and an upper ridge will build over the Central Gulf
Coast region. Rain chances will decrease considerably by Sunday and
Monday along with warmer daytime temperatures. An easterly wave
approaching the Southeast Coast on Tuesday will bring an increase in
rain chances over the southeast portion of Central Alabama. Forecast
heat indices will be close to the 105 degree mark Sunday through
Tuesday and will highlight in the HWO.

58/rose

&&

.AVIATION...
18Z TAF Discussion.

VFR conditions will be most prevalent this afternoon as a mid-level
ridge over the western Atlantic builds further into the region
producing a light, southerly breeze. An upper-level shortwave trough
is situated over the Upper Midwest and Ozarks which is supporting
scattered convection across northern Mississippi. This activity will
move towards the northern terminals later this evening and may
linger after dark, but coverage should be diminishing with the
removal of daytime heating. Ceilings will lower briefly at the
northern sites tomorrow morning, but should begin to improve shortly
after sunrise.

86

&&

.FIRE WEATHER...

Abundant moisture will be present across the region through
Friday, leading to above normal convective rain chances and high
relative humidity values. Southerly transport winds of 5 to 10
mph this afternoon shift to a west to southwesterly direction
Thursday afternoon.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     71  88  70  89  70 /  40  70  40  80  30
Anniston    72  89  72  89  72 /  30  70  40  70  30
Birmingham  73  89  72  89  73 /  40  70  40  80  30
Tuscaloosa  74  89  73  88  73 /  40  70  40  70  30
Calera      72  89  73  87  73 /  40  60  40  70  30
Auburn      73  90  73  87  72 /  20  40  20  60  30
Montgomery  74  94  74  91  73 /  20  50  20  70  20
Troy        73  94  73  91  73 /  20  40  20  60  20

&&

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

&&

Hazardous Weather Outlook
National Weather Service Birmingham AL
333 AM CDT Wed Aug 18 2021

ALZ011>015-017>050-191145-
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-
333 AM CDT Wed Aug 18 2021

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

.DAY ONE...Outlook through Tonight.

No hazardous weather is expected at this time.

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

Heat Indices may reach 105 degrees each afternoon Sunday through
Tuesday.

.SPOTTER INFORMATION STATEMENT...

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

Special Weather Statement
National Weather Service Birmingham AL
744 PM CDT Wed Aug 18 2021

ALZ017-190115-
Blount AL-
744 PM CDT Wed Aug 18 2021

...A strong thunderstorm will impact portions of south central Blount
County through 815 PM CDT...

At 744 PM CDT, Doppler radar was tracking a strong thunderstorm near
Hayden, or 10 miles southwest of Cleveland, moving north at 20 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...
Cleveland, Dallas, Locust Fork, Trafford, Fairview, Hayden, Nectar,
County Line, Bangor and Remlap.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3399 8655 3381 8662 3383 8674 3384 8676
      3384 8680 3397 8677 3398 8676 3399 8676
      3400 8675 3400 8674 3401 8674
TIME...MOT...LOC 0044Z 193DEG 16KT 3389 8671

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

32/Davis