Alert archive / Alabama / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 144, NWS Birmingham, AL

August 21, 2021Blount County, Jefferson County, Walker County, Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at Aug 21, 2021, 3:23 PM CDT for Blount County, Jefferson County, Walker County, Alabama. It was in force for 30 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 21, 2021, 3:23 PM CDT (20:23 UTC)
Expired
Aug 21, 2021, 3:53 PM CDT
In force
30 min
Issued by
NWS Birmingham, AL
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Blount County, AL, Jefferson County, AL, Walker County, AL

The radar

The Birmingham radar (KBMX), 82 km from the middle of the area, began a volume at 20:25 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Aug 21, 3:24 PM CDTTSTM WND DMG1 Sse Sumiton, ALTRAFFIC SIGNAL ALONG U.S. HIGHWAY 78 NEAR THE WALMART DOWNED DUE TO HIGH WINDS. ALSO, A TREE WAS FOUND DOWNED THIS MORNING NEAR THE 100 BLOCK OF WHITLOW ROAD TO THE NORTHWEST OF THIS LOCATION.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 8.4 hours before the alert went out and 81 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Birmingham, AL at 12:00Z on 2021-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 284 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Birmingham, AL at 12:00Z on 2021-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 88 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
284 J/kg
Mixed-layer CIN
-56 J/kg
Mixed-layer LCL
689 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
88 m²/s²
0-3 km storm-relative helicity
86 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

177 
WUUS54 KBMX 212023
SVRBMX
ALC009-073-127-212115-
/O.NEW.KBMX.SV.W.0144.210821T2023Z-210821T2115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Birmingham AL
323 PM CDT Sat Aug 21 2021

The National Weather Service in Birmingham has issued a

* Severe Thunderstorm Warning for...
  Northeastern Walker County in central Alabama...
  Southwestern Blount County in central Alabama...
  Northeastern Jefferson County in central Alabama...

* Until 415 PM CDT.

* At 323 PM CDT, a severe thunderstorm was located over Arkadelphia,
  or 11 miles northeast of Sumiton, moving east at 35 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Gardendale, Sumiton, Cordova, Dora, Blountsville, Cleveland,
  Dallas, Clay, Pinson, Warrior, Kimberly, Morris, Locust Fork,
  Trafford, Allgood, Fairview, Hayden, Sipsey, Nectar and Rosa.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3410 8660 3395 8650 3380 8655 3380 8658
      3377 8658 3376 8654 3368 8653 3373 8719
      3396 8712 3392 8708 3390 8710 3389 8701
      3386 8699 3387 8693 3391 8692 3395 8679
      3403 8670 3406 8671 3405 8668 3408 8670
TIME...MOT...LOC 2023Z 270DEG 28KT 3390 8695 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

89^GSatterwhite
2 follow-up statements
227 
WWUS54 KBMX 212046
SVSBMX

Severe Weather Statement
National Weather Service Birmingham AL
346 PM CDT Sat Aug 21 2021

ALC127-212056-
/O.CAN.KBMX.SV.W.0144.000000T0000Z-210821T2115Z/
Walker AL-
346 PM CDT Sat Aug 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN WALKER COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 3381 8655 3380 8658 3377 8658 3376 8654
      3368 8653 3372 8703 3379 8699 3379 8697
      3380 8697 3380 8695 3385 8696 3387 8694
      3387 8692 3391 8692 3394 8682 3394 8650
TIME...MOT...LOC 2046Z 273DEG 27KT 3383 8679 

$$

ALC009-073-212115-
/O.CON.KBMX.SV.W.0144.000000T0000Z-210821T2115Z/
Blount AL-Jefferson AL-
346 PM CDT Sat Aug 21 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM CDT
FOR SOUTHWESTERN BLOUNT AND NORTHEASTERN JEFFERSON COUNTIES...

At 346 PM CDT, a severe thunderstorm was located over Warrior, or 11
miles north of Gardendale, moving east at 30 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Gardendale, Dallas, Clay, Pinson, Warrior, Kimberly, Morris, Locust
Fork, Trafford, Allgood, Hayden, County Line, Blount Springs,
Arkadelphia, Inland Lake, Palmerdale, Smoke Rise, Village Springs,
Remlap and Clear Springs.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3381 8655 3380 8658 3377 8658 3376 8654
      3368 8653 3372 8703 3379 8699 3379 8697
      3380 8697 3380 8695 3385 8696 3387 8694
      3387 8692 3391 8692 3394 8682 3394 8650
TIME...MOT...LOC 2046Z 273DEG 27KT 3383 8679 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

89^GSatterwhite
295 
WWUS54 KBMX 212053
SVSBMX

Severe Weather Statement
National Weather Service Birmingham AL
353 PM CDT Sat Aug 21 2021

ALC009-073-212103-
/O.CAN.KBMX.SV.W.0144.000000T0000Z-210821T2115Z/
Blount AL-Jefferson AL-
353 PM CDT Sat Aug 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN BLOUNT AND
NORTHEASTERN JEFFERSON COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.

LAT...LON 3381 8655 3380 8658 3377 8658 3376 8654
      3368 8653 3372 8703 3379 8699 3379 8697
      3380 8697 3380 8695 3385 8696 3387 8694
      3387 8692 3391 8692 3394 8682 3394 8650
TIME...MOT...LOC 2052Z 270DEG 28KT 3383 8672 

$$

89^GSatterwhite

The office that day

Everything else NWS Birmingham, AL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 20, 8:27 PM CDTAreal Flood AdvisoryBMXElmore3 hr
Aug 21, 1:45 PM CDTSpecial Weather StatementBMXFayette45 min
Aug 21, 2:11 PM CDTSpecial Weather StatementBMXWinston49 min
Aug 21, 2:30 PM CDTSpecial Weather StatementBMXWalker45 min
Aug 21, 3:02 PM CDTSpecial Weather StatementBMXWalker28 min
Aug 21, 3:12 PM CDTSpecial Weather StatementBMXTuscaloosa48 min
Aug 21, 3:17 PM CDTSpecial Weather StatementBMXCullman43 min
Aug 21, 3:37 PM CDTSpecial Weather StatementBMXHale38 min
Aug 21, 3:45 PM CDTSpecial Weather StatementBMXBibb30 min
Aug 21, 4:58 PM CDTSpecial Weather StatementBMXDallas47 min
Aug 21, 5:53 PM CDTSpecial Weather StatementBMXMontgomery52 min

Nearby

Severe Thunderstorm Warnings in Alabama, 2021Every severe thunderstorm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.