Alert archive / Alabama / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 133, NWS Birmingham, AL

July 31, 2021Blount County, Jefferson County, Walker County, Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at Jul 31, 2021, 2:56 PM CDT for Blount County, Jefferson County, Walker County, Alabama. It was in force for 49 min. 5 reports 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: Jul 31, 2021, 2:56 PM CDT (19:56 UTC)
Expired: Jul 31, 2021, 3:45 PM CDT
In force: 49 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), 43 km from the middle of the area, began a volume at 19:59 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

Time	Report	Where	Remark
Jul 31, 3:24 PM CDT	TSTM WND DMG	1 Ssw Brookside, AL	TREES AND POWERLINES WERE BLOWN DOWN ON CHERRY AVENUE, IN BIRMINGHAM.
Jul 31, 3:25 PM CDT	TSTM WND DMG	2 Se Forestdale, AL	TREES AND POWERLINES WERE BLOWN DOWN ON CHERRY AVENUE, NEAR FULTONDALE.
Jul 31, 3:37 PM CDT	TSTM WND DMG	1 S Mountain Brook, AL	TREE DOWN ON PINE RIDGE ROAD.
Jul 31, 3:40 PM CDT	TSTM WND DMG	Concord, AL	A VERY LARGE PECAN TREE WAS BLOWN DOWN IN CONCORD.
Jul 31, 3:45 PM CDT	TSTM WND DMG	1 Sse Samford Universit, AL	TREES WERE BLOWN DOWN ON SHADES CREEK ROAD, IN VESTAVIA HILLS.

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, 7.9 hours before the alert went out and 42 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1260 J/kg
Mixed-layer CIN: -102 J/kg
Mixed-layer LCL: 1122 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: -46 m²/s²
0-3 km storm-relative helicity: -36 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

661 
WUUS54 KBMX 311956
SVRBMX
ALC009-073-127-312045-
/O.NEW.KBMX.SV.W.0133.210731T1956Z-210731T2045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Birmingham AL
256 PM CDT Sat Jul 31 2021

The National Weather Service in Birmingham has issued a

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

* Until 345 PM CDT.

* At 256 PM CDT, severe thunderstorms were located along a line
  extending from near Dallas to Parrish, moving south at 35 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Birmingham, Hoover, Vestavia Hills, Bessemer, Homewood, Mountain
  Brook, Trussville, Helena, Hueytown, Gardendale, Irondale, Leeds,
  Fairfield, Fultondale, Sumiton, Cordova, Dora, Dallas, Center Point
  and Pleasant Grove.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3393 8665 3352 8654 3347 8661 3347 8667
      3342 8672 3342 8675 3336 8683 3333 8683
      3325 8707 3328 8707 3331 8716 3342 8725
      3346 8734 3349 8733 3348 8729 3350 8729
      3350 8726 3352 8732 3371 8730 3384 8708
TIME...MOT...LOC 1956Z 357DEG 29KT 3385 8670 3372 8725 

HAIL...<.75IN
WIND...60MPH
 
$$

87/GRANTHAM

3 follow-up statements

984 
WWUS54 KBMX 312009
SVSBMX

Severe Weather Statement
National Weather Service Birmingham AL
309 PM CDT Sat Jul 31 2021

ALC009-073-127-312045-
/O.CON.KBMX.SV.W.0133.000000T0000Z-210731T2045Z/
Walker AL-Blount AL-Jefferson AL-
309 PM CDT Sat Jul 31 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM CDT
FOR SOUTHEASTERN WALKER...SOUTHWESTERN BLOUNT AND JEFFERSON
COUNTIES...

At 309 PM CDT, severe thunderstorms were located along a line
extending from near County Line to near Gorgas, moving south at 35
mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Birmingham, Hoover, Vestavia Hills, Bessemer, Homewood, Mountain
Brook, Trussville, Helena, Hueytown, Gardendale, Irondale, Leeds,
Fairfield, Fultondale, Sumiton, Cordova, Dora, Dallas, Center Point
and Pleasant Grove.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3393 8665 3352 8654 3347 8661 3347 8667
      3342 8672 3342 8675 3336 8683 3333 8683
      3325 8707 3328 8707 3331 8716 3342 8725
      3346 8734 3349 8733 3348 8729 3350 8729
      3350 8726 3352 8732 3371 8730 3384 8708
TIME...MOT...LOC 2009Z 357DEG 29KT 3376 8669 3363 8724 

HAIL...<.75IN
WIND...60MPH
 
$$

87/GRANTHAM

130 
WWUS54 KBMX 312021
SVSBMX

Severe Weather Statement
National Weather Service Birmingham AL
321 PM CDT Sat Jul 31 2021

ALC009-127-312031-
/O.CAN.KBMX.SV.W.0133.000000T0000Z-210731T2045Z/
Walker AL-Blount AL-
321 PM CDT Sat Jul 31 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN WALKER AND
SOUTHWESTERN BLOUNT COUNTIES IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

LAT...LON 3376 8661 3352 8654 3342 8675 3333 8683
      3325 8706 3328 8707 3331 8716 3342 8725
      3346 8734 3349 8733 3348 8729 3350 8726
      3353 8727 3352 8725 3355 8719 3360 8719
      3363 8710 3366 8709 3370 8700 3381 8670
TIME...MOT...LOC 2021Z 010DEG 46KT 3365 8662 3357 8674 3356 8702 3347
8718

$$

ALC073-312045-
/O.CON.KBMX.SV.W.0133.000000T0000Z-210731T2045Z/
Jefferson AL-
321 PM CDT Sat Jul 31 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM CDT
FOR JEFFERSON COUNTY...

At 321 PM CDT, severe thunderstorms were located along a line
extending from Grayson Valley to Birmingham to Maytown to Oak Grove,
moving south at 55 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Birmingham, Hoover, Vestavia Hills, Bessemer, Homewood, Mountain
Brook, Trussville, Helena, Hueytown, Gardendale, Irondale, Leeds,
Fairfield, Fultondale, Center Point, Pleasant Grove, Clay, Pinson,
Tarrant and Midfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3376 8661 3352 8654 3342 8675 3333 8683
      3325 8706 3328 8707 3331 8716 3342 8725
      3346 8734 3349 8733 3348 8729 3350 8726
      3353 8727 3352 8725 3355 8719 3360 8719
      3363 8710 3366 8709 3370 8700 3381 8670
TIME...MOT...LOC 2021Z 010DEG 46KT 3365 8662 3357 8674 3356 8702 3347
8718

HAIL...<.75IN
WIND...60MPH
 
$$

87/GRANTHAM

660 
WWUS54 KBMX 312032
SVSBMX

Severe Weather Statement
National Weather Service Birmingham AL
332 PM CDT Sat Jul 31 2021

ALC073-312045-
/O.CON.KBMX.SV.W.0133.000000T0000Z-210731T2045Z/
Jefferson AL-
332 PM CDT Sat Jul 31 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM CDT
FOR JEFFERSON COUNTY...

At 332 PM CDT, severe thunderstorms were located along a line
extending from Alton to Birmingham to near North Johns, moving south
at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Birmingham, Hoover, Vestavia Hills, Bessemer, Homewood, Mountain
Brook, Trussville, Helena, Hueytown, Gardendale, Irondale, Leeds,
Fairfield, Fultondale, Center Point, Pleasant Grove, Clay, Pinson,
Tarrant and Midfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3335 8719 3354 8721 3355 8719 3356 8719
      3375 8661 3352 8654 3342 8675 3333 8683
      3325 8706 3328 8707 3331 8716
TIME...MOT...LOC 2032Z 356DEG 29KT 3358 8660 3349 8688 3340 8716 

HAIL...<.75IN
WIND...60MPH
 
$$

87/GRANTHAM

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 30, 7:07 PM CDT	Special Weather Statement	BMX	Winston	38 min
Jul 30, 7:45 PM CDT	Severe Thunderstorm Warning	BMX	Cherokee, Etowah	31 min
Jul 30, 7:51 PM CDT	Severe Thunderstorm Warning	BMX	Blount	39 min
Jul 31, 2:25 PM CDT	Special Weather Statement	BMX	Russell	50 min
Jul 31, 2:26 PM CDT	Special Weather Statement	BMX	St. Clair	49 min
Jul 31, 2:28 PM CDT	Special Weather Statement	BMX	Chilton	47 min
Jul 31, 2:29 PM CDT	Special Weather Statement	BMX	Dallas	46 min
Jul 31, 2:44 PM CDT	Special Weather Statement	BMX	Shelby	46 min
Jul 31, 2:47 PM CDT	Special Weather Statement	BMX	Jefferson, Walker	43 min
Jul 31, 3:04 PM CDT	Severe Thunderstorm Warning	BMX	Calhoun, St. Clair, Talladega	41 min
Jul 31, 3:09 PM CDT	Special Weather Statement	BMX	Chilton	51 min
Jul 31, 3:11 PM CDT	Special Weather Statement	BMX	Russell	34 min
Jul 31, 3:23 PM CDT	Special Weather Statement	BMX	Coosa	37 min
Jul 31, 3:34 PM CDT	Severe Thunderstorm Warning	BMX	Jefferson, Shelby	41 min
Jul 31, 3:38 PM CDT	Severe Thunderstorm Warning	BMX	Chilton, Coosa, Shelby, Talladega	52 min
Jul 31, 3:41 PM CDT	Special Weather Statement	BMX	Talladega	34 min
Jul 31, 3:57 PM CDT	Special Weather Statement	BMX	Shelby	33 min
Jul 31, 3:59 PM CDT	Special Weather Statement	BMX	Elmore, Montgomery	46 min
Jul 31, 4:12 PM CDT	Special Weather Statement	BMX	Clay, Randolph	48 min
Jul 31, 4:18 PM CDT	Special Weather Statement	BMX	Chambers	42 min
Jul 31, 4:22 PM CDT	Special Weather Statement	BMX	Tallapoosa	53 min
Jul 31, 4:45 PM CDT	Severe Thunderstorm Warning	BMX	Tallapoosa	45 min
Jul 31, 4:49 PM CDT	Special Weather Statement	BMX	Bibb	41 min
Jul 31, 5:00 PM CDT	Special Weather Statement	BMX	Lee	60 min
Jul 31, 6:36 PM CDT	Special Weather Statement	BMX	Barbour, Russell	39 min

Nearby

Severe Thunderstorm Warnings in Alabama, 2021 Every 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.