Alert archive / Alabama / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 36, NWS Birmingham, AL

March 28, 2021Shelby County, Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at Mar 28, 2021, 7:50 AM CDT for Shelby County, Alabama. It was in force for 40 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Mar 28, 2021, 7:50 AM CDT (12:50 UTC)
Expired
Mar 28, 2021, 8:30 AM CDT
In force
40 min
Issued by
NWS Birmingham, AL
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Shelby County, AL

The radar

The Birmingham radar (KBMX), 12 km from the middle of the area, began a volume at 12:50 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Mar 28, 5:10 AM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 0.8 hours before the alert went out and 13 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 2021-03-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 757 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Birmingham, AL at 12:00Z on 2021-03-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 326 square meters per square second.1939587897117Sfc1 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
757 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
650 m above ground
0-6 km bulk shear
74 kt
0-1 km storm-relative helicity
326 m²/s²
0-3 km storm-relative helicity
355 m²/s²
Significant tornado parameter
1.6
Supercell composite
9.1

Open this sounding in Storm Lab

The text

As transmitted.

651 
WUUS54 KBMX 281250
SVRBMX
ALC117-281330-
/O.NEW.KBMX.SV.W.0036.210328T1250Z-210328T1330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Birmingham AL
750 AM CDT Sun Mar 28 2021

The National Weather Service in Birmingham has issued a

* Severe Thunderstorm Warning for...
  Shelby County in central Alabama...

* Until 830 AM CDT.

* At 750 AM CDT, a severe thunderstorm was located near Maylene, or 8
  miles northwest of Montevallo, moving east at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Alabaster, Pelham, Helena, Calera, Chelsea, Montevallo,
  Childersburg, Columbiana, Wilsonville, Vincent, Harpersville,
  Westover, Wilton, American Village, Oak Mountain State Park,
  Maylene, Oak Mountain Amphitheater, University Of Montevallo,
  Shelby County Airport and Lay Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3336 8634 3334 8637 3329 8636 3327 8641
      3328 8643 3323 8647 3320 8646 3319 8650
      3313 8646 3305 8652 3306 8662 3307 8661
      3307 8688 3305 8689 3310 8697 3316 8697
      3317 8703 3325 8703 3327 8695 3333 8688
TIME...MOT...LOC 1250Z 269DEG 36KT 3319 8696 

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

05
4 follow-up statements
257 
WWUS54 KBMX 281255
SVSBMX

Severe Weather Statement
National Weather Service Birmingham AL
755 AM CDT Sun Mar 28 2021

ALC117-281330-
/O.CON.KBMX.SV.W.0036.000000T0000Z-210328T1330Z/
Shelby AL-
755 AM CDT Sun Mar 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 AM CDT
FOR SHELBY COUNTY...

At 755 AM CDT, a severe thunderstorm was located over Maylene, or
near Alabaster, moving east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Alabaster, Pelham, Helena, Calera, Chelsea, Montevallo, Childersburg,
Columbiana, Wilsonville, Vincent, Harpersville, Wilton, American
Village, Maylene, University Of Montevallo, Shelby County Airport,
Lay Lake, Oak Mountain State Park, Shelby and Joe Tucker Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3336 8634 3334 8637 3329 8636 3327 8641
      3328 8643 3323 8647 3320 8646 3319 8650
      3313 8646 3305 8652 3306 8662 3307 8661
      3307 8688 3305 8689 3310 8697 3316 8697
      3317 8703 3322 8695 3332 8682
TIME...MOT...LOC 1255Z 269DEG 36KT 3319 8689 

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

05
011 
WWUS54 KBMX 281302
SVSBMX

Severe Weather Statement
National Weather Service Birmingham AL
802 AM CDT Sun Mar 28 2021

ALC117-281330-
/O.CON.KBMX.SV.W.0036.000000T0000Z-210328T1330Z/
Shelby AL-
802 AM CDT Sun Mar 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 AM CDT
FOR SOUTHERN SHELBY COUNTY...

At 801 AM CDT, a severe thunderstorm was located over Shelby County
Airport, or near Alabaster, moving east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Alabaster, Calera, Montevallo, Childersburg, Columbiana, Wilsonville,
Harpersville, Wilton, American Village, University Of Montevallo,
Shelby County Airport, Lay Lake, Shelby, Beeswax Creek Park, Alabama
4H Center, Shelby Shores, Highway 145 and CR 46, Kelley Branch, Camp
Branch and Alabaster Veterans Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3336 8634 3334 8637 3329 8636 3327 8641
      3328 8643 3323 8647 3320 8646 3319 8650
      3313 8646 3305 8652 3306 8662 3307 8661
      3307 8688 3305 8689 3310 8697 3316 8697
      3320 8683 3329 8657
TIME...MOT...LOC 1301Z 269DEG 36KT 3319 8681 

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

05
102 
WWUS54 KBMX 281312
SVSBMX

Severe Weather Statement
National Weather Service Birmingham AL
812 AM CDT Sun Mar 28 2021

ALC117-281330-
/O.CON.KBMX.SV.W.0036.000000T0000Z-210328T1330Z/
Shelby AL-
812 AM CDT Sun Mar 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 AM CDT
FOR SOUTHEASTERN SHELBY COUNTY...

At 812 AM CDT, severe thunderstorms were located along a line
extending from Childersburg to near Shelby County Airport to Ashby,
moving east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Calera, Montevallo, Columbiana, Wilsonville, Wilton, American
Village, University Of Montevallo, Lay Lake, Shelby, Beeswax Creek
Park, Shelby Shores, Highway 145 and CR 46, Kelley Branch, Spring
Creek and Gaston Steam Plant.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3327 8644 3323 8647 3320 8646 3320 8649
      3319 8650 3317 8650 3313 8646 3309 8651
      3307 8651 3305 8652 3306 8662 3307 8661
      3307 8688 3305 8689 3306 8691 3317 8680
      3329 8638
TIME...MOT...LOC 1312Z 264DEG 36KT 3329 8633 3318 8673 3301 8692 

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

05
273 
WWUS54 KBMX 281320
SVSBMX

Severe Weather Statement
National Weather Service Birmingham AL
820 AM CDT Sun Mar 28 2021

ALC117-281330-
/O.CON.KBMX.SV.W.0036.000000T0000Z-210328T1330Z/
Shelby AL-
820 AM CDT Sun Mar 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 AM CDT
FOR SOUTHEASTERN SHELBY COUNTY...

At 820 AM CDT, severe thunderstorms were located along a line
extending from near Winterboro to near Columbiana to near Brierfield
Ironworks Park, moving east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Calera, Columbiana, Lay Lake, Shelby, Beeswax Creek Park, Shelby
Shores, Highway 145 and CR 46, Spring Creek and Kelley Branch.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3320 8649 3319 8650 3317 8650 3313 8646
      3309 8651 3307 8651 3305 8652 3306 8662
      3307 8661 3307 8688 3316 8670
TIME...MOT...LOC 1320Z 269DEG 36KT 3329 8625 3318 8665 3301 8684 

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

05

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 28, 2:47 AM CDTSevere Thunderstorm WarningBMXMarion43 min
Mar 28, 3:25 AM CDTSpecial Weather StatementBMXWinston35 min
Mar 28, 3:47 AM CDTSevere Thunderstorm WarningBMXFayette, Lamar, Marion58 min
Mar 28, 4:15 AM CDTSpecial Weather StatementBMXWinston45 min
Mar 28, 4:32 AM CDTSevere Thunderstorm WarningBMXFayette, Walker, Winston47 min
Mar 28, 5:17 AM CDTSpecial Weather StatementBMXWalker43 min
Mar 28, 5:46 AM CDTSpecial Weather StatementBMXMarshall29 min
Mar 28, 6:01 AM CDTSpecial Weather StatementBMXTuscaloosa, Walker44 min
Mar 28, 6:13 AM CDTSevere Thunderstorm WarningBMXBlount, Jefferson, Walker62 min
Mar 28, 6:27 AM CDTSpecial Weather StatementBMXJefferson, Tuscaloosa63 min
Mar 28, 6:34 AM CDTSpecial Weather StatementBMXDeKalb26 min
Mar 28, 6:46 AM CDTSpecial Weather StatementBMXBlount, Etowah59 min
Mar 28, 6:59 AM CDTSpecial Weather StatementBMXSt. Clair, Shelby61 min
Mar 28, 7:13 AM CDTSevere Thunderstorm WarningBMXJefferson, St. Clair, Shelby32 min
Mar 28, 7:19 AM CDTSpecial Weather StatementBMXCherokee26 min
Mar 28, 7:37 AM CDTSevere Thunderstorm WarningBMXCalhoun, St. Clair, Talladega38 min
Mar 28, 7:41 AM CDTSpecial Weather StatementBMXBibb, Shelby64 min
Mar 28, 7:45 AM CDTSpecial Weather StatementBMXCherokee30 min
Mar 28, 8:05 AM CDTSpecial Weather StatementBMXClay, Talladega55 min
Mar 28, 8:22 AM CDTSpecial Weather StatementBMXCoosa23 min
Mar 28, 8:23 AM CDTSpecial Weather StatementBMXPerry37 min
Mar 28, 8:38 AM CDTSpecial Weather StatementBMXRandolph37 min
Mar 28, 9:40 AM CDTSpecial Weather StatementBMXClay35 min
Mar 28, 9:44 AM CDTRiver Flood WarningBMXCherokee, Etowah, St. Clair8 days
Mar 28, 10:03 AM CDTSpecial Weather StatementBMXRandolph42 min
Mar 28, 10:33 AM CDTSpecial Weather StatementBMXChambers42 min
Mar 28, 12:38 PM CDTRiver Flood WarningBMXSumter57 hr

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.