Alert archive / Alabama / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 81, NWS Huntsville, AL

August 21, 2021Cullman County, Alabama

NWS Huntsville, AL issued this severe thunderstorm warning at Aug 21, 2021, 3:15 PM CDT for Cullman County, Alabama. It was in force for 30 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
Aug 21, 2021, 3:15 PM CDT (20:15 UTC)
Expired
Aug 21, 2021, 3:45 PM CDT
In force
30 min
Issued by
NWS Huntsville, AL
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County Cullman County, AL

The radar

The Birmingham radar (KBMX), 90 km from the middle of the area, began a volume at 20:15 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 nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 8.3 hours before the alert went out and 89 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.

638 
WUUS54 KHUN 212015
SVRHUN
ALC043-212045-
/O.NEW.KHUN.SV.W.0081.210821T2015Z-210821T2045Z/

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

The National Weather Service in Huntsville Alabama has issued a

* Severe Thunderstorm Warning for...
  Southwestern Cullman County in north central Alabama...

* Until 345 PM CDT.

* At 315 PM CDT, a severe thunderstorm was located near Smith Dam, or
  12 miles southeast of Arley, moving east at 35 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Hanceville, Dodge City, Garden City, Colony, Wilburn, Bremen,
  Arkadelphia, Black Bottom and Smith Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3390 8710 3391 8708 3395 8711 3405 8710
      3408 8670 3408 8669 3407 8670 3406 8668
      3406 8671 3403 8670 3395 8679 3396 8682
      3394 8682 3395 8684 3393 8686 3394 8688
      3392 8689 3391 8692 3387 8692
TIME...MOT...LOC 2015Z 270DEG 29KT 3398 8703 

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

$$

Kula
2 follow-up statements
377 
WWUS54 KHUN 212035
SVSHUN

Severe Weather Statement
National Weather Service Huntsville AL
335 PM CDT Sat Aug 21 2021

ALC043-212045-
/O.CON.KHUN.SV.W.0081.000000T0000Z-210821T2045Z/
Cullman AL-
335 PM CDT Sat Aug 21 2021

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

At 335 PM CDT, a severe thunderstorm was located near Blount Springs,
or 15 miles northeast of Sumiton, moving east at 30 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Hanceville, Dodge City, Garden City, Colony, Wilburn, Bremen,
Arkadelphia, Black Bottom and Smith Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3390 8710 3391 8708 3395 8711 3405 8710
      3408 8670 3408 8669 3407 8670 3406 8668
      3406 8671 3403 8670 3395 8679 3396 8682
      3394 8682 3395 8684 3393 8686 3394 8688
      3392 8689 3391 8692 3387 8692
TIME...MOT...LOC 2035Z 275DEG 26KT 3394 8688 

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

$$

Kula
103 
WWUS54 KHUN 212043
SVSHUN

Severe Weather Statement
National Weather Service Huntsville AL
343 PM CDT Sat Aug 21 2021

ALC043-212053-
/O.EXP.KHUN.SV.W.0081.000000T0000Z-210821T2045Z/
Cullman AL-
343 PM CDT Sat Aug 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN CULLMAN COUNTY
WILL EXPIRE AT 345 PM CDT...
                
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 will be allowed to expire.  However heavy rain
is still possible with this thunderstorm.

LAT...LON 3390 8710 3391 8708 3395 8711 3405 8710
      3408 8670 3408 8669 3407 8670 3406 8668
      3406 8671 3403 8670 3395 8679 3396 8682
      3394 8682 3395 8684 3393 8686 3394 8688
      3392 8689 3391 8692 3387 8692
TIME...MOT...LOC 2043Z 270DEG 29KT 3394 8681 

$$

Kula

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 11:38 AM CDTSpecial Weather StatementHUNLimestone52 min
Aug 21, 12:19 PM CDTSpecial Weather StatementHUNLawrence, Limestone, Madison41 min
Aug 21, 12:43 PM CDTSpecial Weather StatementHUNFranklin47 min
Aug 21, 1:04 PM CDTSpecial Weather StatementHUNLawrence, Madison, Morgan41 min
Aug 21, 1:52 PM CDTSpecial Weather StatementHUNCullman, Morgan38 min
Aug 21, 2:25 PM CDTSpecial Weather StatementHUNCullman50 min
Aug 21, 2:31 PM CDTSpecial Weather StatementHUNLawrence44 min
Aug 21, 3:09 PM CDTSpecial Weather StatementHUNCullman51 min
Aug 21, 6:16 PM CDTSevere Thunderstorm WarningHUNColbert44 min
Aug 21, 6:24 PM CDTTornado WarningHUNColbert23 min
Aug 21, 6:58 PM CDTSpecial Weather StatementHUNFranklin47 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.