Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 79, NWS Huntsville, AL

August 11, 2021Jackson County, Madison County, Alabama; Franklin County, Lincoln County, Moore County, Tennessee

NWS Huntsville, AL issued this severe thunderstorm warning at Aug 11, 2021, 5:38 PM CDT for Jackson County, Madison County, Alabama; Franklin County, Lincoln County, Moore County, Tennessee. It was in force for 25 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 11, 2021, 5:38 PM CDT (22:38 UTC)
Expired
Aug 11, 2021, 6:03 PM CDT
In force
25 min
Issued by
NWS Huntsville, AL
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

Counties Jackson County, AL, Madison County, AL, Franklin County, TN, Lincoln County, TN, Moore County, TN

The radar

The Northeast Alabama radar (KHTX), 18 km from the middle of the area, began a volume at 22:38 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

Nashville Metro, TN (KBNA), launched 12:00Z, 10.6 hours before the alert went out and 134 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, Nashville Metro, TN at 12:00Z on 2021-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2131 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, Nashville Metro, TN at 12:00Z on 2021-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -18 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
2131 J/kg
Mixed-layer CIN
-37 J/kg
Mixed-layer LCL
942 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
-18 m²/s²
0-3 km storm-relative helicity
29 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

120 
WUUS54 KHUN 112238
SVRHUN
ALC071-089-TNC051-103-127-112330-
/O.NEW.KHUN.SV.W.0079.210811T2238Z-210811T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Huntsville AL
538 PM CDT Wed Aug 11 2021

The National Weather Service in Huntsville Alabama has issued a

* Severe Thunderstorm Warning for...
  Northwestern Jackson County in northeastern Alabama...
  Northeastern Madison County in north central Alabama...
  Southeastern Moore County in Middle Tennessee...
  Southeastern Lincoln County in Middle Tennessee...
  Southwestern Franklin County in Middle Tennessee...

* Until 630 PM CDT.

* At 537 PM CDT, a line of severe thunderstorms was located over New 
  Market extending to near Flintville, moving northeast at 5 mph.

  HAZARD...60 mph wind gusts and nickel size hail.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Huntland, New Market, Tims Ford Lake, Lexie Crossroads, Plevna,
  Harmony, Elora, Hurdlow, Marble Hill and Smithland.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

&&

LAT...LON 3525 8623 3500 8622 3498 8621 3496 8621
      3492 8622 3491 8622 3489 8624 3487 8623
      3485 8626 3482 8629 3481 8635 3480 8639
      3488 8645 3517 8647
TIME...MOT...LOC 2237Z 223DEG 6KT 3490 8639 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

KTW
1 follow-up statement
877 
WWUS54 KHUN 112303
SVSHUN

Severe Weather Statement
National Weather Service Huntsville AL
603 PM CDT Wed Aug 11 2021

ALC071-089-TNC051-103-127-112313-
/O.CAN.KHUN.SV.W.0079.000000T0000Z-210811T2330Z/
Jackson AL-Madison AL-Moore TN-Lincoln TN-Franklin TN-
603 PM CDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN JACKSON...
NORTHEASTERN MADISON...SOUTHEASTERN MOORE...SOUTHEASTERN LINCOLN AND
SOUTHWESTERN FRANKLIN 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.  However gusty winds and
heavy rain are still possible with this thunderstorm.

LAT...LON 3525 8623 3500 8622 3498 8621 3496 8621
      3492 8622 3491 8622 3489 8624 3487 8623
      3485 8626 3482 8629 3481 8635 3480 8639
      3488 8645 3517 8647
TIME...MOT...LOC 2301Z 223DEG 6KT 3493 8635 

$$

KTW

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 3:05 PM CDTSpecial Weather StatementHUNJackson40 min
Aug 11, 3:21 PM CDTSpecial Weather StatementHUNMadison24 min
Aug 11, 3:32 PM CDTSpecial Weather StatementHUNDeKalb28 min
Aug 11, 3:47 PM CDTSpecial Weather StatementHUNMarshall28 min
Aug 11, 3:55 PM CDTSpecial Weather StatementHUNJackson35 min
Aug 11, 4:01 PM CDTSevere Thunderstorm WarningHUNJackson29 min
Aug 11, 4:07 PM CDTSpecial Weather StatementHUNLawrence38 min
Aug 11, 4:22 PM CDTSevere Thunderstorm WarningHUNFranklin, Lawrence23 min
Aug 11, 4:35 PM CDTSpecial Weather StatementHUNMorgan40 min
Aug 11, 4:43 PM CDTSpecial Weather StatementHUNMadison47 min
Aug 11, 5:09 PM CDTSpecial Weather StatementHUNMadison, Morgan21 min
Aug 11, 5:17 PM CDTSpecial Weather StatementHUNJackson28 min
Aug 11, 5:21 PM CDTSevere Thunderstorm WarningHUNJackson24 min
Aug 11, 5:46 PM CDTSpecial Weather StatementHUNJackson29 min
Aug 11, 6:17 PM CDTFlash Flood WarningHUNJackson, Madison, Marshall, Morgan79 min

Nearby

Severe Thunderstorm Warnings in Tennessee, 2021Severe 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.