Alert archive / Alabama / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 96, NWS Huntsville, AL

December 11, 2021Colbert County, Franklin County, Alabama

NWS Huntsville, AL issued this severe thunderstorm warning at Dec 11, 2021, 4:29 AM CST for Colbert County, Franklin County, Alabama. It was in force for 31 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: Dec 11, 2021, 4:29 AM CST (10:29 UTC)
Expired: Dec 11, 2021, 5:00 AM CST
In force: 31 min
Issued by: NWS Huntsville, AL
Area: Storm-based polygon
Tornado: Possible
Damage threat: Considerable
Hail: 0.75 in
Wind: 70.0 mph

Counties Colbert County, AL, Franklin County, AL

The radar

The Columbus AFB radar (KGWX), 96 km from the middle of the area, began a volume at 10:30 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.

Issued	Product	Office	Lasted
Dec 11, 3:41 AM CST	Tornado Watch	SPC	6 hr

The nearest sounding before it

Little Rock, AR (KLZK), launched 00:00Z, 10.5 hours before the alert went out and 174 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: 1725 J/kg
Mixed-layer CIN: -13 J/kg
Mixed-layer LCL: 759 m above ground
0-6 km bulk shear: 78 kt
0-1 km storm-relative helicity: 398 m²/s²
0-3 km storm-relative helicity: 420 m²/s²
Significant tornado parameter: 4.8
Supercell composite: 16.2

Open this sounding in Storm Lab

The text

As transmitted.

006 
WUUS54 KHUN 111029
SVRHUN
ALC033-059-111100-
/O.NEW.KHUN.SV.W.0096.211211T1029Z-211211T1100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Huntsville AL
429 AM CST Sat Dec 11 2021

The National Weather Service in Huntsville Alabama has issued a

* Severe Thunderstorm Warning for...
  Western Colbert County in northwestern Alabama...
  Northwestern Franklin County in northwestern Alabama...

* Until 500 AM CST.

* At 429 AM CST, severe thunderstorms were located along a line
  extending from near Midway to 6 miles east of Wheeler to near
  Guntown, moving northeast at 60 mph.

  HAZARD...70 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings.

* Locations impacted include...
  Red Bay, Cherokee, Pleasant Site, Malone, Pogo, Mynot, Mt Hester,
  Margerum, Maud and Allsboro.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

A Tornado Watch remains in effect until 1100 AM CST for northwestern
Alabama.

&&

LAT...LON 3485 8811 3489 8798 3486 8794 3480 8792
      3443 8811 3443 8816
TIME...MOT...LOC 1029Z 238DEG 51KT 3474 8829 3457 8848 3447 8869 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

KTW

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 11, 4:40 AM CST	Tornado Warning	HUN	Colbert, Franklin	22 min
Dec 11, 4:59 AM CST	Severe Thunderstorm Warning Considerable damage threat	HUN	Colbert, Franklin, Lauderdale	31 min
Dec 11, 5:27 AM CST	Severe Thunderstorm Warning Considerable damage threat	HUN	Colbert, Franklin, Lauderdale	33 min
Dec 11, 5:50 AM CST	Severe Thunderstorm Warning	HUN	Colbert, Franklin, Lauderdale, Lawrence, Limestone, Morgan	40 min
Dec 11, 6:31 AM CST	Special Weather Statement	HUN	Lawrence, Limestone, Madison, Morgan	29 min
Dec 11, 6:41 AM CST	Severe Thunderstorm Warning	HUN	Madison	34 min
Dec 11, 7:01 AM CST	Special Weather Statement	HUN	Madison, Morgan	44 min
Dec 11, 7:06 AM CST	Severe Thunderstorm Warning	HUN	Cullman, Jackson, Lawrence, Limestone, Madison, Morgan	24 min
Dec 11, 7:31 AM CST	Severe Thunderstorm Warning	HUN	Cullman, Jackson, Limestone, Madison, Marshall, Morgan	29 min
Dec 11, 7:57 AM CST	Special Weather Statement	HUN	Cullman, Jackson, Marshall, Morgan	48 min
Dec 11, 9:12 AM CST	Special Weather Statement	HUN	DeKalb	33 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.