Alert archive / Alabama / Tornado Warnings in 2021

Tornado Warning 1, NWS Huntsville, AL

March 17, 2021Colbert County, Franklin County, Alabama

NWS Huntsville, AL issued this tornado warning at Mar 17, 2021, 3:40 PM CDT for Colbert County, Franklin County, Alabama. It was in force for 35 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 17, 2021, 3:40 PM CDT (20:40 UTC)
Expired: Mar 17, 2021, 4:15 PM CDT
In force: 35 min
Issued by: NWS Huntsville, AL
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

Counties Colbert County, AL, Franklin County, AL

The radar

The Columbus AFB radar (KGWX), 76 km from the middle of the area, began a volume at 20:39 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
Mar 17, 11:36 AM CDT	Tornado Watch PDS	SPC	7 hr

The nearest sounding before it

Little Rock, AR (KLZK), launched 12:00Z, 8.7 hours before the alert went out and 175 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: 18 J/kg
Mixed-layer CIN: -262 J/kg
Mixed-layer LCL: 1466 m above ground
0-6 km bulk shear: 65 kt
0-1 km storm-relative helicity: 217 m²/s²
0-3 km storm-relative helicity: 186 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

As transmitted.

674 
WFUS54 KHUN 172040
TORHUN
ALC033-059-172115-
/O.NEW.KHUN.TO.W.0001.210317T2040Z-210317T2115Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Huntsville AL
340 PM CDT Wed Mar 17 2021

The National Weather Service in Huntsville Alabama has issued a

* Tornado Warning for...
  Southwestern Colbert County in northwestern Alabama...
  Northwestern Franklin County in northwestern Alabama...

* Until 415 PM CDT.
    
* At 339 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Red Bay, moving east at 25 mph.

  HAZARD...Tornado and quarter size hail.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* Locations impacted include...
  Red Bay, Pleasant Site, Pogo, Dempsey, Little Bear Creek Reservoir,
  Halltown and Cedar Creek Reservoir.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 3461 8814 3467 8797 3443 8791 3440 8816
TIME...MOT...LOC 2039Z 256DEG 21KT 3445 8820 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

25

1 follow-up statement

712 
WWUS54 KHUN 172111
SVSHUN

Severe Weather Statement
National Weather Service Huntsville AL
411 PM CDT Wed Mar 17 2021

ALC033-059-172121-
/O.EXP.KHUN.TO.W.0001.000000T0000Z-210317T2115Z/
Colbert AL-Franklin AL-
411 PM CDT Wed Mar 17 2021

...THE TORNADO WARNING FOR SOUTHWESTERN COLBERT AND NORTHWESTERN
FRANKLIN COUNTIES WILL EXPIRE AT 415 PM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

A Tornado Watch remains in effect until 700 PM CDT for northwestern
Alabama.

LAT...LON 3461 8814 3467 8797 3443 8791 3440 8816
TIME...MOT...LOC 2111Z 256DEG 21KT 3449 8799 

$$

25

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 17, 1:24 AM CDT	Dense Fog Advisory	HUN	Cullman, DeKalb, Jackson, Marshall	7 hr
Mar 17, 7:25 AM CDT	Special Weather Statement	HUN	Morgan	50 min
Mar 17, 7:57 AM CDT	Special Weather Statement	HUN	Madison	48 min
Mar 17, 7:59 AM CDT	Special Weather Statement	HUN	Colbert	46 min
Mar 17, 9:52 AM CDT	Special Weather Statement	HUN	Jackson	23 min
Mar 17, 4:07 PM CDT	Severe Thunderstorm Warning	HUN	Colbert, Franklin, Lauderdale	26 min
Mar 17, 4:17 PM CDT	Flash Flood Watch	HUN	Colbert, Cullman, DeKalb, Franklin, Jackson, Lauderdale and 5 more	8 hr
Mar 17, 4:44 PM CDT	Flash Flood Warning	HUN	Cullman, Morgan	5 hr
Mar 17, 5:24 PM CDT	Areal Flood Warning	HUN	Colbert, Franklin, Lauderdale	9 hr
Mar 17, 5:49 PM CDT	Areal Flood Warning	HUN	Cullman	8 hr
Mar 17, 6:05 PM CDT	Severe Thunderstorm Warning	HUN	Marshall	22 min
Mar 17, 6:44 PM CDT	Tornado Warning	HUN	Cullman	31 min

Nearby

Tornado Warnings in Alabama, 2021 Every tornado warning in 2021 Tornadoes 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.