Alert archive / Alabama / Tornado Warnings in 2021

Tornado Warning 7, NWS Huntsville, AL

August 18, 2021Limestone County, Alabama

NWS Huntsville, AL issued this tornado warning at Aug 18, 2021, 6:36 PM CDT for Limestone County, Alabama. It was in force for 24 min. 4 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 18, 2021, 6:36 PM CDT (23:36 UTC)
Expired: Aug 18, 2021, 7:00 PM CDT
In force: 24 min
Issued by: NWS Huntsville, AL
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.0 in

County Limestone County, AL

The radar

The Northeast Alabama radar (KHTX), 91 km from the middle of the area, began a volume at 23:37 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.

What was reported inside it

Time	Report	Where	Remark
Aug 18, 6:45 PM CDT	TSTM WND DMG	2 Nw Athens, AL	CORRECTS PREVIOUS TSTM WND DMG REPORT FROM 2 NW ATHENS. TREES FELL INTO POWERLINES ALONG MARKET ST, BETWEEN SHANNON ST AND HINE ST. TIME ESTIMATED FROM RADAR. POSSIBLE TORNADO.
Aug 18, 6:45 PM CDT	TSTM WND DMG	2 Nw Athens, AL	TREES FELL INTO POWERLINES ALONG MARKET ST, BETWEEN SHANNON ST AND HINE ST. TIME ESTIMATED FROM RADAR.
Aug 18, 6:51 PM CDT	TORNADO	2 N Athens, AL	TORNADO SPOTTED MOVING AWAY FROM OBSERVERS, WHO WERE LOCATED ALONG US HWY 31 IN TANNER.
Aug 18, 7:00 PM CDT	TSTM WND DMG	1 Nne Athens, AL	DELAYED REPORT. TREE DOWN ACROSS CRESTVIEW ST. TIME ESTIMATED ON BY RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 11.6 hours before the alert went out and 149 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: 259 J/kg
Mixed-layer CIN: -49 J/kg
Mixed-layer LCL: 919 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 70 m²/s²
0-3 km storm-relative helicity: 72 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

647 
WFUS54 KHUN 182336
TORHUN
ALC083-190000-
/O.NEW.KHUN.TO.W.0007.210818T2336Z-210819T0000Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Huntsville AL
636 PM CDT Wed Aug 18 2021

The National Weather Service in Huntsville Alabama has issued a

* Tornado Warning for...
  Northern Limestone County in north central Alabama...

* Until 700 PM CDT
    
* At 636 PM CDT, a severe thunderstorm capable of producing a tornado
  was located 8 miles northwest of Athens, moving east at 30 mph.

  HAZARD...Tornado. 

  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. 

* This dangerous storm will be near...
  Athens around 650 PM CDT. 

Other locations impacted by this tornadic thunderstorm include Cairo,
Cartwright and Elkmont.

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 3483 8721 3492 8720 3493 8688 3472 8690
TIME...MOT...LOC 2336Z 276DEG 24KT 3486 8711 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...0.00 IN

$$

09

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 18, 4:51 PM CDT	Special Weather Statement	HUN	Colbert	39 min
Aug 18, 5:46 PM CDT	Areal Flood Warning	HUN	Colbert, Lauderdale	89 min
Aug 18, 6:09 PM CDT	Areal Flood Warning	HUN	Colbert, Lauderdale	96 min
Aug 18, 6:47 PM CDT	Tornado Warning Tornado observed	HUN	Limestone	28 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.