Alert archive / Alabama / Special Weather Statements in 2021

Special Weather Statement, NWS Huntsville, AL

August 21, 2021Limestone County, Alabama

NWS Huntsville, AL issued this special weather statement at Aug 21, 2021, 11:38 AM CDT for Limestone County, Alabama. It was in force for 52 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, 11:38 AM CDT (16:38 UTC)
Expired: Aug 21, 2021, 12:30 PM CDT
In force: 52 min
Issued by: NWS Huntsville, AL
Hail: 0.00 in
Wind: 30

County Limestone County, AL

The radar

The Northeast Alabama radar (KHTX), 72 km from the middle of the area, began a volume at 16:41 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, 4.6 hours before the alert went out and 133 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: 1243 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 488 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: -5 m²/s²
0-3 km storm-relative helicity: 41 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 1.9

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Huntsville, AL wrote its last area forecast discussion before this special weather statement went out at Aug 21, 9:57 AM CDT, 1 hour 41 minutes earlier.

Area forecast discussion, Aug 21, 9:57 AM CDT, 1 hour 41 minutes before

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Hazardous weather outlook, Aug 21, 3:34 AM CDT, 8 hours 4 minutes before

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In the hours before

Special weather statement, Aug 21, 11:38 AM CDT, 0 minutes before

Special Weather Statement
National Weather Service Huntsville AL
1138 AM CDT Sat Aug 21 2021

ALZ005-006-TNZ096-211730-
Madison AL-Limestone AL-Lincoln TN-
1138 AM CDT Sat Aug 21 2021

...A strong thunderstorm will impact portions of northwestern
Madison, Limestone and southwestern Lincoln Counties through 1230 PM
CDT...

At 1138 AM CDT, Doppler radar was tracking a band of strong
thunderstorms centered near Ardmore, or 14 miles southeast of
Pulaski, moving southeast at 20 mph.

HAZARD...Winds in excess of 30 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Northern Huntsville, Athens, Meridianville, Ardmore, Harvest, Tanner,
Elkmont, Lester, Cartwright and French Mill.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm and may lead
to very low visibility and localized flooding. Do not drive your
vehicle through flooded roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3483 8655 3469 8705 3499 8721 3500 8721
      3499 8684 3514 8683 3516 8677
TIME...MOT...LOC 1638Z 321DEG 19KT 3501 8693

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...30 MPH

Kula

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 21, 12:19 PM CDT	Special Weather Statement	HUN	Lawrence, Limestone, Madison	41 min
Aug 21, 12:43 PM CDT	Special Weather Statement	HUN	Franklin	47 min
Aug 21, 1:04 PM CDT	Special Weather Statement	HUN	Lawrence, Madison, Morgan	41 min
Aug 21, 1:52 PM CDT	Special Weather Statement	HUN	Cullman, Morgan	38 min
Aug 21, 2:25 PM CDT	Special Weather Statement	HUN	Cullman	50 min
Aug 21, 2:31 PM CDT	Special Weather Statement	HUN	Lawrence	44 min
Aug 21, 3:09 PM CDT	Special Weather Statement	HUN	Cullman	51 min
Aug 21, 3:15 PM CDT	Severe Thunderstorm Warning	HUN	Cullman	30 min
Aug 21, 6:16 PM CDT	Severe Thunderstorm Warning	HUN	Colbert	44 min
Aug 21, 6:24 PM CDT	Tornado Warning	HUN	Colbert	23 min
Aug 21, 6:58 PM CDT	Special Weather Statement	HUN	Franklin	47 min

Nearby

Special Weather Statements in Alabama, 2021 Every special weather statement 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.