Alert archive / Alabama / Special Weather Statements in 2021

Special Weather Statement, NWS Huntsville, AL

August 21, 2021Lawrence County, Limestone County, Madison County, Alabama

NWS Huntsville, AL issued this special weather statement at Aug 21, 2021, 12:19 PM CDT for Lawrence County, Limestone County, Madison County, Alabama. It was in force for 41 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, 12:19 PM CDT (17:19 UTC)
Expired
Aug 21, 2021, 1:00 PM CDT
In force
41 min
Issued by
NWS Huntsville, AL
Hail
0.00 in
Wind
30

Counties Lawrence County, AL, Limestone County, AL, Madison County, AL

The radar

The Northeast Alabama radar (KHTX), 86 km from the middle of the area, began a volume at 17:22 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, 5.3 hours before the alert went out and 162 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 2021-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1243 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Nashville Metro, TN at 12:00Z on 2021-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 square meters per square second.193958Sfc1 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
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, 2 hours 22 minutes earlier.

Area forecast discussion, Aug 21, 9:57 AM CDT, 2 hours 22 minutes before
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<body>
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    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
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        The site you requested is temporarily down for maintenance or an unexpected outage.
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        Please try again in a few minutes.
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Hazardous weather outlook, Aug 21, 11:51 AM CDT, 28 minutes before
Hazardous Weather Outlook
National Weather Service Huntsville AL
1151 AM CDT Sat Aug 21 2021

ALZ001>010-016-TNZ076-096-097-220800-
Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan-
Marshall-Jackson-DeKalb-Cullman-Moore-Lincoln-Franklin TN-
1151 AM CDT Sat Aug 21 2021

This Hazardous Weather Outlook is for north central Alabama,
northeast Alabama, northwest Alabama and southern middle Tennessee.

.DAY ONE...This afternoon and tonight.

Showers and thunderstorms will continue on and off through this
afternoon and evening. The main hazard will be localized flash
flooding, but damaging winds will also be possible with stronger
storms.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Isolated to scattered thunderstorms are forecast Sunday. Additional
chances for afternoon and evening showers and thunderstorms will
return Wednesday through Friday.

Temperatures will increase early next week with humidity remaining
elevated. This combination will lead to maximum heat index values of
around 100 degrees, especially along and west of Interstate 65.

.SPOTTER INFORMATION STATEMENT...

Activation of storm spotters and emergency management personnel is
not anticipated at this time.

In the hours before

Special weather statement, Aug 21, 11:38 AM CDT, 41 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
Special weather statement, Aug 21, 12:19 PM CDT, 0 minutes before
Special Weather Statement
National Weather Service Huntsville AL
1219 PM CDT Sat Aug 21 2021

ALZ001-002-004>007-211800-
Lawrence AL-Madison AL-Lauderdale AL-Morgan AL-Limestone AL-
Colbert AL-
1219 PM CDT Sat Aug 21 2021

...Strong thunderstorms will impact portions of western Madison,
eastern Lauderdale, Limestone, southeastern Colbert, northern Morgan
and northern Lawrence Counties through 100 PM CDT...

At 1218 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Killen to Rogersville to near Harvest.
Movement was south 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...
Huntsville, Decatur, Madison, Athens, Moulton, Meridianville,
Redstone Arsenal, Moores Mill, Hazel Green and Priceville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

If on or near Wheeler Lake, get out of the water and move indoors or
inside a vehicle. Remember, lightning can strike out to 10 miles
from the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not
be caught on the water in a thunderstorm.

&&

LAT...LON 3456 8636 3446 8714 3457 8752 3496 8760
      3487 8731 3497 8661
TIME...MOT...LOC 1718Z 341DEG 19KT 3489 8750 3482 8729 3490 8668

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.

IssuedProductOfficeCountiesLasted
Aug 21, 11:38 AM CDTSpecial Weather StatementHUNLimestone52 min
Aug 21, 12:43 PM CDTSpecial Weather StatementHUNFranklin47 min
Aug 21, 1:04 PM CDTSpecial Weather StatementHUNLawrence, Madison, Morgan41 min
Aug 21, 1:52 PM CDTSpecial Weather StatementHUNCullman, Morgan38 min
Aug 21, 2:25 PM CDTSpecial Weather StatementHUNCullman50 min
Aug 21, 2:31 PM CDTSpecial Weather StatementHUNLawrence44 min
Aug 21, 3:09 PM CDTSpecial Weather StatementHUNCullman51 min
Aug 21, 3:15 PM CDTSevere Thunderstorm WarningHUNCullman30 min
Aug 21, 6:16 PM CDTSevere Thunderstorm WarningHUNColbert44 min
Aug 21, 6:24 PM CDTTornado WarningHUNColbert23 min
Aug 21, 6:58 PM CDTSpecial Weather StatementHUNFranklin47 min

Nearby

Special Weather Statements in Alabama, 2021Every 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.