Alert archive / Alabama / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 41, NWS Huntsville, AL

April 14, 2018Cullman County, Alabama

NWS Huntsville, AL issued this severe thunderstorm warning at Apr 14, 2018, 1:21 PM CDT for Cullman County, Alabama. It was in force for 24 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Apr 14, 2018, 1:21 PM CDT (18:21 UTC)
Expired: Apr 14, 2018, 1:45 PM CDT
In force: 24 min
Issued by: NWS Huntsville, AL
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

County Cullman County, AL

The radar

The Birmingham radar (KBMX), 107 km from the middle of the area, began a volume at 18:24 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

Birmingham, AL (KBMX), launched 12:00Z, 6.4 hours before the alert went out and 106 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: 224 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 560 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 275 m²/s²
0-3 km storm-relative helicity: 324 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 3.7

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning 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 severe thunderstorm warning went out at Apr 14, 12:35 PM CDT, 46 minutes earlier.

Area forecast discussion, Apr 14, 12:35 PM CDT, 46 minutes before

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Hazardous weather outlook, Apr 14, 3:15 AM CDT, 10 hours 6 minutes before

Hazardous Weather Outlook
National Weather Service Huntsville AL
315 AM CDT Sat Apr 14 2018

ALZ001>010-016-TNZ076-096-097-150000-
Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan-
Marshall-Jackson-De Kalb-Cullman-Moore-Lincoln-Franklin TN-
315 AM CDT Sat Apr 14 2018

This Hazardous Weather Outlook is for north Alabama and portions of
southern middle Tennessee.

.DAY ONE...Today and Tonight...

Strong to marginally severe thunderstorms will approach northwest
Alabama this morning and increase in coverage through the day
as a cold front approaches. The highest chance of severe storms
would be early this afternoon through tonight. The primary threats
will be damaging winds up to 60 MPH and heavy rainfall of 2 to 4
inches.

The heavy rainfall could result in isolated flash flooding along with
a few rivers and streams rising to near or slightly above flood
stage. A Flash Flood watch is in effect for parts of Northwest
Alabama and refer to it for more details.

There is also a lower threat for brief tornadoes and large hail up
to the size of quarters, mainly Saturday afternoon and evening.

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

Isolated to scattered thunderstorms may linger east of Interstate 65
for the first part of Sunday.

.SPOTTER CALL TO ACTION STATEMENT...

Activation of storm spotters and emergency management personnel is
likely Saturday and Saturday night.

In the hours before

Special weather statement, Apr 14, 9:04 AM CDT, 4 hours 17 minutes before

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Special weather statement, Apr 14, 9:26 AM CDT, 3 hours 55 minutes before

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Special weather statement, Apr 14, 9:46 AM CDT, 3 hours 35 minutes before

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Special weather statement, Apr 14, 10:35 AM CDT, 2 hours 46 minutes before

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Local storm report, Apr 14, 11:17 AM CDT, 2 hours 4 minutes before

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Special weather statement, Apr 14, 1:05 PM CDT, 16 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 14, 6:30 AM CDT	Severe Thunderstorm Warning	HUN	Colbert, Franklin, Lauderdale	60 min
Apr 14, 7:12 AM CDT	Severe Thunderstorm Warning	HUN	Colbert, Franklin, Lauderdale	48 min
Apr 14, 7:45 AM CDT	Special Weather Statement	HUN	Lawrence	60 min
Apr 14, 8:32 AM CDT	Severe Thunderstorm Warning	HUN	Lawrence, Limestone, Morgan	28 min
Apr 14, 9:04 AM CDT	Special Weather Statement	HUN	Madison, Morgan	41 min
Apr 14, 9:46 AM CDT	Special Weather Statement	HUN	Madison	29 min
Apr 14, 10:35 AM CDT	Special Weather Statement	HUN	Jackson	25 min
Apr 14, 1:05 PM CDT	Special Weather Statement	HUN	Cullman	55 min
Apr 14, 1:57 PM CDT	Special Weather Statement	HUN	Cullman	48 min
Apr 14, 2:24 PM CDT	Special Weather Statement	HUN	Jackson	51 min
Apr 14, 2:26 PM CDT	Special Weather Statement	HUN	Marshall	49 min
Apr 14, 5:05 PM CDT	Special Weather Statement	HUN	DeKalb	25 min
Apr 14, 5:31 PM CDT	Special Weather Statement	HUN	DeKalb	29 min
Apr 14, 8:55 AM CDT	Special Weather Statement	HUN	Lincoln	35 min
Apr 14, 9:26 AM CDT	Special Weather Statement	HUN	Franklin, Moore	49 min

Nearby

Severe Thunderstorm Warnings in Alabama, 2018 Every severe thunderstorm warning in 2018

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.