Alert archive / Alabama / Flash Flood Warnings in 2020

Flash Flood Warning 22, NWS Huntsville, AL

August 30, 2020Colbert County, Lauderdale County, Alabama

NWS Huntsville, AL issued this flash flood warning at Aug 30, 2020, 4:58 PM CDT for Colbert County, Lauderdale County, Alabama. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Aug 30, 2020, 4:58 PM CDT (21:58 UTC)
Expired: Aug 30, 2020, 7:44 PM CDT
In force: 3 hr
Issued by: NWS Huntsville, AL
Area: Storm-based polygon
Flood severity: None

Counties Colbert County, AL, Lauderdale County, AL

The radar

The Columbus AFB radar (KGWX), 115 km from the middle of the area, began a volume at 22:02 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

Little Rock, AR (KLZK), launched 12:00Z, 10.0 hours before the alert went out and 203 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: 3 J/kg
Mixed-layer CIN: -385 J/kg
Mixed-layer LCL: 1139 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: 62 m²/s²
0-3 km storm-relative helicity: -18 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood 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 flash flood warning went out at Aug 30, 2:36 PM CDT, 2 hours 22 minutes earlier.

Area forecast discussion, Aug 30, 2:36 PM CDT, 2 hours 22 minutes before

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Hazardous weather outlook, Aug 30, 12:13 PM CDT, 4 hours 45 minutes before

Hazardous Weather Outlook
National Weather Service Huntsville AL
1213 PM CDT Sun Aug 30 2020

ALZ001>010-016-TNZ076-096-097-311100-
Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan-
Marshall-Jackson-DeKalb-Cullman-Moore-Lincoln-Franklin TN-
1213 PM CDT Sun Aug 30 2020

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

.DAY ONE...This afternoon and tonight.

Thunderstorms will become numerous across the area this afternoon and
evening, with gusty winds and heavy rainfall possible. Localized
flooding could result from slow moving storms or storms that
repeatedly move across the same area.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Thunderstorms will be possible on Monday and Tuesday, with gusty
winds and heavy rainfall possible. Lesser coverage of storms is
expected Wednesday through Saturday, with isolated thunderstorms
possible each day during this time.

.SPOTTER INFORMATION STATEMENT...

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

12

In the hours before

Special weather statement, Aug 30, 3:29 PM CDT, 1 hour 29 minutes before

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Special weather statement, Aug 30, 3:49 PM CDT, 1 hour 9 minutes before

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Special weather statement, Aug 30, 4:05 PM CDT, 53 minutes before

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Special weather statement, Aug 30, 4:28 PM CDT, 30 minutes before

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Special weather statement, Aug 30, 4:32 PM CDT, 26 minutes before

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Special weather statement, Aug 30, 4:42 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
Aug 30, 2:19 PM CDT	Special Weather Statement	HUN	Madison	41 min
Aug 30, 2:31 PM CDT	Special Weather Statement	HUN	DeKalb	14 min
Aug 30, 2:50 PM CDT	Special Weather Statement	HUN	DeKalb	25 min
Aug 30, 2:55 PM CDT	Special Weather Statement	HUN	Lauderdale	50 min
Aug 30, 3:07 PM CDT	Special Weather Statement	HUN	Jackson	38 min
Aug 30, 3:18 PM CDT	Special Weather Statement	HUN	DeKalb	27 min
Aug 30, 3:44 PM CDT	Severe Thunderstorm Warning	HUN	Lauderdale, Limestone	31 min
Aug 30, 3:49 PM CDT	Special Weather Statement	HUN	Morgan	26 min
Aug 30, 4:05 PM CDT	Special Weather Statement	HUN	Morgan	40 min
Aug 30, 4:28 PM CDT	Special Weather Statement	HUN	Franklin	32 min
Aug 30, 4:32 PM CDT	Special Weather Statement	HUN	Jackson	43 min
Aug 30, 4:42 PM CDT	Special Weather Statement	HUN	Colbert, Lauderdale	48 min
Aug 30, 4:47 PM CDT	Severe Thunderstorm Warning	HUN	Jackson	28 min
Aug 30, 5:11 PM CDT	Special Weather Statement	HUN	Lauderdale, Lawrence	49 min
Aug 30, 5:32 PM CDT	Flash Flood Warning	HUN	Cullman, Lawrence, Morgan	83 min
Aug 30, 6:55 PM CDT	Areal Flood Warning	HUN	Cullman, Lawrence, Morgan	98 min
Aug 30, 3:31 AM CDT	Special Weather Statement	HUN	Lincoln, Moore	44 min
Aug 30, 5:59 PM CDT	Special Weather Statement	HUN	Franklin, Moore	31 min
Aug 30, 6:32 PM CDT	Special Weather Statement	HUN	Moore	43 min
Aug 30, 6:35 PM CDT	Special Weather Statement	HUN	Franklin	40 min

Nearby

Flash Flood Warnings in Alabama, 2020 Every flash flood warning in 2020

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.