Alert archive / Alabama / Flash Flood Warnings in 2009

Flash Flood Warning 65, NWS Huntsville, AL

August 18, 2009Colbert County, Lauderdale County, Alabama

NWS Huntsville, AL issued this flash flood warning at Aug 18, 2009, 8:32 PM CDT for Colbert County, Lauderdale County, Alabama. It was in force for 118 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: Aug 18, 2009, 8:32 PM CDT (01:32 UTC)
Expired: Aug 18, 2009, 10:30 PM CDT
In force: 118 min
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 01:33 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 00:00Z, 1.5 hours before the alert went out and 180 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: 1550 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 714 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 0 m²/s²
0-3 km storm-relative helicity: 19 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.

In the hours before

Special weather statement, Aug 18, 7:49 PM CDT, 43 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 18, 9:41 PM CDT	Flash Flood Warning	HUN	Lauderdale	108 min

Nearby

Flash Flood Warnings in Alabama, 2009 Every flash flood warning in 2009

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.