Alert archive / Alabama / Areal Flood Warnings in 2009
Areal Flood Warning 21, NWS Huntsville, AL
NWS Huntsville, AL issued this areal flood warning at Sep 21, 2009, 4:59 PM CDT for DeKalb County, Alabama. It was in force for 6 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
- Sep 21, 2009, 4:59 PM CDT (21:59 UTC)
- Expired
- Sep 21, 2009, 11:00 PM CDT
- In force
- 6 hr
- Issued by
- NWS Huntsville, AL
- Area
- Storm-based polygon
- Flood severity
- None
County DeKalb County, AL
The radar
The Northeast Alabama radar (KHTX), 58 km from the middle of the area, began a volume at 22:01 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, 10.0 hours before the alert went out and 168 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.
- Mixed-layer CAPE
- 1524 J/kg
- Mixed-layer CIN
- -8 J/kg
- Mixed-layer LCL
- 500 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 75 m²/s²
- 0-3 km storm-relative helicity
- 93 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.4
What forecasters said that day
The local office's own words before this areal 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 areal flood warning went out at Sep 21, 3:44 PM CDT, 1 hour 15 minutes earlier.
Area forecast discussion, Sep 21, 3:44 PM CDT, 1 hour 15 minutes before
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</html>Hazardous weather outlook, Sep 21, 1:00 PM CDT, 3 hours 59 minutes before
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Special weather statement, Sep 21, 11:14 AM CDT, 5 hours 45 minutes before
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</html>Local storm report, Sep 21, 12:20 PM CDT, 4 hours 39 minutes before
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<div class="status" id="status">Temporary Notice</div>
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Please try again in a few minutes.
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</html>The office that day
Everything else NWS Huntsville, AL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 20, 8:09 PM CDT | Flash Flood Warning | HUN | Madison | 3 hr |
| Sep 21, 11:32 AM CDT | Areal Flood Warning | HUN | DeKalb | 4 hr |
| Sep 21, 4:46 PM CDT | Flash Flood Warning | HUN | DeKalb | 112 min |
Nearby
Areal Flood Warnings in Alabama, 2009Every areal 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.