Alert archive / Alabama / Flash Flood Watches in 2009

Flash Flood Watch 12, NWS Birmingham, AL

July 29, 20096 counties in Alabama

NWS Birmingham, AL issued this flash flood watch at Jul 29, 2009, 12:59 AM CDT for 6 counties in Alabama. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued: Jul 29, 2009, 12:59 AM CDT (05:59 UTC)
Expired: Jul 29, 2009, 7:00 AM CDT
In force: 6 hr
Issued by: NWS Birmingham, AL
Flood severity: None

Counties Bibb County, AL, Greene County, AL, Hale County, AL, Pickens County, AL, Sumter County, AL, Tuscaloosa County, AL

The radar

The Birmingham radar (KBMX), 95 km from the middle of the area, began a volume at 06:00 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

Jackson, MS (KJAN), launched 00:00Z, 6.0 hours before the alert went out and 229 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: 358 J/kg
Mixed-layer CIN: -87 J/kg
Mixed-layer LCL: 1105 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 101 m²/s²
0-3 km storm-relative helicity: 148 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.1

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Birmingham, AL wrote its last area forecast discussion before this flash flood watch went out at Jul 28, 11:48 PM CDT, 1 hour 11 minutes earlier.

Area forecast discussion, Jul 28, 11:48 PM CDT, 1 hour 11 minutes before

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Hazardous weather outlook, Jul 28, 7:43 PM CDT, 5 hours 16 minutes before

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        The site you requested is temporarily down for maintenance or an unexpected outage.
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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 29, 4:57 AM CDT	Areal Flood Advisory	BMX	Greene, Hale, Sumter	3 hr
Jul 29, 8:59 AM CDT	Areal Flood Advisory	BMX	Lowndes, Montgomery	3 hr
Jul 29, 9:01 AM CDT	Flash Flood Watch	BMX	Autauga, Barbour, Bibb, Bullock, Chambers, Chilton and 15 more	4 hr

Nearby

Flash Flood Watches in Alabama, 2009 Every flash flood watch 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.