Alert archive / Alabama / Flash Flood Watches in 2020

Flash Flood Watch 8, NWS Birmingham, AL

April 12, 20208 counties in Alabama

NWS Birmingham, AL issued this flash flood watch at Apr 12, 2020, 3:07 AM CDT for 8 counties in Alabama. It took effect at Apr 12, 2020, 12:00 PM CDT. It was in force for 12 hr.

The area

The counties it named.

The facts

Issued: Apr 12, 2020, 3:07 AM CDT (08:07 UTC)
In effect from: Apr 12, 2020, 12:00 PM CDT
Expired: Apr 13, 2020, 12:00 AM CDT
In force: 12 hr
Issued by: NWS Birmingham, AL
Flood severity: None

Counties Blount County, AL, Cherokee County, AL, Etowah County, AL, Fayette County, AL, Lamar County, AL, Marion County, AL, Walker County, AL, Winston County, AL

The radar

The Birmingham radar (KBMX), 94 km from the middle of the area, began a volume at 08:10 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, 8.1 hours before the alert went out and 244 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2991 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 103 m²/s²
0-3 km storm-relative helicity: 402 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 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 Apr 11, 11:45 PM CDT, 3 hours 22 minutes earlier.

Area forecast discussion, Apr 11, 11:45 PM CDT, 3 hours 22 minutes before

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Hazardous weather outlook, Apr 11, 2:29 PM CDT, 12 hours 38 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 12, 8:12 AM CDT	River Flood Warning	BMX	Greene, Hale, Marengo, Sumter	16 days
Apr 12, 12:23 PM CDT	Special Weather Statement	BMX	Marion	37 min
Apr 12, 3:26 PM CDT	Tornado Warning	BMX	Pickens	64 min
Apr 12, 3:33 PM CDT	Severe Thunderstorm Warning	BMX	Lamar, Marion	40 min
Apr 12, 4:10 PM CDT	Tornado Warning	BMX	Fayette, Tuscaloosa	50 min
Apr 12, 4:40 PM CDT	Tornado Warning	BMX	Walker	49 min
Apr 12, 4:50 PM CDT	Severe Thunderstorm Warning	BMX	Jefferson	55 min
Apr 12, 5:07 PM CDT	Tornado Warning	BMX	Jefferson	53 min
Apr 12, 5:28 PM CDT	Severe Thunderstorm Warning	BMX	Blount, St. Clair	46 min
Apr 12, 5:31 PM CDT	Tornado Warning	BMX	Blount	44 min
Apr 12, 5:50 PM CDT	Severe Thunderstorm Warning	BMX	Etowah	55 min
Apr 12, 5:59 PM CDT	Tornado Warning	BMX	Etowah	35 min
Apr 12, 6:13 PM CDT	Areal Flood Advisory	BMX	Blount, Jefferson, Walker	6 hr
Apr 12, 6:19 PM CDT	Tornado Warning	BMX	Cherokee	56 min
Apr 12, 6:20 PM CDT	Areal Flood Advisory	BMX	Fayette, Lamar, Pickens, Tuscaloosa	6 hr
Apr 12, 6:41 PM CDT	Flash Flood Warning	BMX	Blount	6 hr

Nearby

Flash Flood Watches in Alabama, 2020 Every flash flood watch 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.