Alert archive / Alabama / Flash Flood Watches in 2020

Flash Flood Watch 7, NWS Birmingham, AL

March 3, 202031 counties in Alabama

NWS Birmingham, AL issued this flash flood watch at Mar 3, 2020, 2:35 PM CST for 31 counties in Alabama. It took effect at Mar 4, 2020, 6:00 AM CST. It was in force for 30 hr.

The area

The counties it named.

The facts

Issued: Mar 3, 2020, 2:35 PM CST (20:35 UTC)
In effect from: Mar 4, 2020, 6:00 AM CST
Expired: Mar 5, 2020, 12:00 PM CST
In force: 30 hr
Issued by: NWS Birmingham, AL
Flood severity: None

All 31 counties

Autauga County, AL, Barbour County, AL, Bibb County, AL, Bullock County, AL, Calhoun County, AL, Chambers County, AL, Chilton County, AL, Clay County, AL, Cleburne County, AL, Coosa County, AL, Dallas County, AL, Elmore County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Marengo County, AL, Montgomery County, AL, Perry County, AL, Pickens County, AL, Pike County, AL, Randolph County, AL, Russell County, AL, Shelby County, AL, St. Clair County, AL, Sumter County, AL, Talladega County, AL, Tallapoosa County, AL, Tuscaloosa County, AL

The radar

The Birmingham radar (KBMX), 49 km from the middle of the area, began a volume at 20:35 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, 8.6 hours before the alert went out and 51 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: 242 J/kg
Mixed-layer CIN: -19 J/kg
Mixed-layer LCL: 648 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 119 m²/s²
0-3 km storm-relative helicity: 174 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.3

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 Mar 3, 11:57 AM CST, 2 hours 38 minutes earlier.

Area forecast discussion, Mar 3, 11:57 AM CST, 2 hours 38 minutes before

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Hazardous weather outlook, Mar 3, 1:41 PM CST, 54 minutes before

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In the hours before

Local storm report, Mar 3, 8:49 AM CST, 5 hours 46 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
Mar 2, 8:21 PM CST	Special Weather Statement	BMX	Walker	24 min
Mar 2, 8:39 PM CST	Special Weather Statement	BMX	Jefferson	36 min
Mar 3, 4:48 AM CST	Tornado Warning	BMX	Greene, Sumter	19 min
Mar 3, 5:05 AM CST	Severe Thunderstorm Warning	BMX	Greene, Sumter	40 min
Mar 3, 5:33 AM CST	Severe Thunderstorm Warning	BMX	Hale	42 min
Mar 3, 6:29 AM CST	Tornado Warning	BMX	Bibb, Chilton, Perry	31 min
Mar 3, 6:43 AM CST	Severe Thunderstorm Warning	BMX	Autauga, Chilton, Dallas, Perry	37 min
Mar 3, 11:44 AM CST	Areal Flood Advisory	BMX	Autauga, Dallas, Lowndes, Marengo, Perry	3 hr
Mar 3, 12:24 PM CST	Areal Flood Advisory	BMX	Bullock, Elmore, Macon, Montgomery	3 hr
Mar 3, 1:03 PM CST	Areal Flood Advisory	BMX	Bibb, Greene, Hale, Perry, Sumter	6 hr
Mar 3, 1:09 PM CST	Areal Flood Advisory	BMX	Autauga, Chambers, Chilton, Coosa, Dallas, Elmore and 1 more	6 hr
Mar 3, 1:20 PM CST	River Flood Warning	BMX	Elmore, Montgomery	7 days

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.