Alert archive / Alabama / Flash Flood Watches in 2020

Flash Flood Watch 4, NWS Birmingham, AL

February 11, 202025 counties in Alabama

NWS Birmingham, AL issued this flash flood watch at Feb 11, 2020, 3:43 PM CST for 25 counties in Alabama. It took effect at Feb 12, 2020, 4:00 PM CST. It was in force for 14 hr.

The area

The counties it named.

The facts

Issued
Feb 11, 2020, 3:43 PM CST (21:43 UTC)
In effect from
Feb 12, 2020, 4:00 PM CST
Expired
Feb 13, 2020, 6:00 AM CST
In force
14 hr
Issued by
NWS Birmingham, AL
Flood severity
None
All 25 counties

Bibb County, AL, Blount County, AL, Calhoun County, AL, Cherokee County, AL, Chilton County, AL, Clay County, AL, Cleburne County, AL, Coosa County, AL, Etowah County, AL, Fayette County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Lamar County, AL, Marion County, AL, Perry County, AL, Pickens County, AL, Randolph County, AL, Shelby County, AL, St. Clair County, AL, Sumter County, AL, Talladega County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL

The radar

The Birmingham radar (KBMX), 31 km from the middle of the area, began a volume at 21:47 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, 9.7 hours before the alert went out and 30 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-pSkew-T log-p diagram, Birmingham, AL at 12:00Z on 2020-02-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 169 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Birmingham, AL at 12:00Z on 2020-02-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 248 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
169 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
586 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
248 m²/s²
0-3 km storm-relative helicity
332 m²/s²
Significant tornado parameter
0.2
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 Feb 11, 12:22 PM CST, 3 hours 21 minutes earlier.

Area forecast discussion, Feb 11, 12:22 PM CST, 3 hours 21 minutes before
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Hazardous weather outlook, Feb 11, 3:00 AM CST, 12 hours 43 minutes before
Hazardous Weather Outlook
National Weather Service Birmingham AL
300 AM CST Tue Feb 11 2020

ALZ011>015-017>050-121200-
Marion-Lamar-Fayette-Winston-Walker-Blount-Etowah-Calhoun-Cherokee-
Cleburne-Pickens-Tuscaloosa-Jefferson-Shelby-St. Clair-Talladega-
Clay-Randolph-Sumter-Greene-Hale-Perry-Bibb-Chilton-Coosa-Tallapoosa-
Chambers-Marengo-Dallas-Autauga-Lowndes-Elmore-Montgomery-Macon-
Bullock-Lee-Russell-Pike-Barbour-
300 AM CST Tue Feb 11 2020

This Hazardous Weather Outlook is for the counties served by the
National Weather Service office in Birmingham.

.DAY ONE...Outlook through Tonight.

Periods of heavy rainfall are expected through tonight. Recent
rainfall has produced saturated soil conditions, and any additional
rainfall could produce flash flooding issues.

Many area rivers are in or expected to rise above flood stage.
Please see the latest river statements for specific details on the
rises and expected crest values.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

There is a potential for severe storms Wednesday night into early
Thursday morning. Damaging winds and a couple of tornadoes appear
possible.

Periods of heavy rainfall are expected Wednesday night through
Thursday. Recent heavy rainfall has produced saturated soil
conditions, and any additional rainfall could produce flash flooding
issues.

Many rivers will continue to rise over the next few days. Many have
reached flood stage or will reach flood stage. Please see the latest
river statements for specific details on the rises and expected
crest values.

.SPOTTER INFORMATION STATEMENT...

Activation of storm spotters and emergency management may be
necessary Wednesday night.

In the hours before

Local storm report, Feb 11, 1:09 PM CST, 2 hours 34 minutes before
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Special weather statement, Feb 11, 1:58 PM CST, 1 hour 45 minutes before
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Special weather statement, Feb 11, 2:46 PM CST, 57 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Feb 10, 6:13 PM CSTAreal Flood WarningBMXBibb, Greene, Jefferson, Pickens, Shelby, Sumter and 1 more6 hr
Feb 10, 8:25 PM CSTAreal Flood WarningBMXCalhoun, Clay, Cleburne, Coosa, Randolph, St. Clair and 1 more6 hr
Feb 10, 8:29 PM CSTAreal Flood WarningBMXBibb, Chilton, Hale, Perry6 hr
Feb 10, 11:13 PM CSTAreal Flood AdvisoryBMXFayette, Lamar, Marion, Walker, Winston6 hr
Feb 11, 12:03 AM CSTAreal Flood AdvisoryBMXBlount, Cherokee, Etowah6 hr
Feb 11, 12:19 AM CSTAreal Flood WarningBMXBibb, Greene, Jefferson, Pickens, Shelby, Sumter and 1 more6 hr
Feb 11, 12:26 AM CSTAreal Flood WarningBMXFayette, Lamar, Marion, Walker, Winston6 hr
Feb 11, 2:38 AM CSTAreal Flood AdvisoryBMXCalhoun, Chilton, Clay, Cleburne, Coosa, Randolph and 2 more4 hr
Feb 11, 3:03 AM CSTRiver Flood WarningBMXDallas6 days
Feb 11, 6:13 AM CSTFlash Flood WarningBMXTuscaloosa3 hr
Feb 11, 7:37 AM CSTAreal Flood AdvisoryBMXBibb, Shelby, Talladega3 hr
Feb 11, 8:35 AM CSTRiver Flood WarningBMXAutauga, Dallas, Lowndes4 days
Feb 11, 1:58 PM CSTSpecial Weather StatementBMXElmore47 min
Feb 11, 2:39 PM CSTRiver Flood WarningBMXChambers, Elmore, Macon, Randolph, Tallapoosa29 hr
Feb 11, 2:46 PM CSTSpecial Weather StatementBMXLee44 min

Nearby

Flash Flood Watches in Alabama, 2020Every 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.