Alert archive / Alabama / Flash Flood Warnings in 2021

Flash Flood Warning 2, NWS Birmingham, AL

March 17, 2021Jefferson County, Alabama

NWS Birmingham, AL issued this flash flood warning at Mar 17, 2021, 2:51 PM CDT for Jefferson County, Alabama. It was in force for 2 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Mar 17, 2021, 2:51 PM CDT (19:51 UTC)
Expired: Mar 17, 2021, 5:00 PM CDT
In force: 2 hr
Issued by: NWS Birmingham, AL
Area: Storm-based polygon
Flood severity: None

County Jefferson County, AL

The radar

The Birmingham radar (KBMX), 46 km from the middle of the area, began a volume at 19:50 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.

What was reported inside it

Time	Report	Where	Remark
Mar 17, 3:15 PM CDT	FLASH FLOOD	1 Ne Ensley, AL	VILLAGE CREEK AT AVENUE W WENT INTO FLOOD STAGE AND CAUSED MINOR FLOODING IN ENSLEY. ADDITIONALLY, THERE WERE SEVERAL ROADS IN THE BIRMINGHAM METRO AREA THAT WERE TEMPORARILY IMPASSABLE DUE TO HIGH WATER.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 7.9 hours before the alert went out and 44 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: 658 J/kg
Mixed-layer CIN: -112 J/kg
Mixed-layer LCL: 759 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 169 m²/s²
0-3 km storm-relative helicity: 301 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.1

Open this sounding in Storm Lab

The text

As transmitted.

281 
WGUS54 KBMX 171951
FFWBMX
ALC073-172200-
/O.NEW.KBMX.FF.W.0002.210317T1951Z-210317T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Birmingham AL
251 PM CDT Wed Mar 17 2021

The National Weather Service in Birmingham has issued a

* Flash Flood Warning for...
  Jefferson County in central Alabama...

* Until 500 PM CDT.

* At 251 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Flash flooding is ongoing or 
  expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Doppler radar.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other
           drainage and low lying areas.

* Some locations that will experience flash flooding include...
  Birmingham, Hoover, Vestavia Hills, Bessemer, Homewood, Mountain 
  Brook, Trussville, Hueytown, Gardendale, Irondale, Leeds, 
  Fairfield, Fultondale, Center Point, Pleasant Grove, Pinson, 
  Tarrant, Midfield, Adamsville and Brighton.

This also includes Village Creek at Avenue W which will rise into 
the 10 to 12 foot range.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 3325 8701 3344 8729 3346 8734 3347 8729
      3350 8729 3350 8726 3351 8727 3354 8724
      3354 8719 3357 8720 3363 8712 3363 8709
      3365 8709 3360 8702 3365 8679 3371 8670
      3361 8656 3347 8662 3347 8667 3343 8670

FLASH FLOOD...RADAR INDICATED

$$

75/Linhares

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 16, 9:59 PM CDT	Special Weather Statement	BMX	Sumter	46 min
Mar 16, 10:11 PM CDT	Severe Thunderstorm Warning	BMX	Sumter	24 min
Mar 16, 10:38 PM CDT	Special Weather Statement	BMX	Hale	37 min
Mar 17, 1:27 AM CDT	Dense Fog Advisory	BMX	Autauga, Barbour, Blount, Bullock, Calhoun, Chambers and 22 more	6 hr
Mar 17, 11:18 AM CDT	Special Weather Statement	BMX	Jefferson	27 min
Mar 17, 12:13 PM CDT	Tornado Warning	BMX	Dallas	47 min
Mar 17, 12:19 PM CDT	Areal Flood Advisory	BMX	Jefferson, Tuscaloosa	2 hr
Mar 17, 12:21 PM CDT	Severe Thunderstorm Warning	BMX	Fayette, Lamar, Marion	25 min
Mar 17, 12:41 PM CDT	Tornado Warning	BMX	Autauga	64 min
Mar 17, 12:59 PM CDT	Tornado Warning	BMX	Greene, Sumter	61 min
Mar 17, 1:18 PM CDT	Tornado Warning	BMX	Autauga, Chilton, Elmore	57 min
Mar 17, 1:40 PM CDT	Severe Thunderstorm Warning	BMX	Pickens, Tuscaloosa	28 min
Mar 17, 1:52 PM CDT	Tornado Warning	BMX	Greene, Hale, Marengo, Sumter	41 min
Mar 17, 1:58 PM CDT	Tornado Warning	BMX	Marengo	62 min
Mar 17, 1:59 PM CDT	Tornado Warning	BMX	Greene, Hale	46 min
Mar 17, 2:02 PM CDT	Tornado Warning Tornado observed	BMX	Chilton, Coosa	58 min
Mar 17, 2:09 PM CDT	Tornado Warning	BMX	Marengo	66 min
Mar 17, 2:14 PM CDT	Tornado Warning	BMX	Jefferson, Walker	61 min
Mar 17, 2:20 PM CDT	Tornado Warning Tornado observed	BMX	Tuscaloosa	40 min
Mar 17, 2:33 PM CDT	Tornado Warning Tornado observed	BMX	Clay, Coosa, Talladega	42 min
Mar 17, 2:44 PM CDT	Flash Flood Warning	BMX	Hale, Marengo, Perry	2 hr
Mar 17, 2:47 PM CDT	Areal Flood Advisory	BMX	Greene, Pickens, Sumter, Tuscaloosa	2 hr
Mar 17, 2:48 PM CDT	Areal Flood Advisory	BMX	Blount, Jefferson, Walker	2 hr
Mar 17, 2:48 PM CDT	Areal Flood Advisory	BMX	Fayette, Lamar, Marion, Walker, Winston	2 hr
Mar 17, 2:53 PM CDT	Tornado Warning Tornado observed	BMX	Tuscaloosa	52 min
Mar 17, 2:54 PM CDT	Tornado Warning	BMX	Dallas, Marengo, Perry	66 min
Mar 17, 2:58 PM CDT	Tornado Warning	BMX	Blount, Jefferson	34 min
Mar 17, 3:21 PM CDT	Tornado Warning	BMX	Tuscaloosa	54 min
Mar 17, 3:25 PM CDT	Flash Flood Warning	BMX	Tuscaloosa	2 hr
Mar 17, 3:28 PM CDT	Areal Flood Advisory	BMX	Dallas, Perry	2 hr
Mar 17, 3:34 PM CDT	Tornado Warning Tornado observed	BMX	Jefferson, Walker	56 min
Mar 17, 3:37 PM CDT	Tornado Warning	BMX	Marengo	38 min
Mar 17, 3:58 PM CDT	Tornado Warning Tornado observed	BMX	Jefferson	47 min
Mar 17, 3:58 PM CDT	Tornado Warning	BMX	Dallas, Perry	47 min
Mar 17, 4:12 PM CDT	Tornado Warning	BMX	Dallas	48 min
Mar 17, 4:28 PM CDT	Tornado Warning Tornado observed	BMX	Marengo	62 min
Mar 17, 4:36 PM CDT	Tornado Warning Tornado observed	BMX	Jefferson	54 min
Mar 17, 4:40 PM CDT	Tornado Warning	BMX	Autauga	50 min
Mar 17, 4:43 PM CDT	Tornado Warning	BMX	Dallas, Perry	47 min
Mar 17, 5:00 PM CDT	Tornado Warning	BMX	Chilton	60 min
Mar 17, 5:09 PM CDT	Areal Flood Advisory	BMX	Jefferson	111 min
Mar 17, 5:15 PM CDT	Tornado Warning	BMX	Chilton	60 min
Mar 17, 5:16 PM CDT	Tornado Warning Tornado observed	BMX	Blount	44 min
Mar 17, 5:23 PM CDT	Tornado Warning	BMX	Dallas, Marengo, Perry	67 min
Mar 17, 5:26 PM CDT	Areal Flood Advisory	BMX	Autauga, Chilton, Dallas, Hale, Marengo, Perry and 1 more	3 hr
Mar 17, 5:41 PM CDT	Tornado Warning	BMX	Marengo	23 min
Mar 17, 5:42 PM CDT	Tornado Warning	BMX	Chilton, Coosa, Shelby, Talladega	48 min
Mar 17, 5:48 PM CDT	Tornado Warning	BMX	Blount	42 min
Mar 17, 5:56 PM CDT	Areal Flood Advisory	BMX	Walker, Winston	44 min
Mar 17, 6:09 PM CDT	Tornado Warning	BMX	Chilton, Coosa, Shelby, Talladega	13 min
Mar 17, 6:40 PM CDT	Flash Flood Warning	BMX	Walker, Winston	3 hr
Mar 17, 6:48 PM CDT	Tornado Warning	BMX	Dallas	42 min

Nearby

Flash Flood Warnings in Alabama, 2021 Every flash flood warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.