Alert archive / Alabama / Flash Flood Warnings in 2021

Flash Flood Warning 33, NWS Birmingham, AL

June 20, 2021Jefferson County, Alabama

NWS Birmingham, AL issued this flash flood warning at Jun 20, 2021, 2:00 AM CDT for Jefferson County, Alabama. It was in force for 3 hr. 2 reports 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: Jun 20, 2021, 2:00 AM CDT (07:00 UTC)
Expired: Jun 20, 2021, 5:00 AM CDT
In force: 3 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 06:58 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
Jun 20, 3:34 AM CDT	FLASH FLOOD	1 Ne Ensley, AL	ENSA1 AT 14.22 FT. (VILLAGE CREEK AT AVENUE W) AREAS OF SIGNIFICANT FLASH FLOODING CONTINUES ACROSS THE BIRMINGHAM METRO.
Jun 20, 3:42 AM CDT	FLASH FLOOD	1 Ese Bent Brook Golf C, AL	GWDA1 AT 12.32 FT. (SHADES CREEK NEAR GREENWOOD).

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 00:00Z, 7.0 hours before the alert went out and 45 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: 380 J/kg
Mixed-layer CIN: -34 J/kg
Mixed-layer LCL: 475 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 190 m²/s²
0-3 km storm-relative helicity: 231 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

As transmitted.

083 
WGUS54 KBMX 200700
FFWBMX
ALC073-201000-
/O.NEW.KBMX.FF.W.0033.210620T0700Z-210620T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Birmingham AL
200 AM CDT Sun Jun 20 2021

The National Weather Service in Birmingham has issued a

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

* Until 500 AM CDT.

* At 200 AM CDT, Emergency Management reported thunderstorms 
  producing heavy rain in the Birmingham Metro area. Between 2 and 4 
  inches of rain have fallen. Flash flooding remains ongoing. Levels 
  across Village Creek remain well into Moderate Flood stage.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Emergency Management reported.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor 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, Moody, 
  Fairfield, Fultondale, Sumiton, Center Point, Pleasant Grove, 
  Clay, Pinson and Tarrant.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3384 8689 3384 8676 3377 8665 3377 8654
      3356 8655 3352 8652 3347 8660 3347 8667
      3325 8698 3325 8707 3328 8707 3331 8716
      3346 8734 3349 8733 3348 8729 3353 8727
      3355 8719 3361 8718 3366 8706 3379 8701

FLASH FLOOD...OBSERVED

$$

40/Sizemore

1 follow-up statement

847 
WGUS74 KBMX 200955
FFSBMX

Flash Flood Statement
National Weather Service Birmingham AL
455 AM CDT Sun Jun 20 2021

ALC073-201005-
/O.EXP.KBMX.FF.W.0033.000000T0000Z-210620T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Jefferson AL-
455 AM CDT Sun Jun 20 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 5 AM CDT EARLY THIS MORNING 
FOR JEFFERSON COUNTY...

Heavy rainfall has ended and water levels are beginning to recede 
across Jefferson County. Please continue to heed remaining road 
closures.

A Flash Flood Watch remains in effect until 700 AM CDT for portions 
of central Alabama, east central Alabama, northeast Alabama, 
southeast Alabama and west central Alabama.

LAT...LON 3384 8689 3384 8676 3377 8665 3377 8654
      3356 8655 3352 8652 3347 8660 3347 8667
      3325 8698 3325 8707 3328 8707 3331 8716
      3346 8734 3349 8733 3348 8729 3353 8727
      3355 8719 3361 8718 3366 8706 3379 8701

$$

40/Sizemore

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 19, 8:53 PM CDT	Areal Flood Advisory	BMX	Jefferson, Shelby	3 hr
Jun 19, 9:06 PM CDT	Flash Flood Warning	BMX	Jefferson	5 hr
Jun 19, 9:53 PM CDT	Flash Flood Warning	BMX	Cherokee	3 hr
Jun 19, 11:29 PM CDT	Special Weather Statement	BMX	Bullock, Macon, Pike	46 min
Jun 19, 11:53 PM CDT	Areal Flood Advisory	BMX	Blount	3 hr
Jun 20, 12:15 AM CDT	Special Weather Statement	BMX	Barbour, Russell	45 min
Jun 20, 1:05 AM CDT	Areal Flood Warning	BMX	Tuscaloosa	7 hr
Jun 20, 1:12 AM CDT	Areal Flood Warning	BMX	Cherokee	6 hr
Jun 20, 1:15 AM CDT	Areal Flood Advisory	BMX	Etowah	4 hr
Jun 20, 1:57 AM CDT	Areal Flood Advisory	BMX	Barbour	2 hr
Jun 20, 4:16 AM CDT	Areal Flood Warning	BMX	Cherokee	32 hr
Jun 20, 10:06 AM CDT	River Flood Warning	BMX	Greene, Hale, Marengo	5 days

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.