Alert archive / Alabama / Flash Flood Warnings in 2020

Flash Flood Warning 21, NWS Mobile, AL

August 11, 20204 counties in Alabama

NWS Mobile, AL issued this flash flood warning at Aug 11, 2020, 6:36 PM CDT for 4 counties in Alabama. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Aug 11, 2020, 6:36 PM CDT (23:36 UTC)
Expired: Aug 11, 2020, 9:57 PM CDT
In force: 3 hr
Issued by: NWS Mobile, AL
Area: Storm-based polygon
Flood severity: None

Counties Clarke County, AL, Conecuh County, AL, Escambia County, AL, Monroe County, AL

The radar

The Mobile radar (KMOB), 103 km from the middle of the area, began a volume at 23:36 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, 11.6 hours before the alert went out and 218 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: 953 J/kg
Mixed-layer CIN: -99 J/kg
Mixed-layer LCL: 1192 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 53 m²/s²
0-3 km storm-relative helicity: 63 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

735 
WGUS54 KMOB 112336
FFWMOB
ALC025-035-053-099-120530-
/O.NEW.KMOB.FF.W.0021.200811T2336Z-200812T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mobile AL
636 PM CDT Tue Aug 11 2020

The National Weather Service in Mobile has issued a

* Flash Flood Warning for...
  Southwestern Conecuh County in south central Alabama...
  Western Escambia County in south central Alabama...
  Southwestern Monroe County in south central Alabama...
  East Central Clarke County in southwestern Alabama...

* Until 1230 AM CDT.

* At 633 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 4 inches of rain 
  have fallen over the past one to two hours and additional heavy 
  rainfall is expected as storms move slowly over 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...
  Atmore, Brewton, Frisco City, McCullough, East Brewton, Uriah, 
  Excel, Repton, Pollard, Riverview, I65 And AL 113, I65 And AL 21, 
  I65 And CR 1, Poarch Creek Reservation, Barnett Crossroads, 
  Goodway, Huxford, Megargel, Range and Halls Crossroads.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3142 8770 3160 8770 3139 8703 3100 8705
      3101 8752

FLASH FLOOD...RADAR INDICATED

$$

21

1 follow-up statement

223 
WGUS74 KMOB 120257
FFSMOB

Flash Flood Statement
National Weather Service Mobile AL
957 PM CDT Tue Aug 11 2020

ALC025-035-053-099-120307-
/O.CAN.KMOB.FF.W.0021.000000T0000Z-200812T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clarke AL-Conecuh AL-Escambia AL-Monroe AL-
957 PM CDT Tue Aug 11 2020

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHWESTERN CONECUH, 
WESTERN ESCAMBIA, SOUTHWESTERN MONROE AND EAST CENTRAL CLARKE 
COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat.

LAT...LON 3142 8770 3160 8770 3139 8703 3100 8705
      3101 8752

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 7:32 PM CDT	Special Weather Statement	MOB	Crenshaw	43 min
Aug 10, 8:15 PM CDT	Special Weather Statement	MOB	Crenshaw	30 min
Aug 11, 5:54 AM CDT	Special Weather Statement	MOB	Baldwin	36 min
Aug 11, 6:42 AM CDT	Areal Flood Advisory	MOB	Baldwin	3 hr
Aug 11, 12:39 PM CDT	Special Weather Statement	MOB	Wilcox	51 min
Aug 11, 1:30 PM CDT	Special Weather Statement	MOB	Wilcox	45 min
Aug 11, 2:09 PM CDT	Special Weather Statement	MOB	Crenshaw	66 min
Aug 11, 3:03 PM CDT	Special Weather Statement	MOB	Crenshaw	57 min
Aug 11, 3:17 PM CDT	Severe Thunderstorm Warning	MOB	Covington, Crenshaw	43 min
Aug 11, 3:45 PM CDT	Special Weather Statement	MOB	Covington	60 min
Aug 11, 3:53 PM CDT	Special Marine Warning	MOB		52 min
Aug 11, 4:13 PM CDT	Special Weather Statement	MOB	Covington	62 min
Aug 11, 4:51 PM CDT	Areal Flood Advisory	MOB	Conecuh, Covington, Escambia	3 hr
Aug 11, 5:01 PM CDT	Special Marine Warning	MOB		59 min
Aug 11, 5:04 PM CDT	Severe Thunderstorm Warning	MOB	Clarke, Monroe	41 min
Aug 11, 5:14 PM CDT	Special Weather Statement	MOB	Escambia	76 min
Aug 11, 5:28 PM CDT	Severe Thunderstorm Warning	MOB	Conecuh, Monroe	62 min
Aug 11, 5:37 PM CDT	Special Marine Warning	MOB		83 min
Aug 11, 5:43 PM CDT	Areal Flood Advisory	MOB	Conecuh, Escambia, Monroe	3 hr
Aug 11, 5:52 PM CDT	Severe Thunderstorm Warning	MOB	Escambia	53 min
Aug 11, 6:19 PM CDT	Special Weather Statement	MOB	Baldwin	56 min
Aug 11, 6:40 PM CDT	Special Marine Warning	MOB		95 min
Aug 11, 6:54 PM CDT	Special Weather Statement	MOB	Baldwin	66 min

Nearby

Flash Flood Warnings in Alabama, 2020 Every flash flood warning 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.