Alert archive / Alabama / Flash Flood Warnings in 2021

Flash Flood Warning 23, NWS Mobile, AL

May 5, 2021Mobile County, Alabama

NWS Mobile, AL issued this flash flood warning at May 5, 2021, 8:57 AM CDT for Mobile County, Alabama. It was in force for 4 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: May 5, 2021, 8:57 AM CDT (13:57 UTC)
Expired: May 5, 2021, 1:24 PM CDT
In force: 4 hr
Issued by: NWS Mobile, AL
Area: Storm-based polygon
Flood severity: None

County Mobile County, AL

The radar

The Mobile radar (KMOB), 39 km from the middle of the area, began a volume at 14:00 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

Slidell Radar S, LA (KSIL), launched 12:00Z, 2.0 hours before the alert went out and 132 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: 6 J/kg
Mixed-layer CIN: -305 J/kg
Mixed-layer LCL: 750 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 96 m²/s²
0-3 km storm-relative helicity: 260 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 5.2

Open this sounding in Storm Lab

The text

As transmitted.

669 
WGUS54 KMOB 051357
FFWMOB
ALC097-052000-
/O.NEW.KMOB.FF.W.0023.210505T1357Z-210505T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mobile AL
857 AM CDT Wed May 5 2021

The National Weather Service in Mobile has issued a

* Flash Flood Warning for...
  Southern Mobile County in southwestern Alabama...

* Until 300 PM CDT Wednesday.

* At 857 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Additional rainfall amounts of 
  2 to 4 inches are possible in the warned area which will fall on 
  saturated ground. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  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...
  Grand Bay, Bayou La Batre, Dauphin Island, Coden, Alabama Port, 
  Delchamps, Kirewakra, Dixon Corner, Fowl River, South Orchard, 
  Faustinas, Mon Louis, Smithport, Bayleys Corner, Laurendine, Belle 
  Fontaine and Sunny Cove.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3039 8840 3040 8840 3047 8840 3052 8806
      3016 8804 3013 8833 3014 8836 3034 8840
      3035 8839 3037 8840 3038 8841

FLASH FLOOD...RADAR INDICATED

$$

1 follow-up statement

523 
WGUS74 KMOB 051824
FFSMOB

Flash Flood Statement
National Weather Service Mobile AL
124 PM CDT Wed May 5 2021

ALC097-051834-
/O.CAN.KMOB.FF.W.0023.000000T0000Z-210505T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mobile AL-
124 PM CDT Wed May 5 2021

...FLASH FLOOD WARNING FOR SOUTHERN MOBILE COUNTY HAS BEEN REPLACED 
WITH A FLOOD ADVISORY...

While the threat of flash flooding has ended, standing water remains 
over numerous roadways.

LAT...LON 3039 8840 3040 8840 3047 8840 3052 8806
      3016 8804 3013 8833 3014 8836 3034 8840
      3035 8839 3037 8840 3038 8841

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
May 4, 7:26 PM CDT	Special Marine Warning	MOB		2 hr
May 4, 7:28 PM CDT	Special Weather Statement	MOB	Covington, Escambia	62 min
May 4, 7:33 PM CDT	Special Weather Statement	MOB	Baldwin, Mobile	57 min
May 4, 7:44 PM CDT	Severe Thunderstorm Warning	MOB	Covington, Crenshaw	32 min
May 4, 8:15 PM CDT	River Flood Warning	MOB	Baldwin	29 hr
May 4, 8:20 PM CDT	Areal Flood Advisory	MOB	Mobile	6 hr
May 4, 8:28 PM CDT	Areal Flood Advisory	MOB	Baldwin	6 hr
May 4, 8:36 PM CDT	Flash Flood Warning	MOB	Mobile	6 hr
May 4, 9:41 PM CDT	Special Marine Warning	MOB		94 min
May 5, 12:35 AM CDT	Areal Flood Advisory	MOB	Baldwin	4 hr
May 5, 1:50 AM CDT	Flash Flood Warning	MOB	Baldwin	6 hr
May 5, 2:27 AM CDT	River Flood Warning	MOB	Baldwin	23 hr
May 5, 2:30 AM CDT	River Flood Warning	MOB	Baldwin	22 hr
May 5, 2:50 AM CDT	Special Marine Warning	MOB		85 min
May 5, 6:29 AM CDT	Special Weather Statement	MOB	Baldwin	46 min
May 5, 7:07 AM CDT	Areal Flood Advisory	MOB	Mobile	3 hr
May 5, 7:19 AM CDT	Special Marine Warning	MOB		86 min
May 5, 7:43 AM CDT	Flash Flood Warning	MOB	Baldwin	6 hr
May 5, 8:00 AM CDT	River Flood Warning	MOB	Clarke, Monroe, Wilcox	7 days
May 5, 8:00 AM CDT	River Flood Warning	MOB	Dallas, Monroe, Wilcox	4 days
May 5, 8:31 AM CDT	Special Marine Warning	MOB		59 min
May 5, 12:02 PM CDT	Special Marine Warning	MOB		88 min
May 5, 1:24 PM CDT	Areal Flood Advisory	MOB	Mobile	96 min
May 5, 1:26 PM CDT	Special Marine Warning	MOB		64 min
May 5, 1:44 PM CDT	Areal Flood Advisory	MOB	Baldwin	3 hr

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.