Alert archive / Alabama / Flash Flood Warnings in 2021

Flash Flood Warning 20, NWS Mobile, AL

May 4, 2021Mobile County, Alabama

NWS Mobile, AL issued this flash flood warning at May 4, 2021, 8:36 PM CDT for Mobile County, Alabama. It was in force for 6 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
May 4, 2021, 8:36 PM CDT (01:36 UTC)
Expired
May 5, 2021, 2:45 AM CDT
In force
6 hr
Issued by
NWS Mobile, AL
Area
Storm-based polygon
Flood severity
None

County Mobile County, AL

The radar

The Mobile radar (KMOB), 15 km from the middle of the area, began a volume at 01:39 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

TimeReportWhereRemark
May 4, 8:50 PM CDTFLASH FLOOD1 W Downtown Mobile, ALSEVERAL INTERSECTIONS UNDER WATER ALONG OLD SHELL RD (NAMELY, THE INTERSECTIONS AT HALLET ST AND PINE ST.). REPORTS VIA SOCIAL MEDIA.

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

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 1.6 hours before the alert went out and 162 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, Slidell Radar S, LA at 00:00Z on 2021-05-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3152 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Slidell Radar S, LA at 00:00Z on 2021-05-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 120 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
3152 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
647 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
120 m²/s²
0-3 km storm-relative helicity
159 m²/s²
Significant tornado parameter
3.1
Supercell composite
10.5

Open this sounding in Storm Lab

The text

As transmitted.

935 
WGUS54 KMOB 050136
FFWMOB
ALC097-050745-
/O.NEW.KMOB.FF.W.0020.210505T0136Z-210505T0745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mobile AL
836 PM CDT Tue May 4 2021

The National Weather Service in Mobile has issued a

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

* Until 245 AM CDT Wednesday.

* At 836 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. The expected rainfall rate is 1 to 2 inches in 1 
  hour. Additional rainfall amounts of 1 to 3 inches are possible in 
  the warned area. 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...
  Midtown Mobile, Downtown Mobile, Prichard, Chickasaw, I10 And I65, 
  I65 And I165, Tacon, Mertz, Neshota, Navco and Plateau.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 3060 8813 3062 8816 3068 8816 3075 8811
      3077 8807 3077 8806 3077 8803 3076 8803
      3066 8803 3065 8806 3061 8805 3061 8811

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 4, 7:26 PM CDTSpecial Marine WarningMOB2 hr
May 4, 7:28 PM CDTSpecial Weather StatementMOBCovington, Escambia62 min
May 4, 7:33 PM CDTSpecial Weather StatementMOBBaldwin, Mobile57 min
May 4, 7:44 PM CDTSevere Thunderstorm WarningMOBCovington, Crenshaw32 min
May 4, 8:15 PM CDTRiver Flood WarningMOBBaldwin29 hr
May 4, 8:20 PM CDTAreal Flood AdvisoryMOBMobile6 hr
May 4, 8:28 PM CDTAreal Flood AdvisoryMOBBaldwin6 hr
May 4, 9:41 PM CDTSpecial Marine WarningMOB94 min
May 5, 12:35 AM CDTAreal Flood AdvisoryMOBBaldwin4 hr
May 5, 1:50 AM CDTFlash Flood WarningMOBBaldwin6 hr
May 5, 2:27 AM CDTRiver Flood WarningMOBBaldwin23 hr
May 5, 2:30 AM CDTRiver Flood WarningMOBBaldwin22 hr
May 5, 2:50 AM CDTSpecial Marine WarningMOB85 min
May 5, 6:29 AM CDTSpecial Weather StatementMOBBaldwin46 min
May 5, 7:07 AM CDTAreal Flood AdvisoryMOBMobile3 hr
May 5, 7:19 AM CDTSpecial Marine WarningMOB86 min
May 5, 7:43 AM CDTFlash Flood WarningMOBBaldwin6 hr
May 5, 8:00 AM CDTRiver Flood WarningMOBClarke, Monroe, Wilcox7 days
May 5, 8:00 AM CDTRiver Flood WarningMOBDallas, Monroe, Wilcox4 days
May 5, 8:31 AM CDTSpecial Marine WarningMOB59 min
May 5, 8:57 AM CDTFlash Flood WarningMOBMobile4 hr
May 5, 12:02 PM CDTSpecial Marine WarningMOB88 min
May 5, 1:24 PM CDTAreal Flood AdvisoryMOBMobile96 min
May 5, 1:26 PM CDTSpecial Marine WarningMOB64 min
May 5, 1:44 PM CDTAreal Flood AdvisoryMOBBaldwin3 hr

Nearby

Flash Flood Warnings in Alabama, 2021Every 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.