Alert archive / Alabama / Areal Flood Warnings in 2021

Areal Flood Warning 4, NWS Mobile, AL

April 16, 2021Mobile County, Alabama

NWS Mobile, AL issued this areal flood warning at Apr 16, 2021, 8:39 AM CDT for Mobile County, Alabama. It was in force for 24 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
Apr 16, 2021, 8:39 AM CDT (13:39 UTC)
Expired
Apr 17, 2021, 8:30 AM CDT
In force
24 hr
Issued by
NWS Mobile, AL
Area
Storm-based polygon
Flood severity
None

County Mobile County, AL

The radar

The Mobile radar (KMOB), 47 km from the middle of the area, began a volume at 13:42 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, 1.7 hours before the alert went out and 150 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 12:00Z on 2021-04-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2021-04-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 152 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
822 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
152 m²/s²
0-3 km storm-relative helicity
208 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1

Open this sounding in Storm Lab

The text

As transmitted.

977 
WGUS44 KMOB 161339
FLWMOB

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Mobile AL
839 AM CDT Fri Apr 16 2021

ALC097-171330-
/O.NEW.KMOB.FA.W.0004.210416T1339Z-210417T1330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mobile AL-
839 AM CDT Fri Apr 16 2021

The National Weather Service in Mobile has issued a

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

* Until 830 AM CDT Saturday.

* At 839 AM CDT, Doppler radar indicated heavy rain due to 
  thunderstorms moving in from the west. Flooding is ongoing or 
  expected to begin shortly in the warned area. Between 6 and 8 
  inches of rain fell yesterday, and much more over the past week to 
  ten days.

* Given the rain during the past several days on Dauphin Island and 
  above normal tide levels, there is no way for the water to drain, 
  especially leading into and falling away from the time of high 
  tide. This will only get worse as more rain falls beginning this 
  morning, another round this evening and yet another round 
  tomorrow. This could equal or surpass the flooding experienced 
  yesterday on Dauphin Island. This is not just the typical flooding 
  that is usually experienced on the west end. An Areal Flood 
  Warning will remain in effect for inundation flooding until the 
  water recedes.

* Some locations that will experience flooding include...
  Dauphin Island.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles. Move your personal property to higher 
ground before the water begins to rise again beginning with the 
round of rain today and the one incoming later this evening.

&&

LAT...LON 3024 8823 3025 8823 3026 8813 3026 8810
      3027 8812 3033 8815 3033 8813 3031 8813
      3028 8812 3025 8807 3024 8809 3024 8812
      3025 8813

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 16, 6:19 AM CDTSpecial Marine WarningMOB71 min
Apr 16, 6:46 AM CDTSpecial Marine WarningMOB9 min
Apr 16, 8:19 AM CDTSpecial Marine WarningMOB41 min
Apr 16, 8:26 AM CDTSpecial Marine WarningMOB2 hr
Apr 16, 9:13 AM CDTSpecial Marine WarningMOB92 min

Nearby

Areal Flood Warnings in Alabama, 2021Every areal 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.