Alert archive / Alabama / Areal Flood Advisories in 2021

Areal Flood Advisory 21, NWS Mobile, AL

May 4, 2021Mobile County, Alabama

NWS Mobile, AL issued this areal flood advisory at May 4, 2021, 8:20 PM CDT for Mobile County, Alabama. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: May 4, 2021, 8:20 PM CDT (01:20 UTC)
Expired: May 5, 2021, 2:15 AM CDT
In force: 6 hr
Issued by: NWS Mobile, AL
Area: Storm-based polygon

County Mobile County, AL

The radar

The Mobile radar (KMOB), 14 km from the middle of the area, began a volume at 01:22 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 00:00Z, 1.3 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-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: 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.

297 
WGUS84 KMOB 050120
FLSMOB

Flood Advisory
National Weather Service Mobile AL
820 PM CDT Tue May 4 2021

ALC097-050715-
/O.NEW.KMOB.FA.Y.0021.210505T0120Z-210505T0715Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mobile AL-
820 PM CDT Tue May 4 2021

The National Weather Service in Mobile has issued a

* Urban and Small Stream Flood Advisory for Poor Drainage Areas 
  for...
  Central Mobile County in southwestern Alabama...

* Until 215 AM CDT.

* At 820 PM CDT, Doppler radar indicated heavy rain due to 
  thunderstorms. This will cause urban and small stream flooding. 
  Overflowing poor drainage areas will cause minor flooding in the 
  advisory area. Up to 0.5 inches of rain have fallen. A Flash Flood 
  Warning may be later needed.

* Ponding of water in low lying areas, overflowing poor drainage 
  areas and rapid rises on small creeks, especially those in the 
  greater Mobile Metro.

* Some locations that will experience flooding include...
  Midtown Mobile, Downtown Mobile, Prichard, Tillmans Corner, 
  Saraland, Theodore, Chickasaw, Satsuma, Semmes, Tanner Williams, 
  Mobile Regional Airport, I10 And I65, I65 And I165, I65 And AL 
  158, Wheelerville, West Hill, Orchard, Forest Hill, Dawes and 
  Seven Hills.

Additional rainfall amounts of 1 to 3 inches are expected over the 
area. This additional rain will result in minor flooding.

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 3080 8842 3088 8799 3079 8800 3078 8802
      3075 8803 3075 8802 3074 8802 3078 8800
      3073 8801 3068 8800 3066 8802 3065 8806
      3061 8805 3057 8809 3054 8808 3051 8810
      3052 8840

$$

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, 8:28 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, 8:57 AM CDT	Flash Flood Warning	MOB	Mobile	4 hr
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

Areal Flood Advisories in Alabama, 2021 Every areal flood advisory 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.