Alert archive / Alabama / Flash Flood Warnings in 2020

Flash Flood Warning 37, NWS Mobile, AL

October 28, 20204 counties in Alabama

NWS Mobile, AL issued this flash flood warning at Oct 28, 2020, 9:26 PM CDT for 4 counties in Alabama. It was in force for 5 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: Oct 28, 2020, 9:26 PM CDT (02:26 UTC)
Expired: Oct 29, 2020, 2:07 AM CDT
In force: 5 hr
Issued by: NWS Mobile, AL
Area: Storm-based polygon
Flood severity: None

Counties Choctaw County, AL, Clarke County, AL, Monroe County, AL, Wilcox County, AL

The radar

The Mobile radar (KMOB), 156 km from the middle of the area, began a volume at 02:26 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 00:00Z, 2.4 hours before the alert went out and 164 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: 155 J/kg
Mixed-layer CIN: -18 J/kg
Mixed-layer LCL: 753 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 261 m²/s²
0-3 km storm-relative helicity: 330 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 2.9

Open this sounding in Storm Lab

The text

As transmitted.

786 
WGUS54 KMOB 290226
FFWMOB
ALC023-025-099-131-290830-
/O.NEW.KMOB.FF.W.0037.201029T0226Z-201029T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mobile AL
926 PM CDT Wed Oct 28 2020

The National Weather Service in Mobile has issued a

* Flash Flood Warning for...
  North Central Monroe County in south central Alabama...
  Western Wilcox County in south central Alabama...
  Central Choctaw County in southwestern Alabama...
  Clarke County in southwestern Alabama...

* Until 330 AM CDT Thursday.

* At 925 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin within 
  the next couple of hours.

  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...
  Thomasville, Butler, Grove Hill, Whatley, Pine Hill, Silas, 
  Coffeeville, Pennington, Vredenburgh, Fulton, Gilbertown, Yellow 
  Bluff, Toxey, Springfield, Rural, Glover, Tallahatta Springs, 
  Chilton, Greenwood and Roundhill.

Additional rainfall amounts of 2 to 5 inches are possible in the 
warned area.

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 3186 8847 3231 8800 3231 8793 3228 8793
      3230 8798 3228 8802 3217 8801 3208 8804
      3205 8812 3200 8810 3201 8762 3213 8762
      3213 8752 3226 8752 3227 8746 3188 8723
      3139 8777 3168 8792 3179 8847

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...2-5 INCHES IN 5 HOURS 

$$

JMM

1 follow-up statement

315 
WGUS74 KMOB 290707
FFSMOB

Flash Flood Statement
National Weather Service Mobile AL
207 AM CDT Thu Oct 29 2020

ALC023-025-099-131-290717-
/O.CAN.KMOB.FF.W.0037.000000T0000Z-201029T0830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Choctaw AL-Clarke AL-Monroe AL-Wilcox AL-
207 AM CDT Thu Oct 29 2020

...FLASH FLOOD WARNING IS CANCELLED FOR NORTH CENTRAL MONROE, 
WESTERN WILCOX, CENTRAL CHOCTAW AND CLARKE COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 3186 8847 3231 8800 3231 8793 3228 8793
      3230 8798 3228 8802 3217 8801 3208 8804
      3205 8812 3200 8810 3201 8762 3213 8762
      3213 8752 3226 8752 3227 8746 3188 8723
      3139 8777 3168 8792 3179 8847

$$

JLH

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 28, 7:11 PM CDT	Tornado Warning	MOB	Escambia	16 min
Oct 28, 7:47 PM CDT	Tornado Warning	MOB	Baldwin	16 min
Oct 28, 7:57 PM CDT	Special Marine Warning	MOB		2 hr
Oct 28, 8:14 PM CDT	Special Marine Warning	MOB		2 hr
Oct 28, 8:43 PM CDT	Flash Flood Warning	MOB	Choctaw, Clarke, Mobile, Washington	5 hr
Oct 28, 9:16 PM CDT	Special Marine Warning	MOB		119 min
Oct 28, 10:49 PM CDT	Special Marine Warning	MOB		116 min
Oct 29, 4:08 AM CDT	Small Craft Advisory	MOB		28 hr

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.