Alert archive / Alabama / Flash Flood Warnings in 2021

Flash Flood Warning 40, NWS Huntsville, AL

September 19, 2021Madison County, Marshall County, Alabama

NWS Huntsville, AL issued this flash flood warning at Sep 19, 2021, 7:25 AM CDT for Madison County, Marshall County, Alabama. It was in force for 3 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: Sep 19, 2021, 7:25 AM CDT (12:25 UTC)
Expired: Sep 19, 2021, 10:18 AM CDT
In force: 3 hr
Issued by: NWS Huntsville, AL
Area: Storm-based polygon
Flood severity: None

Counties Madison County, AL, Marshall County, AL

The radar

The Northeast Alabama radar (KHTX), 41 km from the middle of the area, began a volume at 12:27 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

Time	Report	Where	Remark
Sep 19, 9:30 AM CDT	FLASH FLOOD	1 Sse Gurley, AL	CAR SUBMERGED ON HWY 72 BETWEEN GURLEY AND PAINT ROCK. PICTURE SEEN ON SOCIAL MEDIA.

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

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 0.4 hours before the alert went out and 161 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: 92 J/kg
Mixed-layer CIN: -60 J/kg
Mixed-layer LCL: 895 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 11 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

543 
WGUS54 KHUN 191225
FFWHUN
ALC089-095-191530-
/O.NEW.KHUN.FF.W.0040.210919T1225Z-210919T1530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Huntsville AL
725 AM CDT Sun Sep 19 2021

The National Weather Service in Huntsville has issued a

* Flash Flood Warning for...
  Central Madison County in north central Alabama...
  Northwestern Marshall County in northeastern Alabama...

* Until 1030 AM CDT.

* At 725 AM CDT, Doppler radar indicated 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 2 inches are possible in the warned area. 
  Flash flooding is ongoing or expected to begin shortly.

  HAZARD...Flash flooding caused by heavy rain.

  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...
  Huntsville, Guntersville, Arab, Moores Mill, Meridianville, Hazel 
  Green, Owens Cross Roads, Gurley, Morgan City, New Market, Union 
  Grove, Hampton Cove, Brownsboro, Maysville, Ryland, Eddy, Plevna 
  and Mountain View.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3457 8656 3499 8655 3499 8632 3490 8633
      3487 8635 3483 8633 3480 8635 3479 8633
      3476 8634 3474 8636 3463 8636 3462 8634
      3428 8626 3431 8657 3447 8657 3455 8655

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

$$

70/DD

2 follow-up statements

886 
WGUS74 KHUN 191407
FFSHUN

Flash Flood Statement
National Weather Service Huntsville AL
907 AM CDT Sun Sep 19 2021

ALC089-095-191530-
/O.CON.KHUN.FF.W.0040.000000T0000Z-210919T1530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Madison AL-Marshall AL-
907 AM CDT Sun Sep 19 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1030 AM CDT THIS 
MORNING FOR CENTRAL MADISON AND NORTHWESTERN MARSHALL COUNTIES...

At 907 AM CDT, Doppler radar indicated heavy rain across the warned 
area. Between 2 and 3 inches of rain have fallen. The expected 
rainfall rate is 0.5 to 1 inch in 1 hour. Additional rainfall 
amounts of 1 to 2 inches are possible in the warned area. Flash 
flooding is ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by heavy rain.

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...
  Huntsville, Guntersville, Arab, Moores Mill, Meridianville, Hazel 
  Green, Owens Cross Roads, Gurley, Morgan City, New Market, Union 
  Grove, Hampton Cove, Brownsboro, Maysville, Ryland, Eddy, Plevna 
  and Mountain View.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3457 8656 3499 8655 3499 8632 3490 8633
      3487 8635 3483 8633 3480 8635 3479 8633
      3476 8634 3474 8636 3463 8636 3462 8634
      3428 8626 3431 8657 3447 8657 3455 8655

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...0.5-1 INCH IN 1 HOUR

$$

GH

530 
WGUS74 KHUN 191518
FFSHUN

Flash Flood Statement
National Weather Service Huntsville AL
1018 AM CDT Sun Sep 19 2021

ALC089-095-191528-
/O.CAN.KHUN.FF.W.0040.000000T0000Z-210919T1530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Madison AL-Marshall AL-
1018 AM CDT Sun Sep 19 2021

...FLASH FLOOD WARNING FOR CENTRAL MADISON AND NORTHWESTERN MARSHALL 
COUNTIES HAS BEEN REPLACED WITH A FLOOD WARNING...

Rain rates have decreased, but residual flooding is still ongoing

LAT...LON 3457 8656 3499 8655 3499 8632 3490 8633
      3487 8635 3483 8633 3480 8635 3479 8633
      3476 8634 3474 8636 3463 8636 3462 8634
      3428 8626 3431 8657 3447 8657 3455 8655

$$

GH

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 19, 4:21 AM CDT	Flash Flood Warning	HUN	Jackson	3 hr
Sep 19, 7:29 AM CDT	Areal Flood Warning	HUN	Jackson	9 hr
Sep 19, 8:23 AM CDT	River Flood Warning	HUN	Jackson, Madison, Marshall	4 days
Sep 19, 8:27 AM CDT	River Flood Warning	HUN	Madison	41 hr
Sep 19, 10:18 AM CDT	Areal Flood Warning	HUN	Madison, Marshall	6 hr
Sep 19, 10:59 AM CDT	Areal Flood Warning	HUN	Madison, Morgan	5 hr
Sep 19, 12:49 PM CDT	Areal Flood Warning	HUN	Limestone, Morgan	3 hr
Sep 19, 1:13 PM CDT	Flash Flood Warning	HUN	Madison, Marshall, Morgan	3 hr
Sep 19, 3:52 PM CDT	Areal Flood Warning	HUN	Jackson, Limestone, Madison, Marshall, Morgan	6 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.