Alert archive / Alabama / Flash Flood Warnings in 2021

Flash Flood Warning 24, NWS Huntsville, AL

July 18, 20214 counties in Alabama

NWS Huntsville, AL issued this flash flood warning at Jul 18, 2021, 9:07 PM CDT for 4 counties in Alabama. It was in force for 3 hr. 4 reports 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
Jul 18, 2021, 9:07 PM CDT (02:07 UTC)
Expired
Jul 19, 2021, 12:15 AM CDT
In force
3 hr
Issued by
NWS Huntsville, AL
Area
Storm-based polygon
Flood severity
None

Counties Lawrence County, AL, Limestone County, AL, Madison County, AL, Morgan County, AL

The radar

The Northeast Alabama radar (KHTX), 90 km from the middle of the area, began a volume at 02:11 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
Jul 18, 9:11 PM CDTFLASH FLOOD3 Ne Trinity, ALFLOODING REPORTED AT THE INTERSECTION OF WOODALL ROAD AND HIGHWAY 20.
Jul 18, 9:47 PM CDTFLASH FLOOD4 W Mooresville, ALCORRECTS PREVIOUS FLASH FLOOD REPORT FROM 4 W MOORESVILLE. FLOODING REPORTED AT THE Y JUST BEFORE THE HUDSON MEMORIAL BRIDGE ON HIGHWAY 20.
Jul 18, 9:47 PM CDTFLASH FLOOD4 W Mooresville, ALFLOODING REPORTED AT THIS LOCATION.
Jul 18, 10:09 PM CDTFLASH FLOOD3 Nne Decatur, ALCORRECTS PREVIOUS FLASH FLOOD REPORT FROM 3 NNE DECATUR. FLOODING REPORTED AND THE INTERSECTION OF CHURCH AND 6TH AVENUE NE.

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

The nearest sounding before it

Birmingham, AL (KBMX), launched 00:00Z, 2.1 hours before the alert went out and 165 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, Birmingham, AL at 00:00Z on 2021-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 200 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, Birmingham, AL at 00:00Z on 2021-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 square meters per square second.1939Sfc1 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
200 J/kg
Mixed-layer CIN
-66 J/kg
Mixed-layer LCL
867 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
75 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

029 
WGUS54 KHUN 190207
FFWHUN
ALC079-083-089-103-190515-
/O.NEW.KHUN.FF.W.0024.210719T0207Z-210719T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Huntsville AL
907 PM CDT Sun Jul 18 2021

The National Weather Service in Huntsville has issued a

* Flash Flood Warning for...
  Southern Limestone County in north central Alabama...
  Southwestern Madison County in north central Alabama...
  Northern Morgan County in north central Alabama...
  Northeastern Lawrence County in northwestern Alabama...

* Until 1215 AM CDT.

* At 907 PM CDT, Doppler radar and automated rain gauges indicated 
  heavy rain falling across the warned area. Between 2 and 3 inches 
  of rain have fallen. 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 and automated gauges.

  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...
  Decatur, Madison, Redstone Arsenal, Priceville, Trinity, Triana, 
  Tanner, Huntsville International Airport, Hillsboro, Mooresville, 
  Belle Mina, Caddo, Wheeler and Valhermoso Springs.

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 3479 8726 3464 8661 3447 8664 3458 8728

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

GH
2 follow-up statements
543 
WGUS74 KHUN 190312
FFSHUN

Flash Flood Statement
National Weather Service Huntsville AL
1012 PM CDT Sun Jul 18 2021

ALC079-083-089-103-190515-
/O.CON.KHUN.FF.W.0024.000000T0000Z-210719T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lawrence AL-Limestone AL-Madison AL-Morgan AL-
1012 PM CDT Sun Jul 18 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1215 AM CDT MONDAY 
FOR SOUTHERN LIMESTONE, SOUTHWESTERN MADISON, NORTHERN MORGAN AND 
NORTHEASTERN LAWRENCE COUNTIES...

At 1012 PM CDT, Doppler radar and automated rain gauges indicated 
that heavy rain was falling across the warned area. Between 3 and 5 
inches of rain have fallen. 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 and automated gauges.

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...
  Decatur, Madison, Redstone Arsenal, Priceville, Trinity, Triana, 
  Tanner, Huntsville International Airport, Hillsboro, Mooresville, 
  Belle Mina, Caddo, Wheeler and Valhermoso Springs.

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 3479 8726 3464 8661 3447 8664 3458 8728

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

GH
009 
WGUS74 KHUN 190511
FFSHUN

Flash Flood Statement
National Weather Service Huntsville AL
1211 AM CDT Mon Jul 19 2021

ALC079-083-089-103-190521-
/O.EXP.KHUN.FF.W.0024.000000T0000Z-210719T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lawrence AL-Limestone AL-Madison AL-Morgan AL-
1211 AM CDT Mon Jul 19 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 1215 AM CDT EARLY THIS MORNING 
FOR SOUTHERN LIMESTONE, SOUTHWESTERN MADISON, NORTHERN MORGAN AND 
NORTHEASTERN LAWRENCE COUNTIES...

Flood waters have receded. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 3479 8726 3464 8661 3447 8664 3458 8728

$$

KTW

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 18, 7:09 PM CDTSpecial Weather StatementHUNMadison36 min
Jul 18, 7:16 PM CDTSpecial Weather StatementHUNCullman44 min
Jul 18, 7:20 PM CDTSpecial Weather StatementHUNLimestone40 min
Jul 18, 7:44 PM CDTSpecial Weather StatementHUNFranklin46 min
Jul 19, 9:19 AM CDTFlash Flood WatchHUNColbert, Cullman, DeKalb, Franklin, Jackson, Lauderdale and 5 more34 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.