Alert archive / Alabama / Flash Flood Watches in 2021

Flash Flood Watch 3, NWS Huntsville, AL

March 24, 202111 counties in Alabama; Franklin County, Lincoln County, Moore County, Tennessee

NWS Huntsville, AL issued this flash flood watch at Mar 24, 2021, 1:43 PM CDT for 11 counties in Alabama; Franklin County, Lincoln County, Moore County, Tennessee. It took effect at Mar 25, 2021, 1:00 AM CDT. It was in force for 22 hr.

The area

The counties it named.

The facts

Issued
Mar 24, 2021, 1:43 PM CDT (18:43 UTC)
In effect from
Mar 25, 2021, 1:00 AM CDT
Expired
Mar 25, 2021, 11:03 PM CDT
In force
22 hr
Issued by
NWS Huntsville, AL
Flood severity
None

Counties Colbert County, AL, Cullman County, AL, DeKalb County, AL, Franklin County, AL, Jackson County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, Franklin County, TN, Lincoln County, TN, Moore County, TN

The radar

The Northeast Alabama radar (KHTX), 69 km from the middle of the area, began a volume at 18:46 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

Nashville Metro, TN (KBNA), launched 12:00Z, 6.7 hours before the alert went out and 159 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, Nashville Metro, TN at 12:00Z on 2021-03-24Temperature 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, Nashville Metro, TN at 12:00Z on 2021-03-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 199 square meters per square second.1939587897Sfc1 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
700 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
199 m²/s²
0-3 km storm-relative helicity
304 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

892 
WGUS64 KHUN 241843
FFAHUN

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Huntsville AL
143 PM CDT Wed Mar 24 2021

ALZ001>010-016-TNZ076-096-097-250745-
/O.NEW.KHUN.FF.A.0003.210325T0600Z-210326T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan-
Marshall-Jackson-DeKalb-Cullman-Moore-Lincoln-Franklin TN-
Including the cities of Russellville, Winchester, Fort Payne, Red 
Bay, Cullman, Town Creek, Cowan, Estill Springs, Huntsville, 
Sheffield, Arab, Sewanee, Decatur, Lynchburg, Athens, Muscle Shoals, 
Decherd, Fayetteville, Albertville, Guntersville, Boaz, Rainsville, 
Tuscumbia, Moulton, Florence, and Scottsboro
143 PM CDT Wed Mar 24 2021

...FLASH FLOOD WATCH IN EFFECT FROM 1 AM CDT THURSDAY THROUGH LATE 
THURSDAY NIGHT...

The National Weather Service in Huntsville has issued a

* Flash Flood Watch for portions of Alabama and southern middle 
  Tennessee, including the following areas, in Alabama, Colbert, 
  Cullman, DeKalb, Franklin AL, Jackson, Lauderdale, Lawrence, 
  Limestone, Madison, Marshall and Morgan. In southern middle 
  Tennessee, Franklin TN, Lincoln and Moore.

* From 1 AM CDT Thursday through late Thursday night

* Widespread heavy rainfall is forecast early Thursday morning as a 
  warm front lifts northwards through the Tennessee Valley. This 
  round of rain will produce 1 to 2 inches of rainfall across the 
  area. This event will saturate the soils across the area. Another 
  round of heavy rainfall is forecast later Thursday afternoon as 
  severe storms approach from the west. These storms will be 
  proficient rain producers. This additional rainfall will 
  exacerbate any ongoing issues and lead to additional flooding 
  issues Thursday afternoon and evening.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that conditions may develop that lead to 
Flash Flooding. Flash Flooding is a very dangerous situation. You 
should monitor later forecasts and be prepared to take action should 
Flash Flood Warnings be issued.

&&

$$

MA
4 follow-up statements
982 
WGUS64 KHUN 250809
FFAHUN

Flood Watch
National Weather Service Huntsville AL
309 AM CDT Thu Mar 25 2021

ALZ001>010-016-TNZ076-096-097-251615-
/O.CON.KHUN.FF.A.0003.000000T0000Z-210326T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan-
Marshall-Jackson-DeKalb-Cullman-Moore-Lincoln-Franklin TN-
Including the cities of Florence, Muscle Shoals, Sheffield, 
Tuscumbia, Russellville, Red Bay, Moulton, Town Creek, Athens, 
Huntsville, Decatur, Albertville, Boaz, Guntersville, Arab, 
Scottsboro, Fort Payne, Rainsville, Cullman, Lynchburg, 
Fayetteville, Winchester, Sewanee, Decherd, Estill Springs, 
and Cowan
309 AM CDT Thu Mar 25 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH LATE TONIGHT...

The Flash Flood Watch continues for

* Portions of Alabama and southern middle Tennessee, including 
  the following areas, in Alabama, Colbert, Cullman, DeKalb, 
  Franklin AL, Jackson, Lauderdale, Lawrence, Limestone, 
  Madison, Marshall, and Morgan. In southern middle Tennessee, 
  Franklin TN, Lincoln, and Moore. 

* Now through 1 AM Friday morning. 

* Multiple rounds of heavy rainfall from through 1 AM CDT Friday
  will cause excessive rainfall amounts of 2 to 4 inches, with  
  locally higher amounts possible.

* Heavy rainfall will cause excess runoff and flash flooding in 
  the watch area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that conditions may develop that lead
to Flash Flooding. Flash Flooding is a very dangerous situation.
You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.

&&

$$
717 
WGUS64 KHUN 251707
FFAHUN

Flood Watch
National Weather Service Huntsville AL
1207 PM CDT Thu Mar 25 2021

ALZ001>010-016-TNZ076-096-097-260115-
/O.CON.KHUN.FF.A.0003.000000T0000Z-210326T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan-
Marshall-Jackson-DeKalb-Cullman-Moore-Lincoln-Franklin TN-
Including the cities of Russellville, Winchester, Fort Payne, Red 
Bay, Cullman, Town Creek, Cowan, Estill Springs, Huntsville, 
Sheffield, Arab, Sewanee, Decatur, Lynchburg, Athens, Muscle Shoals, 
Decherd, Fayetteville, Albertville, Guntersville, Boaz, Rainsville, 
Tuscumbia, Moulton, Florence, and Scottsboro
1207 PM CDT Thu Mar 25 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH LATE TONIGHT...

The Flash Flood Watch continues for

* Portions of Alabama and southern middle Tennessee, including the 
  following areas, in Alabama, Colbert, Cullman, DeKalb, Franklin 
  AL, Jackson, Lauderdale, Lawrence, Limestone, Madison, Marshall 
  and Morgan. In southern middle Tennessee, Franklin TN, Lincoln and 
  Moore.

* Through late tonight

* Widespread rainfall this morning has saturated the soils across 
  North Alabama and Southern Middle Tennessee. Another round of 
  storms is forecast this afternoon and evening. These storms will 
  produce heavy rainfall with an additional 1 to 2 inches of 
  rainfall possible. This will exacerbate any ongoing flooding 
  issues and lead to additional flooding issues. The flash flood 
  watch continues through tonight.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that conditions may develop that lead to 
Flash Flooding. Flash Flooding is a very dangerous situation. You 
should monitor later forecasts and be prepared to take action should 
Flash Flood Warnings be issued.

&&

$$

MA
534 
WGUS64 KHUN 260110
FFAHUN

Flood Watch
National Weather Service Huntsville AL
810 PM CDT Thu Mar 25 2021

ALZ001>010-016-TNZ076-096-097-260600-
/O.CON.KHUN.FF.A.0003.000000T0000Z-210326T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan-
Marshall-Jackson-DeKalb-Cullman-Moore-Lincoln-Franklin TN-
Including the cities of Russellville, Winchester, Fort Payne, Red 
Bay, Cullman, Town Creek, Cowan, Estill Springs, Huntsville, 
Sheffield, Arab, Sewanee, Decatur, Lynchburg, Athens, Muscle Shoals, 
Decherd, Fayetteville, Albertville, Guntersville, Boaz, Rainsville, 
Tuscumbia, Moulton, Florence, and Scottsboro
810 PM CDT Thu Mar 25 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 1 AM CDT FRIDAY...

The Flash Flood Watch continues for

* Portions of Alabama and southern middle Tennessee, including the 
  following areas, in Alabama, Colbert, Cullman, DeKalb, Franklin 
  AL, Jackson, Lauderdale, Lawrence, Limestone, Madison, Marshall 
  and Morgan. In southern middle Tennessee, Franklin TN, Lincoln and 
  Moore.

* Until 1 AM CDT Friday

* A secondary band of moderate to heavy showers and thunderstorms 
  will sweep eastward across the Tennessee Valley this evening with 
  a cold front. The additional rainfall will aggravate pre-existing 
  flooding issues across the region, and could enhance the threat 
  for flash flooding once again.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that conditions may develop that lead to 
Flash Flooding. Flash Flooding is a very dangerous situation. You 
should monitor later forecasts and be prepared to take action should 
Flash Flood Warnings be issued.

&&

$$

70/DD
622 
WGUS64 KHUN 260403
FFAHUN

Flood Watch
National Weather Service Huntsville AL
1103 PM CDT Thu Mar 25 2021

ALZ001>010-016-TNZ076-096-097-260515-
/O.CAN.KHUN.FF.A.0003.000000T0000Z-210326T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan-
Marshall-Jackson-DeKalb-Cullman-Moore-Lincoln-Franklin TN-
Including the cities of Russellville, Winchester, Fort Payne, Red 
Bay, Cullman, Town Creek, Cowan, Estill Springs, Huntsville, 
Sheffield, Arab, Sewanee, Decatur, Lynchburg, Athens, Muscle Shoals, 
Decherd, Fayetteville, Albertville, Guntersville, Boaz, Rainsville, 
Tuscumbia, Moulton, Florence, and Scottsboro
1103 PM CDT Thu Mar 25 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of Alabama and southern middle 
Tennessee, including the following areas, in Alabama, Colbert, 
Cullman, DeKalb, Franklin AL, Jackson, Lauderdale, Lawrence, 
Limestone, Madison, Marshall and Morgan. In southern middle 
Tennessee, Franklin TN, Lincoln and Moore has been cancelled.

A couple of bands of light to moderate showers will shift eastward 
across northeast Alabama late this evening, ahead of a cold front. 
However, the rainfall is not expected to result in additional flash 
flooding and the Flood Watch has been cancelled. Although flooding 
is no longer expected to pose a threat, please continue to heed 
remaining road closures.

$$

70/DD

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 24, 9:32 AM CDTRiver Flood WarningHUNJackson, Madison, Marshall9 days
Mar 24, 9:34 AM CDTRiver Flood WarningHUNMadison47 hr

Nearby

Flash Flood Watches in Alabama, 2021Flash Flood Watches in Tennessee, 2021Every flash flood watch 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.