Alert archive / Alabama / Flash Flood Warnings in 2023

Flash Flood Warning 21, NWS Huntsville, AL

August 4, 2023Morgan County, Alabama

NWS Huntsville, AL issued this flash flood warning at Aug 4, 2023, 3:48 AM CDT for Morgan County, Alabama. It was in force for 3 hr. 2 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
Aug 4, 2023, 3:48 AM CDT (08:48 UTC)
Expired
Aug 4, 2023, 6:30 AM CDT
In force
3 hr
Issued by
NWS Huntsville, AL
Area
Storm-based polygon
Flood severity
None

County Morgan County, AL

The radar

The Northeast Alabama radar (KHTX), 93 km from the middle of the area, began a volume at 08:51 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
Aug 4, 4:30 AM CDTFLOOD2 N Decatur, ALLee St blocked due to flooding.
Aug 4, 5:36 AM CDTFLOOD1 E Decatur, ALFlooding on Country Club Rd just past Fairway Dr.

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, 8.8 hours before the alert went out and 163 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 2023-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 109 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 2023-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 131 square meters per square second.193958Sfc1 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
109 J/kg
Mixed-layer CIN
-268 J/kg
Mixed-layer LCL
1450 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
131 m²/s²
0-3 km storm-relative helicity
163 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

119 
WGUS54 KHUN 040848
FFWHUN
ALC103-041130-
/O.NEW.KHUN.FF.W.0021.230804T0848Z-230804T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Huntsville AL
348 AM CDT Fri Aug 4 2023

The National Weather Service in Huntsville has issued a

* Flash Flood Warning for...
  Northwestern Morgan County in north central Alabama...

* Until 630 AM CDT.

* At 348 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across northwest Morgan County. Between 1 and 2 inches 
  of rain have fallen. Additional rainfall amounts of 1 to 2 inches 
  are possible. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  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...
  Decatur and Trinity.

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 3465 8704 3460 8694 3459 8693 3453 8696
      3457 8710 3468 8710 3468 8709 3467 8709
      3466 8707 3465 8705

FLASH FLOOD...RADAR INDICATED

$$

RSB
1 follow-up statement
261 
WGUS74 KHUN 041005
FFSHUN

Flash Flood Statement
National Weather Service Huntsville AL
505 AM CDT Fri Aug 4 2023

ALC103-041130-
/O.CON.KHUN.FF.W.0021.000000T0000Z-230804T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Morgan AL-
505 AM CDT Fri Aug 4 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 AM CDT THIS 
MORNING FOR NORTHWESTERN MORGAN COUNTY...

At 505 AM CDT, Doppler radar indicated thunderstorms producing heavy 
rain across northwest Alabama. Between 1 and 4 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 thunderstorms.

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...
  Decatur and Trinity.

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 3465 8704 3460 8694 3459 8693 3453 8696
      3457 8710 3468 8710 3468 8709 3467 8709
      3466 8707 3465 8705

FLASH FLOOD...RADAR INDICATED

$$

RSB

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 3:15 AM CDTSpecial Weather StatementHUNColbert45 min
Aug 4, 4:26 AM CDTFlash Flood WarningHUNLauderdale, Limestone2 hr
Aug 4, 4:33 AM CDTFlash Flood WarningHUNCullman4 hr
Aug 4, 6:31 AM CDTAreal Flood WarningHUNLauderdale, Limestone, Morgan3 hr
Aug 4, 8:19 AM CDTAreal Flood WarningHUNCullman101 min

Nearby

Flash Flood Warnings in Alabama, 2023Every flash flood warning in 2023

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.