Alert archive / Alabama / Flash Flood Warnings in 2012

Flash Flood Warning 30, NWS Huntsville, AL

July 19, 2012Colbert County, Alabama

NWS Huntsville, AL issued this flash flood warning at Jul 19, 2012, 7:23 PM CDT for Colbert County, Alabama. It was in force for 75 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 19, 2012, 7:23 PM CDT (00:23 UTC)
Expired
Jul 19, 2012, 8:38 PM CDT
In force
75 min
Issued by
NWS Huntsville, AL
Area
Storm-based polygon
Flood severity
None

County Colbert County, AL

The radar

The Columbus AFB radar (KGWX), 112 km from the middle of the area, began a volume at 00:24 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, 0.4 hours before the alert went out and 177 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 2012-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1296 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 2012-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 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
1296 J/kg
Mixed-layer CIN
-22 J/kg
Mixed-layer LCL
1289 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
44 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

886 
WGUS54 KHUN 200023
FFWHUN
ALC033-200230-
/O.NEW.KHUN.FF.W.0030.120720T0023Z-120720T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HUNTSVILLE AL
723 PM CDT THU JUL 19 2012

THE NATIONAL WEATHER SERVICE IN HUNTSVILLE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN COLBERT COUNTY IN NORTHWEST ALABAMA...

* UNTIL 930 PM CDT

* AT 720 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS PORTIONS 
  OF EASTERN AND SOUTHEASTERN COLBERT COUNTY. RADAR ESTIMATES INDICATE  
  THAT 2 TO LOCALLY 3 INCHES OF RAINFALL HAS ALREADY FALLEN IN SOME  
  AREAS SINCE 6 PM. AN ADDITIONAL 1 TO 2 INCHES OF RAINFALL IS       
  POSSIBLE THROUGH 9 PM WHICH WILL CAUSE FLASH FLOODING. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...     
  LEIGHTON...WHITEOAK...SPRING VALLEY.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...
COUNTRY ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND
OTHER LOW LYING AREAS ARE SUBJECT TO FLOODING.

&&

LAT...LON 3474 8746 3465 8746 3465 8748 3463 8748
      3460 8751 3458 8751 3457 8752 3458 8766
      3474 8768

$$
2 follow-up statements
612 
WGUS74 KHUN 200100
FFSHUN

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
800 PM CDT THU JUL 19 2012

ALC033-200230-
/O.CON.KHUN.FF.W.0030.000000T0000Z-120720T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
COLBERT AL-
800 PM CDT THU JUL 19 2012

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR EAST CENTRAL COLBERT
COUNTY UNTIL 930 PM CDT...

AT 757 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A 
CLUSTER OF SLOW MOVING THUNDERSTORMS ACROSS EASTERN COLBERT COUNTY. 
RADAR ESTIMATES INDICATE THAT 2 TO LOCALLY 4 INCHES OF RAIN HAVE 
ALREADY FALLEN IN A NARROW CORRIDOR FROM JUST WEST OF LEIGHTON TO 
WHITEOAK TO NEAR SPRING VALLEY. LOCALLY HEAVY RAINFALL WILL REMAIN 
POSSIBLE IN THE SPRING VALLEY AREA THROUGH 9 PM...BUT THE RAIN HAS 
BEGUN TO TAPER OFF QUICKLY IN WHITEOAK AND LEIGHTON. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLOODING OF SMALL CREEKS
AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY ROADS
AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW LYING
AREAS ARE ALSO SUBJECT TO FLOODING.

&&

LAT...LON 3474 8751 3467 8749 3465 8749 3464 8749
      3461 8751 3460 8751 3460 8753 3461 8766
      3473 8768

$$
058 
WGUS74 KHUN 200138
FFSHUN

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
838 PM CDT THU JUL 19 2012

ALC033-200153-
/O.CAN.KHUN.FF.W.0030.000000T0000Z-120720T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
COLBERT AL-
838 PM CDT THU JUL 19 2012

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTHEASTERN
COLBERT COUNTY IS CANCELLED...

EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. STREAMS
AND CREEKS IN THE WARNED AREA HAVE RECEDED OR WERE BEGINNING TO
RECEDE...ENDING THE FLOOD THREAT. IF FLOODING HAS BEEN OBSERVED...
PLEASE REPORT IT TO YOUR LOCAL LAW ENFORCEMENT AGENCY.

LAT...LON 3474 8751 3467 8749 3465 8749 3464 8749
      3461 8751 3460 8751 3460 8753 3461 8766
      3473 8768

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 19, 7:13 PM CDTSevere Thunderstorm WarningHUNColbert47 min
Jul 20, 3:54 AM CDTSpecial Weather StatementHUNJackson51 min
Jul 20, 4:09 AM CDTSpecial Weather StatementHUNLimestone51 min
Jul 20, 4:22 AM CDTSpecial Weather StatementHUNJackson38 min
Jul 20, 4:51 AM CDTSpecial Weather StatementHUNDeKalb39 min
Jul 20, 5:15 AM CDTSpecial Weather StatementHUNMorgan45 min

Nearby

Flash Flood Warnings in Alabama, 2012Every flash flood warning in 2012

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.