Alert archive / Alabama / Flash Flood Warnings in 2011

Flash Flood Warning 45, NWS Huntsville, AL

July 30, 2011Madison County, Alabama; Lincoln County, Tennessee

NWS Huntsville, AL issued this flash flood warning at Jul 30, 2011, 11:54 AM CDT for Madison County, Alabama; Lincoln County, Tennessee. It was in force for 90 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 30, 2011, 11:54 AM CDT (16:54 UTC)
Expired: Jul 30, 2011, 1:24 PM CDT
In force: 90 min
Issued by: NWS Huntsville, AL
Area: Storm-based polygon
Flood severity: None

Counties Madison County, AL, Lincoln County, TN

The radar

The Northeast Alabama radar (KHTX), 61 km from the middle of the area, began a volume at 16:56 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, 4.9 hours before the alert went out and 107 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: 1824 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 652 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: -6 m²/s²
0-3 km storm-relative helicity: 13 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.

040 
WGUS54 KHUN 301654
FFWHUN
ALC089-TNC103-301930-
/O.NEW.KHUN.FF.W.0045.110730T1654Z-110730T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1154 AM CDT SAT JUL 30 2011

THE NATIONAL WEATHER SERVICE IN HUNTSVILLE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHERN MADISON COUNTY IN NORTH CENTRAL ALABAMA...
  WESTERN LINCOLN COUNTY IN TENNESSEE...

* UNTIL 230 PM CDT

* AT 1153 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR            
  INDICATED SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL       
  ACROSS THE WESTERN HALF OF LINCOLN COUNTY IN TENNESSEE...WHICH     
  WILL MOVE INTO NORTHERN MADISON COUNTY IN ALABAMA.  RAINFALL       
  AMOUNTS OF 2 TO 4 INCHES ARE LIKELY IN SOME AREAS WITHIN A ONE     
  HOUR PERIOD.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...     
  FAYETTEVILLE...TAFT...MERIDIANVILLE...MOORES MILL...HAZEL GREEN    
  AND PETERSBURG.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN HILLY TERRAIN THERE ARE HUNDREDS OF LOW WATER CROSSINGS WHICH ARE
POTENTIALLY DANGEROUS IN HEAVY RAIN. DO NOT ATTEMPT TO TRAVEL ACROSS
FLOODED ROADS. FIND ALTERNATE ROUTES. IT ONLY TAKES A FEW INCHES OF
SWIFTLY FLOWING WATER TO CARRY VEHICLES AWAY.

&&

LAT...LON 3515 8655 3474 8635 3493 8675 3511 8684
      3522 8684 3526 8683 3527 8682 3526 8674
      3531 8668 3533 8664 3532 8661

$$

KULA

1 follow-up statement

108 
WGUS74 KHUN 301824
FFSHUN

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
124 PM CDT SAT JUL 30 2011

ALC089-TNC103-301839-
/O.CAN.KHUN.FF.W.0045.000000T0000Z-110730T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MADISON AL-LINCOLN TN-
124 PM CDT SAT JUL 30 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR WESTERN LINCOLN AND
NORTHERN MADISON COUNTIES IS CANCELLED...

EXCESS RUNOFF FROM HEAVY RAIN HAS DIMINISHED...BUT MINOR STREET 
FLOODING AND PONDING OF WATER COULD STILL BE IN PROGRESS.  MOTORISTS 
SHOULD CONTINUE TO EXERCISE CAUTION.

IF FLOODING HAS BEEN OBSERVED...PLEASE REPORT IT TO YOUR LOCAL LAW 
ENFORCEMENT AGENCY.


LAT...LON 3515 8655 3474 8635 3493 8675 3511 8684
      3522 8684 3526 8683 3527 8682 3526 8674
      3531 8668 3533 8664 3532 8661

$$


KULA

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 30, 10:59 AM CDT	Special Weather Statement	HUN	Madison	46 min
Jul 30, 11:18 AM CDT	Flash Flood Warning	HUN	Madison	2 hr
Jul 30, 12:14 PM CDT	Flash Flood Warning	HUN	Madison	88 min
Jul 30, 12:33 PM CDT	Special Weather Statement	HUN	Limestone	42 min
Jul 30, 3:36 PM CDT	Special Weather Statement	HUN	Cullman	24 min
Jul 30, 6:27 PM CDT	Special Weather Statement	HUN	Morgan	33 min
Jul 30, 6:36 PM CDT	Special Weather Statement	HUN	Lawrence	24 min
Jul 30, 6:58 PM CDT	Special Weather Statement	HUN	Lawrence	32 min
Jul 30, 11:40 AM CDT	Special Weather Statement	HUN	Lincoln	65 min

Nearby

Flash Flood Warnings in Alabama, 2011 Flash Flood Warnings in Tennessee, 2011 Every flash flood warning in 2011

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.