Alert archive / Alabama / Flash Flood Warnings in 2011

Flash Flood Warning 35, NWS Birmingham, AL

July 21, 2011Clay County, Talladega County, Alabama

NWS Birmingham, AL issued this flash flood warning at Jul 21, 2011, 3:35 AM CDT for Clay County, Talladega County, Alabama. It was in force for 3 hr. 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 21, 2011, 3:35 AM CDT (08:35 UTC)
Expired: Jul 21, 2011, 6:30 AM CDT
In force: 3 hr
Issued by: NWS Birmingham, AL
Area: Storm-based polygon
Flood severity: None

Counties Clay County, AL, Talladega County, AL

The radar

The Birmingham radar (KBMX), 75 km from the middle of the area, began a volume at 08:37 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, 8.6 hours before the alert went out and 76 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: 642 J/kg
Mixed-layer CIN: -66 J/kg
Mixed-layer LCL: 994 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 21 m²/s²
0-3 km storm-relative helicity: 101 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.

124 
WGUS54 KBMX 210835
FFWBMX
ALC027-121-211130-
/O.NEW.KBMX.FF.W.0035.110721T0835Z-110721T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE BIRMINGHAM AL
335 AM CDT THU JUL 21 2011

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL TALLADEGA COUNTY IN EAST CENTRAL ALABAMA...
  NORTHEASTERN CLAY COUNTY IN EAST CENTRAL ALABAMA...

* UNTIL 630 AM CDT

* AT 333 AM CDT...NATIONAL WEATHER SERVICE INDICATED SLOW MOVING     
  THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA.     
  ESTIMATED AMOUNTS OF TWO TO THREE INCHES HAVE BEEN OBSERVED BY     
  RADAR...WITH AN ADDITIONAL ONE TO TWO INCHES EXPECTED AS THE       
  STORMS CONTINUE TO MOVE OVER THE SAME AREA.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  TALLADEGA...ALPINE BAY RESORT...BARFIELD...LOGAN MARTIN DAM AND
  WALDO.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. DO
NOT ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND TO
ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN
WATER BEGINS RISING.

&&

TO REPORT SEVERE WEATHER...
CALL 1-800-856-0758.

LAT...LON 3334 8565 3336 8635 3339 8638 3346 8630
      3350 8629 3350 8626 3349 8626 3350 8623
      3347 8589 3347 8578 3344 8564 3342 8564

$$

16

1 follow-up statement

958 
WGUS74 KBMX 211002
FFSBMX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
502 AM CDT THU JUL 21 2011

ALC027-121-211130-
/O.CON.KBMX.FF.W.0035.000000T0000Z-110721T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLAY AL-TALLADEGA AL-
502 AM CDT THU JUL 21 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR CENTRAL TALLADEGA AND
NORTHEASTERN CLAY COUNTIES UNTIL 630 AM CDT...

AT 459 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. 
RAINFALL ESTIMATES RANGE FROM 2 TO 3 INCHES OVER THE PAST 3 
HOURS...WITH AN ADDITIONAL 1 INCH OVER THE NEXT HOUR. RAINFALL HAS 
DECREASED OVER THE PAST HOUR...FLOODING IS STILL POSSIBLE.

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLASH FLOODING INCLUDE...
TALLADEGA...ALPINE...ALPINE BAY RESORT...BARFIELD...LOGAN MARTIN DAM
AND WALDO.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLOODING IS OBSERVED...ACT QUICKLY. DO NOT
ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND. DO NOT
STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 3334 8565 3336 8635 3339 8638 3346 8630
      3350 8629 3350 8626 3349 8626 3350 8623
      3347 8589 3347 8578 3344 8564 3342 8564

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 21, 3:17 AM CDT	Areal Flood Advisory	BMX	Clay, Randolph, St. Clair, Shelby, Talladega	118 min
Jul 21, 4:04 AM CDT	Areal Flood Advisory	BMX	Jefferson, St. Clair, Walker	3 hr
Jul 21, 4:30 AM CDT	Flash Flood Warning	BMX	Jefferson	4 hr
Jul 21, 5:19 AM CDT	Areal Flood Advisory	BMX	Calhoun, Clay, Cleburne, Randolph, Talladega	116 min
Jul 21, 7:00 AM CDT	Areal Flood Advisory	BMX	Fayette, Lamar, Walker	3 hr
Jul 21, 7:19 AM CDT	Flash Flood Warning	BMX	St. Clair	3 hr
Jul 21, 8:06 AM CDT	Flash Flood Warning	BMX	Walker	3 hr
Jul 21, 8:46 AM CDT	Flash Flood Warning	BMX	Walker	3 hr

Nearby

Flash Flood Warnings in Alabama, 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.