Alert archive / Alabama / Special Weather Statements in 2021

Special Weather Statement, NWS Birmingham, AL

July 9, 2021DeKalb County, Alabama

NWS Birmingham, AL issued this special weather statement at Jul 9, 2021, 12:21 PM CDT for DeKalb County, Alabama. It was in force for 24 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 9, 2021, 12:21 PM CDT (17:21 UTC)
Expired: Jul 9, 2021, 12:45 PM CDT
In force: 24 min
Issued by: NWS Birmingham, AL

County DeKalb County, AL

The radar

The Northeast Alabama radar (KHTX), 72 km from the middle of the area, began a volume at 17:22 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

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 5.4 hours before the alert went out and 155 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: 785 J/kg
Mixed-layer CIN: -37 J/kg
Mixed-layer LCL: 638 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: 39 m²/s²
0-3 km storm-relative helicity: 22 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

910 
WWUS84 KBMX 091721
SPSBMX

Special Weather Statement
National Weather Service Birmingham AL
1221 PM CDT Fri Jul 9 2021
 
ALZ020-091745-
Cherokee AL-
1221 PM CDT Fri Jul 9 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN CHEROKEE COUNTY
UNTIL 1245 PM CDT...

At 1219 PM CDT, Doppler radar was tracking a cluster of strong 
thunderstorms near Fort Payne, moving east at 45 mph.

Pea size hail and winds in excess of 40 mph will be possible with
these storms.

Locations impacted include...
Little River Canyon National Preserve, Blanche, New Moon, Broomtown,
Fullerton and Chesterfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning are occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3452 8551 3429 8546 3432 8570 3436 8566
      3437 8563 3439 8562 3444 8558 3447 8558
      3447 8557 3449 8557 3449 8556 3450 8556
      3450 8555 3453 8552
TIME...MOT...LOC 1719Z 290DEG 39KT 3450 8562 

$$

15

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 8, 7:43 PM CDT	Special Weather Statement	BMX	Sumter	47 min
Jul 8, 8:23 PM CDT	Special Weather Statement	BMX	Marengo	22 min
Jul 9, 12:47 PM CDT	Special Weather Statement	BMX	DeKalb	43 min
Jul 9, 12:50 PM CDT	Special Weather Statement	BMX	Tuscaloosa	40 min
Jul 9, 1:57 PM CDT	Special Weather Statement	BMX	Bibb	33 min
Jul 9, 2:42 PM CDT	Special Weather Statement	BMX	Shelby	33 min
Jul 9, 3:08 PM CDT	Special Weather Statement	BMX	Coosa	37 min
Jul 9, 4:08 PM CDT	Special Weather Statement	BMX	Barbour	37 min
Jul 9, 4:25 PM CDT	Special Weather Statement	BMX	Tallapoosa	35 min
Jul 9, 4:49 PM CDT	Special Weather Statement	BMX	Blount	26 min
Jul 9, 5:14 PM CDT	Special Weather Statement	BMX	Blount	46 min
Jul 9, 5:19 PM CDT	Special Weather Statement	BMX	Lee	41 min
Jul 9, 5:51 PM CDT	Special Weather Statement	BMX	Russell	24 min
Jul 9, 5:56 PM CDT	Special Weather Statement	BMX	St. Clair	49 min
Jul 9, 6:17 PM CDT	Special Weather Statement	BMX	Russell	28 min
Jul 9, 6:20 PM CDT	Special Weather Statement	BMX	Winston	25 min
Jul 9, 6:35 PM CDT	Special Weather Statement	BMX	Coosa, Shelby, Tuscaloosa	40 min

Nearby

Special Weather Statements in Alabama, 2021 Every special weather statement 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.