Alert archive / Alabama / Tornado Warnings in 2017

Tornado Warning 52, NWS Birmingham, AL

August 31, 2017Bibb County, Perry County, Alabama

NWS Birmingham, AL issued this tornado warning at Aug 31, 2017, 7:12 PM CDT for Bibb County, Perry County, Alabama. It was in force for 21 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: Aug 31, 2017, 7:12 PM CDT (00:12 UTC)
Expired: Aug 31, 2017, 7:33 PM CDT
In force: 21 min
Issued by: NWS Birmingham, AL
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Bibb County, AL, Perry County, AL

The radar

The Birmingham radar (KBMX), 56 km from the middle of the area, began a volume at 00:12 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Aug 31, 11:13 AM CDT	Tornado Watch	SPC	11 hr

The nearest sounding before it

Birmingham, AL (KBMX), launched 00:00Z, 0.2 hours before the alert went out and 56 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: 545 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 1112 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 258 m²/s²
0-3 km storm-relative helicity: 347 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 11.0

Open this sounding in Storm Lab

The text

As transmitted.

012 
WFUS54 KBMX 010012
TORBMX
ALC007-105-010100-
/O.NEW.KBMX.TO.W.0052.170901T0012Z-170901T0100Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Birmingham AL
712 PM CDT THU AUG 31 2017

The National Weather Service in Birmingham has issued a

* Tornado Warning for...
  North central Perry County in central Alabama...
  Southwestern Bibb County in central Alabama...

* Until 800 PM CDT
    
* At 711 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Heiberger, or 12 miles north of Marion, moving
  northeast at 30 mph.

  HAZARD...Tornado. 

  SOURCE...Radar indicated rotation. 

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely. 

* Locations impacted include...
  Brent, Centreville, Eoline, West Centreville and Ellards. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 3274 8735 3281 8743 3310 8716 3302 8702
TIME...MOT...LOC 0011Z 221DEG 28KT 3280 8736 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

32/Davis

1 follow-up statement

502 
WWUS54 KBMX 010033
SVSBMX

Severe Weather Statement
National Weather Service Birmingham AL
733 PM CDT THU AUG 31 2017

ALC007-105-010042-
/O.CAN.KBMX.TO.W.0052.000000T0000Z-170901T0100Z/
Perry AL-Bibb AL-
733 PM CDT THU AUG 31 2017

...THE TORNADO WARNING FOR NORTH CENTRAL PERRY AND SOUTHWESTERN BIBB
COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore the warning has been cancelled.

A tornado watch remains in effect until 800 PM CDT for central
Alabama.

However, a Tornado Warning still REMAINS in effect for northern 
Bibb County!

LAT...LON 3274 8735 3281 8743 3310 8716 3302 8702
TIME...MOT...LOC 0030Z 221DEG 28KT 3293 8723 

$$

32/Davis

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 31, 7:37 PM CDT	Tornado Warning	BMX	Jefferson, Tuscaloosa	38 min
Aug 31, 8:31 PM CDT	Areal Flood Advisory	BMX	Bibb, Blount, Chilton, Jefferson, Shelby, Tuscaloosa	119 min
Aug 31, 8:33 PM CDT	Special Weather Statement	BMX	Bibb, Chilton, Jefferson, Perry, St. Clair, Shelby	72 min
Aug 31, 8:41 PM CDT	Severe Thunderstorm Warning	BMX	Bibb, Chilton, Shelby	49 min
Aug 31, 9:14 PM CDT	Severe Thunderstorm Warning	BMX	Jefferson, St. Clair, Shelby, Talladega	46 min
Aug 31, 9:55 PM CDT	Special Weather Statement	BMX	Chilton, Talladega	35 min
Aug 31, 9:59 PM CDT	Special Weather Statement	BMX	Calhoun, St. Clair, Talladega	46 min
Aug 31, 10:15 PM CDT	Special Weather Statement	BMX	Etowah	45 min

Nearby

Tornado Warnings in Alabama, 2017 Every tornado warning in 2017 Tornadoes in 2017

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.