Alert archive / Oklahoma / Tornado Warnings in 2011

Tornado Warning 21, NWS Norman, OK

April 22, 2011Pottawatomie County, Oklahoma

NWS Norman, OK issued this tornado warning at Apr 22, 2011, 6:27 PM CDT for Pottawatomie County, Oklahoma. It was in force for 33 min. 5 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Apr 22, 2011, 6:27 PM CDT (23:27 UTC)
Expired: Apr 22, 2011, 7:00 PM CDT
In force: 33 min
Issued by: NWS Norman, OK
Area: Storm-based polygon

County Pottawatomie County, OK

The radar

The Norman radar (KTLX), 27 km from the middle of the area, began a volume at 23:27 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.

What was reported inside it

Time	Report	Where	Remark
Apr 22, 6:38 PM CDT	HAIL 1.25	Bethel Acres, OK
Apr 22, 6:40 PM CDT	HAIL 1.75	1 W Tecumseh, OK	DELAYED REPORT FROM POTTAWATOMIE NATION
Apr 22, 6:40 PM CDT	HAIL 2.75	2 S Tecumseh, OK	AMATEUR RADIO REPORT OF BASEBALL SIZED HAIL 2 MILES SOUTH OF STATE HIGHWAY 9 AND 2 MILES EAST OF HIGHWAY 102.
Apr 22, 6:42 PM CDT	HAIL 1.75	3 E Pink, OK
Apr 22, 7:04 PM CDT	HAIL 1	Tecumseh, OK

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

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

Issued	Product	Office	Lasted
Apr 22, 3:47 PM CDT	Tornado Watch	SPC	8 hr

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 11.5 hours before the alert went out and 40 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: 1839 J/kg
Mixed-layer CIN: -330 J/kg
Mixed-layer LCL: 987 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 514 m²/s²
0-3 km storm-relative helicity: 647 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

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

026 
WFUS54 KOUN 222327
TOROUN
OKC125-230000-
/O.NEW.KOUN.TO.W.0021.110422T2327Z-110423T0000Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE NORMAN OK
627 PM CDT FRI APR 22 2011

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A

* TORNADO WARNING FOR...
  CENTRAL POTTAWATOMIE COUNTY IN CENTRAL OKLAHOMA...

* UNTIL 700 PM CDT

* AT 627 PM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED A SEVERE
  THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR PINK...MOVING
  NORTHEAST AT 10 MPH.

* LOCATIONS IN THE WARNING INCLUDE BETHEL ACRES...PINK...SHAWNEE AND
  TECUMSEH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. LEAVE MOBILE HOMES AND VEHICLES. IF POSSIBLE...MOVE
TO A BASEMENT OR STORM SHELTER. OTHERWISE MOVE TO AN INTERIOR ROOM OR
HALLWAY ON THE LOWEST FLOOR. STAY AWAY FROM WINDOWS AND OUTSIDE
WALLS.

&&

LAT...LON 3542 9688 3523 9685 3522 9714 3529 9714
TIME...MOT...LOC 2327Z 245DEG 10KT 3526 9711

$$


..SPEG.

1 follow-up statement

121 
WWUS54 KOUN 222349
SVSOUN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
649 PM CDT FRI APR 22 2011

OKC125-230000-
/O.CON.KOUN.TO.W.0021.000000T0000Z-110423T0000Z/
POTTAWATOMIE OK-
649 PM CDT FRI APR 22 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 700 PM CDT FOR CENTRAL
POTTAWATOMIE COUNTY...

AT 648 PM CDT...NATIONAL WEATHER SERVICE RADAR DETECTED A SEVERE 
THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR BETHEL ACRES OR 
ABOUT 5 MILES EAST OF PINK. THE AREA OF CIRCULATION WAS MOVING 
EAST-NORTHEAST AT 10 MPH. ALTHOUGH THE ROTATION HAS CURRENTLY 
WEAKENED IN THE LOWEST LEVELS... ROTATION PERSISTS IN THE MID LEVELS 
OF THE STORM AND THE STORM IS STILL CAPABLE OF PRODUCING A TORNADO.

* LOCATIONS IN THE WARNING INCLUDE BETHEL ACRES...PINK...SHAWNEE AND
  TECUMSEH.

LAT...LON 3542 9688 3523 9685 3522 9714 3529 9714
TIME...MOT...LOC 2348Z 250DEG 10KT 3529 9703

$$


..SPEG.

The office that day

Everything else NWS Norman, OK issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 21, 10:24 PM CDT	Special Weather Statement	OUN	Jackson	36 min
Apr 21, 10:51 PM CDT	Special Weather Statement	OUN	Tillman	24 min
Apr 21, 10:52 PM CDT	Special Weather Statement	OUN	Tillman	23 min
Apr 22, 4:50 PM CDT	Special Weather Statement	OUN	Lincoln	15 min
Apr 22, 5:01 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln	29 min
Apr 22, 5:33 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln	42 min
Apr 22, 5:46 PM CDT	Special Weather Statement	OUN	Cleveland, McClain	14 min
Apr 22, 6:03 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Garvin, McClain, Pottawatomie	57 min
Apr 22, 6:12 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Pottawatomie, Seminole	48 min
Apr 22, 6:26 PM CDT	Severe Thunderstorm Warning	OUN	Jefferson	64 min

Nearby

Tornado Warnings in Oklahoma, 2011 Every tornado warning in 2011 Tornadoes 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.