Alert archive / Oklahoma / Tornado Warnings in 2011
Tornado Warning 31, NWS Norman, OK
NWS Norman, OK issued this tornado warning at May 21, 2011, 6:54 PM CDT for Johnston County, Murray County, Pontotoc County, Oklahoma. It was in force for 51 min. 2 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
- May 21, 2011, 6:54 PM CDT (23:54 UTC)
- Expired
- May 21, 2011, 7:45 PM CDT
- In force
- 51 min
- Issued by
- NWS Norman, OK
- Area
- Storm-based polygon
Counties Johnston County, OK, Murray County, OK, Pontotoc County, OK
The radar
The Norman radar (KTLX), 93 km from the middle of the area, began a volume at 23:54 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 |
|---|---|---|---|
| May 21, 7:00 PM CDT | HAIL 1.75 | 2 N Sulphur, OK | |
| May 21, 7:40 PM CDT | TORNADO | 1 Ese Hickory, OK | MULTIPLE REPORTS |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Norman, OK (KOUN), launched 12:00Z, 11.9 hours before the alert went out and 87 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.
- Mixed-layer CAPE
- 75 J/kg
- Mixed-layer CIN
- -375 J/kg
- Mixed-layer LCL
- 1414 m above ground
- 0-6 km bulk shear
- 57 kt
- 0-1 km storm-relative helicity
- 305 m²/s²
- 0-3 km storm-relative helicity
- 321 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted, in the capitals the NWS used until 2016.
520 WFUS54 KOUN 212354 TOROUN OKC069-099-123-220045- /O.NEW.KOUN.TO.W.0031.110521T2354Z-110522T0045Z/ BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE NORMAN OK 654 PM CDT SAT MAY 21 2011 THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A * TORNADO WARNING FOR... SOUTHWESTERN PONTOTOC COUNTY IN EAST CENTRAL OKLAHOMA... NORTHWESTERN JOHNSTON COUNTY IN SOUTHEAST OKLAHOMA... EASTERN MURRAY COUNTY IN SOUTHERN OKLAHOMA... * UNTIL 745 PM CDT * AT 655 PM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR SULPHUR...MOVING NORTHEAST AT 15 MPH. * LOCATIONS IN THE WARNING INCLUDE HICKORY...ROFF...SCULLIN AND SULPHUR. 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 3466 9681 3446 9674 3445 9703 3454 9707 TIME...MOT...LOC 2355Z 237DEG 12KT 3451 9699 $$ 30
2 follow-up statements
209 WWUS54 KOUN 220011 SVSOUN SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE NORMAN OK 711 PM CDT SAT MAY 21 2011 OKC069-099-123-220045- /O.CON.KOUN.TO.W.0031.000000T0000Z-110522T0045Z/ MURRAY OK-JOHNSTON OK-PONTOTOC OK- 711 PM CDT SAT MAY 21 2011 ...A TORNADO WARNING REMAINS IN EFFECT UNTIL 745 PM CDT FOR SOUTHWESTERN PONTOTOC...NORTHWESTERN JOHNSTON AND EASTERN MURRAY COUNTIES... AT 711 PM CDT...NATIONAL WEATHER SERVICE RADAR DETECTED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR SULPHUR...MOVING EAST AT 20 MPH. HAIL TO THE SIZE OF GOLF BALLS WILL ALSO BE POSSIBLE WITH THIS STORM. * LOCATIONS IN THE WARNING INCLUDE HICKORY...ROFF...SCULLIN AND SULPHUR. LAT...LON 3449 9698 3456 9702 3466 9681 3446 9674 TIME...MOT...LOC 0011Z 256DEG 17KT 3453 9691 $$ 30
559 WWUS54 KOUN 220025 SVSOUN SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE NORMAN OK 725 PM CDT SAT MAY 21 2011 OKC069-099-123-220045- /O.CON.KOUN.TO.W.0031.000000T0000Z-110522T0045Z/ MURRAY OK-JOHNSTON OK-PONTOTOC OK- 725 PM CDT SAT MAY 21 2011 ...A TORNADO WARNING REMAINS IN EFFECT UNTIL 745 PM CDT FOR SOUTHWESTERN PONTOTOC...NORTHWESTERN JOHNSTON AND NORTHEASTERN MURRAY COUNTIES... AT 725 PM CDT...NATIONAL WEATHER SERVICE RADAR DETECTED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR HICKORY...MOVING EAST AT 20 MPH. * LOCATIONS IN THE WARNING INCLUDE HICKORY...ROFF AND SCULLIN. LAT...LON 3452 9691 3459 9695 3466 9681 3448 9675 TIME...MOT...LOC 0025Z 256DEG 17KT 3454 9684 $$ 30
The office that day
Everything else NWS Norman, OK issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 20, 8:59 PM CDT | River Flood Warning | OUN | Lincoln, Oklahoma, Pottawatomie | 62 min |
| May 21, 1:46 PM CDT | River Flood Warning | OUN | Cotton | 26 hr |
| May 21, 6:21 PM CDT | Special Weather Statement | OUN | Murray | 9 min |
| May 21, 6:31 PM CDT | Severe Thunderstorm Warning | OUN | Murray, Pontotoc | 44 min |
Nearby
Tornado Warnings in Oklahoma, 2011Every tornado warning in 2011Tornadoes 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.