Alert archive / Oklahoma / Tornado Warnings in 2013

Tornado Warning 37, NWS Norman, OK

May 20, 2013Jefferson County, Oklahoma

NWS Norman, OK issued this tornado warning at May 20, 2013, 5:39 PM CDT for Jefferson County, Oklahoma. It was in force for 36 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: May 20, 2013, 5:39 PM CDT (22:39 UTC)
Expired: May 20, 2013, 6:15 PM CDT
In force: 36 min
Issued by: NWS Norman, OK
Area: Storm-based polygon

County Jefferson County, OK

The radar

The Altus AFB radar (KFDR), 118 km from the middle of the area, began a volume at 22:39 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this tornado warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

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

Issued	Product	Office	Lasted
May 20, 1:10 PM CDT	Tornado Watch	SPC	9 hr

The nearest sounding before it

Fort Worth, TX (KFWD), launched 12:00Z, 10.7 hours before the alert went out and 129 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: 747 J/kg
Mixed-layer CIN: -390 J/kg
Mixed-layer LCL: 893 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 275 m²/s²
0-3 km storm-relative helicity: 216 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.

253 
WFUS54 KOUN 202239
TOROUN
OKC067-202315-
/O.NEW.KOUN.TO.W.0037.130520T2239Z-130520T2315Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE NORMAN OK
539 PM CDT MON MAY 20 2013

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTH CENTRAL JEFFERSON COUNTY IN SOUTHERN OKLAHOMA...

* UNTIL 615 PM CDT
    
* AT 535 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED 5 MILES SOUTH OF TERRAL...AND MOVING EAST AT 40
  MPH.

* LOCATIONS IMPACTED INCLUDE...
  TERRAL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW IN A STORM SHELTER OR AN INTERIOR ROOM OF A STURDY
BUILDING. STAY AWAY FROM DOORS AND WINDOWS.
&&

LAT...LON 3388 9796 3393 9795 3397 9771 3395 9772
      3393 9776 3392 9776 3392 9779 3389 9778
      3390 9780 3388 9780 3386 9784 3385 9788
TIME...MOT...LOC 2238Z 280DEG 51KT 3382 9792 

$$

1 follow-up statement

179 
WWUS54 KOUN 202307
SVSOUN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
607 PM CDT MON MAY 20 2013

OKC067-202316-
/O.EXP.KOUN.TO.W.0037.000000T0000Z-130520T2315Z/
JEFFERSON OK-
607 PM CDT MON MAY 20 2013

...THE TORNADO WARNING FOR SOUTH CENTRAL JEFFERSON COUNTY WILL EXPIRE
AT 615 PM CDT...
        
THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE AREA.
THEREFORE THE WARNING WILL BE ALLOWED TO EXPIRE.

REMEMBER...A SEVERE THUNDERSTORM WARNING STILL REMAINS IN EFFECT FOR
SOUTHERN JEFFERSON COUNTY UNTIL 630 PM.

LAT...LON 3388 9796 3393 9795 3397 9771 3395 9772
      3393 9776 3392 9776 3392 9779 3389 9778
      3390 9780 3388 9780 3386 9784 3385 9788
TIME...MOT...LOC 2306Z 280DEG 51KT 3382 9792 

$$

What forecasters said that day

The local office's own words before this tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Norman, OK wrote its last area forecast discussion before this tornado warning went out at May 20, 1:52 PM CDT, 3 hours 47 minutes earlier.

Area forecast discussion, May 20, 1:52 PM CDT, 3 hours 47 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
152 PM CDT MON MAY 20 2013

.DISCUSSION...

...SEVERE THUNDERSTORMS EXPECTED THIS AFTERNOON AND EVENING ACROSS
MUCH OF OKLAHOMA AND WESTERN NORTH TEXAS...

RAPID THUNDERSTORM DEVELOPMENT IS EXPECTED OVER THE NEXT HOUR OR
TWO ALONG THE DRYLINE AND STATIONARY BOUNDARY. THIS WILL MAINLY
BE ALONG I44 FROM OKC SOUTHWARD...AND ALONG AND EAST OF I35 NORTH
OF OKC. RETURNS ALREADY BEING OBSERVED EAST OF LAWTON. MOST
RECENT MESOANALYSIS AND 18Z SOUNDING SUGGEST VERY LARGE HAIL AND
THE POSSIBILITY OF TORNADOES ESPECIALLY JUST SOUTH/SW OF METRO NE
OF TRIPLE POINT. STORMS SHOULD REMAIN DISCRETE UNTIL LATER
TONIGHT...PERHAPS MERGING ACROSS SOUTH CENTRAL/EAST CENTRAL OK
PRODUCING VERY HEAVY RAINFALL...HAIL...AND THE THREAT OF DAMAGING
WINDS ACROSS SE OK. ANOTHER ROUND OF ELEVATED CONVECTION MAY BE
POSSIBLE VERY LATE TONIGHT THROUGH EARLY TOMORROW MORNING AS
SHORTWAVE TROUGH IMPACTS THE AREA. COOLER TEMPS ARE EXPECTED
TOMORROW WITH THUNDERSTORMS CONTINUING PERHAPS THROUGH THE DAY
ACROSS SE OK.

A BREAK IN RAIN/THUNDERSTORM CHANCES WILL OCCUR WED...BUT WILL
RETURN THURS THROUGH SATURDAY AS SUBTLE SHORTWAVE TROUGHS ROUNDING
THE RIDGE AXIS IMPACT THE REGION AND ANOTHER WEAK COLD FRONT
ENTERS THE AREA. EXPECT NEAR AVG TEMPS THROUGH THE EXTENDED.

&&

.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK  64  76  60  84 /  50  30  10  10
HOBART OK         61  82  58  88 /  20  20  10  10
WICHITA FALLS TX  68  82  62  89 /  30  20  10  10
GAGE OK           54  81  53  85 /  20  10   0  10
PONCA CITY OK     59  78  55  80 /  40  20  10  10
DURANT OK         70  78  65  85 /  60  60  40  10

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&

30/03

Hazardous weather outlook, May 20, 12:30 PM CDT, 5 hours 9 minutes before

HAZARDOUS WEATHER OUTLOOK...OUTLOOK UNCHANGED
NATIONAL WEATHER SERVICE NORMAN OK
1230 PM CDT MON MAY 20 2013

OKZ004>048-050>052-TXZ083>090-211000-
HARPER-WOODS-ALFALFA-GRANT-KAY-ELLIS-WOODWARD-MAJOR-GARFIELD-NOBLE-
ROGER MILLS-DEWEY-CUSTER-BLAINE-KINGFISHER-LOGAN-PAYNE-BECKHAM-
WASHITA-CADDO-CANADIAN-OKLAHOMA-LINCOLN-GRADY-MCCLAIN-CLEVELAND-
POTTAWATOMIE-SEMINOLE-HUGHES-HARMON-GREER-KIOWA-JACKSON-TILLMAN-
COMANCHE-STEPHENS-GARVIN-MURRAY-PONTOTOC-COAL-COTTON-JEFFERSON-
CARTER-JOHNSTON-ATOKA-LOVE-MARSHALL-BRYAN-HARDEMAN-FOARD-WILBARGER-
WICHITA-KNOX-BAYLOR-ARCHER-CLAY-
1230 PM CDT MON MAY 20 2013

THIS HAZARDOUS WEATHER OUTLOOK COVERS NORTHERN...WESTERN...
CENTRAL...AND SOUTHERN OKLAHOMA...AND WESTERN NORTH TEXAS.

.DAY ONE...TODAY AND TONIGHT...

THUNDERSTORM OUTLOOK...
THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THROUGH TONIGHT
ACROSS PORTIONS OF OKLAHOMA AND WESTERN NORTH TEXAS. A FEW TORNADOES
ARE EXPECTED.

LOCATION...
THE MODERATE RISK AREA IS SOUTHEAST OF A LINE FROM WICHITA FALLS
TEXAS...TO LAWTON OKLAHOMA...TO EL RENO...TO GUTHRIE...TO
STILLWATER. A SLIGHT RISK AREA SURROUNDS THE MODERATE RISK...
AND IS EAST OF A LINE FROM MUNDAY TO VERNON IN TEXAS...AND
ALTUS...TO WEATHERFORD...TO MEDFORD IN OKLAHOMA.

TIMING...
ALTHOUGH SEVERE THUNDERSTORMS WILL BE POSSIBLE FROM 1 PM THROUGH
MIDNIGHT...THE PEAK HOURS FOR SEVERE WEATHER...INCLUDING TORNADOES...
WILL BE BETWEEN 3 PM AND 8 PM THIS AFTERNOON AND EVENING.

IMPACTS...
TORNADOES...POTENTIALLY STRONG WITH LONG TRACKS...ALONG WITH BASEBALL
SIZED HAIL AND DAMAGING WINDS ARE LIKELY WITH THE STRONGEST STORMS
WITHIN THE MODERATE RISK AREA. PING PONG BALL SIZED HAIL AND WINDS TO
ABOUT 60 MPH ARE EXPECTED WITH THE STRONGER STORMS WITHIN THE SLIGHT
RISK AREA.

RECOMMENDED ACTIONS...
STORM SPOTTER GROUPS AND EMERGENCY MANAGEMENT PERSONNEL ACROSS THE
RISK AREAS SHOULD PLAN FOR SEVERE WEATHER OPERATIONS FROM 1 PM UNTIL
MIDNIGHT.

DISCUSSION...
THE WEATHER SITUATION TODAY VERY MUCH RESEMBLES YESTERDAY. WARM...
UNSTABLE AIR WILL AGAIN LIE EAST OF A COLD FRONT/DRYLINE COMBINATION
THAT WILL BE OVER WESTERN AND CENTRAL OKLAHOMA...AND WESTERN NORTH
TEXAS. VERTICAL WIND PROFILES WILL AGAIN SUPPORT ROTATING UPDRAFTS
AND SUPERCELL THUNDERSTORMS...ESPECIALLY IN THE MODERATE RISK AREA.
A SLIGHTLY WEAKER CAPPING INVERSION IS INDICATED...WHICH SUGGESTS
A SLIGHTLY EARLIER BEGINNING OF STORM DEVELOPMENT...COMPARED TO
YESTERDAY. STORMS ARE EXPECTED TO BE FAIRLY SPARSE EARLY IN THE
EVENT...THEN MERGE INTO SMALL CLUSTERS DURING THE EVENING.

LATEST HIGH RESOLUTION NUMERICAL MODEL FORECASTS COUPLED WITH TRENDS
IN OTHER WEATHER DATA SETS SUGGEST THE INTIAL THREAT WILL FOCUS IN
CENTRAL OKLAHOMA IN THE INTERSTATE 44 CORRIDOR...INCLUDING THE OKLAHOMA
CITY METRO AREA. WE EXPECT STORMS TO RAPIDLY DEVELOP AROUND 1 OR 2 PM
IN THESE AREAS AND BECOME SEVERE AS THEY MOVE EAST. THE GREATEST RISK FOR
TORNADOES WILL BE SOUTH OF INTERSTATE 40 AND EAST OF INSTERSTATE 44.

PROBABILITY TABLE...
VALID THROUGH 700 AM CDT TUESDAY MAY 21.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
              NWS NORMAN COUNTY WARNING AREA...100 PERCENT.
PROBABILITY OF SEVERE STORMS IF STORMS OCCUR...NEAR 100 PERCENT.

OTHER HAZARDOUS WEATHER...
HOT...DRY...AND BREEZY CONDITIONS WILL RESULT IN ELEVATED WILDFIRE
POTENTIAL IN WESTERN NORTH TEXAS THIS AFTERNOON AND EARLY EVENING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY...

THUNDERSTORM OUTLOOK...
SEVERE STORMS WILL BE POSSIBLE AGAIN ON TUESDAY...MAINLY ACROSS THE
SOUTHEAST HALF OF OKLAHOMA. ISOLATED SEVERE STORMS WILL BE POSSIBLE
EACH DAY FROM WEDNESDAY THROUGH FRIDAY. THUNDERSTORMS ARE NOT
CURRENTLY EXPECTED ON SATURDAY AND SUNDAY.

OTHER HAZARDOUS WEATHER...
NONE.

THE NEXT SCHEDULED HAZARDOUS WEATHER OUTLOOK WILL BE ISSUED AT 5 AM
TUESDAY AND UPDATED AS NEEDED.

CMS/16

In the hours before

Local storm report, May 20, 4:19 PM CDT, 1 hour 20 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
419 PM CDT MON MAY 20 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0412 PM     HAIL             WILL ROGERS AIRPORT     35.39N 97.60W
05/20/2013  M2.00 INCH       OKLAHOMA           OK   OFFICIAL NWS OBS

&&

JPIKE

Local storm report, May 20, 4:32 PM CDT, 1 hour 7 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
432 PM CDT MON MAY 20 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0430 PM     TORNADO          1 W MEEKER              35.50N 96.91W
05/20/2013                   LINCOLN            OK   BROADCAST MEDIA

            REPORTED BY KWTV

&&

KURTZ

Special weather statement, May 20, 4:43 PM CDT, 56 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
443 PM CDT MON MAY 20 2013

OKZ027>029-202215-
MCCLAIN OK-GRADY OK-CLEVELAND OK-
443 PM CDT MON MAY 20 2013

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN MCCLAIN...EAST
CENTRAL GRADY AND CENTRAL CLEVELAND COUNTIES UNTIL 515 PM CDT...

AT 441 PM CDT...A STRONG THUNDERSTORM WAS LOCATED 4 MILES NORTHEAST
OF BRADLEY...MOVING NORTHEAST AT 35 MPH.

HAZARDS INCLUDE...
HAIL UP TO THE SIZE OF NICKELS...
WIND GUSTS TO 50 MPH...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

STORM INTENSITY IS INCREASING AND SEVERE WEATHER MAY DEVELOP RAPIDLY.
STAY ALERT AND LISTEN FOR WARNINGS.

&&

LAT...LON 3499 9719 3486 9767 3496 9778 3522 9736
TIME...MOT...LOC 2141Z 238DEG 31KT 3493 9765

Local storm report, May 20, 4:44 PM CDT, 55 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
444 PM CDT MON MAY 20 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0440 PM     HAIL             WICHITA FALLS           33.91N 98.50W
05/20/2013  E1.75 INCH       WICHITA            TX   PUBLIC

&&

JPIKE

Local storm report, May 20, 4:54 PM CDT, 45 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
454 PM CDT MON MAY 20 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0256 PM     TORNADO          NEWCASTLE               35.25N 97.60W
05/20/2013                   MCCLAIN            OK   BROADCAST MEDIA

            LIFTED AROUND 336 PM. ESTIMATED PATH LENGTH OF 20 MILES
            THRU NEWCASTLE, MOORE, AND SOUTH OKC. PRELIMINARY DAMAGE
            RATING OF AT LEAST EF4.

&&

EM

Local storm report, May 20, 4:56 PM CDT, 43 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
456 PM CDT MON MAY 20 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0453 PM     HAIL             WICHITA FALLS           33.91N 98.50W
05/20/2013  E1.75 INCH       WICHITA            TX   PUBLIC

            5 MILES WEST OF FISHER RD

&&

JPIKE

The office that day

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

Issued	Product	Office	Counties	Lasted
May 19, 7:17 PM CDT	Special Weather Statement	OUN	Kay	43 min
May 19, 7:26 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln	34 min
May 19, 7:29 PM CDT	Severe Thunderstorm Warning	OUN	Kay	46 min
May 19, 8:14 PM CDT	Severe Thunderstorm Warning	OUN	Kay	16 min
May 19, 8:30 PM CDT	Special Weather Statement	OUN	Noble	30 min
May 19, 9:00 PM CDT	Special Weather Statement	OUN	Noble	30 min
May 19, 9:33 PM CDT	Severe Thunderstorm Warning	OUN	Noble	27 min
May 20, 1:34 PM CDT	Special Weather Statement	OUN	Stephens	26 min
May 20, 1:49 PM CDT	Special Weather Statement	OUN	Stephens	26 min
May 20, 2:00 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, Grady, McClain	60 min
May 20, 2:01 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Grady, Stephens	59 min
May 20, 2:12 PM CDT	Severe Thunderstorm Warning	OUN	Canadian, Cleveland, Grady, McClain, Oklahoma	48 min
May 20, 2:18 PM CDT	Severe Thunderstorm Warning	OUN	Canadian, Logan, Oklahoma	42 min
May 20, 2:20 PM CDT	Special Weather Statement	OUN	Cotton	40 min
May 20, 2:22 PM CDT	Severe Thunderstorm Warning	OUN	Cotton	53 min
May 20, 2:39 PM CDT	Severe Thunderstorm Warning	OUN	Cotton, Jefferson, Stephens	66 min
May 20, 2:40 PM CDT	Tornado Warning	OUN	Cleveland, Grady, McClain, Oklahoma	35 min
May 20, 2:42 PM CDT	Tornado Warning	OUN	Carter, Garvin, Grady, Stephens	33 min
May 20, 3:01 PM CDT	Tornado Warning Emergency	OUN	Cleveland, McClain, Oklahoma	44 min
May 20, 3:07 PM CDT	Severe Thunderstorm Warning	OUN	Cotton, Jefferson, Stephens	53 min
May 20, 3:11 PM CDT	Tornado Warning	OUN	Carter, Garvin, Grady, Stephens	64 min
May 20, 3:21 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Logan, Payne	39 min
May 20, 3:26 PM CDT	Tornado Warning	OUN	Cotton, Jefferson	64 min
May 20, 3:40 PM CDT	Tornado Warning	OUN	Cleveland, Lincoln, Oklahoma, Pottawatomie	35 min
May 20, 3:58 PM CDT	Tornado Warning	OUN	Garvin, Stephens	62 min
May 20, 3:59 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Lincoln, Oklahoma	46 min
May 20, 4:10 PM CDT	Tornado Warning	OUN	Lincoln	35 min
May 20, 4:14 PM CDT	Tornado Warning	OUN	Jefferson	61 min
May 20, 4:36 PM CDT	Tornado Warning	OUN	Garvin, McClain, Pottawatomie	39 min
May 20, 4:42 PM CDT	Tornado Warning	OUN	Lincoln	33 min
May 20, 4:43 PM CDT	Special Weather Statement	OUN	McClain	32 min
May 20, 4:49 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Grady, McClain	56 min
May 20, 4:58 PM CDT	Tornado Warning	OUN	Carter, Jefferson, Love	62 min
May 20, 5:00 PM CDT	Severe Thunderstorm Warning	OUN	Hughes	30 min
May 20, 5:05 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, Hughes, McClain, Pontotoc, Pottawatomie, Seminole	55 min
May 20, 5:06 PM CDT	Tornado Warning	OUN	Jefferson	39 min
May 20, 5:14 PM CDT	Severe Thunderstorm Warning	OUN	Jefferson, Stephens	46 min
May 20, 5:16 PM CDT	Severe Thunderstorm Warning	OUN	Logan, Noble, Payne	44 min
May 20, 5:30 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Johnston, Murray	60 min
May 20, 5:52 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Jefferson, Love	38 min
May 20, 5:57 PM CDT	Tornado Warning	OUN	Carter, Johnston, Marshall	48 min
May 20, 6:08 PM CDT	Severe Thunderstorm Warning	OUN	Coal, Johnston, Murray, Pontotoc	67 min
May 20, 6:12 PM CDT	Areal Flood Advisory	OUN	Cotton, Jefferson	3 hr
May 20, 6:36 PM CDT	Severe Thunderstorm Warning	OUN	Jefferson, Love	39 min
May 20, 6:37 PM CDT	Tornado Warning	OUN	Atoka, Coal, Johnston	23 min
May 20, 6:40 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Johnston	65 min
May 20, 6:40 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Love, Marshall	50 min
May 20, 6:44 PM CDT	Special Weather Statement	OUN	Oklahoma	46 min
May 20, 6:47 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Logan, Oklahoma	43 min
May 20, 6:54 PM CDT	Tornado Warning	OUN	Atoka, Coal, Johnston	36 min

Nearby

Tornado Warnings in Oklahoma, 2013 Every tornado warning in 2013 Tornadoes in 2013

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.