Alert archive / Oklahoma / Tornado Warnings in 2012

Tornado Warning 41, NWS Norman, OK

April 30, 2012Alfalfa County, Grant County, Oklahoma

NWS Norman, OK issued this tornado warning at Apr 30, 2012, 7:58 PM CDT for Alfalfa County, Grant County, Oklahoma. It was in force for 47 min. 1 report 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 30, 2012, 7:58 PM CDT (00:58 UTC)
Expired
Apr 30, 2012, 8:45 PM CDT
In force
47 min
Issued by
NWS Norman, OK
Area
Storm-based polygon

Counties Alfalfa County, OK, Grant County, OK

The radar

The Vance AFB radar (KVNX), 14 km from the middle of the area, began a volume at 01:00 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

TimeReportWhereRemark
Apr 30, 8:10 PM CDTTORNADO4 Nnw Nash, OKLOCAL BROADCAST MEDIA AND A STORM CHASER OBSERVED A TORNADO THAT BEGAN ABOUT 4 MILES NORTH-NORTHWEST OF NASH. IT IS SOMEWHAT UNCERTAIN AT THIS TIME WHETHER THIS WAS A SINGLE TORNADO OR IF MORE THAN ONE TORNADO OCCURRED. THE TORNADIC CIRCULATION BEGAN TO OCCLUD

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.

IssuedProductOfficeLasted
Apr 30, 5:42 PM CDTTornado WatchSPC7 hr
Apr 30, 7:30 PM CDTTornado WatchSPC7 hr

The nearest sounding before it

Lamont, OK (KLMN), launched 00:00Z, 1.0 hours before the alert went out and 50 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-pSkew-T log-p diagram, Lamont, OK at 00:00Z on 2012-05-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2077 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lamont, OK at 00:00Z on 2012-05-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 86 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
2077 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
1205 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
86 m²/s²
0-3 km storm-relative helicity
246 m²/s²
Significant tornado parameter
2.4
Supercell composite
16.5

Open this sounding in Storm Lab

The text

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

129 
WFUS54 KOUN 010058
TOROUN

OKC003-053-010145-
/O.NEW.KOUN.TO.W.0041.120501T0058Z-120501T0145Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE NORMAN OK
758 PM CDT MON APR 30 2012

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A

* TORNADO WARNING FOR...
  GRANT COUNTY IN  OKLAHOMA...
  NORTHEASTERN ALFALFA COUNTY IN  OKLAHOMA...

* UNTIL 845 PM CDT

* AT 756 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED 
  STRONG ROTATION WITH A SEVERE THUNDERSTORM NEAR GREAT SALT PLAINS 
  LAKE...MOVING NORTH AT 20 MPH.  HAIL TO THE SIZE OF TENNIS BALLS
  ARE ALSO POSSIBLE.

* LOCATIONS IMPACTED INCLUDE...
  WAKITA AND GREAT SALT PLAINS LAKE. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3672 9787 3668 9789 3672 9827 3700 9820
      3699 9783
TIME...MOT...LOC 0056Z 200DEG 18KT 3675 9820 

$$
1 follow-up statement
253 
WWUS54 KOUN 010120
SVSOUN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
820 PM CDT MON APR 30 2012

OKC003-010155-
/O.CAN.KOUN.TO.W.0041.000000T0000Z-120501T0145Z/
ALFALFA OK-
820 PM CDT MON APR 30 2012

...THE TORNADO WARNING FOR NORTHEASTERN ALFALFA COUNTY IS 
CANCELLED...

THE TORNADIC THUNDERSTORM WHICH PROMPTED THE WARNING HAS MOVED
INTO WESTERN GRANT COUNTY...THEREFORE THE WARNING FOR ALFALFA
COUNTY HAS BEEN CANCELLED. 

LAT...LON 3699 9783 3672 9787 3668 9789 3672 9810
      3700 9810
TIME...MOT...LOC 0118Z 237DEG 15KT 3673 9804 

$$

OKC053-010145-
/O.CON.KOUN.TO.W.0041.000000T0000Z-120501T0145Z/
GRANT OK-
820 PM CDT MON APR 30 2012

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 845 PM CDT FOR GRANT 
COUNTY...

AT 814 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A 
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS 
STORM WAS LOCATED 4 MILES NORTH OF NASH...MOVING NORTHEAST AT 15 
MPH. 

LOCATIONS IMPACTED INCLUDE...
WAKITA AND MANCHESTER. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3699 9783 3672 9787 3668 9789 3672 9810
      3700 9810
TIME...MOT...LOC 0114Z 237DEG 15KT 3673 9804 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 30, 7:14 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Grant46 min
Apr 30, 7:26 PM CDTTornado WarningOUNAlfalfa34 min
Apr 30, 7:32 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Woods58 min
Apr 30, 7:54 PM CDTSpecial Weather StatementOUNHarmon36 min
Apr 30, 8:09 PM CDTSevere Thunderstorm WarningOUNBeckham, Greer, Harmon66 min
Apr 30, 8:17 PM CDTSpecial Weather StatementOUNGreer, Washita28 min
Apr 30, 8:23 PM CDTSevere Thunderstorm WarningOUNBeckham, Greer, Kiowa, Washita67 min
Apr 30, 8:27 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Woods63 min
Apr 30, 8:39 PM CDTTornado WarningOUNGrant51 min
Apr 30, 9:08 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Grant52 min
Apr 30, 9:10 PM CDTTornado WarningOUNKiowa, Washita16 min
Apr 30, 9:13 PM CDTSevere Thunderstorm WarningOUNGreer, Harmon, Jackson62 min
Apr 30, 9:28 PM CDTTornado WarningOUNGrant, Kay32 min
Apr 30, 9:32 PM CDTSpecial Weather StatementOUNKiowa43 min
Apr 30, 9:39 PM CDTSevere Thunderstorm WarningOUNCaddo, Comanche, Greer, Jackson, Kiowa, Washita51 min
Apr 30, 9:40 PM CDTTornado WarningOUNGrant35 min
Apr 30, 9:57 PM CDTSevere Thunderstorm WarningOUNGarfield, Grant, Kay, Noble48 min
Apr 30, 9:58 PM CDTTornado WarningOUNGrant, Kay47 min
Apr 30, 10:04 PM CDTFlash Flood WarningOUNGrant, Kay4 hr
Apr 30, 10:05 PM CDTAreal Flood AdvisoryOUNGreer, Harmon, Jackson4 hr
Apr 30, 10:15 PM CDTSevere Thunderstorm WarningOUNGreer, Harmon, Jackson, Kiowa60 min
Apr 30, 10:18 PM CDTTornado WarningOUNKay27 min
Apr 30, 10:20 PM CDTTornado WarningOUNGreer, Harmon, Jackson14 min
Apr 30, 10:33 PM CDTSevere Thunderstorm WarningOUNCaddo, Comanche, Cotton, Grady, Kiowa, Stephens and 2 more57 min
Apr 30, 10:36 PM CDTSevere Thunderstorm WarningOUNGarfield, Grant, Kay, Noble54 min
Apr 30, 10:54 PM CDTSpecial Weather StatementOUNBlaine, Canadian, Custer, Dewey, Kingfisher51 min
Apr 30, 11:11 PM CDTSevere Thunderstorm WarningOUNCaddo, Comanche, Greer, Harmon, Jackson, Kiowa and 1 more53 min
Apr 30, 11:25 PM CDTSpecial Weather StatementOUNLincoln35 min
Apr 30, 11:28 PM CDTSevere Thunderstorm WarningOUNGarfield, Kay, Noble51 min
Apr 30, 11:30 PM CDTSpecial Weather StatementOUNComanche, Grady, McClain, Stephens60 min
Apr 30, 11:32 PM CDTSevere Thunderstorm WarningOUNCanadian, Cleveland, Grady, McClain, Oklahoma43 min
Apr 30, 11:57 PM CDTSevere Thunderstorm WarningOUNCleveland, Lincoln, Oklahoma, Pottawatomie48 min
May 1, 12:12 AM CDTSevere Thunderstorm WarningOUNCleveland, Pottawatomie, Seminole34 min
May 1, 12:25 AM CDTSpecial Weather StatementOUNDewey35 min
May 1, 12:30 AM CDTSpecial Weather StatementOUNGarvin, McClain, Murray, Pontotoc30 min
May 1, 12:51 AM CDTSpecial Weather StatementOUNPottawatomie, Seminole39 min
May 1, 12:57 AM CDTSpecial Weather StatementOUNGarvin, Murray, Pontotoc33 min
May 1, 1:29 AM CDTSpecial Weather StatementOUNCoal, Hughes, Johnston, Pontotoc, Seminole46 min
May 1, 2:11 AM CDTSpecial Weather StatementOUNCoal49 min

Nearby

Tornado Warnings in Oklahoma, 2012Every tornado warning in 2012Tornadoes in 2012

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.