Alert archive / Oklahoma / Mesoscale Discussions in 2012

Mesoscale Discussion 518

April 13, 201226 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Apr 13, 2012, 11:45 PM CDT for 26 counties in Oklahoma. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued
Apr 13, 2012, 11:45 PM CDT (04:45 UTC)
Expired
Apr 14, 2012, 1:15 AM CDT
In force
90 min
Issued by
the Storm Prediction Center
All 26 counties

Beckham County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Cleveland County, OK, Comanche County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Garfield County, OK, Grady County, OK, Greer County, OK, Jackson County, OK, Kingfisher County, OK, Kiowa County, OK, Lincoln County, OK, Logan County, OK, Major County, OK, McClain County, OK, Noble County, OK, Oklahoma County, OK, Payne County, OK, Pottawatomie County, OK, Roger Mills County, OK, Washita County, OK, Woodward County, OK

The radar

The Vance AFB radar (KVNX), 133 km from the middle of the area, began a volume at 04:44 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 4.8 hours before the alert went out and 136 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, Norman, OK at 00:00Z on 2012-04-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2227 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Norman, OK at 00:00Z on 2012-04-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 269 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
2227 J/kg
Mixed-layer CIN
-11 J/kg
Mixed-layer LCL
617 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
269 m²/s²
0-3 km storm-relative helicity
389 m²/s²
Significant tornado parameter
3.5
Supercell composite
15.6

Open this sounding in Storm Lab

The text

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

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 13, 7:35 PM CDTMesoscale DiscussionSPCBeckham, Blaine, Caddo, Canadian, Cleveland, Comanche and 24 more55 min
Apr 13, 8:36 PM CDTTornado WatchSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Cleveland and 31 more7 hr
Apr 13, 9:58 PM CDTMesoscale DiscussionSPCBeckham, Blaine, Caddo, Canadian, Cleveland, Comanche and 19 more92 min
Apr 14, 2:40 AM CDTMesoscale DiscussionSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Cleveland and 31 more65 min
Apr 14, 3:42 AM CDTTornado WatchSPCCraig, Creek, Delaware, Kay, Lincoln, Logan and 11 more5 hr
Apr 14, 7:11 AM CDTMesoscale DiscussionSPCCraig, Delaware, Kay, Logan, Mayes, Noble and 8 more64 min
Apr 14, 9:42 AM CDTMesoscale DiscussionSPCBeaver, Beckham, Ellis, Harper, Roger Mills, Texas93 min
Apr 14, 10:43 AM CDTTornado Watch PDSSPCAlfalfa, Beckham, Blaine, Custer, Dewey, Ellis and 12 more7 hr
Apr 14, 11:44 AM CDTMesoscale DiscussionSPCAlfalfa, Beaver, Ellis, Garfield, Grant, Harper and 3 more61 min
Apr 14, 12:11 PM CDTMesoscale DiscussionSPCGrant, Kay, Noble, Osage, Pawnee, Washington64 min
Apr 14, 1:23 PM CDTMesoscale DiscussionSPCBeaver, Beckham, Blaine, Caddo, Canadian, Carter and 21 more2 hr
Apr 14, 3:01 PM CDTMesoscale DiscussionSPCAlfalfa, Beckham, Custer, Dewey, Ellis, Greer and 9 more29 min
Apr 14, 3:48 PM CDTMesoscale DiscussionSPCAlfalfa, Beckham, Blaine, Custer, Dewey, Ellis and 10 more57 min
Apr 14, 4:54 PM CDTMesoscale DiscussionSPCAlfalfa, Dewey, Ellis, Grant, Harper, Major and 3 more66 min
Apr 14, 5:24 PM CDTTornado Watch PDSSPCAlfalfa, Beaver, Beckham, Blaine, Custer, Dewey and 18 more9 hr

Nearby

Mesoscale Discussions in Oklahoma, 2012Every mesoscale discussion 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.