Alert archive / Oklahoma / Mesoscale Discussions in 2012

Mesoscale Discussion 1915

September 7, 201230 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Sep 7, 2012, 2:44 PM CDT for 30 counties in Oklahoma. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Sep 7, 2012, 2:44 PM CDT (19:44 UTC)
Expired
Sep 7, 2012, 4:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%
All 30 counties

Beckham County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Cleveland County, OK, Comanche County, OK, Creek County, OK, Custer County, OK, Dewey County, OK, Garfield County, OK, Garvin County, OK, Grady County, OK, Greer County, OK, Hughes County, OK, Kingfisher County, OK, Kiowa County, OK, Lincoln County, OK, Logan County, OK, McClain County, OK, Murray County, OK, Noble County, OK, Okfuskee County, OK, Oklahoma County, OK, Pawnee County, OK, Payne County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK, Stephens County, OK, Washita County, OK

The radar

The Norman radar (KTLX), 40 km from the middle of the area, began a volume at 19:44 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 nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 7.7 hours before the alert went out and 34 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 12:00Z on 2012-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 460 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 12:00Z on 2012-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -47 square meters per square second.193958Sfc1 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
460 J/kg
Mixed-layer CIN
-231 J/kg
Mixed-layer LCL
2065 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
-47 m²/s²
0-3 km storm-relative helicity
60 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

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
Sep 6, 7:17 PM CDTMesoscale DiscussionSPCBeaver, Harper88 min
Sep 7, 2:35 PM CDTSevere Thunderstorm WatchSPCAdair, Cherokee, Craig, Delaware, Haskell, Latimer and 12 more6 hr
Sep 7, 6:06 PM CDTMesoscale DiscussionSPCHaskell, Latimer, LeFlore, Sequoyah84 min

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.