Alert archive / Oklahoma / Mesoscale Discussions in 2005

Mesoscale Discussion 617

April 20, 200515 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Apr 20, 2005, 8:45 PM CDT for 15 counties in Oklahoma. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued: Apr 20, 2005, 8:45 PM CDT (01:45 UTC)
Expired: Apr 20, 2005, 10:15 PM CDT
In force: 90 min
Issued by: the Storm Prediction Center

Counties Caddo County, OK, Canadian County, OK, Cleveland County, OK, Comanche County, OK, Cotton County, OK, Garfield County, OK, Garvin County, OK, Grady County, OK, Jefferson County, OK, Kingfisher County, OK, Logan County, OK, McClain County, OK, Noble County, OK, Oklahoma County, OK, Stephens County, OK

The nearest sounding before it

Lamont, OK (KLMN), launched 00:00Z, 1.8 hours before the alert went out and 195 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: 2678 J/kg
Mixed-layer CIN: -74 J/kg
Mixed-layer LCL: 1336 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 52 m²/s²
0-3 km storm-relative helicity: 141 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.7

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.

Issued	Product	Office	Counties	Lasted
Apr 20, 9:51 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Beckham, Custer, Dewey, Ellis, Greer and 9 more	84 min
Apr 21, 1:23 PM CDT	Mesoscale Discussion	SPC	Adair	67 min
Apr 21, 1:45 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Cherokee, Delaware, Ottawa	5 hr
Apr 21, 5:14 PM CDT	Mesoscale Discussion	SPC	Adair, Atoka, Carter, Cherokee, Choctaw, Coal and 25 more	2 hr
Apr 21, 6:10 PM CDT	Tornado Watch	SPC	Ottawa	7 hr
Apr 21, 6:15 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Cherokee, Delaware, Haskell, Hughes, Latimer and 9 more	7 hr

Nearby

Mesoscale Discussions in Oklahoma, 2005 Every mesoscale discussion in 2005

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.