Alert archive / Oklahoma / Mesoscale Discussions in 2011

Mesoscale Discussion 274

March 26, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Mar 26, 2011, 2:41 AM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Mar 26, 2011, 2:41 AM CDT (07:41 UTC)
Expired: Mar 26, 2011, 4:45 AM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 41 counties

Clark County, AR, Columbia County, AR, Hempstead County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Montgomery County, AR, Nevada County, AR, Pike County, AR, Polk County, AR, Sevier County, AR, Bossier Parish, LA, Webster Parish, LA, Atoka County, OK, Bryan County, OK, Choctaw County, OK, Coal County, OK, Hughes County, OK, Johnston County, OK, Latimer County, OK, Marshall County, OK, McCurtain County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Pushmataha County, OK, Seminole County, OK, Bowie County, TX, Camp County, TX, Cass County, TX, Delta County, TX, Fannin County, TX, Franklin County, TX, Grayson County, TX, Hopkins County, TX, Lamar County, TX, Marion County, TX, Morris County, TX, Red River County, TX, Titus County, TX

The radar

The Shreveport radar (KSHV), 149 km from the middle of the area, began a volume at 07:40 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 00:00Z, 7.7 hours before the alert went out and 310 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1965 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 143 m²/s²
0-3 km storm-relative helicity: 294 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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
Mar 25, 7:31 PM CDT	Mesoscale Discussion	SPC	Calhoun, Clark, Columbia, Hempstead, Howard, Lafayette and 7 more	89 min
Mar 25, 10:50 PM CDT	Severe Thunderstorm Watch	SPC	Columbia, Crawford, Franklin, Hempstead, Howard, Lafayette and 11 more	7 hr
Mar 25, 11:40 PM CDT	Mesoscale Discussion	SPC	Crawford, Franklin, Madison, Newton, Washington	65 min
Mar 26, 2:27 PM CDT	Mesoscale Discussion	SPC	Ashley, Bradley, Calhoun, Chicot, Columbia, Desha and 8 more	63 min
Mar 26, 3:27 PM CDT	Tornado Watch	SPC	Ashley, Bradley, Calhoun, Chicot, Desha, Drew and 2 more	7 hr
Mar 26, 4:33 PM CDT	Mesoscale Discussion	SPC	Columbia, Lafayette, Miller	57 min

Nearby

Mesoscale Discussions in Oklahoma, 2011 Mesoscale Discussions in Texas, 2011 Mesoscale Discussions in Arkansas, 2011 Every mesoscale discussion in 2011

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.