Alert archive / Oklahoma / Mesoscale Discussions in 2018

Mesoscale Discussion 82

February 21, 201810 counties in Oklahoma; 7 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Feb 21, 2018, 12:44 PM CST for 10 counties in Oklahoma; 7 counties in Texas. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Feb 21, 2018, 12:44 PM CST (18:44 UTC)
Expired: Feb 21, 2018, 4:45 PM CST
In force: 4 hr
Issued by: the Storm Prediction Center

Counties Carter County, OK, Coal County, OK, Garvin County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Love County, OK, Marshall County, OK, Murray County, OK, Pontotoc County, OK, Clay County, TX, Cooke County, TX, Denton County, TX, Jack County, TX, Montague County, TX, Palo Pinto County, TX, Wise County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 141 km from the middle of the area, began a volume at 18:48 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

Shreveport, LA (KBAD), launched 12:00Z, 6.7 hours before the alert went out and 384 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: 1043 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 529 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 151 m²/s²
0-3 km storm-relative helicity: 175 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 4.1

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 21, 7:57 AM CST	Mesoscale Discussion	SPC	Carter, Comanche, Cotton, Jackson, Jefferson, Kiowa and 2 more	4 hr
Feb 21, 5:01 PM CST	Mesoscale Discussion	SPC	Adair, Cherokee, Craig, Delaware, Mayes, Muskogee and 4 more	5 hr
Feb 21, 9:07 AM CST	Mesoscale Discussion	SPC	Newton, Orange	113 min
Feb 21, 9:48 AM CST	Tornado Watch	SPC	Newton, Orange	7 hr
Feb 21, 12:28 PM CST	Mesoscale Discussion	SPC	Hardin, Jasper, Jefferson, Newton, Orange, Sabine	92 min
Feb 21, 3:03 PM CST	Mesoscale Discussion	SPC	Newton, Orange	117 min

Nearby

Mesoscale Discussions in Oklahoma, 2018 Mesoscale Discussions in Texas, 2018 Every mesoscale discussion in 2018

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.