Alert archive / Oklahoma / Mesoscale Discussions in 2013

Mesoscale Discussion 734

May 20, 20134 counties in Oklahoma; Cooke County, Grayson County, Montague County, Texas

The Storm Prediction Center issued this mesoscale discussion at May 20, 2013, 6:33 PM CDT for 4 counties in Oklahoma; Cooke County, Grayson County, Montague County, Texas. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued: May 20, 2013, 6:33 PM CDT (23:33 UTC)
Expired: May 20, 2013, 7:30 PM CDT
In force: 57 min
Issued by: the Storm Prediction Center

Counties Bryan County, OK, Johnston County, OK, Love County, OK, Marshall County, OK, Cooke County, TX, Grayson County, TX, Montague County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 144 km from the middle of the area, began a volume at 23:37 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.

Tornado Watch 195May 20, 7:40 PM CDT

The nearest sounding before it

Fort Worth, TX (KFWD), launched 12:00Z, 11.6 hours before the alert went out and 116 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: 747 J/kg
Mixed-layer CIN: -390 J/kg
Mixed-layer LCL: 893 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 275 m²/s²
0-3 km storm-relative helicity: 216 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

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
May 19, 8:53 PM CDT	Mesoscale Discussion	SPC	Adair, Atoka, Bryan, Canadian, Carter, Cherokee and 48 more	67 min
May 19, 10:44 PM CDT	Tornado Watch	SPC	Adair, Cherokee, Craig, Creek, Delaware, Haskell and 19 more	5 hr
May 20, 2:44 AM CDT	Mesoscale Discussion	SPC	Craig, Delaware, Mayes, Nowata, Osage, Ottawa and 3 more	2 hr
May 20, 12:26 PM CDT	Mesoscale Discussion	SPC	Adair, Atoka, Bryan, Canadian, Carter, Cherokee and 42 more	2 hr
May 20, 1:10 PM CDT	Tornado Watch	SPC	Adair, Atoka, Bryan, Caddo, Canadian, Carter and 49 more	9 hr
May 20, 2:31 PM CDT	Mesoscale Discussion	SPC	Craig, Creek, Lincoln, Logan, Nowata, Okfuskee and 7 more	119 min
May 20, 5:34 PM CDT	Mesoscale Discussion	SPC	Love	56 min
May 20, 1:19 PM CDT	Mesoscale Discussion	SPC	Bell, Bosque, Brown, Burnet, Callahan, Clay and 29 more	116 min
May 20, 2:21 PM CDT	Tornado Watch	SPC	Bosque, Brown, Burnet, Callahan, Coleman, Collin and 33 more	8 hr

Nearby

Mesoscale Discussions in Oklahoma, 2013 Mesoscale Discussions in Texas, 2013 Every mesoscale discussion in 2013

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.