Alert archive / Oklahoma / Mesoscale Discussions in 2015

Mesoscale Discussion 531

May 7, 20156 counties in Oklahoma; Collin County, Cooke County, Grayson County, Texas

The Storm Prediction Center issued this mesoscale discussion at May 7, 2015, 4:24 AM CDT for 6 counties in Oklahoma; Collin County, Cooke County, Grayson County, Texas. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued: May 7, 2015, 4:24 AM CDT (09:24 UTC)
Expired: May 7, 2015, 5:30 AM CDT
In force: 66 min
Issued by: the Storm Prediction Center

Counties Bryan County, OK, Carter County, OK, Cotton County, OK, Jefferson County, OK, Love County, OK, Marshall County, OK, Collin County, TX, Cooke County, TX, Grayson County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 129 km from the middle of the area, began a volume at 09:23 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

Fort Worth, TX (KFWD), launched 00:00Z, 9.4 hours before the alert went out and 100 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: 1584 J/kg
Mixed-layer CIN: -18 J/kg
Mixed-layer LCL: 1221 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 115 m²/s²
0-3 km storm-relative helicity: 147 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 7.7

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
May 6, 8:08 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Beckham, Blaine, Caddo, Canadian, Comanche and 17 more	67 min
May 6, 8:51 PM CDT	Tornado Watch	SPC	Alfalfa, Blaine, Caddo, Canadian, Carter, Cleveland and 26 more	5 hr
May 6, 10:53 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Blaine, Caddo, Canadian, Carter, Cleveland and 26 more	2 hr
May 7, 1:16 AM CDT	Severe Thunderstorm Watch	SPC	Cotton, Jefferson, Love, Marshall, Tillman	4 hr
May 7, 10:20 AM CDT	Mesoscale Discussion	SPC	Comanche, Cotton, Greer, Harmon, Jackson, Kiowa and 1 more	115 min
May 7, 12:52 PM CDT	Mesoscale Discussion	SPC	Bryan, Carter, Comanche, Cotton, Jefferson, Johnston and 5 more	113 min
May 7, 1:10 PM CDT	Severe Thunderstorm Watch	SPC	Caddo, Canadian, Cleveland, Comanche, Cotton, Garvin and 10 more	7 hr
May 7, 2:47 PM CDT	Mesoscale Discussion	SPC	Cimarron	118 min
May 7, 3:51 PM CDT	Mesoscale Discussion	SPC	Bryan, Carter, Love, Marshall	114 min
May 7, 4:33 PM CDT	Severe Thunderstorm Watch	SPC	Atoka, Bryan, Carter, Coal, Johnston, Love and 3 more	7 hr
May 7, 6:19 PM CDT	Mesoscale Discussion	SPC	Atoka, Bryan, Carter, Choctaw, Cleveland, Coal and 11 more	86 min
May 7, 5:41 PM CDT	Mesoscale Discussion	SPC	Brown, Callahan, Comanche, Eastland, Erath, Fisher and 7 more	94 min

Nearby

Mesoscale Discussions in Oklahoma, 2015 Mesoscale Discussions in Texas, 2015 Every mesoscale discussion in 2015

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.