Alert archive / Texas / Mesoscale Discussions in 2007

Mesoscale Discussion 850

May 21, 200715 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 21, 2007, 2:51 PM CDT for 15 counties in Texas. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: May 21, 2007, 2:51 PM CDT (19:51 UTC)
Expired: May 21, 2007, 4:15 PM CDT
In force: 84 min
Issued by: the Storm Prediction Center

Counties Brewster County, TX, Crane County, TX, Crockett County, TX, Ector County, TX, Irion County, TX, Midland County, TX, Pecos County, TX, Reagan County, TX, Schleicher County, TX, Sutton County, TX, Terrell County, TX, Tom Green County, TX, Upton County, TX, Val Verde County, TX, Ward County, TX

The radar

The Midland/Odessa radar (KMAF), 157 km from the middle of the area, began a volume at 19:51 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.

Severe Thunderstorm Watch 284May 21, 3:20 PM CDT

The nearest sounding before it

Midland Regional, TX (KMAF), launched 12:00Z, 7.9 hours before the alert went out and 158 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: 402 J/kg
Mixed-layer CIN: -189 J/kg
Mixed-layer LCL: 743 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 63 m²/s²
0-3 km storm-relative helicity: 34 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
May 21, 2:17 PM CDT	Mesoscale Discussion	SPC	Anderson, Austin, Bell, Bosque, Brazoria, Brazos and 35 more	58 min
May 21, 3:17 PM CDT	Severe Thunderstorm Watch	SPC	Brewster, Crane, Crockett, Edwards, Jeff Davis, Kinney and 9 more	8 hr
May 21, 3:55 PM CDT	Mesoscale Discussion	SPC	Carson, Gray, Hansford, Hutchinson, Moore, Ochiltree and 3 more	65 min
May 21, 4:06 PM CDT	Severe Thunderstorm Watch	SPC	Armstrong, Carson, Collingsworth, Deaf Smith, Donley, Gray and 12 more	7 hr
May 21, 6:03 PM CDT	Mesoscale Discussion	SPC	Hemphill, Lipscomb, Ochiltree, Roberts	87 min

Nearby

Mesoscale Discussions in Texas, 2007 Every mesoscale discussion in 2007

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.