Alert archive / Texas / Mesoscale Discussions in 2017

Mesoscale Discussion 1494

August 13, 2017Cotton County, Jefferson County, Tillman County, Oklahoma; 12 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Aug 13, 2017, 11:24 PM CDT for Cotton County, Jefferson County, Tillman County, Oklahoma; 12 counties in Texas. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued: Aug 13, 2017, 11:24 PM CDT (04:24 UTC)
Expired: Aug 14, 2017, 1:00 AM CDT
In force: 96 min
Issued by: the Storm Prediction Center

Counties Cotton County, OK, Jefferson County, OK, Tillman County, OK, Archer County, TX, Baylor County, TX, Clay County, TX, Dickens County, TX, Foard County, TX, Haskell County, TX, King County, TX, Knox County, TX, Stonewall County, TX, Throckmorton County, TX, Wichita County, TX, Wilbarger County, TX

The radar

The Altus AFB radar (KFDR), 97 km from the middle of the area, began a volume at 04:28 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

Amarillo Airport, TX (KAMA), launched 00:00Z, 4.4 hours before the alert went out and 240 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: 2289 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 1216 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 53 m²/s²
0-3 km storm-relative helicity: 130 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 8.3

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
Aug 13, 9:13 PM CDT	Mesoscale Discussion	SPC	Cimarron, Texas	92 min
Aug 14, 3:32 PM CDT	Mesoscale Discussion	SPC	Cimarron	2 hr
Aug 13, 8:53 PM CDT	Mesoscale Discussion	SPC	Briscoe, Castro, Childress, Cottle, Floyd, Hall and 2 more	97 min

Nearby

Mesoscale Discussions in Texas, 2017 Mesoscale Discussions in Oklahoma, 2017 Every mesoscale discussion in 2017

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.