Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 423

April 22, 201511 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 22, 2015, 9:22 PM CDT for 11 counties in Texas. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued: Apr 22, 2015, 9:22 PM CDT (02:22 UTC)
Expired: Apr 22, 2015, 10:15 PM CDT
In force: 53 min
Issued by: the Storm Prediction Center

Counties Archer County, TX, Baylor County, TX, Foard County, TX, Haskell County, TX, Jack County, TX, Knox County, TX, Palo Pinto County, TX, Shackelford County, TX, Stephens County, TX, Throckmorton County, TX, Young County, TX

The radar

The Dyess AFB radar (KDYX), 60 km from the middle of the area, began a volume at 02:24 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 96Apr 22, 10:25 PM CDT

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 2.4 hours before the alert went out and 167 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: 800 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 1005 m above ground
0-6 km bulk shear: 75 kt
0-1 km storm-relative helicity: 91 m²/s²
0-3 km storm-relative helicity: 238 m²/s²
Significant tornado parameter: 1.2
Supercell composite: 8.3

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
Apr 22, 10:25 PM CDT	Severe Thunderstorm Watch	SPC	Bosque, Dallas, Denton, Eastland, Ellis, Erath and 11 more	6 hr
Apr 23, 2:12 AM CDT	Mesoscale Discussion	SPC	Bosque, Erath, Hamilton, Hill, McLennan, Somervell	2 hr
Apr 23, 3:35 PM CDT	Mesoscale Discussion	SPC	Bell, Blanco, Bosque, Burnet, Coryell, Falls and 15 more	115 min
Apr 23, 5:03 PM CDT	Severe Thunderstorm Watch	SPC	Bell, Burnet, Coryell, Falls, Limestone, McLennan and 3 more	3 hr

Nearby

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.