Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 838

May 21, 201115 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 21, 2011, 3:53 PM CDT for 15 counties in Texas. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued: May 21, 2011, 3:53 PM CDT (20:53 UTC)
Expired: May 21, 2011, 5:00 PM CDT
In force: 67 min
Issued by: the Storm Prediction Center

Counties Bosque County, TX, Burnet County, TX, Coryell County, TX, Dallas County, TX, Ellis County, TX, Gillespie County, TX, Hamilton County, TX, Hill County, TX, Hood County, TX, Johnson County, TX, Lampasas County, TX, Llano County, TX, McLennan County, TX, Somervell County, TX, Tarrant County, TX

The radar

The Ft Hood radar (KGRK), 105 km from the middle of the area, began a volume at 20:55 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 12:00Z, 8.9 hours before the alert went out and 159 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: 87 J/kg
Mixed-layer CIN: -337 J/kg
Mixed-layer LCL: 1835 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 203 m²/s²
0-3 km storm-relative helicity: 181 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 20, 9:06 PM CDT	Mesoscale Discussion	SPC	Bowie, Camp, Cass, Cherokee, Gregg, Harrison and 7 more	114 min
May 21, 1:18 PM CDT	Mesoscale Discussion	SPC	Bandera, Bosque, Burnet, Coryell, Erath, Gillespie and 12 more	117 min
May 21, 1:45 PM CDT	Severe Thunderstorm Watch	SPC	Bandera, Bell, Blanco, Bosque, Burnet, Comal and 29 more	7 hr
May 21, 5:42 PM CDT	Mesoscale Discussion	SPC	Bell, Blanco, Bosque, Burnet, Collin, Cooke and 28 more	2 hr

Nearby

Mesoscale Discussions in Texas, 2011 Every mesoscale discussion in 2011

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.