Alert archive / Texas / Mesoscale Discussions in 2016

Mesoscale Discussion 662

May 21, 201616 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 21, 2016, 11:35 AM CDT for 16 counties in Texas. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued: May 21, 2016, 11:35 AM CDT (16:35 UTC)
Expired: May 21, 2016, 1:00 PM CDT
In force: 85 min
Issued by: the Storm Prediction Center
Chance of a watch: 5%

Counties Austin County, TX, Brazoria County, TX, Brazos County, TX, Burleson County, TX, Chambers County, TX, Colorado County, TX, Fort Bend County, TX, Grimes County, TX, Hardin County, TX, Harris County, TX, Liberty County, TX, Montgomery County, TX, San Jacinto County, TX, Walker County, TX, Waller County, TX, Washington County, TX

The radar

The Houston radar (KHGX), 94 km from the middle of the area, began a volume at 16:38 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

Lake Charles Mun, LA (KLCH), launched 12:00Z, 4.6 hours before the alert went out and 256 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: 752 J/kg
Mixed-layer CIN: -139 J/kg
Mixed-layer LCL: 886 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 79 m²/s²
0-3 km storm-relative helicity: 77 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.8

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
May 21, 2:25 PM CDT	Mesoscale Discussion	SPC	Bailey, Castro, Cochran, Dallam, Deaf Smith, Hansford and 9 more	95 min
May 21, 2:43 PM CDT	Severe Thunderstorm Watch	SPC	Armstrong, Bailey, Carson, Castro, Cochran, Dallam and 18 more	7 hr
May 21, 2:50 PM CDT	Mesoscale Discussion	SPC	Brewster, Loving, Presidio, Reeves	85 min
May 21, 6:26 PM CDT	Mesoscale Discussion	SPC	Armstrong, Bailey, Carson, Castro, Cochran, Dallam and 18 more	2 hr

Nearby

Mesoscale Discussions in Texas, 2016 Every mesoscale discussion in 2016

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.