Alert archive / Texas / Mesoscale Discussions in 2017

Mesoscale Discussion 638

May 3, 201715 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 3, 2017, 11:23 AM CDT for 15 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 3, 2017, 11:23 AM CDT (16:23 UTC)
Expired: May 3, 2017, 1:30 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 80%

Counties Coryell County, TX, Dallas County, TX, Ellis County, TX, Falls County, TX, Freestone County, TX, Henderson County, TX, Hill County, TX, Kaufman County, TX, Leon County, TX, Limestone County, TX, McLennan County, TX, Navarro County, TX, Rains County, TX, Rockwall County, TX, Van Zandt County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 85 km from the middle of the area, began a volume at 16:26 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 191May 3, 12:35 PM CDT

The nearest sounding before it

Fort Worth, TX (KFWD), launched 12:00Z, 4.4 hours before the alert went out and 107 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: 2100 J/kg
Mixed-layer CIN: -222 J/kg
Mixed-layer LCL: 684 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 157 m²/s²
0-3 km storm-relative helicity: 238 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

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 3, 1:30 AM CDT	Mesoscale Discussion	SPC	Collingsworth, Donley, Gray, Hemphill, Wheeler	2 hr
May 3, 7:04 AM CDT	Mesoscale Discussion	SPC	Angelina, Chambers, Hardin, Houston, Jasper, Jefferson and 12 more	86 min
May 3, 7:32 AM CDT	Tornado Watch	SPC	Angelina, Chambers, Hardin, Jasper, Jefferson, Liberty and 10 more	9 hr
May 3, 7:48 AM CDT	Mesoscale Discussion	SPC	Bowie, Camp, Cass, Delta, Fannin, Franklin and 11 more	117 min
May 3, 10:07 AM CDT	Mesoscale Discussion	SPC	Angelina, Hardin, Jasper, Jefferson, Newton, Orange and 3 more	83 min
May 3, 12:34 PM CDT	Severe Thunderstorm Watch	SPC	Anderson, Bell, Bosque, Bowie, Camp, Cass and 38 more	5 hr
May 3, 1:48 PM CDT	Mesoscale Discussion	SPC	Anderson, Bowie, Camp, Cass, Cherokee, Coryell and 31 more	87 min
May 3, 1:58 PM CDT	Mesoscale Discussion	SPC	Angelina, Chambers, Hardin, Jasper, Jefferson, Newton and 4 more	62 min
May 3, 3:48 PM CDT	Mesoscale Discussion	SPC	Angelina, Chambers, Hardin, Houston, Jasper, Jefferson and 12 more	87 min
May 3, 3:59 PM CDT	Mesoscale Discussion	SPC	Anderson, Bell, Bowie, Camp, Cass, Cherokee and 17 more	91 min
May 3, 5:00 PM CDT	Severe Thunderstorm Watch	SPC	Angelina, Austin, Bastrop, Brazoria, Brazos, Burleson and 29 more	7 hr

Nearby

Mesoscale Discussions in Texas, 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.