Alert archive / Texas / Mesoscale Discussions in 2017

Mesoscale Discussion 513

April 17, 20179 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 17, 2017, 2:40 AM CDT for 9 counties in Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Apr 17, 2017, 2:40 AM CDT (07:40 UTC)
Expired: Apr 17, 2017, 5:15 AM CDT
In force: 3 hr
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Brooks County, TX, Duval County, TX, Jim Hogg County, TX, Jim Wells County, TX, Kenedy County, TX, Kleberg County, TX, Nueces County, TX, Webb County, TX, Willacy County, TX

The radar

The Corpus Christi radar (KCRP), 109 km from the middle of the area, began a volume at 07:41 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

Corpus Christi, TX (KCRP), launched 00:00Z, 7.7 hours before the alert went out and 121 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: 1320 J/kg
Mixed-layer CIN: -100 J/kg
Mixed-layer LCL: 1005 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 18 m²/s²
0-3 km storm-relative helicity: 28 m²/s²
Significant tornado parameter: -0.1
Supercell composite: -1.9

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
Apr 16, 7:01 PM CDT	Mesoscale Discussion	SPC	Armstrong, Briscoe, Childress, Collingsworth, Cottle, Crosby and 25 more	59 min
Apr 16, 9:06 PM CDT	Mesoscale Discussion	SPC	Coke, Crockett, Dimmit, Edwards, Glasscock, Irion and 9 more	2 hr
Apr 16, 9:33 PM CDT	Mesoscale Discussion	SPC	Armstrong, Briscoe, Childress, Collingsworth, Cottle, Crosby and 26 more	57 min
Apr 17, 4:50 PM CDT	Mesoscale Discussion	SPC	Brooks, Duval, Jim Hogg, Jim Wells, Kenedy, Kleberg and 4 more	115 min

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.