Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 1880

October 24, 201516 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Oct 24, 2015, 12:50 PM CDT for 16 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Oct 24, 2015, 12:50 PM CDT (17:50 UTC)
Expired: Oct 24, 2015, 3:15 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Aransas County, TX, Brazoria County, TX, Brooks County, TX, Calhoun County, TX, Cameron County, TX, Galveston County, TX, Hidalgo County, TX, Jackson County, TX, Jim Wells County, TX, Kenedy County, TX, Kleberg County, TX, Matagorda County, TX, Nueces County, TX, Refugio County, TX, San Patricio County, TX, Willacy County, TX

The radar

The Corpus Christi radar (KCRP), 85 km from the middle of the area, began a volume at 17:54 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.

Tornado Watch 520Oct 24, 2:40 PM CDT

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 12:00Z, 5.8 hours before the alert went out and 67 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: 1121 J/kg
Mixed-layer CIN: -4 J/kg
Mixed-layer LCL: 628 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 87 m²/s²
0-3 km storm-relative helicity: 140 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 3.8

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
Oct 24, 2:44 PM CDT	Tornado Watch	SPC	Aransas, Brazoria, Calhoun, Chambers, Fort Bend, Galveston and 9 more	7 hr
Oct 24, 6:14 PM CDT	Mesoscale Discussion	SPC	Aransas, Brazoria, Calhoun, Chambers, Fort Bend, Galveston and 5 more	91 min

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.