Alert archive / Texas / Mesoscale Discussions in 2004

Mesoscale Discussion 2412

November 20, 20049 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Nov 20, 2004, 12:23 PM CST for 9 counties in Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Nov 20, 2004, 12:23 PM CST (18:23 UTC)
Expired: Nov 20, 2004, 3:00 PM CST
In force: 3 hr
Issued by: the Storm Prediction Center

Counties Bee County, TX, Calhoun County, TX, Goliad County, TX, Jackson County, TX, Live Oak County, TX, Matagorda County, TX, Refugio County, TX, San Patricio County, TX, Victoria County, TX

The radar

The Corpus Christi radar (KCRP), 99 km from the middle of the area, began a volume at 18:22 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 12:00Z, 6.4 hours before the alert went out and 96 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: 1551 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 534 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 173 m²/s²
0-3 km storm-relative helicity: 154 m²/s²
Significant tornado parameter: 1.2
Supercell composite: 7.2

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
Nov 19, 11:26 PM CST	Mesoscale Discussion	SPC	Brazoria, Calhoun, Chambers, Fort Bend, Galveston, Harris and 4 more	2 hr
Nov 20, 1:55 PM CST	Mesoscale Discussion	SPC	Bosque, Brown, Burnet, Callahan, Coleman, Comanche and 28 more	2 hr
Nov 20, 5:11 PM CST	Mesoscale Discussion	SPC	Brazoria, Calhoun, Colorado, Fort Bend, Jackson, Lavaca and 3 more	2 hr

Nearby

Mesoscale Discussions in Texas, 2004 Every mesoscale discussion in 2004

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.