Alert archive / Texas / Mesoscale Discussions in 2004

Mesoscale Discussion 475

April 25, 200418 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 25, 2004, 6:10 AM CDT for 18 counties in Texas. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued: Apr 25, 2004, 6:10 AM CDT (11:10 UTC)
Expired: Apr 25, 2004, 7:15 AM CDT
In force: 65 min
Issued by: the Storm Prediction Center

Counties Aransas County, TX, Austin County, TX, Brazoria County, TX, Calhoun County, TX, Colorado County, TX, DeWitt County, TX, Fort Bend County, TX, Goliad County, TX, Harris County, TX, Jackson County, TX, Lavaca County, TX, Matagorda County, TX, Montgomery County, TX, Refugio County, TX, Victoria County, TX, Waller County, TX, Washington County, TX, Wharton County, TX

The radar

The Houston radar (KHGX), 145 km from the middle of the area, began a volume at 11:12 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, 11.2 hours before the alert went out and 181 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: 641 J/kg
Mixed-layer CIN: -88 J/kg
Mixed-layer LCL: 730 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 52 m²/s²
0-3 km storm-relative helicity: 84 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

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
Apr 25, 1:29 PM CDT	Mesoscale Discussion	SPC	Armstrong, Briscoe, Carson, Childress, Collingsworth, Cottle and 19 more	3 hr
Apr 25, 2:20 PM CDT	Severe Thunderstorm Watch	SPC	Archer, Armstrong, Baylor, Briscoe, Carson, Castro and 27 more	7 hr
Apr 25, 5:14 PM CDT	Mesoscale Discussion	SPC	Archer, Armstrong, Baylor, Briscoe, Carson, Castro and 27 more	2 hr
Apr 25, 5:53 PM CDT	Mesoscale Discussion	SPC	Bandera, Edwards, Gillespie, Kerr, Kimble, Mason and 5 more	97 min

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.