Alert archive / Texas / Mesoscale Discussions in 2003

Mesoscale Discussion 491

April 18, 200318 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 18, 2003, 9:21 PM CDT for 18 counties in Texas. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued: Apr 18, 2003, 9:21 PM CDT (02:21 UTC)
Expired: Apr 18, 2003, 10:15 PM CDT
In force: 54 min
Issued by: the Storm Prediction Center

Counties Bandera County, TX, Bexar County, TX, Blanco County, TX, Comal County, TX, Dimmit County, TX, Edwards County, TX, Frio County, TX, Gillespie County, TX, Kendall County, TX, Kerr County, TX, Kimble County, TX, Kinney County, TX, Maverick County, TX, Medina County, TX, Real County, TX, Uvalde County, TX, Val Verde County, TX, Zavala County, TX

The nearest sounding before it

Del Rio, TX (KDRT), launched 00:00Z, 2.4 hours before the alert went out and 64 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: 1941 J/kg
Mixed-layer CIN: -151 J/kg
Mixed-layer LCL: 1672 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 52 m²/s²
0-3 km storm-relative helicity: 212 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 2.3

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 18, 8:31 PM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Borden, Childress, Clay, Cottle and 19 more	2 hr
Apr 18, 9:50 PM CDT	Severe Thunderstorm Watch	SPC	Archer, Baylor, Borden, Callahan, Childress, Clay and 29 more	6 hr
Apr 18, 11:32 PM CDT	Mesoscale Discussion	SPC	Baylor, Childress, Cottle, Crosby, Dickens, Foard and 13 more	118 min
Apr 19, 1:20 AM CDT	Tornado Watch	SPC	Archer, Baylor, Borden, Childress, Clay, Collingsworth and 21 more	7 hr
Apr 19, 1:25 AM CDT	Severe Thunderstorm Watch	SPC	Wheeler	7 hr
Apr 19, 4:11 AM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Clay, Fisher, Foard, Hardeman and 10 more	2 hr
Apr 19, 9:01 AM CDT	Mesoscale Discussion	SPC	Bowie, Camp, Cass, Collin, Delta, Ellis and 18 more	3 hr
Apr 19, 2:02 PM CDT	Mesoscale Discussion	SPC	Collin, Dallas, Delta, Ellis, Fannin, Grayson and 4 more	88 min
Apr 19, 3:15 PM CDT	Mesoscale Discussion	SPC	Collin, Dallas, Delta, Ellis, Fannin, Grayson and 4 more	2 hr

Nearby

Mesoscale Discussions in Texas, 2003 Every mesoscale discussion in 2003

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.