Alert archive / Texas / Mesoscale Discussions in 2003

Mesoscale Discussion 634

April 29, 2003Marshall County, Oklahoma; 13 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 29, 2003, 11:16 PM CDT for Marshall County, Oklahoma; 13 counties in Texas. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued: Apr 29, 2003, 11:16 PM CDT (04:16 UTC)
Expired: Apr 30, 2003, 1:15 AM CDT
In force: 119 min
Issued by: the Storm Prediction Center

Counties Marshall County, OK, Bosque County, TX, Collin County, TX, Cooke County, TX, Coryell County, TX, Dallas County, TX, Denton County, TX, Ellis County, TX, Grayson County, TX, Hill County, TX, Johnson County, TX, Rockwall County, TX, Somervell County, TX, Tarrant County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 80 km from the middle of the area, began a volume at 04:16 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

Fort Worth, TX (KFWD), launched 00:00Z, 4.3 hours before the alert went out and 52 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: 1115 J/kg
Mixed-layer CIN: -159 J/kg
Mixed-layer LCL: 1578 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 19 m²/s²
0-3 km storm-relative helicity: 75 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

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 29, 9:05 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Beckham, Blaine, Caddo, Canadian, Comanche and 17 more	85 min
Apr 29, 9:20 PM CDT	Severe Thunderstorm Watch	SPC	Love	3 hr
Apr 30, 4:02 PM CDT	Mesoscale Discussion	SPC	Beckham, Caddo, Comanche, Custer, Greer, Harmon and 5 more	118 min
Apr 30, 6:05 PM CDT	Severe Thunderstorm Watch	SPC	Alfalfa, Blaine, Caddo, Canadian, Comanche, Cotton and 14 more	5 hr
Apr 29, 8:19 PM CDT	Mesoscale Discussion	SPC	Brooks, Cameron, Duval, Hidalgo, Jim Hogg, Jim Wells and 6 more	86 min
Apr 30, 2:13 PM CDT	Mesoscale Discussion	SPC	Brown, Coleman, Concho, Edwards, Kimble, McCulloch and 4 more	92 min

Nearby

Mesoscale Discussions in Texas, 2003 Mesoscale Discussions in Oklahoma, 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; radar from the NEXRAD Level II archive.