Alert archive / Texas / Mesoscale Discussions in 2006

Mesoscale Discussion 2291

December 21, 200612 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Dec 21, 2006, 8:53 AM CST for 12 counties in Texas. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued: Dec 21, 2006, 8:53 AM CST (14:53 UTC)
Expired: Dec 21, 2006, 10:30 AM CST
In force: 97 min
Issued by: the Storm Prediction Center

Counties Atascosa County, TX, Bastrop County, TX, Caldwell County, TX, Colorado County, TX, DeWitt County, TX, Fayette County, TX, Gonzales County, TX, Guadalupe County, TX, Karnes County, TX, Lavaca County, TX, Lee County, TX, Wilson County, TX

The radar

The Austin/San Antonio radar (KEWX), 74 km from the middle of the area, began a volume at 14:55 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.

Severe Thunderstorm Watch 879Dec 21, 12:00 PM CST

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 12:00Z, 2.9 hours before the alert went out and 192 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: 173 J/kg
Mixed-layer CIN: -240 J/kg
Mixed-layer LCL: 690 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 135 m²/s²
0-3 km storm-relative helicity: 193 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.4

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
Dec 21, 11:53 AM CST	Mesoscale Discussion	SPC	Austin, Brazoria, Colorado, DeWitt, Fort Bend, Galveston and 9 more	67 min
Dec 21, 12:04 PM CST	Severe Thunderstorm Watch	SPC	Aransas, Austin, Bee, Brazoria, Calhoun, Colorado and 20 more	6 hr
Dec 21, 2:22 PM CST	Mesoscale Discussion	SPC	Chambers, Hardin, Harris, Jasper, Jefferson, Liberty and 4 more	83 min
Dec 21, 2:28 PM CST	Severe Thunderstorm Watch	SPC	Chambers, Galveston, Hardin, Jasper, Jefferson, Liberty and 5 more	8 hr
Dec 21, 4:56 PM CST	Mesoscale Discussion	SPC	Angelina, Aransas, Austin, Bee, Brazoria, Calhoun and 29 more	94 min

Nearby

Mesoscale Discussions in Texas, 2006 Every mesoscale discussion in 2006

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.