Alert archive / Texas / Mesoscale Discussions in 2009

Mesoscale Discussion 484

April 16, 200917 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 16, 2009, 3:53 PM CDT for 17 counties in Texas. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued: Apr 16, 2009, 3:53 PM CDT (20:53 UTC)
Expired: Apr 16, 2009, 5:00 PM CDT
In force: 67 min
Issued by: the Storm Prediction Center

Counties Borden County, TX, Briscoe County, TX, Crosby County, TX, Dawson County, TX, Dickens County, TX, Fisher County, TX, Floyd County, TX, Garza County, TX, Hale County, TX, Hall County, TX, Howard County, TX, Kent County, TX, Lubbock County, TX, Lynn County, TX, Mitchell County, TX, Motley County, TX, Scurry County, TX

The radar

The Lubbock radar (KLBB), 64 km from the middle of the area, began a volume at 20:56 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.

Tornado Watch 157Apr 16, 4:45 PM CDT

The nearest sounding before it

Midland Regional, TX (KMAF), launched 12:00Z, 8.9 hours before the alert went out and 178 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: 1226 J/kg
Mixed-layer CIN: -157 J/kg
Mixed-layer LCL: 581 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 118 m²/s²
0-3 km storm-relative helicity: 86 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.1

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 16, 11:20 AM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Collingsworth, Gray, Hansford, Hardeman and 8 more	115 min
Apr 16, 1:41 PM CDT	Mesoscale Discussion	SPC	Armstrong, Briscoe, Carson, Crosby, Dickens, Donley and 18 more	64 min
Apr 16, 2:42 PM CDT	Severe Thunderstorm Watch	SPC	Armstrong, Bailey, Briscoe, Carson, Castro, Childress and 38 more	7 hr
Apr 16, 4:42 PM CDT	Tornado Watch	SPC	Andrews, Borden, Briscoe, Castro, Childress, Coke and 34 more	7 hr
Apr 16, 5:56 PM CDT	Mesoscale Discussion	SPC	Andrews, Borden, Briscoe, Castro, Childress, Coke and 36 more	94 min
Apr 16, 6:33 PM CDT	Mesoscale Discussion	SPC	Armstrong, Bailey, Carson, Cochran, Collingsworth, Dallam and 18 more	87 min

Nearby

Mesoscale Discussions in Texas, 2009 Every mesoscale discussion in 2009

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.