Alert archive / Texas / Mesoscale Discussions in 2009

Mesoscale Discussion 507

April 17, 20094 states

The Storm Prediction Center issued this mesoscale discussion at Apr 17, 2009, 8:33 PM MDT for 4 states. It was in force for 27 min.

The area

The outline as issued.

The facts

Issued: Apr 17, 2009, 8:33 PM MDT (02:33 UTC)
Expired: Apr 17, 2009, 9:00 PM MDT
In force: 27 min
Issued by: the Storm Prediction Center

All 35 counties

Prowers County, CO, Grant County, KS, Haskell County, KS, Meade County, KS, Morton County, KS, Seward County, KS, Stanton County, KS, Stevens County, KS, Beaver County, OK, Beckham County, OK, Ellis County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Roger Mills County, OK, Texas County, OK, Childress County, TX, Collingsworth County, TX, Cottle County, TX, Foard County, TX, Gray County, TX, Hansford County, TX, Hardeman County, TX, Haskell County, TX, Hemphill County, TX, Jones County, TX, King County, TX, Knox County, TX, Lipscomb County, TX, Ochiltree County, TX, Roberts County, TX, Shackelford County, TX, Stonewall County, TX, Taylor County, TX, Wheeler County, TX

The radar

The Amarillo radar (KAMA), 113 km from the middle of the area, began a volume at 02:36 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

Dodge City, (KDDC), launched 00:00Z, 2.6 hours before the alert went out and 277 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: 26 J/kg
Mixed-layer CIN: -163 J/kg
Mixed-layer LCL: 565 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 149 m²/s²
0-3 km storm-relative helicity: 175 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 17, 6:53 PM MDT	Mesoscale Discussion	SPC	Kiowa, Lincoln	67 min
Apr 18, 12:14 PM MDT	Mesoscale Discussion	SPC	Barber, Clark, Comanche, Edwards, Finney, Ford and 6 more	61 min
Apr 18, 12:28 PM MDT	Tornado Watch	SPC	Barber, Clark, Comanche, Edwards, Ellis, Finney and 12 more	6 hr
Apr 18, 1:49 PM MDT	Mesoscale Discussion	SPC	Butler, Chase, Chautauqua, Cherokee, Cowley, Elk and 14 more	86 min
Apr 18, 2:26 PM MDT	Severe Thunderstorm Watch	SPC	Barton, Butler, Chase, Cowley, Ellsworth, Harper and 11 more	7 hr
Apr 18, 3:23 PM MDT	Severe Thunderstorm Watch	SPC	Allen, Anderson, Bourbon, Chautauqua, Cherokee, Coffey and 10 more	8 hr
Apr 18, 2:11 PM MDT	Severe Thunderstorm Watch	SPC	Atoka, Bryan, Caddo, Canadian, Carter, Cleveland and 27 more	9 hr
Apr 18, 4:14 PM MDT	Mesoscale Discussion	SPC	Alfalfa, Bryan, Canadian, Carter, Cleveland, Coal and 24 more	91 min
Apr 17, 10:44 PM MDT	Mesoscale Discussion	SPC	Atascosa, La Salle, McMullen	61 min
Apr 18, 2:22 AM MDT	Mesoscale Discussion	SPC	Atascosa, Bandera, Bastrop, Bee, Bexar, Blanco and 34 more	113 min
Apr 18, 3:21 AM MDT	Severe Thunderstorm Watch	SPC	Aransas, Atascosa, Austin, Bandera, Bastrop, Bee and 43 more	7 hr
Apr 18, 5:32 AM MDT	Mesoscale Discussion	SPC	Atascosa, Bandera, Bastrop, Bexar, Caldwell, Comal and 17 more	118 min
Apr 18, 8:47 AM MDT	Mesoscale Discussion	SPC	Anderson, Angelina, Austin, Brazoria, Brazos, Chambers and 22 more	28 min
Apr 18, 8:53 AM MDT	Tornado Watch	SPC	Anderson, Angelina, Austin, Brazoria, Brazos, Burleson and 23 more	6 hr
Apr 18, 9:52 AM MDT	Mesoscale Discussion	SPC	Aransas, Atascosa, Bee, Calhoun, DeWitt, Duval and 15 more	53 min
Apr 18, 10:26 AM MDT	Mesoscale Discussion	SPC	Anderson, Angelina, Austin, Brazoria, Brazos, Burleson and 29 more	2 hr
Apr 18, 12:01 PM MDT	Tornado Watch	SPC	Hardin, Jasper, Jefferson, Newton, Orange, Sabine and 3 more	7 hr
Apr 18, 12:43 PM MDT	Mesoscale Discussion	SPC	Angelina, Austin, Brazoria, Chambers, Fort Bend, Galveston and 10 more	92 min
Apr 18, 2:38 PM MDT	Mesoscale Discussion	SPC	Hardin, Jasper, Jefferson, Newton, Orange, Sabine and 3 more	97 min
Apr 18, 4:46 PM MDT	Mesoscale Discussion	SPC	Hardin, Jasper, Jefferson, Newton, Orange, Sabine and 3 more	59 min

Nearby

Mesoscale Discussions in Texas, 2009 Mesoscale Discussions in Oklahoma, 2009 Mesoscale Discussions in Kansas, 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.