Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 208

March 8, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Mar 8, 2011, 6:27 PM CST for 4 states. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued: Mar 8, 2011, 6:27 PM CST (00:27 UTC)
Expired: Mar 8, 2011, 7:30 PM CST
In force: 63 min
Issued by: the Storm Prediction Center

All 43 counties

Bradley County, AR, Calhoun County, AR, Columbia County, AR, Hempstead County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Sevier County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Morehouse Parish, LA, Ouachita Parish, LA, Union Parish, LA, Webster Parish, LA, McCurtain County, OK, Bowie County, TX, Camp County, TX, Cass County, TX, Delta County, TX, Franklin County, TX, Gregg County, TX, Harrison County, TX, Hopkins County, TX, Hunt County, TX, Kaufman County, TX, Lamar County, TX, Marion County, TX, Morris County, TX, Rains County, TX, Red River County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 69 km from the middle of the area, began a volume at 00:28 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 44Mar 8, 7:35 PM CST

The nearest sounding before it

Shreveport, LA (KSHV), launched 00:00Z, 0.5 hours before the alert went out and 70 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: 2021 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 557 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 261 m²/s²
0-3 km storm-relative helicity: 247 m²/s²
Significant tornado parameter: 2.4
Supercell composite: 12.7

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
Mar 8, 7:37 PM CST	Tornado Watch	SPC	Ashley, Bradley, Calhoun, Columbia, Hempstead, Lafayette and 4 more	7 hr
Mar 8, 9:40 PM CST	Mesoscale Discussion	SPC	Columbia, Lafayette, Union	65 min
Mar 9, 1:28 AM CST	Mesoscale Discussion	SPC	Ashley, Union	92 min
Mar 9, 6:28 AM CST	Mesoscale Discussion	SPC	Ashley, Union	92 min
Mar 9, 2:39 AM CST	Tornado Watch	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 16 more	5 hr
Mar 9, 4:39 AM CST	Mesoscale Discussion	SPC	Ascension, Assumption, East Baton Rouge, Iberville, Livingston, Orleans and 9 more	66 min
Mar 9, 7:26 AM CST	Tornado Watch	SPC	Plaquemines, Saint Bernard	6 hr
Mar 9, 9:31 AM CST	Mesoscale Discussion	SPC	Plaquemines, Saint Bernard	59 min

Nearby

Mesoscale Discussions in Texas, 2011 Mesoscale Discussions in Arkansas, 2011 Mesoscale Discussions in Louisiana, 2011 Every mesoscale discussion in 2011

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.