Alert archive / Arkansas / Mesoscale Discussions in 2009

Mesoscale Discussion 91

February 10, 200925 counties in Arkansas; 7 counties in Oklahoma; 18 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Feb 10, 2009, 8:34 PM CST for 25 counties in Arkansas; 7 counties in Oklahoma; 18 counties in Texas. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued: Feb 10, 2009, 8:34 PM CST (02:34 UTC)
Expired: Feb 10, 2009, 10:00 PM CST
In force: 86 min
Issued by: the Storm Prediction Center

All 50 counties

Conway County, AR, Crawford County, AR, Faulkner County, AR, Franklin County, AR, Garland County, AR, Hempstead County, AR, Howard County, AR, Johnson County, AR, Little River County, AR, Logan County, AR, Madison County, AR, Montgomery County, AR, Newton County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pope County, AR, Saline County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Sevier County, AR, Van Buren County, AR, Washington County, AR, Yell County, AR, Choctaw County, OK, Haskell County, OK, Latimer County, OK, LeFlore County, OK, McCurtain County, OK, Pushmataha County, OK, Sequoyah County, OK, Bowie County, TX, Camp County, TX, Cass County, TX, Delta County, TX, Franklin County, TX, Gregg County, TX, Henderson County, TX, Hopkins County, TX, Hunt County, TX, Lamar 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 Western Arkansas radar (KSRX), 120 km from the middle of the area, began a volume at 02:35 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.

The nearest sounding before it

Shreveport, LA (KSHV), launched 00:00Z, 2.6 hours before the alert went out and 198 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: 367 J/kg
Mixed-layer CIN: -98 J/kg
Mixed-layer LCL: 785 m above ground
0-6 km bulk shear: 64 kt
0-1 km storm-relative helicity: 410 m²/s²
0-3 km storm-relative helicity: 547 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 10.5

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
Feb 10, 6:13 PM CST	Mesoscale Discussion	SPC	Crawford, Washington	92 min
Feb 10, 9:30 PM CST	Tornado Watch	SPC	Baxter, Benton, Boone, Carroll, Clark, Cleburne and 42 more	7 hr
Feb 10, 11:13 PM CST	Mesoscale Discussion	SPC	Baxter, Boone, Cleburne, Conway, Faulkner, Fulton and 18 more	92 min
Feb 10, 11:45 PM CST	Tornado Watch	SPC	Arkansas, Clay, Craighead, Crittenden, Cross, Greene and 12 more	6 hr
Feb 11, 12:37 AM CST	Mesoscale Discussion	SPC	Ashley, Bradley, Calhoun, Chicot, Cleveland, Desha and 3 more	53 min
Feb 11, 1:04 AM CST	Tornado Watch	SPC	Ashley, Bradley, Calhoun, Chicot, Cleveland, Desha and 3 more	5 hr
Feb 11, 2:30 AM CST	Mesoscale Discussion	SPC	Arkansas, Clay, Craighead, Crittenden, Cross, Fulton and 18 more	90 min
Feb 11, 4:01 AM CST	Mesoscale Discussion	SPC	Ashley, Bradley, Calhoun, Chicot, Cleveland, Columbia and 6 more	89 min
Feb 11, 5:26 AM CST	Mesoscale Discussion	SPC	Mississippi	64 min
Feb 10, 7:18 PM CST	Mesoscale Discussion	SPC	Carter, Cleveland, Garvin, Jefferson, Lincoln, McClain and 1 more	57 min
Feb 10, 9:46 PM CST	Mesoscale Discussion	SPC	Austin, Brazoria, Calhoun, Chambers, Colorado, DeWitt and 13 more	29 min
Feb 10, 9:57 PM CST	Severe Thunderstorm Watch	SPC	Aransas, Austin, Bastrop, Bee, Brazoria, Caldwell and 25 more	5 hr

Nearby

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