Alert archive / Arkansas / Mesoscale Discussions in 2011

Mesoscale Discussion 2345

November 20, 201110 counties in Arkansas; 4 counties in Oklahoma; 5 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Nov 20, 2011, 8:02 PM CST for 10 counties in Arkansas; 4 counties in Oklahoma; 5 counties in Texas. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued: Nov 20, 2011, 8:02 PM CST (02:02 UTC)
Expired: Nov 20, 2011, 9:00 PM CST
In force: 58 min
Issued by: the Storm Prediction Center

Counties Howard County, AR, Little River County, AR, Logan County, AR, Montgomery County, AR, Pike County, AR, Polk County, AR, Scott County, AR, Sebastian County, AR, Sevier County, AR, Yell County, AR, Choctaw County, OK, LeFlore County, OK, McCurtain County, OK, Pushmataha County, OK, Bowie County, TX, Delta County, TX, Fannin County, TX, Lamar County, TX, Red River County, TX

The radar

The Western Arkansas radar (KSRX), 101 km from the middle of the area, began a volume at 02:05 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

Shreveport, LA (KSHV), launched 00:00Z, 2.0 hours before the alert went out and 223 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: 1025 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 1147 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 109 m²/s²
0-3 km storm-relative helicity: 208 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 8.0

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
Nov 21, 3:40 AM CST	Mesoscale Discussion	SPC	Crittenden, Cross, Lee, St. Francis	95 min
Nov 21, 9:03 AM CST	Mesoscale Discussion	SPC	Beckham, Caddo, Comanche, Cotton, Custer, Grady and 8 more	57 min
Nov 21, 3:44 PM CST	Mesoscale Discussion	SPC	Atoka, Beckham, Bryan, Caddo, Canadian, Carter and 33 more	91 min
Nov 21, 3:46 PM CST	Mesoscale Discussion	SPC	Anderson, Bell, Bosque, Camp, Cass, Cherokee and 37 more	119 min

Nearby

Mesoscale Discussions in Arkansas, 2011 Mesoscale Discussions in Texas, 2011 Mesoscale Discussions in Oklahoma, 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.