Alert archive / Louisiana / Mesoscale Discussions in 2014

Mesoscale Discussion 124

February 20, 20144 states

The Storm Prediction Center issued this mesoscale discussion at Feb 20, 2014, 3:11 PM CST for 4 states. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued: Feb 20, 2014, 3:11 PM CST (21:11 UTC)
Expired: Feb 20, 2014, 4:45 PM CST
In force: 94 min
Issued by: the Storm Prediction Center

All 49 counties

Ashley County, AR, Chicot County, AR, Desha County, AR, Beauregard Parish, LA, Bienville Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Tensas Parish, LA, Union Parish, LA, Vernon Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Bolivar County, MS, Carroll County, MS, Grenada County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Leflore County, MS, Montgomery County, MS, Sharkey County, MS, Sunflower County, MS, Tallahatchie County, MS, Warren County, MS, Washington County, MS, Yalobusha County, MS, Yazoo County, MS, Hardin County, TX, Jasper County, TX, Newton County, TX, Polk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Tyler County, TX

The radar

The Ft Polk radar (KPOE), 116 km from the middle of the area, began a volume at 21:13 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 15Feb 20, 6:05 PM CST

The nearest sounding before it

Shreveport, LA (KBAD), launched 12:00Z, 9.2 hours before the alert went out and 128 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: 22 J/kg
Mixed-layer CIN: -480 J/kg
Mixed-layer LCL: 671 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 420 m²/s²
0-3 km storm-relative helicity: 590 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
Feb 20, 11:01 AM CST	Mesoscale Discussion	SPC	Arkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 12 more	119 min
Feb 20, 12:47 PM CST	Severe Thunderstorm Watch	SPC	Arkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 18 more	7 hr
Feb 20, 1:45 PM CST	Mesoscale Discussion	SPC	Clay, Craighead, Crittenden, Cross, Greene, Lee and 4 more	2 hr
Feb 20, 2:23 PM CST	Tornado Watch	SPC	Clay, Craighead, Crittenden, Cross, Greene, Lawrence and 6 more	7 hr
Feb 20, 5:29 PM CST	Mesoscale Discussion	SPC	Crittenden, Mississippi	46 min
Feb 20, 5:55 PM CST	Mesoscale Discussion	SPC	Acadia, Allen, Ascension, Avoyelles, Beauregard, Caldwell and 26 more	35 min

Nearby

Mesoscale Discussions in Louisiana, 2014 Mesoscale Discussions in Mississippi, 2014 Mesoscale Discussions in Texas, 2014 Every mesoscale discussion in 2014

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.