Alert archive / Louisiana / Mesoscale Discussions in 2012

Mesoscale Discussion 2217

December 25, 2012Chicot County, Arkansas; 5 parishes in Louisiana

The Storm Prediction Center issued this mesoscale discussion at Dec 25, 2012, 3:22 PM CST for Chicot County, Arkansas; 5 parishes in Louisiana. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued: Dec 25, 2012, 3:22 PM CST (21:22 UTC)
Expired: Dec 25, 2012, 4:15 PM CST
In force: 53 min
Issued by: the Storm Prediction Center

Counties Chicot County, AR, Caldwell Parish, LA, East Carroll Parish, LA, Morehouse Parish, LA, Richland Parish, LA, West Carroll Parish, LA

The radar

The Jackson/Brandon,MS radar (KDGX), 160 km from the middle of the area, began a volume at 21:25 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

Jackson, MS (KJAN), launched 12:00Z, 9.4 hours before the alert went out and 150 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: 1 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 659 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 253 m²/s²
0-3 km storm-relative helicity: 361 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.4

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
Dec 25, 9:02 AM CST	Severe Thunderstorm Watch	SPC	Ashley, Chicot, Union	7 hr
Dec 25, 12:11 PM CST	Mesoscale Discussion	SPC	Cleburne, Conway, Crawford, Faulkner, Franklin, Garland and 20 more	5 hr
Dec 25, 12:23 PM CST	Mesoscale Discussion	SPC	Ashley, Chicot	67 min
Dec 25, 1:00 PM CST	Mesoscale Discussion	SPC	Columbia, Hempstead, Lafayette, Little River, Miller, Nevada	5 hr
Dec 25, 2:14 PM CST	Mesoscale Discussion	SPC	Baxter, Boone, Carroll, Clay, Craighead, Cross and 10 more	4 hr
Dec 25, 1:01 AM CST	Mesoscale Discussion	SPC	Allen, Beauregard, Sabine, Vernon	59 min
Dec 25, 1:37 AM CST	Severe Thunderstorm Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, De Soto and 9 more	7 hr
Dec 25, 5:56 AM CST	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, De Soto and 10 more	94 min
Dec 25, 7:00 AM CST	Mesoscale Discussion	SPC	Acadia, Allen, Ascension, Assumption, Beauregard, Calcasieu and 24 more	60 min
Dec 25, 7:28 AM CST	Tornado Watch	SPC	Acadia, Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia and 19 more	6 hr
Dec 25, 8:46 AM CST	Mesoscale Discussion	SPC	Allen, Avoyelles, Beauregard, Bienville, Calcasieu, Caldwell and 21 more	59 min
Dec 25, 9:17 AM CST	Tornado Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 10 more	8 hr
Dec 25, 12:19 PM CST	Mesoscale Discussion	SPC	Acadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 35 more	71 min
Dec 25, 12:58 PM CST	Tornado Watch PDS	SPC	Ascension, Assumption, Catahoula, Concordia, East Baton Rouge, East Feliciana and 20 more	9 hr
Dec 25, 3:44 PM CST	Mesoscale Discussion	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 19 more	91 min

Nearby

Mesoscale Discussions in Louisiana, 2012 Mesoscale Discussions in Arkansas, 2012 Every mesoscale discussion in 2012

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.