Alert archive / Arkansas / Mesoscale Discussions in 2009

Mesoscale Discussion 2213

December 8, 20094 states

The Storm Prediction Center issued this mesoscale discussion at Dec 8, 2009, 9:43 AM CST for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Dec 8, 2009, 9:43 AM CST (15:43 UTC)
Expired
Dec 8, 2009, 11:45 AM CST
In force
2 hr
Issued by
the Storm Prediction Center
All 61 counties

Arkansas County, AR, Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Clark County, AR, Cleveland County, AR, Columbia County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Grant County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Jefferson County, AR, Lafayette County, AR, Lincoln County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Phillips County, AR, Pike County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, East Carroll Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Richland Parish, LA, Union Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Bolivar County, MS, Carroll County, MS, Coahoma County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Leflore County, MS, Panola County, MS, Quitman County, MS, Sharkey County, MS, Sunflower County, MS, Tallahatchie County, MS, Tunica County, MS, Washington County, MS, Yazoo County, MS, Bowie County, TX, Cass County, TX, Harrison County, TX, Marion County, TX, Morris County, TX

The radar

The Shreveport radar (KSHV), 156 km from the middle of the area, began a volume at 15:43 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

Jackson, MS (KJAN), launched 12:00Z, 3.7 hours before the alert went out and 256 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-pSkew-T log-p diagram, Jackson, MS at 12:00Z on 2009-12-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Jackson, MS at 12:00Z on 2009-12-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 264 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
495 m above ground
0-6 km bulk shear
71 kt
0-1 km storm-relative helicity
264 m²/s²
0-3 km storm-relative helicity
389 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

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.

IssuedProductOfficeCountiesLasted
Dec 8, 1:25 PM CSTTornado WatchSPCAshley, Chicot, Union8 hr
Dec 7, 10:41 PM CSTMesoscale DiscussionSPCAssumption, Iberia, St. Mary, Terrebonne2 hr
Dec 8, 12:12 PM CSTMesoscale DiscussionSPCAllen, Avoyelles, Beauregard, Caldwell, Catahoula, Concordia and 15 more93 min
Dec 8, 5:12 PM CSTMesoscale DiscussionSPCAlcorn, Benton, Calhoun, Chickasaw, Itawamba, Lafayette and 8 more63 min
Dec 8, 5:48 PM CSTTornado WatchSPCAlcorn, Benton, Calhoun, Chickasaw, Itawamba, Lafayette and 9 more6 hr
Dec 8, 5:55 PM CSTMesoscale DiscussionSPCClarke, Forrest, Jasper, Jones, Kemper, Lamar and 5 more95 min

Nearby

Mesoscale Discussions in Arkansas, 2009Mesoscale Discussions in Louisiana, 2009Mesoscale Discussions in Mississippi, 2009Every 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.