Alert archive / Mississippi / Mesoscale Discussions in 2011

Mesoscale Discussion 279

March 26, 201114 counties in Arkansas; 8 parishes in Louisiana; 27 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Mar 26, 2011, 2:27 PM CDT for 14 counties in Arkansas; 8 parishes in Louisiana; 27 counties in Mississippi. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued
Mar 26, 2011, 2:27 PM CDT (19:27 UTC)
Expired
Mar 26, 2011, 3:30 PM CDT
In force
63 min
Issued by
the Storm Prediction Center
All 49 counties

Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Columbia County, AR, Desha County, AR, Drew County, AR, Hempstead County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Union County, AR, Bossier Parish, LA, Claiborne Parish, LA, East Carroll Parish, LA, Lincoln Parish, LA, Morehouse Parish, LA, Union Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Attala County, MS, Bolivar County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Grenada County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Kemper County, MS, Leake County, MS, Leflore County, MS, Lowndes County, MS, Madison County, MS, Monroe County, MS, Montgomery County, MS, Neshoba County, MS, Noxubee County, MS, Oktibbeha County, MS, Sharkey County, MS, Sunflower County, MS, Washington County, MS, Webster County, MS, Winston County, MS, Yazoo County, MS

The radar

The Little Rock radar (KLZK), 172 km from the middle of the area, began a volume at 19:29 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, 7.5 hours before the alert went out and 214 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 2011-03-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1152 joules per kilogram.LCLLFCEL10008507005003002001001 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 2011-03-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 204 square meters per square second.19395878Sfc1 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
1152 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
472 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
204 m²/s²
0-3 km storm-relative helicity
244 m²/s²
Significant tornado parameter
1.2
Supercell composite
9.1

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
Mar 25, 7:31 PM CDTMesoscale DiscussionSPCCalhoun, Clark, Columbia, Hempstead, Howard, Lafayette and 7 more89 min
Mar 25, 10:50 PM CDTSevere Thunderstorm WatchSPCColumbia, Crawford, Franklin, Hempstead, Howard, Lafayette and 11 more7 hr
Mar 25, 11:40 PM CDTMesoscale DiscussionSPCCrawford, Franklin, Madison, Newton, Washington65 min
Mar 26, 2:41 AM CDTMesoscale DiscussionSPCClark, Columbia, Hempstead, Howard, Lafayette, Little River and 6 more2 hr
Mar 26, 3:27 PM CDTTornado WatchSPCAshley, Bradley, Calhoun, Chicot, Desha, Drew and 2 more7 hr
Mar 26, 4:33 PM CDTMesoscale DiscussionSPCColumbia, Lafayette, Miller57 min
Mar 26, 10:21 AM CDTMesoscale DiscussionSPCCalhoun, Chickasaw, Choctaw, Clay, Lowndes, Monroe and 3 more54 min
Mar 26, 11:25 AM CDTMesoscale DiscussionSPCClay, Kemper, Lauderdale, Lowndes, Monroe, Neshoba and 4 more95 min

Nearby

Mesoscale Discussions in Mississippi, 2011Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Louisiana, 2011Every 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.