Alert archive / Arkansas / Mesoscale Discussions in 2011

Mesoscale Discussion 1883

August 7, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Aug 7, 2011, 1:46 PM CDT for 4 states. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued
Aug 7, 2011, 1:46 PM CDT (18:46 UTC)
Expired
Aug 7, 2011, 3:45 PM CDT
In force
119 min
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, Crittenden County, AR, Cross County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Garland County, AR, Grant County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Jackson County, AR, Jefferson County, AR, Lafayette County, AR, Lee County, AR, Lincoln County, AR, Little River County, AR, Lonoke County, AR, Miller County, AR, Mississippi County, AR, Monroe County, AR, Nevada County, AR, Ouachita County, AR, Phillips County, AR, Pike County, AR, Poinsett County, AR, Polk County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, Sevier County, AR, St. Francis County, AR, Union County, AR, White County, AR, Woodruff County, AR, Bolivar County, MS, Coahoma County, MS, DeSoto County, MS, Lafayette County, MS, Leflore County, MS, Marshall County, MS, Panola County, MS, Quitman County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Tunica County, MS, Washington County, MS, Yalobusha County, MS, McCurtain County, OK, Fayette County, TN, Lauderdale County, TN, Shelby County, TN, Tipton County, TN

The radar

The Little Rock radar (KLZK), 47 km from the middle of the area, began a volume at 18:48 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

Little Rock, AR (KLZK), launched 12:00Z, 6.8 hours before the alert went out and 204 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, Little Rock, AR at 12:00Z on 2011-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2280 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, Little Rock, AR at 12:00Z on 2011-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 99 square meters per square second.1939Sfc1 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
2280 J/kg
Mixed-layer CIN
-140 J/kg
Mixed-layer LCL
1283 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
99 m²/s²
0-3 km storm-relative helicity
122 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.

IssuedProductOfficeCountiesLasted
Aug 7, 5:20 PM CDTMesoscale DiscussionSPCBenton115 min
Aug 7, 6:07 PM CDTSevere Thunderstorm WatchSPCBenton, Carroll5 hr
Aug 7, 6:10 PM CDTMesoscale DiscussionSPCChickasaw, Itawamba, Lafayette, Lee, Monroe, Pontotoc and 3 more2 hr
Aug 7, 2:21 PM CDTMesoscale DiscussionSPCBeaver, Beckham, Ellis, Greer, Harmon, Harper and 5 more114 min

Nearby

Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Mississippi, 2011Mesoscale Discussions in Tennessee, 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.