Alert archive / Arkansas / Mesoscale Discussions in 2011

Mesoscale Discussion 2198

September 25, 201127 counties in Arkansas; 6 counties in Mississippi; 5 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Sep 25, 2011, 2:03 PM CDT for 27 counties in Arkansas; 6 counties in Mississippi; 5 counties in Tennessee. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Sep 25, 2011, 2:03 PM CDT (19:03 UTC)
Expired
Sep 25, 2011, 4:30 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 38 counties

Arkansas County, AR, Bradley County, AR, Calhoun County, AR, Clark County, AR, Cleveland County, AR, Crittenden County, AR, Cross County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Garland County, AR, Grant County, AR, Hot Spring County, AR, Jefferson County, AR, Lee County, AR, Lincoln County, AR, Lonoke County, AR, Mississippi County, AR, Monroe County, AR, Ouachita County, AR, Phillips County, AR, Poinsett County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, St. Francis County, AR, Woodruff County, AR, Bolivar County, MS, Coahoma County, MS, DeSoto County, MS, Quitman County, MS, Tate County, MS, Tunica County, MS, Fayette County, TN, Haywood County, TN, Lauderdale County, TN, Shelby County, TN, Tipton County, TN

The radar

The Little Rock radar (KLZK), 107 km from the middle of the area, began a volume at 19:03 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

Little Rock, AR (KLZK), launched 12:00Z, 7.1 hours before the alert went out and 126 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 2011-09-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 552 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 2011-09-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 127 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
552 J/kg
Mixed-layer CIN
-212 J/kg
Mixed-layer LCL
1112 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
127 m²/s²
0-3 km storm-relative helicity
295 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

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
Sep 25, 3:19 PM CDTTornado WatchSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 12 more9 hr
Sep 25, 6:10 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Chicot, Crittenden, Desha, Drew and 3 more95 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.