Alert archive / Arkansas / Mesoscale Discussions in 2007

Mesoscale Discussion 486

April 13, 200725 counties in Arkansas; 8 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 13, 2007, 10:55 PM CDT for 25 counties in Arkansas; 8 counties in Mississippi. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Apr 13, 2007, 10:55 PM CDT (03:55 UTC)
Expired
Apr 14, 2007, 12:30 AM CDT
In force
95 min
Issued by
the Storm Prediction Center
All 33 counties

Arkansas County, AR, Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Cleveland County, AR, Cross County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Faulkner County, AR, Grant County, AR, Jefferson County, AR, Lee County, AR, Lincoln County, AR, Lonoke County, AR, Monroe County, AR, Ouachita County, AR, Phillips County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, St. Francis County, AR, White County, AR, Woodruff County, AR, Bolivar County, MS, Coahoma County, MS, Humphreys County, MS, Leflore County, MS, Quitman County, MS, Sunflower County, MS, Tunica County, MS, Washington County, MS

The radar

The Little Rock radar (KLZK), 98 km from the middle of the area, began a volume at 03:58 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 00:00Z, 3.9 hours before the alert went out and 170 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 00:00Z on 2007-04-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 2007-04-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 622 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
762 m above ground
0-6 km bulk shear
70 kt
0-1 km storm-relative helicity
622 m²/s²
0-3 km storm-relative helicity
1200 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5

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
Apr 13, 8:42 PM CDTMesoscale DiscussionSPCColumbia, Hempstead, Lafayette, Little River, Miller, Nevada and 1 more2 hr
Apr 14, 1:41 AM CDTTornado WatchSPCAshley, Chicot6 hr
Apr 14, 1:34 AM CDTMesoscale DiscussionSPCAdams, Carroll, Claiborne, Copiah, Franklin, Hinds and 11 more56 min
Apr 14, 6:17 AM CDTMesoscale DiscussionSPCAmite, Attala, Claiborne, Clarke, Copiah, Covington and 27 more88 min
Apr 14, 7:11 AM CDTSevere Thunderstorm WatchSPCAmite, Attala, Carroll, Choctaw, Clarke, Clay and 34 more6 hr
Apr 14, 10:07 AM CDTMesoscale DiscussionSPCGeorge, Greene, Harrison, Jackson53 min
Apr 14, 10:26 AM CDTTornado WatchSPCClarke, Forrest, George, Greene, Hancock, Harrison and 5 more7 hr
Apr 14, 2:12 PM CDTMesoscale DiscussionSPCClarke, Forrest, George, Greene, Hancock, Harrison and 5 more63 min
Apr 14, 5:04 PM CDTMesoscale DiscussionSPCGeorge, Greene, Hancock, Harrison, Jackson, Perry and 2 more56 min
Apr 14, 5:26 PM CDTTornado WatchSPCGeorge, Greene, Jackson, Perry, Stone, Wayne6 hr

Nearby

Mesoscale Discussions in Arkansas, 2007Mesoscale Discussions in Mississippi, 2007Every mesoscale discussion in 2007

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.