Alert archive / Arkansas / Mesoscale Discussions in 2004

Mesoscale Discussion 1555

July 7, 200415 counties in Arkansas; 5 parishes in Louisiana; 8 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jul 7, 2004, 10:20 AM CDT for 15 counties in Arkansas; 5 parishes in Louisiana; 8 counties in Mississippi. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued: Jul 7, 2004, 10:20 AM CDT (15:20 UTC)
Expired: Jul 7, 2004, 11:15 AM CDT
In force: 55 min
Issued by: the Storm Prediction Center

All 28 counties

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, Lafayette County, AR, Lincoln County, AR, Nevada County, AR, Ouachita County, AR, Union County, AR, Claiborne Parish, LA, East Carroll Parish, LA, Morehouse Parish, LA, Union Parish, LA, West Carroll Parish, LA, Bolivar County, MS, Humphreys County, MS, Issaquena County, MS, Leflore County, MS, Sharkey County, MS, Sunflower County, MS, Washington County, MS, Yazoo County, MS

The radar

The Little Rock radar (KLZK), 140 km from the middle of the area, began a volume at 15:20 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

Jackson, MS (KJAN), launched 12:00Z, 3.3 hours before the alert went out and 241 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2132 J/kg
Mixed-layer CIN: -14 J/kg
Mixed-layer LCL: 580 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 29 m²/s²
0-3 km storm-relative helicity: 45 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.

Issued	Product	Office	Counties	Lasted
Jul 7, 1:12 PM CDT	Mesoscale Discussion	SPC	Arkansas, Chicot, Crittenden, Cross, Desha, Drew and 6 more	2 hr

Nearby

Mesoscale Discussions in Arkansas, 2004 Mesoscale Discussions in Mississippi, 2004 Mesoscale Discussions in Louisiana, 2004 Every mesoscale discussion in 2004

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.