Alert archive / Mississippi / Mesoscale Discussions in 2004

Mesoscale Discussion 1718

July 16, 200420 counties in Arkansas; 10 parishes in Louisiana; 29 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jul 16, 2004, 9:18 PM CDT for 20 counties in Arkansas; 10 parishes in Louisiana; 29 counties in Mississippi. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued: Jul 16, 2004, 9:18 PM CDT (02:18 UTC)
Expired: Jul 16, 2004, 10:45 PM CDT
In force: 87 min
Issued by: the Storm Prediction Center

All 59 counties

Arkansas County, AR, Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Cleveland County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Grant County, AR, Jefferson County, AR, Lee County, AR, Lincoln County, AR, Lonoke County, AR, Monroe County, AR, Phillips County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, St. Francis County, AR, Catahoula Parish, LA, Concordia Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Ouachita Parish, LA, Richland Parish, LA, Tensas Parish, LA, West Carroll Parish, LA, Adams County, MS, Amite County, MS, Bolivar County, MS, Claiborne County, MS, Coahoma County, MS, Copiah County, MS, Franklin County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Jefferson Davis County, MS, Lamar County, MS, Lawrence County, MS, Leflore County, MS, Lincoln County, MS, Madison County, MS, Marion County, MS, Pike County, MS, Rankin County, MS, Sharkey County, MS, Simpson County, MS, Sunflower County, MS, Walthall County, MS, Warren County, MS, Washington County, MS, Wilkinson County, MS, Yazoo County, MS

The radar

The Little Rock radar (KLZK), 172 km from the middle of the area, began a volume at 02:19 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.

Severe Thunderstorm Watch 652Jul 16, 9:45 PM CDT

The nearest sounding before it

Jackson, MS (KJAN), launched 00:00Z, 2.3 hours before the alert went out and 183 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: 227 J/kg
Mixed-layer CIN: -153 J/kg
Mixed-layer LCL: 1375 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 189 m²/s²
0-3 km storm-relative helicity: 424 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

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 16, 9:45 PM CDT	Severe Thunderstorm Watch	SPC	Arkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 17 more	5 hr
Jul 17, 2:18 AM CDT	Mesoscale Discussion	SPC	Ashley, Bradley, Calhoun, Chicot, Cleveland, Drew and 2 more	57 min
Jul 17, 6:25 PM CDT	Mesoscale Discussion	SPC	Bienville, Caldwell, De Soto, Grant, Jackson, LaSalle and 6 more	2 hr

Nearby

Mesoscale Discussions in Mississippi, 2004 Mesoscale Discussions in Arkansas, 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.