Alert archive / Mississippi / Mesoscale Discussions in 2007

Mesoscale Discussion 585

April 25, 20077 parishes in Louisiana; 26 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 25, 2007, 1:23 PM CDT for 7 parishes in Louisiana; 26 counties in Mississippi. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued: Apr 25, 2007, 1:23 PM CDT (18:23 UTC)
Expired: Apr 25, 2007, 2:30 PM CDT
In force: 67 min
Issued by: the Storm Prediction Center

All 33 counties

Catahoula Parish, LA, Concordia Parish, LA, East Feliciana Parish, LA, Franklin Parish, LA, Madison Parish, LA, Tensas Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Copiah County, MS, Covington County, MS, Franklin County, MS, Hinds County, MS, Issaquena County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Lawrence County, MS, Leake County, MS, Lincoln County, MS, Madison County, MS, Neshoba County, MS, Newton County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Smith County, MS, Warren County, MS, Wilkinson County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 76 km from the middle of the area, began a volume at 18:22 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.

Tornado Watch 188Apr 25, 1:50 PM CDT

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 6.4 hours before the alert went out and 70 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: 90 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 726 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 136 m²/s²
0-3 km storm-relative helicity: 130 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

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
Apr 25, 2:10 AM CDT	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, Jackson and 6 more	65 min
Apr 25, 9:00 AM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 7 more	60 min
Apr 25, 9:13 AM CDT	Tornado Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 10 more	8 hr
Apr 25, 1:46 PM CDT	Tornado Watch	SPC	Catahoula, Concordia, East Baton Rouge, East Carroll, East Feliciana, Franklin and 9 more	5 hr
Apr 25, 3:05 PM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 6 more	55 min
Apr 25, 6:15 PM CDT	Mesoscale Discussion	SPC	Bossier, Caddo, Claiborne, De Soto, Webster	90 min
Apr 25, 5:40 PM CDT	Mesoscale Discussion	SPC	Adams, Amite, Attala, Carroll, Choctaw, Claiborne and 20 more	95 min

Nearby

Mesoscale Discussions in Mississippi, 2007 Mesoscale Discussions in Louisiana, 2007 Every 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.