Alert archive / Mississippi / Mesoscale Discussions in 2016

Mesoscale Discussion 227

March 17, 201618 parishes in Louisiana; 25 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Mar 17, 2016, 12:58 PM CDT for 18 parishes in Louisiana; 25 counties in Mississippi. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued: Mar 17, 2016, 12:58 PM CDT (17:58 UTC)
Expired: Mar 17, 2016, 2:30 PM CDT
In force: 92 min
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 43 counties

Allen Parish, LA, Avoyelles Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, LaSalle Parish, LA, Natchitoches Parish, LA, Rapides Parish, LA, Red River Parish, LA, Sabine Parish, LA, Tensas Parish, LA, Vernon Parish, LA, West Feliciana Parish, LA, Winn Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, Greene County, MS, Hinds County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Lamar County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS, Perry County, MS, Pike County, MS, Rankin County, MS, Simpson County, MS, Smith County, MS, Walthall County, MS, Wayne County, MS, Wilkinson County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 140 km from the middle of the area, began a volume at 18:02 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 46Mar 17, 1:20 PM CDT

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 6.0 hours before the alert went out and 135 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1748 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: -25 m²/s²
0-3 km storm-relative helicity: 93 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 17, 9:37 AM CDT	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Caldwell, Catahoula, Claiborne and 16 more	83 min
Mar 17, 1:19 PM CDT	Severe Thunderstorm Watch	SPC	Allen, Avoyelles, Beauregard, Bienville, Caldwell, Catahoula and 28 more	9 hr
Mar 17, 3:48 PM CDT	Mesoscale Discussion	SPC	Avoyelles, Catahoula, Concordia, East Feliciana, Franklin, Grant and 12 more	87 min
Mar 17, 6:22 PM CDT	Mesoscale Discussion	SPC	Avoyelles, Bienville, Caddo, Caldwell, Catahoula, Concordia and 23 more	53 min
Mar 17, 7:44 AM CDT	Mesoscale Discussion	SPC	George, Greene, Harrison, Jackson	2 hr

Nearby

Mesoscale Discussions in Mississippi, 2016 Mesoscale Discussions in Louisiana, 2016 Every mesoscale discussion in 2016

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.