Alert archive / Louisiana / Mesoscale Discussions in 2025

Mesoscale Discussion 1024

May 28, 202529 parishes in Louisiana; 29 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at May 28, 2025, 1:07 PM CDT for 29 parishes in Louisiana; 29 counties in Mississippi. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued: May 28, 2025, 1:07 PM CDT (18:07 UTC)
Expired: May 28, 2025, 2:30 PM CDT
In force: 83 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch possible
Chance of a watch: 60%

All 58 counties

Ascension Parish, LA, Assumption Parish, LA, Avoyelles Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Iberville Parish, LA, Jefferson Parish, LA, Lafayette Parish, LA, LaSalle Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Pointe Coupee Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, St. Mary Parish, LA, Tangipahoa Parish, LA, Tensas Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson 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, Pearl River County, MS, Perry County, MS, Pike County, MS, Simpson County, MS, Smith County, MS, Stone County, MS, Walthall County, MS, Wayne County, MS, Wilkinson County, MS

The radar

The Hammond radar (KHDC), 57 km from the middle of the area, began a volume at 18:11 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 344May 28, 3:20 PM CDT

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 6.1 hours before the alert went out and 75 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: 2432 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 613 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 17 m²/s²
0-3 km storm-relative helicity: 60 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 2.4

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
May 28, 3:19 PM CDT	Severe Thunderstorm Watch	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberville, Livingston and 8 more	5 hr
May 28, 5:53 PM CDT	Mesoscale Discussion	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberville, Lafourche and 11 more	2 hr
May 27, 7:35 PM CDT	Mesoscale Discussion	SPC	George, Greene, Jackson, Stone	85 min

Nearby

Mesoscale Discussions in Louisiana, 2025 Mesoscale Discussions in Mississippi, 2025 Every mesoscale discussion in 2025

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.