Alert archive / Louisiana / Mesoscale Discussions in 2015

Mesoscale Discussion 452

April 25, 2015Baldwin County, Mobile County, Washington County, Alabama; 33 parishes in Louisiana; 22 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 25, 2015, 9:35 AM CDT for Baldwin County, Mobile County, Washington County, Alabama; 33 parishes in Louisiana; 22 counties in Mississippi. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued: Apr 25, 2015, 9:35 AM CDT (14:35 UTC)
Expired: Apr 25, 2015, 11:30 AM CDT
In force: 115 min
Issued by: the Storm Prediction Center

All 58 counties

Baldwin County, AL, Mobile County, AL, Washington County, AL, Acadia Parish, LA, Ascension Parish, LA, Assumption Parish, LA, Avoyelles Parish, LA, Cameron Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Jefferson Parish, LA, Lafayette Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Plaquemines 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, Terrebonne Parish, LA, Vermilion Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Amite 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, 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, Stone County, MS, Walthall County, MS, Wayne County, MS, Wilkinson County, MS

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 2.6 hours before the alert went out and 33 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: 1826 J/kg
Mixed-layer CIN: -15 J/kg
Mixed-layer LCL: 565 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 69 m²/s²
0-3 km storm-relative helicity: 93 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 4.6

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, 12:50 AM CDT	Tornado Watch	SPC	Dallas, Fayette, Greene, Hale, Lamar, Marengo and 4 more	6 hr
Apr 25, 2:07 AM CDT	Mesoscale Discussion	SPC	Choctaw, Greene, Pickens, Sumter, Tuscaloosa	83 min
Apr 25, 4:12 AM CDT	Mesoscale Discussion	SPC	Baldwin, Butler, Choctaw, Clarke, Conecuh, Dallas and 9 more	63 min
Apr 25, 5:00 AM CDT	Tornado Watch	SPC	Autauga, Baldwin, Barbour, Bullock, Butler, Clarke and 18 more	7 hr
Apr 25, 7:41 AM CDT	Mesoscale Discussion	SPC	Coffee, Covington, Dale, Geneva, Henry, Houston	94 min
Apr 25, 1:36 PM CDT	Severe Thunderstorm Watch	SPC	Baldwin, Butler, Clarke, Conecuh, Covington, Crenshaw and 5 more	4 hr
Apr 25, 1:50 PM CDT	Mesoscale Discussion	SPC	Baldwin, Butler, Clarke, Conecuh, Covington, Crenshaw and 4 more	85 min
Apr 25, 2:10 PM CDT	Mesoscale Discussion	SPC	Autauga, Bibb, Bullock, Calhoun, Chambers, Chilton and 19 more	95 min
Apr 25, 3:07 PM CDT	Severe Thunderstorm Watch	SPC	Barbour, Coffee, Dale, Geneva, Henry, Houston and 1 more	7 hr
Apr 25, 4:38 PM CDT	Severe Thunderstorm Watch	SPC	Bullock, Chambers, Clay, Lee, Macon, Randolph and 2 more	5 hr
Apr 24, 7:46 PM CDT	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, Jackson and 7 more	89 min
Apr 24, 9:20 PM CDT	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 13 more	55 min
Apr 24, 9:59 PM CDT	Tornado Watch	SPC	Bienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 14 more	4 hr
Apr 24, 11:45 PM CDT	Mesoscale Discussion	SPC	Caldwell, East Carroll, Franklin, Jackson, Madison, Morehouse and 5 more	90 min
Apr 25, 7:12 AM CDT	Severe Thunderstorm Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 10 more	6 hr
Apr 25, 10:41 AM CDT	Severe Thunderstorm Watch	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 16 more	7 hr

Nearby

Mesoscale Discussions in Louisiana, 2015 Mesoscale Discussions in Mississippi, 2015 Mesoscale Discussions in Alabama, 2015 Every mesoscale discussion in 2015

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.