Alert archive / Louisiana / Mesoscale Discussions in 2020

Mesoscale Discussion 558

May 8, 202033 parishes in Louisiana; 14 counties in Mississippi; 7 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 8, 2020, 9:30 AM CDT for 33 parishes in Louisiana; 14 counties in Mississippi; 7 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 8, 2020, 9:30 AM CDT (14:30 UTC)
Expired
May 8, 2020, 11:30 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
60%
All 54 counties

Acadia Parish, LA, Allen Parish, LA, Ascension Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Grant Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, LaSalle Parish, LA, Livingston Parish, LA, Natchitoches Parish, LA, Orleans Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Sabine 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, Tangipahoa Parish, LA, Vernon Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Forrest County, MS, Franklin County, MS, Hancock County, MS, Harrison County, MS, Lamar County, MS, Marion County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Stone County, MS, Walthall County, MS, Wilkinson County, MS, Angelina County, TX, Jasper County, TX, Nacogdoches County, TX, Newton County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX

The radar

The Ft Polk radar (KPOE), 85 km from the middle of the area, began a volume at 14:34 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 nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 2.5 hours before the alert went out and 142 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-pSkew-T log-p diagram, Lake Charles Mun, LA at 12:00Z on 2020-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 590 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lake Charles Mun, LA at 12:00Z on 2020-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 180 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
590 J/kg
Mixed-layer CIN
-306 J/kg
Mixed-layer LCL
754 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
180 m²/s²
0-3 km storm-relative helicity
410 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.

IssuedProductOfficeCountiesLasted
May 8, 3:06 AM CDTSevere Thunderstorm WatchSPCBienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 11 more7 hr
May 8, 5:22 AM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 11 more83 min
May 8, 1:36 PM CDTSevere Thunderstorm WatchSPCAcadia, Allen, Ascension, Assumption, Beauregard, Calcasieu and 19 more6 hr
May 8, 2:47 PM CDTMesoscale DiscussionSPCAcadia, Assumption, Calcasieu, Iberville, Jefferson Davis, Lafayette and 4 more118 min
May 7, 7:40 PM CDTSevere Thunderstorm WatchSPCGray, Hemphill, Lipscomb, Ochiltree, Roberts, Wheeler7 hr
May 7, 8:05 PM CDTMesoscale DiscussionSPCArcher, Jack, Palo Pinto, Young85 min
May 7, 8:27 PM CDTSevere Thunderstorm WatchSPCEllis, Jack, Johnson, Palo Pinto, Parker, Tarrant and 2 more4 hr
May 7, 9:24 PM CDTMesoscale DiscussionSPCLipscomb96 min
May 7, 9:53 PM CDTMesoscale DiscussionSPCJack, Johnson, Parker, Tarrant, Wise67 min
May 7, 11:12 PM CDTMesoscale DiscussionSPCHemphill, Wheeler2 hr
May 8, 2:30 AM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Clay, Collin, Cooke and 17 more2 hr

Nearby

Mesoscale Discussions in Louisiana, 2020Mesoscale Discussions in Mississippi, 2020Mesoscale Discussions in Texas, 2020Every mesoscale discussion in 2020

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.