Alert archive / Louisiana / Mesoscale Discussions in 2020

Mesoscale Discussion 557

May 8, 20207 counties in Arkansas; 17 parishes in Louisiana; 7 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 8, 2020, 5:22 AM CDT for 7 counties in Arkansas; 17 parishes in Louisiana; 7 counties in Texas. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
May 8, 2020, 5:22 AM CDT (10:22 UTC)
Expired
May 8, 2020, 6:45 AM CDT
In force
83 min
Issued by
the Storm Prediction Center
All 31 counties

Bradley County, AR, Calhoun County, AR, Cleveland County, AR, Columbia County, AR, Dallas County, AR, Ouachita County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Sabine Parish, LA, Union Parish, LA, Webster Parish, LA, Winn Parish, LA, Camp County, TX, Gregg County, TX, Harrison County, TX, Marion County, TX, Panola County, TX, Shelby County, TX, Upshur County, TX

The radar

The Shreveport radar (KSHV), 35 km from the middle of the area, began a volume at 10:24 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

Shreveport, LA (KSHV), launched 00:00Z, 10.4 hours before the alert went out and 32 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, Shreveport, LA at 00:00Z on 2020-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Shreveport, LA at 00:00Z on 2020-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2002 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
334 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, 2:30 AM CDTMesoscale DiscussionSPCLafayette, Little River, Miller, Sevier2 hr
May 8, 3:06 AM CDTSevere Thunderstorm WatchSPCBradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 15 more7 hr
May 8, 9:30 AM CDTMesoscale DiscussionSPCAcadia, Allen, Ascension, Avoyelles, Beauregard, Catahoula and 27 more2 hr
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

Nearby

Mesoscale Discussions in Louisiana, 2020Mesoscale Discussions in Arkansas, 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.