Alert archive / Louisiana / Mesoscale Discussions in 2019

Mesoscale Discussion 439

April 24, 20198 parishes in Louisiana; Sabine County, San Augustine County, Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 24, 2019, 11:57 PM CDT for 8 parishes in Louisiana; Sabine County, San Augustine County, Texas. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued
Apr 24, 2019, 11:57 PM CDT (04:57 UTC)
Expired
Apr 25, 2019, 1:00 AM CDT
In force
63 min
Issued by
the Storm Prediction Center

Counties Bienville Parish, LA, Bossier Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Natchitoches Parish, LA, Red River Parish, LA, Sabine Parish, LA, Webster Parish, LA, Sabine County, TX, San Augustine County, TX

The radar

The Shreveport radar (KSHV), 61 km from the middle of the area, began a volume at 04:58 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 (KBAD), launched 00:00Z, 5.0 hours before the alert went out and 60 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 2019-04-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 94 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, Shreveport, LA at 00:00Z on 2019-04-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 123 square meters per square second.193958Sfc1 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
94 J/kg
Mixed-layer CIN
-68 J/kg
Mixed-layer LCL
1094 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
123 m²/s²
0-3 km storm-relative helicity
240 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.6

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
Apr 24, 7:35 PM CDTMesoscale DiscussionSPCVernon85 min
Apr 24, 11:19 PM CDTMesoscale DiscussionSPCBeauregard, Natchitoches, Sabine, Vernon86 min
Apr 24, 11:52 PM CDTTornado WatchSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 19 more8 hr
Apr 25, 2:08 AM CDTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Bossier and 24 more67 min
Apr 25, 2:43 AM CDTSevere Thunderstorm WatchSPCCatahoula, Concordia, East Carroll, Franklin, Madison, Morehouse and 3 more6 hr
Apr 25, 5:02 AM CDTMesoscale DiscussionSPCCatahoula, Concordia, East Carroll, Franklin, Madison, Richland and 2 more58 min
Apr 25, 5:24 AM CDTMesoscale DiscussionSPCAcadia, Allen, Beauregard, Calcasieu, Evangeline, Grant and 7 more66 min
Apr 25, 7:10 AM CDTMesoscale DiscussionSPCAcadia, Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia and 22 more2 hr
Apr 25, 8:06 AM CDTTornado WatchSPCAcadia, Ascension, Assumption, Avoyelles, East Baton Rouge, East Feliciana and 26 more8 hr
Apr 25, 11:48 AM CDTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 17 more117 min
Apr 25, 3:14 PM CDTMesoscale DiscussionSPCJefferson, Plaquemines, Saint Bernard2 hr

Nearby

Mesoscale Discussions in Louisiana, 2019Mesoscale Discussions in Texas, 2019Every mesoscale discussion in 2019

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.