Alert archive / Louisiana / Mesoscale Discussions in 2017

Mesoscale Discussion 322

March 24, 20175 counties in Arkansas; 7 parishes in Louisiana; 4 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 24, 2017, 8:39 PM CDT for 5 counties in Arkansas; 7 parishes in Louisiana; 4 counties in Texas. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued
Mar 24, 2017, 8:39 PM CDT (01:39 UTC)
Expired
Mar 24, 2017, 9:45 PM CDT
In force
66 min
Issued by
the Storm Prediction Center
Chance of a watch
80%

Counties Columbia County, AR, Lafayette County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Red River Parish, LA, Webster Parish, LA, Harrison County, TX, Marion County, TX, Panola County, TX, Shelby County, TX

The radar

The Shreveport radar (KSHV), 30 km from the middle of the area, began a volume at 01:40 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.

The nearest sounding before it

Shreveport, LA (KBAD), launched 00:00Z, 1.7 hours before the alert went out and 23 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 2017-03-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 24 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 2017-03-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 276 square meters per square second.1939587897Sfc1 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
24 J/kg
Mixed-layer CIN
-86 J/kg
Mixed-layer LCL
1519 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
276 m²/s²
0-3 km storm-relative helicity
418 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.9

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
Mar 24, 9:14 PM CDTSevere Thunderstorm WatchSPCArkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 13 more6 hr
Mar 24, 9:36 PM CDTMesoscale DiscussionSPCBaxter, Boone, Carroll, Clay, Cleburne, Conway and 29 more54 min
Mar 24, 11:41 PM CDTMesoscale DiscussionSPCAshley, Chicot64 min
Mar 25, 12:05 AM CDTSevere Thunderstorm WatchSPCAshley, Chicot5 hr
Mar 25, 1:05 AM CDTMesoscale DiscussionSPCClay, Craighead, Crittenden, Cross, Greene, Lee and 4 more115 min
Mar 24, 9:23 PM CDTTornado WatchSPCCaldwell, De Soto, Grant, LaSalle, Natchitoches, Red River and 2 more6 hr
Mar 24, 9:58 PM CDTMesoscale DiscussionSPCAllen, Beauregard, Calcasieu, Evangeline, Jefferson Davis, Rapides and 2 more62 min
Mar 24, 10:28 PM CDTTornado WatchSPCAllen, Beauregard, Calcasieu, Evangeline, Jefferson Davis, Rapides and 1 more6 hr
Mar 25, 2:08 AM CDTMesoscale DiscussionSPCAcadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 6 more67 min
Mar 25, 3:06 AM CDTMesoscale DiscussionSPCCatahoula, Concordia, East Carroll, Franklin, Madison, Richland and 1 more54 min
Mar 25, 5:25 AM CDTMesoscale DiscussionSPCAllen, Beauregard, Calcasieu, Vernon2 hr
Mar 25, 12:08 PM CDTMesoscale DiscussionSPCJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 1 more3 hr
Mar 24, 7:07 PM CDTTornado WatchSPCAngelina, Austin, Brazos, Burleson, Cherokee, Colorado and 20 more5 hr

Nearby

Mesoscale Discussions in Louisiana, 2017Mesoscale Discussions in Arkansas, 2017Mesoscale Discussions in Texas, 2017Every mesoscale discussion in 2017

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.