Mesoscale Discussion 521

Issued

Apr 15, 2023, 7:52 AM CDT (12:52 UTC)

Expired

Apr 15, 2023, 9:15 AM CDT

In force

83 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch possible

Chance of a watch

40%

Counties Acadia Parish, LA, Allen Parish, LA, Assumption Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, East Baton Rouge Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, Pointe Coupee Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA, Vermilion Parish, LA, West Baton Rouge Parish, LA

The Lake Charles radar (KLCH), 77 km from the middle of the area, began a volume at 12:53 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.

674 
ACUS11 KWNS 151253
SWOMCD
SPC MCD 151252 
LAZ000-151415-

Mesoscale Discussion 0521
NWS Storm Prediction Center Norman OK
0752 AM CDT Sat Apr 15 2023

Areas affected...Portions of southern LA

Concerning...Severe potential...Watch possible 

Valid 151252Z - 151415Z

Probability of Watch Issuance...40 percent

SUMMARY...A cluster of thunderstorms will move eastward this morning
while potentially posing some threat for damaging winds. The need
for a watch remains uncertain.

DISCUSSION...A small cluster of mainly elevated thunderstorms
associated with a subtle shortwave trough has persisted through the
early morning hours across central into coastal/southeast TX, and is
entering southwest LA as of 1250Z. The 12Z sounding from LCH has
steep mid-level lapse rates, and a reservoir of 3000+ MUCAPE. If
even modest daytime heating can occur ahead of this activity, the
remaining low-level cap may erode sufficiently to allow convection
to become surface based as it tracks eastward along a marine warm
front. Although both low-level and deep-layer shear are fairly
modest at the moment per recent VWP estimates from LCH, this shear
may still be sufficient for modest updraft organization. If this
convection can persist and strengthen, it may pose a threat for
mainly damaging winds across parts of southern LA. Convective
evolution and intensity with this cluster remains rather uncertain,
as does the need for a potential watch. Regardless, trends will be
closely monitored.

..Gleason/Thompson.. 04/15/2023

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...LIX...LCH...

LAT...LON   30189355 30759320 30899224 30669110 30019096 29599120
            29589254 29829338 30189355

Mesoscale Discussions in Louisiana, 2023Every mesoscale discussion in 2023

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.