Mesoscale Discussion 332

Issued

Apr 8, 2021, 2:08 AM CDT (07:08 UTC)

Expired

Apr 8, 2021, 4:15 AM CDT

In force

2 hr

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch unlikely

Chance of a watch

20%

Counties Baldwin County, AL, Mobile County, AL, Livingston Parish, LA, Orleans Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint John the Baptist Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Washington Parish, LA, George County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Pearl River County, MS, Stone County, MS

The Mobile radar (KMOB), 100 km from the middle of the area, began a volume at 07:07 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.

383 
ACUS11 KWNS 080709
SWOMCD
SPC MCD 080708 
ALZ000-MSZ000-LAZ000-080915-

Mesoscale Discussion 0332
NWS Storm Prediction Center Norman OK
0208 AM CDT Thu Apr 08 2021

Areas affected...Portions of coastal LA/MS/AL

Concerning...Severe potential...Watch unlikely 

Valid 080708Z - 080915Z

Probability of Watch Issuance...20 percent

SUMMARY...Mainly an isolated threat for damaging winds continues
early this morning. Watch issuance remains unlikely.

DISCUSSION...Convection across southern LA has evolved into multiple
small bowing segments over the past couple of hours. Occasional
strong to damaging winds remain possible with two of these segments
over a small part of coastal southeastern LA at 07Z. Recent VWPs
from KLIX still show a strongly veering and strengthening wind
profile with height through mid levels. 0-1 km shear of 35 kt and
0-1 SRH around 200-300 m2/s2 clearly favor the potential for updraft
rotation and a brief tornado. Multiple, but generally weak,
low-level circulations embedded within the bowing segments have
occurred early this morning. Current expectations are for this
isolated severe threat to continue for at least the next couple of
hours as storms move eastward from coastal southeastern LA into
southern MS/AL. Surface observations show that low-level moisture
gradually decreases with eastward extent, and mesoanalysis estimates
show a similar decrease in boundary-layer instability. Ongoing
strong to severe storms should eventually weaken as they encounter a
less unstable airmass. Watch issuance will probably not be needed,
as the spatial and temporal extents of the severe threat are
expected to remain small/short.

..Gleason/Edwards.. 04/08/2021

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

ATTN...WFO...MOB...JAN...LIX...

LAT...LON   30429078 30879009 31048945 31108868 31008792 30858767
            30248767 30168873 30008909 29738926 29638948 29909044
            30429078

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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.