Mesoscale Discussion 281

Issued

Mar 27, 2021, 2:34 PM CDT (19:34 UTC)

Expired

Mar 27, 2021, 4:30 PM CDT

In force

116 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch possible

Chance of a watch

60%

The St Louis radar (KLSX), 108 km from the middle of the area, began a volume at 19:37 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

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• Severe Thunderstorm Watch 62Mar 27, 4:45 PM CDT

534 
ACUS11 KWNS 271935
SWOMCD
SPC MCD 271934 
ILZ000-MOZ000-272130-

Mesoscale Discussion 0281
NWS Storm Prediction Center Norman OK
0234 PM CDT Sat Mar 27 2021

Areas affected...South-central Missouri into western Illinois

Concerning...Severe potential...Watch possible 

Valid 271934Z - 272130Z

Probability of Watch Issuance...60 percent

SUMMARY...Severe thunderstorms are expected to develop along ahead
of cold front this afternoon and evening. Severe wind gusts and hail
will be possible with any strong storms. A weather watch is
possible.

DISCUSSION...Afternoon visible satellite data showed deepening
cumulus towers located along and east of a diffuse cold front and
wave cyclone stretching from northeast Oklahoma into southern
Missouri. Deepening of the initial convective updrafts and eventual
thunderstorm development is likely over the next couple of hours as
the lower atmosphere continues to destabilize ahead of a mid-level
trough across the upper Midwest. SPC mesoanalysis shows surface
dewpoints in the 50s F overlain by mid-level lapse rates approaching
8 C/km are supporting 500-1500 J/kg of MUCAPE across much southern
Missouri. Surface obs and regional VWPs show strongly veered surface
flow with long but mostly straight line hodographs. Deep-layer shear
near 60 kts should favor a mix of splitting cells and short line
segments capable of damaging wind gusts and severe hail. With much
of the mid-level flow parallel to the slow moving surface front and
high LCLs favoring stronger cold pool development, storm mergers and
upscale growth with a greater threat for damaging wind gusts appears
likely as storms move northeast toward western Illinois later
tonight. A weather watch may be needed in the next couple of hours
for the threat of severe hail/wind through this evening.

..Lyons/Thompson.. 03/27/2021

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

ATTN...WFO...ILX...LSX...SGF...EAX...

LAT...LON   39009289 39469235 39739205 40059132 40129058 40059009
            39778987 38998987 38379002 37989054 37609135 37339215
            37239270 37319317 37379349 37559373 37829391 38479339
            39009289

Mesoscale Discussions in Missouri, 2021Mesoscale Discussions in Illinois, 2021Every mesoscale discussion in 2021

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.