MD 0531 CONCERNING TORNADO WATCH 139… FOR EAST-CENTRAL MO INTO WEST-CENTRAL IL
Mesoscale Discussion 0531
NWS Storm Prediction Center Norman OK
0507 PM CDT Sat Apr 15 2023
Areas affected...East-central MO into west-central IL
Concerning...Tornado Watch 139...
Valid 152207Z - 152330Z
The severe weather threat for Tornado Watch 139 continues.
SUMMARY...A significant wind threat will spread toward the
Mississippi River over the next 1-2 hours, in addition to a
continued risk of very large hail and a tornado or two.
DISCUSSION...Multiple cell mergers have resulted in the development
of a large and intense HP supercell structure that recently moved
out of Maries County, MO. Strong midlevel rotation has been noted
with this cell on radar, and a 97 mph measured gust was reported at
2141 UTC near Vichy, MO. Additional upscale growth appears likely,
with additional cell development noted both north and south along
the larger-scale outflow, and also ahead of the ongoing convection
across Franklin County, MO. This may result in the development of a
bowing segment that will approach the MS River with a continued
significant-wind threat.
In addition to the wind risk, moderate buoyancy, steep midlevel
lapse rates, and sufficient deep-layer shear will continue to
support a very large hail threat (including a risk of wind-driven
hail) with any discrete cells, and also stronger updrafts within the
developing QLCS. Also, while low-level flow is not overly strong,
backed surface winds are resulting in sufficient low-level shear/SRH
for a tornado or two, either with any stronger discrete supercell,
or with line-embedded circulations within a developing QLCS.
..Dean.. 04/15/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LSX...SGF...
LAT...LON 38519170 39159138 39299017 39088975 38658964 38158980
37889008 37859076 37859151 38159163 38519170
