MD 0785 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR NORTHEAST MISSOURI INTO CENTRAL ILLINOIS
Mesoscale Discussion 0785
NWS Storm Prediction Center Norman OK
1126 AM CDT Sat May 13 2023
Areas affected...Northeast Missouri into central Illinois
Concerning...Severe potential...Watch possible
Valid 131626Z - 131830Z
Probability of Watch Issuance...40 percent
SUMMARY...Thunderstorms developing across northeast Missouri may
undergo intensification over the next few hours, posing a severe
hail/damaging wind threat. Trends will be monitored, and watch
issuance is possible if a robust/widespread severe threat becomes
apparent.
DISCUSSION...Visible satellite imagery has depicted a subtle MCV
tracking northeast from western to northern MO over the past few
hours. Lift ahead of this feature to the east/northeast (likely
augmented by somewhat weak low-level convergence along a diffuse
warm frontal zone) has been sufficient for convective initiation of
a few cells across northeast MO. GOES IR imagery and lightning
trends show intensification of these cells over the past 30 minutes.
Downstream from this activity, surface temperatures have warmed well
into the upper 70s and low 80s, which is much faster than depicted
by most recent guidance. The development of a shallow cumulus field
across southwest IL further supports this idea of rather quick
destabilization. Consequently, the downstream environment will
become more supportive of storm maintenance as inhibition continues
to erode with MLCAPE approaching 2000 J/kg. Easterly low-level flow
is supporting effective bulk shear values near 35-40 knots, and
somewhat elongated hodographs in the 1-6 km layer will favor
supercell structures with an attendant hail/severe wind risk.
Confidence in the longevity and coverage of this threat is somewhat
low given weak/localized forcing for ascent, but trends will
continue to be monitored and a watch is possible if a
robust/widespread threat becomes apparent.
..Moore/Mosier.. 05/13/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...ILX...LSX...DVN...
LAT...LON 38969191 39449201 39849205 40049168 40978933 40598866
39678838 39128844 38658865 38428937 38819171 38969191
