MD 0189 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR NORTHEAST MISSOURI TO NORTHERN ILLINOIS AND SOUTHERN WISCONSIN
Mesoscale Discussion 0189
NWS Storm Prediction Center Norman OK
0125 PM CST Mon Mar 04 2024
Areas affected…Northeast Missouri to northern Illinois and
southern Wisconsin
Concerning…Severe potential…Watch unlikely
Valid 041925Z – 042130Z
Probability of Watch Issuance…20 percent
SUMMARY…Additional thunderstorm development is expected along and
just ahead of cold front from southern Wisconsin into eastern Iowa,
northwest Illinois, and northeast Missouri in the next 1-3 hours.
Thunderstorms will primarily pose a damaging wind and severe hail
risk.
DISCUSSION…Gradual destabilization is ongoing across portions of
MO/IA/IL as temperatures climb into the low to mid 70s amid broken
cloud cover and continued northward moisture return. Recent
temperature/dewpoint observations are higher than anticipated by
recent guidance by as much as a few degrees, suggesting that MLCIN
is likely eroding slightly faster than depicted by guidance and/or
mesoanalyses. Satellite imagery bears this out with slowly deepening
cumulus developing from northeast MO to western IL and a recent
intensification of previously anemic convection along the IA/IL
border. High-res guidance suggests additional convection is likely
in the next couple of hours along and ahead of the cold front, but
the aforementioned observed trends hint at the potential for earlier
initiation.
Regardless of precise timing, initially semi-discrete cells should
undergo upscale growth owing to strengthening forcing for ascent and
undercutting nature of the front, as well as mean storm motion and
deep-layer shear vectors oriented northeast along the boundary.
Consequently, an initial hail threat should transition to a damaging
wind threat threat heading into the late afternoon hours and with
eastward extent. Poor boundary-normal deep-layer shear should limit
overall storm organization/intensity. A low-end tornado threat may
materialize across northern IL where backed low-level flow in the
vicinity of the warm front may locally enhance effective SRH.
However, this may be conditional on realizing at least a
semi-discrete storm mode. Additionally, the northward extent of the
warm sector into southern WI is uncertain given extensive cloud
cover and falling temperatures north of the surface warm front.
Given these concerns, watch issuance is not anticipated.
..Moore/Hart.. 03/04/2024
…Please see www.spc.noaa.gov for graphic product…
ATTN…WFO…LOT…ILX…MKX…LSX…DVN…ARX…DMX…EAX…
LAT…LON 41818741 41548752 41368794 40249048 40019105 39789180
39709265 39829310 40159337 40459329 40749300 40959236
41109211 41439171 43298995 43498966 43478876 42918777
42418756 41818741
