LOT no likey
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
837 PM CDT Wed Jun 15 2022
.MESOSCALE DISCUSSION...
Bottom Line Up Front:
Convective trends are somewhat unclear through the late evening,
but in the near term (within the next hour or so), signs point
toward a more hostile environment for maintenance or development
severe convection over the CWA. Conditions may eventually become
more favorable, but are thought not to be imminently favorable for
severe storms, so we`re not anticipating a watch until/unless
there is a change in convective trends.
In-Depth Details:
The thinking hasn`t changed significantly from the previous
discussion below. We`ve noted that thunderstorm cores over the DVN
CWA near the MS River have struggled with eastward extent toward
the far northwest CWA. This is likely owing to the mixing out of
dew points that occurred this afternoon and resulting in
increasing stability eastward (lower MLCAPE and increasing MLCIN)
on latest SPC mesoanalysis. With the cold front itself now pushing
into extreme northwest Illinois, the narrow moist axis featuring
strongest instability may be even more narrow than depicted on the
mesoanalysis graphics.
With the above being said, since we`re headed toward sunset and
loss of solar insolation, there is reason to cast doubt on near
term hourly guidance continuing to insist on the instability axis
folding eastward through the late evening, and thus lowers
confidence on an appreciable severe threat extending eastward into
the northwest and western CWA and points east. A mini segment of
convection has fired on the immediate cold front where there is
better boundary layer convergence from northeast Cedar County Iowa
to southwest Jo Daviess County. However, even here the strongest
core is quite small in areal extent, and with north-northeast
motion of individual cores, any threat from this cluster/segment
may stay west of our northwest CWA counties. Furthermore,
convective coverage is much more sparse south of this until
reaching intense convection over far northeast MO and southeast
IA.
Given the instability question and currently more hostile
environment in place approaching sunset, after collaboration with
SPC there are not imminent plans for a watch. We will continue to
closely monitor trends, as favorable deep layer bulk shear for
severe weather will remain in place, so if we see signs of
improving support for convective maintenance and intensification,
watch issuance may become needed for portions of the CWA.