LOT can smell it
Thus far, the new activity near the Minnesota and Iowa border has
remained largely cellular and disorganized. However, have noted
evidence of a southward push of the overall complex (a recent
28kt wind gust at an AWOS station out of the north under one of
the cores). Accordingly, current thinking is that there should
still be a southward propagation to the new development into
northern Iowa in the coming hours and perhaps as far south as
central or even southern Iowa by mid-morning, much in line with
prior thinking. Will also have to watch if there is any
expansion of trailing thunderstorms across west- central
Minnesota as it would also be poised to move southward along the
instability axis into northern Iowa later this morning. With
all of this in mind, still do see an off-ramp from a severe
weather day in our local area in the form of a prohibitive
"wall" of stable air in Iowa left over from early- day
thunderstorms that blocks the surface-based instability axis
from arcing northeastward into northern Illinois and southern
Wisconsin later this afternoon.
With all of that said, would be remiss to ignore the possibility
that the early-day thunderstorms largely fall apart by daybreak
and/or have a much more limited footprint than currently
expected. Exploring the scenario where the instability axis
does reach (at least part of) our area later today, the
kinematic wind field would still be very favorable for severe
weather and support supercells and bowing clusters with a threat
for all hazards. There could very well be more than one round of
storms with a mid-afternoon round tied to a subtle lead impulse
embedded in the northwesterly flow on the eastern edge of the
instability axis and another round later in the evening and
overnight period tied to the dominant upper-level wave. It is
worth noting the HRRR is stubbornly persistent in showing this
scenario today.
