Area Forecast Discussion
National Weather Service Northern Indiana
535 AM EST Sun Feb 14 2021
Confidence is medium in the forecast overall, with
greater confidence in the southeast and lower confidence along the
northwestern fringes. The totals occur over a 36 hour period, so we
fall short of warning criteria in our far southeastern CWA. In
collaboration with neighbors, opted to keep a high-end advisory for
now, with potential for upgrade to a warning if the more aggressive
solutions (NAM/ECMWF) look more likely.
The first system will lift in
tonight and exit by Monday afternoon/early evening before the next
system if the GFS/GEM are correct. However, the ECMWF and especially
the NAM keep the precipitation ongoing through that period, and
develop a coupled jet structure right around 00z--which really amps
things up as far as forcing goes. In addition, the ECMWF/NAM also
have a weaker surface high sprawled across the midwest (as opposed
to the GEM/GFS solution), which allows for that secondary low to
lift further northwest as the stronger mid level trough inches
eastward into Monday night/Tuesday.
As far as Thursday`s system goes, both the ECMWF/GFS bring the upper
level trough into the upper Great Lakes, and the subsequent strong
surface low northeastward from the gulf into the lower Great
Lakes/Ohio (the GFS faster and deeper with the system). With a
negatively tilted trough and deepening surface low, I tend to go
with the stronger solution and further northwest track. So have
likely pops in the eastern CWA (mainly along/east of I 69) late
Wednesday night into Thursday evening, and high end chances for the
central CWA (lowest west half). Think this could be a better system
than these first two, but a lot could change by then with this
active short/mid term forecast so will hold off on any further
discussion.
So IWX may go to a warning, who knows. Forecasting 3-5 inches for us right now. Also a possible second "better" system on Thursday!