Scientific Forecaster Discussion
fxus63 kmkx 221754
Area forecast discussion
National Weather Service Milwaukee/Sullivan WI
1154 am CST Fri Nov 22 2019
the skies have cleared early, so have bumped up high temps by a
few degrees for this afternoon. Otherwise, the rest is on track.
MVFR ceilings continue to disspate as drier air moves in with a
ridge of high pressure pushing in. Winds will lighten up as well
going into the overnight period. VFR conditions will prevail
through tomorrow with perhaps some high level clouds coming in
from the south on Saturday.
Previous discussion... (issued 251 am CST Fri Nov 22 2019)
Today and tonight...forecast confidence is moderate.
Main issue today will be when the low clouds will dissipate and/or
move out of the area. There is an extensive area of low clouds
over the region early this morning. Models are not handling this
area of low clouds very well, and this deck may very well linger
through the morning and perhaps this afternoon. For now, kept
mostly cloudy skies through the morning, before clearing out by
early this afternoon. This may need adjustments, as this deck may
be slower to dissipate.
The gusty northwest winds are expected to weaken this morning, as
high pressure sets up to the south of the area. Highs today will
depend on how long the clouds hang around. For now, think there
should be enough sun this afternoon to bring highs into the middle
30s, which is still below seasonal normals.
500 mb low should move slowly east from the Central Plains into
Missouri tonight. The circulation and possible clouds associated
with it should remain mostly just south of the area by later
tonight. Lows should be in the middle 20s.
Saturday through Monday...forecast confidence is high.
The mid level northwest flow is quite busy with short wave energy
over the weekend into early next week. However, any precip with
these features stays either to the north or south of southern
Wisconsin. We should remain dry through the period, though it
looks mostly cloudy through the stretch. Temps will modify a few
degrees each day...that's good news.
Tuesday and Wednesday...forecast confidence remains quite low.
This period has a lot of folks concerned and looking for an answer
to the question of whether we will see snow across the region.
Unfortunately, answering that question didn't get much easier
with the 00z runs of the long range models. There continues to be
a huge spread in the deterministic and ensemble output. The latest
operational run of the European model (ecmwf) is looking like the GFS from 36-48
hours ago. Which is a strong low spreading copious precip across
southern Wisconsin. Meanwhile, the GFS is shifting farther
southeast now, just clipping southeast Wisconsin with precip. The
Canadian and the European model (ecmwf) bring a very intense low over Southern Lake
Michigan Tuesday evening...the GFS has a low over central
Indiana. Looking at the 50 members of the European model (ecmwf) ensemble shows an
incredible spread in solutions...from lows over northern Minnesota to
Kentucky, or none at all. At this point, the National guidance
from wpc is doing a large blend of the guidance and coming up with
a solution similar to the GFS, though the influence from the
European model (ecmwf) pulls the low closer to southeast WI. Then the other issue would be
temps. The European model (ecmwf) looks warm and wet, while the GFS is colder with
snow. As much as we'd like to give everyone a clear answer about
what to expect, we can't. Tuesday afternoon through Tuesday night
would be the period of concern here, so if you're traveling
during that time, keep up with the forecast. It is a fast moving
system, so it looks like it will be out of here by Wednesday, one
of the bigger travel days of the Holiday week.
Thursday and Friday...forecast confidence is low.
High pressure quickly moves through Wednesday night and exits on
Thursday...allowing another trough of low pressure to drift across
the region. That trough looks slow moving and will bring a chance
of precip later Thursday into Friday. The weather pattern is
incredibly progressive, so timing and intensity in the long range
is in question.
Allowing the Gale Warning over the open waters of Lake Michigan to
expire at 3 am CST, as northwest wind gusts have weakened to
around 30 knots or less. Winds and waves will gradually subside
over the lake today.
The Small Craft Advisory will linger until 6 am CST for the
nearshore waters, until gusts decrease under 22 knots. Northwest
winds will gradually weaken this morning, becoming west this
Gusty southwest winds should occur over northern portions of the
lake tonight into Saturday, with gusts to 30 knots at times. Waves
should build in this area as a result. Weaker winds will occur to
the South. West winds should then occur over the lake on Sunday.
Gusty winds and building waves may occur Tuesday night into
Wednesday night over Lake Michigan, though there is still a good
amount of uncertainty with where low pressure may track.