Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
FXUS63 KMKX 170951
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
451 AM CDT MON OCT 17 2016
.TODAY AND TONIGHT...Forecast Confidence Is Medium.
The warm front is moving nwd through srn WI early this morning.
Temps are warming into the upper 60s to lower 70s with the passage
of the front along with the dissipation of the fog. Stratus clouds
are thinning out as well with models appearing to over forecast the
stratus for today. Thus expect more sunshine today with sct-bkn
cumulus. With 925 mb temps warming into the lower 20C range, near
record high temps in the lower 80s will be possible mainly in the
srn half of the CWA.
Windy conditions may then develop for late this afternoon and
tonight, when strong low pressure tracks from se MN toward Lake
Superior. A swly 60 kt LLJ will develop, and given very mild
temps continuing after dark, some mixing will continue with wind
gusts of 30-40 mph.
Precip. chances are very low this morning, since the upper wave
and warm advection is most focused to the north. Otherwise, will
go dry for later today and tonight with another upper wave
associated with the low pressure area focusing to the north once
again. A dry cold frontal passage is then expected early Tue
morning, since the atmosphere will likely remain capped.
.TUESDAY THROUGH WEDNESDAY NIGHT...Forecast Confidence Is Medium.
Models are in fairly good agreement with features during this
period. They take the cold front southeast of the area Tuesday
morning. Cold air advection then is strong through Tuesday
afternoon and night, and weakens but continues into Wednesday
At 500 mb, west southwest flow on Tuesday becomes more southwesterly
Wednesday into Wednesday night, as a somewhat broad trough moves
east into Iowa and northern Missouri. There is some differential
cyclonic vorticity advection that pushes northeast into the area
Area forecast soundings are rather dry during this period, so it
looks to be a dry stretch of weather. Despite the cold air
advection Tuesday, it looks to be a rather mild day, with highs in
the middle to upper 60s. Temperatures will then show a slight
downward trend Tuesday night into Wednesday night, but still
should remain above seasonal normals.
.THURSDAY THROUGH SUNDAY...Forecast Confidence Is Medium.
Models differ for Thursday between the ECMWF and GFS. The ECMWF
shows light QPF moving through the area, with an extension of the
500 mb vorticity maximum within the passing trough. The GFS is dry
during this time. Kept the lower end PoPs for showers for Thursday
in the southeast portions of the area for now. There is
uncertainty with these low end chances for showers are, and it may
end up dry for Thursday.
500 mb flow then becomes northwesterly Friday into Sunday across
the region, as the trough exits to the east. The ECMWF brings some
QPF Friday night into Saturday with a passing 500 mb vorticity
maximum. However, the GFS is dry. Kept the dry forecast going,
until more consistency is seen among the models for Friday night
into Saturday. Temperatures look to trend closer to seasonal
normals during this period.
Srn WI is on the srn periphery of sct-bkn010-030 stratus clouds this
morning. Believe the scattered to sometimes broken cloud coverage
will continue but raise to 3-4 kft as cumulus clouds this afternoon.
Areas of fog will continue near Lake MI but mainly north of Port
Washington. Gusty winds in the 20 mph range is forecast for today
but will become swly with gusts of 30-40 mph this evening as a swly
60 kt llj develops. A cold frontal passage is then expected early
Tue am with winds decreasing but shifting nwly.
The marine dense fog advisory was extended from Port Washington
to just north of Sheboygan until 12z. South winds and the passage
of the warm front will dissipate the fog by sunrise.
Otherwise, a Small Craft Advisory is in effect today and tonight
south of Port Washington, while going into effect tonight north
of Port Washington. Breezy south winds today will become swly and
gusty tonight ahead of the approaching cold front. Wind gusts up
to 33 kts are expected. Some brief gale force gusts are possible.
High waves will build over the open waters.
LM...SMALL CRAFT ADVISORY from 10 AM this morning to 7 AM CDT
Tuesday for LMZ644>646.
DENSE FOG ADVISORY until 7 AM CDT this morning for LMZ643.
SMALL CRAFT ADVISORY from 7 PM this evening to 7 AM CDT Tuesday
TODAY/TONIGHT AND AVIATION/MARINE...Gehring
TUESDAY THROUGH SUNDAY...Wood