Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
FXUS63 KMKX 022140
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
340 PM CST Fri Dec 2 2016
TODAY AND TONIGHT...Forecast confidence is high.
Low pressure will continue to move across eastern Cananda and Maine
as high pressure approaches from the west. The high will move just
south of the region on Saturday with mid level ridging overhead. Low
level flow will be weak and soundings indicate moisture will remain
trapped beneath an inversion around 850 to 900mb. So overcast skies
are expected to linger through the day, but dry weather will prevail.
Went above model guidance for min temperatures tonight in
collaboration with neighbors with the stratus in place.
SUNDAY... Forecast confidence is high.
Accumulating snow of 1 to 2 inches is expected on Sunday. This will
cause travel headaches. The first snowfall of the season often
catches people off guard. No winter weather advisory is anticipated
at this time, but be aware of the potential impacts of this first
light snow of the season.
An upper trough will swing through the Upper Midwest early Sunday
morning and take on a negative tilt by the afternoon when it reaches
the Great Lakes. 600mb warm air advection and upper divergence from
a passing upper jet to our south will aid in general lift for
southern WI. Precip type will be snow in the morning, but change to
a rain/snow mix during the afternoon as temps warm into the mid 30s.
Models are all showing a very similar outcome, so this is a high
confidence event. Probabilistic graphics show that there is a 60%
chance of 1 inch or more and a 25% chance of 2 inches or more. There
is a max potential for 2-3 inches across the area. Check out the
graphics in the www.weather.gov/mkx/winter webpage.
MONDAY AND TUESDAY... Forecast confidence is medium.
Expect quiet weather Monday with increasing clouds.
A closed upper low over northern Mexico will make its way over to
the Tennessee area by Tue morning. This is farther south than
yesterday`s forecast. Meanwhile, a large upper trough over south
central Canada will dip down through the Upper Midwest and drop much
colder air into southern Wisconsin by Tue evening. This cold front
could bring some light snow or a rain/snow mix to the area, but
WEDNESDAY THROUGH FRIDAY... Forecast confidence is medium.
The ECMWF and Canadian models backed off significantly for snow in
srn WI Wed night/Thu. The GFS remains dry for srn WI. We could still
get clipped by light snow from a system passing to our south, but
still just a chance and with minor accumulation.
High confidence in much colder temperatures for late next week.
Model soundings and upstream observations indicate overcast skies
with 2500 to 3000 ft ceilings will persist through at least Saturday
morning. Eastern WI will see 3000 to 3500 ceilings at times this
evening due to mixing. Some models have been showing a period of
several hours of VFR tonight, but that may be too optimistic given
the current conditions so confidence is low at this time.
There is a better chance for VFR ceilings Saturday afternoon as high
pressure helps scour out some low level moisture.
Winds will be weak out of the west tonight. Southwest winds will
increase on Sunday veering west Sunday night. Wind gusts will
approach small craft advisory levels Sunday night.
There is a chance for sustained gusty winds and high waves at times
starting Tuesday night. However, there remains considerable
uncertainty with how things will evolve with systems moving through
TONIGHT/Saturday AND AVIATION/MARINE...Marquardt
Saturday NIGHT THROUGH Friday...Cronce