Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
FXUS63 KMKX 292055
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
255 PM CST Tue Nov 29 2016
TONIGHT AND WEDNESDAY...Forecast Confidence...High
There will probably be some mid level clouds in the central and
eastern forecast area this evening, but otherwise expect mainly
clear skies to continue overnight. This should allow temps to drop
into the low 30s most places, as winds will be light.
Clouds will increase from west to east tomorrow morning as low
pressure draws near. Should see light precip move in from the west
in the afternoon. Saturation looks decent in model soundings, but
not seeing a lot of lift. Though temps aloft look plenty cold enough
for snow, there is uncertainty if the precip will be too light to
cause much wetbulbing of the surface temps and thus keep precip as
mainly rain. Temps are right on the edge for snow though and the NAM
is colder in the low levels suggesting mainly snow. Thus decided to
go with mainly a rain/snow mix for the afternoon hours. High temps
will be mildest in the east where it will take longer to for clouds
Wednesday night through Friday...Forecast confidence medium.
Light rain and snow will continue Wed night and may linger into
Thu AM as a shortwave trough on the srn periphery of the larger
upper low moves across srn WI. Little to no snow accum is expected
with temps remaining mostly above freezing through the night.
Otherwise, cyclogenesis is expected Wed night over srn Ontario
Canada with the low occluding over Quebec Canada. A trough will
extend to the west into central WI but will gradually weaken
through Fri. The trough will weaken enough to preclude any mention
of precipitation for Thu night and Fri. Temps will remain slightly
above normal through this period.
.LONG TERM...Saturday through Tuesday...Forecast confidence
A ridge of high pressure will move across WI on Sat followed by an
open wave of low pressure for Sun into Sun night. A couple areas
of cyclogenesis will then be ongoing for Mon-Tue. One low will
track from the nrn USA Rockies to Hudson Bay while the other area
will track from the Gulf coast to the ern Great Lakes. There is
some uncertainty on the evolution of these features and current
chances of rain and snow are only 20-30 percent. Temps will remain
slightly above normal.
VFR conditions will likely persist into Wednesday morning ahead of
an approaching low. Light precipitation and lower clouds are
expected to then move in from the west by Wed afternoon as the low
moves eastward through the state. A blend of model temps at the
surface and aloft puts precip type right on the edge of either rain
or snow, so decided to just stick with a rain snow mix. If snow does
occur, accumulations are not expected given the borderline temps.
Lighter winds continue to allow waves to subside this afternoon. The
3 pm Small Craft Advisory expiration time for the southern zones and
6 pm for the northern zones still looks reasonable based on latest
wave forecast. Winds could get near advisory levels again later Wed
night into Thursday.
LM...SMALL CRAFT ADVISORY until 6 PM CST this evening for
TONIGHT/Wednesday AND AVIATION/MARINE...DDV
Wednesday NIGHT THROUGH Tuesday...Gehring