NWS-Milwaukee/Sullivan Forecast Discussion
FXUS63 KMKX 280350 AAA
AFDMKX
Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
950 PM CST Sat Dec 27 2025
.KEY MESSAGES...
- Dense fog may continue to spread northeast across the rest of
the area overnight into Sunday morning.
- Warm temperatures and rain on Sunday will transition to snow
as temperatures drop rapidly below freezing Sunday night.
Expect widespread accumulations between 1 to 3 inches through
Monday morning. Areas north of a line from Dodgeville to Port
Washington stand the best chance to see between 3 to 5 inches
of snowfall and gusty winds, and a Winter Weather Advisory is
in effect for those regions.
- Wind gusts up to 50 MPH will be possible Sunday night through
Monday. Winds up to 55 MPH may briefly occur along the Lake
Michigan shoreline. A Wind Advisory has been issued for all of
southern Wisconsin.
- Polar air returns Sunday night and continues through the end
of next week, with temperatures remaining at or below normal.
- Confidence has increased in storm force gusts Sunday night
through Monday night. A Storm Warning is in effect for this
time frame.
&&
.UPDATE...
Issued 950 PM CST Sat Dec 27 2025
Dense fog continues for areas southwest of Madison, where a
Dense Fog Advisory is in effect until noon CST Sunday. There is
potential for the dense fog to spread across the rest of the
area overnight into Sunday morning, as steady warm air advection
in the low levels continues to feed moisture into the area.
Will monitor web cameras and airport observations and expand
the advisory northeastward if necessary. The dense fog should
dissipate once rain starts to develop and move northeast into
the area by later Sunday morning into the early afternoon.
Otherwise, the headlines look reasonable for now with the Winter
Weather Advisory in the north half with Dane and Iowa Counties
Sunday night into Monday morning, and the Wind Advisory for the
entire area Sunday night into Monday. Will have to monitor the
Marquette/Green Lake County and nearby areas and see if higher
snowfall amounts may occur there. There may be some rumbles of
thunder that sneak into far southeast Wisconsin as well Sunday
before the front moves through.
Wood
&&
.SHORT TERM...
Issued 349 PM CST Sat Dec 27 2025
Tonight through Monday Night:
Subtle warm moist advection is anticipated overnight as sfc low
pressure moves out of the Central Plains towards southern WI and
a week warm front approaches the WI/IL border. With the WAA,
fog is expected to spread in coverage overnight and light
drizzle is anticipated to blossom over southern WI this evening
and continue through the overnight hours. Some of the fog may
become dense on a scattered basis.
There'll be a bit of a lull in the drizzle after dawn tomorrow
as the forcing for ascent from the WAA moves east into Lower
Michigan. Fog will linger until rain moves in during the mid
morning and continues through the afternoon as PVA from an
approaching deep 500mb trough over the western Corn Belt
overspreads the frontal boundary and the center of the sfc low
moves directly over southern WI.
Late Sunday afternoon into Sunday evening, the low will rapidly
deepen as it passes over southern Lake Michigan into the Mitten
of Michigan State. As this happens, very strong winds are
expected to spread into southern Wisconsin driven by a tight
pressure gradient, causing very strong cold advection. A quick
transition from rain to snow is expected from west to east
between 6 and 9pm, with snow continuing overnight as the
deformation band from the intensifying sfc low pivots and sinks
southeast into Monday morning. While soundings show a fairly
deep dendritic growth zone from 900 to 650mb at times, the
strong winds to 50 mph will likely breakdown the dendrites to
needles during the snow event, driving down snow ratios.
Snow is expected to then end Monday morning as the surface low
pulls northeast, with cold breezy conditions expected for the
rest of Monday.
A Winter Weather Advisory has been issued generally along and
north of a line from Dodgeville to Port Washington from 6PM
Sunday to Noon Monday. Along and north of this line, snow
totals will range from 3 to 5 inches, while totals will be less
south of this line. Blowing snow will generally be a concern
everywhere however, given the high wind gusts to 50 mph. Impacts
will be heightened in the advisory area given higher snow
totals.
A Wind Advisory has also been issued from 6PM Sunday to 6PM
Monday. Wind gusts up to 50 mph will be possible everywhere in
southern WI during that time period. Some gusts to 55 mph may
occur early Monday morning along the Lake Michigan shoreline.
CMiller
&&
.LONG TERM...
Issued 250 PM CST Sat Dec 27 2025
Tuesday through Saturday:
An area of warm advection aloft is expected Tuesday into Tuesday
night as a weak shortwave pushes through. This will bring light
snow chances to at least the northeast forecast area, with models
varying on how far southwest the light snow will reach.
Temperatures will be a few degrees below normal Tue, with mostly
cloudy skies anticipated.
A cold front will move through by late Tue night, keeping highs a
bit under normal on Wednesday. Another shortwave will move through
later Wed into Wed night, brining more light snow chances to the
area. This system currently looks a little more likely to bring
some light snow accumulations to the area than the Tue wave, with
up to an inch possible per 12Z guidance.
A colder airmass will continue to push into southern Wisconsin
Wednesday night into Thursday behind the departing shortwave. Wind
chills may dip to the 0 to -10 range later Wed night (New Year's
Eve) into early Thursday, with highs New Year's Day likely only
reaching the teens. High pressure is expected to bring dry weather
Thursday and Friday, with below normal temps continuing on
Friday. Temps should warm back towards normal Saturday, with
precip chances returning the the area by later Sat or Sat night.
DDV
&&
.AVIATION...
Issued 950 PM CST Sat Dec 27 2025
Dense fog with visibility of one quarter mile or less continues
for areas southwest of Madison, and there is potential for the
dense fog to spread across the rest of the area overnight into
Sunday morning.
For now, have one half to one quarter mile visibility for
terminals overnight into Sunday morning, with continued low
ceilings of 200 to 400 feet AGL. The gusty southeast winds near
the lake may be limiting the dense fog for terminals nearby, but
these winds should weaken overnight and may allow for the fog
to become more dense. Generally light and variable winds should
occur Sunday morning and early afternoon.
The dense fog should dissipate once rain starts to develop and
move northeast into the area by later Sunday morning into the
early afternoon. It may move into Kenosha and Milwaukee sooner,
so visibility values may improve there first. Visibility of one
half to one mile or so should then prevail through Sunday,
becoming 1 to 2 miles Sunday night.
The ceilings should remain around 500 feet AGL or less into
most of the rest of Sunday, before rising above 1000 feet AGL
behind the cold front Sunday night. There may be some rumbles of
thunder that sneak into far southeast Wisconsin as well Sunday
before the front moves through.
The rain will quickly change to snow later Sunday afternoon into
early Sunday evening west to east as the cold front moves
through. The snow should be more of a powdery and fluffy
character. Snowfall rates of one quarter to one half inch per
hour should occur north of Madison and Milwaukee, including
toward Sheboygan. Lower rates and amounts are expected toward
Janesville and Kenosha.
Strong west to northwest winds are expected behind the front
later Sunday afternoon into Sunday night, which will bring some
blowing and drifting snow. Gusts of 40 to 45 knots are possible
later Sunday night into early Monday morning.
Wood
&&
.MARINE...
Issued 950 PM CST Sat Dec 27 2025
Moderate southeasterly winds will continue overnight, as low
pressure around 29.6 inches approaches from the Central Plains.
Winds are anticipated to ease Sunday morning, as the low moves
closer to the lake and passes over the southern end of the lake
through the afternoon.
A Small Craft Advisory is in effect for the nearshore waters
into Sunday morning, for gusty southeast winds and building
waves into the overnight hours, and lingering elevated waves
into Sunday morning.
Sunday night, following the passage of the low, very strong
northwest winds are expected, as the surface low deepens to
around 28.9 inches as it moves northeast toward Lake Huron.
Storm force gusts between 50 to 55 knots are expected Sunday
night into Monday night, with the peak in gusts occuring between
3 AM CST to 6 PM CST Monday.
A Storm Warning is in effect for all of the open waters of Lake
Michigan from 7 PM CST Sunday evening to 6 AM CST Tuesday. High
waves are also anticipated, highest toward the eastern half of
the lake.
While gales should ease after 6 AM CST Tuesday, breezy
northwest to west winds are anticipated to continue through the
week, as northwest flow and cold air take hold.
A Gale Warning is in effect for the nearshore waters Sunday
evening into Monday evening, for frequent northwest gales to 45
knots.
CMiller/Wood
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Dense Fog Advisory...WIZ062-WIZ067-WIZ068 until noon Sunday.
Wind Advisory...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056-WIZ057-
WIZ058-WIZ059-WIZ060-WIZ062-WIZ063-WIZ064-WIZ065-WIZ066-
WIZ067-WIZ068-WIZ069-WIZ070-WIZ071-WIZ072...6 PM Sunday
to 6 PM Monday.
Winter Weather Advisory...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056-
WIZ057-WIZ058-WIZ059-WIZ060-WIZ062-WIZ063...6 PM Sunday
to noon Monday.
LM...Storm Warning...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-
LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-
LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...7 PM Sunday
to 6 AM Tuesday.
Gale Warning...LMZ643-LMZ644...9 PM Sunday to midnight Tuesday.
Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 9 AM
Sunday.
Gale Warning...LMZ645-LMZ646...6 PM Sunday to midnight Tuesday.
&&
$$
Visit us at weather.gov/milwaukee
Follow us on Facebook, X, and YouTube at:
www.facebook.com/NWSMilwaukee
www.x.com/NWSMilwaukee
www.youtube.com/NWSMilwaukee