NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 120520
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1220 AM CDT Thu Mar 12 2026

.KEY MESSAGES...

- Widespread rain expected Thursday night. Some rain-snow mix is
  possible across the far north, with any accumulation remaining
  light (half inch or less). Snow showers along the front
  possible and even some post frontal freezing drizzle Friday
  morning.

- Very gusty non-thunderstorm winds expected during the day
  Friday. Very gusty winds may start as early as Thursday
  evening. Wind Advisory in effect midnight Friday through 6pm.

- Confidence is increasing for significant accumulating snow and
  blowing snow Saturday night through Sunday night. Where
  exactly the heaviest snow will fall remains uncertain. Pay
  close attention to the forecast if planning to travel during
  this time frame.

- Accumulating sleet/freezing rain will be possible for parts of
  southern WI during this event as well.

&&

.SHORT TERM...
Issued 1159 PM CDT Wed Mar 11 2026

Today through Friday:

Conditions have quieted across the area with clear skies
expected for most of tonight with high pressure largely
dominating the region. A brief, transitory period of light
snow/flurries cannot be ruled out late tonight given some
midlevel moisture in the DGZ and some weak omega (perhaps from
mild WAA). But the drier air in the low levels likely prevent
much if anything from reaching the ground. Otherwise quiet
weather is expected through rest of tonight.

Thursday will start fairly quiet as a upper low and
corresponding surface low from the north central US will dig
and strengthen into the Great Lakes region toward the late
afternoon/early evening hours. Generally models have come into
line on this event with models suggestive that this event will
really wrap up and strengthen as it slides through northern WI.
The track and strength of the system has largely led to system
to trend toward a largely rain event for southern WI. Strong
southerly LLJ (upwards of 80 kts) with bring strong WAA in
addition to the PVA from the upper low. This should allow for
some rain primarily ahead of the front during the evening and
overnight hours. Earlier rain likelihood (60+%) will be largely
restricted toward central WI where the better forcing near the
surface low exists and where the moisture profiles near the
surface are better initially. Further south, chances ahead of
the front are lower (35-55%) given some drier air that may need
to be overcome first.

I should begin the mention that some CAMs are suggestive of some
frontal based snow showers Early Friday morning that may
potentially be fairly heavy. With the strong winds expected,
this situation definitely raises some concern for snow squalls.
While there remains high uncertainty with this, it becomes
something to watch for in models over the next 24 hrs. Then
behind the front we really see CAMs dry things out in the DGZ,
in fact, given cooling temperatures some freezing drizzle cannot
be ruled out behind the front though snow will be possible as
well, particularly further north toward the low where moisture
in the DGZ may persist somewhat. Otherwise precip largely pushes
out by mid morning Friday.

The primary story with this event will likely be the potential
impacts from wind. The strong southerly LLJ will push in
Thursday evening, which will start to increase the concern for
strong winds reaching the surface given that low level sounding
profiles are fairly moist to dry adiabatic. The LLJ will also
get stronger toward the early overnight hours. These factors in
conjunction with the increased precip likelihood has caused
increased concern for Wind Advisory criteria by the mid evening
hours. This particularly true if we see the best precip
potential during the late evening and early overnight periods as
precip loading could be a major factor in whether we end up
seeing those high end winds Thursday night. However, because it
is an overnight period it becomes more difficult to expect winds
to naturally mix down. For now, we have started the Wind
Advisory at midnight with an end time of 6PM, but the start time
could be shifted earlier or later depending on the exact timing
of the precip, the precip loading potential and whether we
should expect much mixing overnight at all. Into the daytime
hours, winds will shift westerly behind the front and with
strong CAA and daytime heating we should expect to mix down
winds aloft with a much higher degree of certainty. Winds will
start to come back down late afternoon as the surface low begins
to push out with weak high pressure moving in.

Kuroski

&&

.LONG TERM...
Issued 1159 PM CDT Wed Mar 11 2026

Friday night through Wednesday:

Friday night winds will continue to decrease with a period of
high pressure at the surface and zonal flow aloft. Into the day
Saturday, a band of midlevel moisture and WAA will slide into
southwest WI and continue north through the day. Initially
limited forcing and dry air may limit precip potential but
gradually WAA will strengthen and begin to bring snow across
southern WI. Into Saturday evening and night 850mb WAA will
increase significantly with LLJ factoring in as well as upper
level PVA. Into Sunday additional concern will come from the
impact of banding and strong Fgen that will play a significant
roll in how this system plays out.

It remains difficult to gauge the level of impact this will have
at this time for southern WI as there are two main uncertainties
and sensitivities that will significantly affect the impact this
has on any individual area. The phasing of this system suggest
there are still uncertainties in track and also, although
related, the location of the freezing line. These two factors
will determine in large part the impact this system has. At this
point we know it is going to snow a lot somewhere and there also
may be significant impacts from sleet and freezing rain
potential, primarily for Saturday night and Sunday. While there
is no current consensus among models at this time there is the
general sense the freezing line will be over southern WI
somewhere with heavy snow potential directly north of that line.
This has certainly increased concern for both heavy snow and
icing impacts. We will continue to monitor changes over the next
48 hours as models being to focus in on the exact where and when
of this event.

Otherwise Monday morning remaining snow on the back end of this
system will push out through the day with weak high pressure
pushing in by Monday evening. Tuesday looks largely dry at this
time but into midweek there are some semblances of a few
features that may bring some activity but uncertainty beyond the
weekend event remains high.

Kuroski

&&

.AVIATION...
Issued 1159 PM CDT Wed Mar 11 2026

VFR conditions largely expected tonight. Cannot rule out a
brief period of flurries/light snow late tonight but chances
look very slim. Then attention turns to later Thursday afternoon
as precip starts to move in with the next system. Evening and
early overnight this should feature largely rain showers with
some snow mixing in toward central WI. Late overnight may
feature some frontal snow showers, possibly briefly heavy but
that remains somewhat uncertain. Then some post frontal freezing
drizzle will be possible but too remains fairly uncertain. The
other primary factor with this event is winds may increase
substantially Thursday evening into Friday. Very strong winds
(35-45 kts) aloft may mix down overnight with the precipitation.
If they do not then strong LLWS is to be expected overnight at
around 45-55 kts aloft as low as 1kft from the south. Strong
winds will continue into Friday behind the front though winds
will be out of the northwest. Friday winds are more likely to
reach the ground, however.

Kuroski

&&

.MARINE...
Issued 1159 PM CDT Wed Mar 11 2026

Low pressure over southeast Ontario/southwest Quebec will
continue to pull away to the northeast the remainder of tonight.
Northwest winds have largely come below gale force.

Lighter winds the rest of tonight into early Thursday as high
pressure briefly moves through. Strong low pressure is then
expected to move through northern Wisconsin into northern
Michigan Thursday night into Friday. Increasing southerly winds
are expected later Thursday into Thursday night ahead of the
low. Though the cold lake may dampen the gust potential Thursday
night, southerly gales are still likely, especially given the
precipitation potential over the lake with a few storm force
gusts possible. There is a better chance for west to northwest
gales on Friday behind the low, with a few gusts to storm force
not out of the question. A Gale Warning will be going into
effect for Thursday evening through Friday evening.

Winds are expected to ease Friday night into Saturday as high
pressure moves in from the northwest. Another strong low
pressure system is likely to move through the region late in the
weekend into early next week, with another round of gales
likely, perhaps even storm force gusts. A colder airmass behind
the low may lead to a round of heavy freezing spray Sunday
night into Monday as the strong winds and higher waves linger.

Kuroski

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Wind Advisory...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056-WIZ057-
     WIZ058-WIZ059-WIZ060-WIZ062-WIZ063-WIZ064-WIZ065-WIZ066-
     WIZ067-WIZ068-WIZ069-WIZ070-WIZ071-WIZ072...midnight
     Friday to 6 PM Friday.

LM...Gale Warning...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-
     LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-
     LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 until 1 AM
     Thursday.

     Gale Watch...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
     LMZ567-LMZ643-LMZ644-LMZ645-LMZ646-LMZ669-LMZ671-LMZ673-
     LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-
     LMZ878...7 PM Thursday to 1 AM Saturday.

&&

$$

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