NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 060808
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
208 AM CST Tue Jan 6 2026

.KEY MESSAGES...

- Light glaze of ice possible (~40-60% chances) in freezing rain
  early this morning in Marquette & Green Lake Counties. Winter
  Weather Advisory has been issued through 9 AM this morning.

- Patchy fog expected tonight. Freezing fog is possible and
  slick spots are possible north of I-94.

- Additional precipitation expected (~50-80% chances or greater)
  areawide near & after sunrise today. Cannot rule out patchy
  freezing rain early this morning where ground temperatures are
  a bit cooler.

- Temperatures trending well above normal Wednesday through Thursday.

- Becoming more active later in the week, with multiple chances
  Thursday night into Friday (60-90%, more rain) and another
  more so late Friday night through Saturday night (30-60%, more
  snow). Accumulating snow Saturday looking increasingly likely.

&&

.SHORT TERM...
Issued 100 AM CST Mon Jan 5 2026

Today through Tuesday:

700-500mb Fgen banding set up just north of the CWA and given
current trends and track, precip has drifted north over the
keeping northern parts of the CWA dry in large part. The concern
with Winter Weather Advisory conditions were that with
significant midlevel WAA and below freezing temps that this
would lead to freezing rain. While this concern has been
mitigated in large part due to where this banding set up there
will still likely be a period of freezing rain for Marquette and
Green Lake counties over the next few hours before we warm up
at the surface due to surface WAA. A glace of ice cannot be
ruled out as the back edge of the Fgen swings back through the
northwest parts of the CWA.

Central parts of the CWA has begun to see precip chances
increase in the southwest parts of the CWA that will continue to
blossom as additional low level moisture, increased WAA and a
strong shortwave slides in. Outside of the far northwest of the
CWA the rest of the CWA should largely see just rain as
temperatures remain at or just above freezing. Even with
temperatures at freezing, and pavement temps around freezing the
latent heat processes involved in freezing and the fact that we
may be able to warm advect further over the next few hours
suggests that rain is the most likely with patchy freezing rain
where pavement temps are subfreezing. Even with patchy freezing
rain this will only last a short period as we most certainly
begin warm advecting post sunrise. We will need to monitor
trends though as some evaporative processes may play a role in
turning temps back down and some pavement temps might be low
enough for prolonged impact. It is also worth mentioning some
patchy fog is possible and even some freezing fog though this is
expected to be limited and of little impact overall.

Later into the morning and through the afternoon lingering
moisture aloft and more specifically at 500mb with some PVA and
even some WAA at 700mb there will likely continue to be rain
chances into the late afternoon but likely exiting by the early
evening as forcing and moisture both push out of the region.
Weak high pressure will nudge into the region from the south
tonight with weak ridging aloft.

Weak surface high pressure and weak UL ridging along with
midlevel dry air will keep the region dry through the day
Wednesday and Wednesday night ahead of the developing system to
the west

Kuroski

&&

.LONG TERM...
Issued 200 AM CST Mon Jan 5 2026

Thursday through Monday:

Synopsis:

A high amplitude upper trough will develop over the western U.S.
on Thursday. There are three shortwave troughs to note within
this system. The first stems from the remnants of a closed upper
low off the coast of srn CA and the Baja Peninsula. This feature
will track across far nrn MX and lift into New Mexico while
weakening into a shortwave trough early Thu AM. It will make its
way into the center of the country by 18Z Thu and the resultant
surface low will bring our next chance of precip to southern WI
Thu afternoon and night.

The second shortwave trough of interest will drop down from the
Pacific Northwest and dig across AZ and NM Thu nt into Fri AM. The
shortwave will lift through the Midwest as it shears out, but the
speed at which it does this differs between models. When you
compare locations at 12Z Sat, the 00Z operational GFS is over west
central IL and the 00z operational ECMWF is way back in west
central MO. The upper trough maintains a positive tilt during
this time.

The third shortwave will swing down through Alberta Fri afternoon
and through the Dakotas and MN around 12Z Sat. The interaction of
the second and third shortwaves will be key for how the system
evolves beyond 12Z Sat. The slower shortwave #2 would allow for
the two shortwaves (2 and 3) to phase and create a deeper surface
low over Lower Michigan (stronger cyclogenesis). This would
produce heavier precip and stronger winds over southern WI.

The Day 5 cluster analysis reveals a larger spread/variance in
the ensembles for the speed of the upper trough than the amplitude
of the upper trough as it crosses the US. The GEFS is generally
in one camp and the ENS is in another, with the GEPS dispersed
between both (per the phase space).

Precip types for southern Wisconsin:

With temperatures in the 40s as the precip moves into southern WI
on Thursday, the precip type will be all rain. As the low pulls
away Thu night, colder air will work its way in, so there is a
possibility of a brief changeover to snow early Friday morning as
the precip ends. One thing to note is that our forecast has a
chance of precip all day Friday, but the majority of the day looks
like it will be dry at this time. Friday night lows should be just
below freezing.

The next round of precip is expected to spread into southern WI
early Saturday morning. With the column of air all below freezing,
the precip type is expected to be snow on Saturday. Accumulating
snow with increasing northerly winds is our message for now. The
details will be determined by the phasing and strength of the
system.

Cronce

&&

.AVIATION...
Issued 100 AM CST Mon Jan 5 2026

As the moisture gradually increases tonight we will see the
development of MVFR (southwest WI) to as low as LIFR (eastern
and central WI). This may include some VSBY reductions with a
combination of patchy fog and precip. Toward central WI some
freezing rain is possible and even likely toward west central
WI. However, impacts for southern WI will be limited as
temperatures are likely to remain just above freezing. In any
case rain is expected from much of southern WI this morning with
some lingering rain through early this evening primarily toward
central and east central WI. Expect low CIGS much of the TAF
period perhaps just starting to clear out toward daylight
Wednesday morning. VSBYS concerns will be more patchy but may
also continue until Wednesday morning with some patchy fog
concerns overnight. We will be monitoring conditions/trends
this morning for any freezing rain concerns.

Kuroski

&&

.MARINE...
Issued 100 AM CST Mon Jan 5 2026

A low will cross the southern third of the lake near daybreak
today, moving into Lower Michigan by the afternoon hours. Winds
will shift out of the northwest behind the departing low
this afternoon and evening. Rain is expected across the open
waters through today into this evening, with some rain-snow mix
possible over far northern Lake Michigan. Some fog is possible
early this morning, though dense fog is not anticipated at this
time.

High pressure will build over the Ohio River Valley on
Wednesday, bringing a southwest wind shift across the waters.
South-southwest winds will continue through the day on Thursday
as low pressure moves from the northern Great Plains into the
Mississippi River Valley. Low pressure will cross southern Lake
Michigan on Friday, progressing east into Quebec through
Saturday night. The low's approach and passage will bring
increasing northerly winds Thursday night into Friday evening,
with winds shifting out of the west- northwest Saturday through
Saturday night behind the departing low. Depending on the low's
central pressure, periods of gales may be possible Saturday and
Saturday night. Forecast guidance remains uncertain regarding
said central pressure, so trends will be closely monitored
through this week. Periods of rain and snow are expected Friday
through Sunday.

Kuroski

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Winter Weather Advisory...WIZ046-WIZ047 until 9 AM Tuesday.

LM...None.
&&

$$

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