Waukesha, Wisconsin 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

106
FXUS63 KMKX 131538 AAA
AFDMKX

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
938 AM CST Tue Jan 13 2026

.KEY MESSAGES...

- Mild and windy today, with highs in the mid to upper 40s.

- Strong cold front brings gusty winds and much colder
  temperatures overnight into Wednesday. Scattered snow showers
  are expected late tonight.

- Much colder through the extended, with the exception of a
  slight moderation on Friday. Several chances for light snow
  through the remainder of the forecast period.

&&

.UPDATE...
Issued 938 AM CST Tue Jan 13 2026

With temperatures that are already mild this morning and
clearing skies, bumped up the temps for today into the upper 40s
for most of srn WI (mid 40s toward central). Gusty southwest
winds are over-performing this morning, but they will diminish
with the clearing as they become westerly. However, winds near
the lakeshore will remain gusty all day due to deeper mixing.

A series of weak mid level shortwave troughs will cross WI today
and tonight, with each one bringing successively colder temps
and chances for very light rain showers/sprinkles and eventually
light snow showers/flurries. The Arctic front will arrive in
central WI around midnight and southeast WI around 3 AM. Expect
scattered to numerous flurries or light snow showers along the
front. A dusting of snow is possible and will be accompanied by
gusty north-northwest winds.

Cronce

&&

.SHORT TERM...
Issued 240 AM CST Tue Jan 13 2026

Today and Tonight:

A mild day is expected across the region today, with continued
warm advection along the south side of a strong shortwave, which
is moving across northern Wisconsin this morning. A few rain
showers are possible over central and east central Wisconsin
this morning, but most of the area should remain dry during
the daytime hours today. Look for highs to reach the mid to
upper 40s, with a few spots near the Illinois state line
approaching 50. West winds will gust to between 25 and 30 MPH
at times.

Deepening low pressure over southern Ontario will push an
initial cold front through the area early this evening, followed
by a stronger Arctic front overnight. Temperatures will rapidly
fall during the overnight hours, reaching the low to mid 20s by
daybreak. Showery precipitation is expected overnight tonight as
a strong shortwave pushes through the area. This will mainly be
in the form of snow, though a few rain drops may briefly mix in
at onset.

Boxell

&&

.LONG TERM...
Issued 240 AM CST Tue Jan 13 2026

Wednesday through Monday:

Scattered snow showers may continue into Wednesday morning,
before ending by mid day/early afternoon. Overall very minor
accumulations will be possible with probs showing a moderate
confidence of a widespread dusting. Can`t completely rule out
some amounts around a couple tenths of an inch up to an inch of
snow but this looks to be the outlier with a less than 10%
chance of occuring.

The gusty north winds over Lake Michigan and the cold air over the
warm lake will cause LES to develop. This would ideally create a
nice north-south band of snow. Any single banded snowfall down the
lake will be capable of producing some heavy snowfall, but
thankfully due to the wind direction this is trending more over
the central portion of the lake. While our lakeshore cities
could get clipped by some snow, but should be left largely
untouched by the heavier snowfall that is expected along the
IL/IN border on the south side of Lake Michigan. Therefore,
continued the low chances for some snow, but not expecting much
if any impacts from it at this time.

By Thursday high pressure will move into the Mississippi Valley,
then continue east into the Ohio River Valley by Friday. This
will bring a return of southwesterly winds and milder
temperatures for the end of the work week. Another trough is on
the horizon for Thursday night into Friday, but there is a bit
of uncertainty on timing and location here. Guidance does show a
trough digging down from Canada, but there are multiple
shortwaves within the upper level flow and slight differences in
track would impact precipitation duration. So expect changes in
timing and duration moving toward for this one. For the weekend
and into early next week more north winds and CAA return for a
chilly and dry forecast.

Patterson

&&

.AVIATION...
Issued 938 AM CST Tue Jan 13 2026

Skies cleared out this morning. Lower clouds with bases around
3500 ft will wrap into south central WI by early evening and
then MVFR ceilings are expected around midnight. An arctic front
will bring lower MVFR ceilings and scattered snow showers late
tonight into Wednesday morning. A dusting of snow is possible by
daybreak, along with blustery north-northwest winds. Snow
chances will quickly taper off Wednesday morning as drier air
works into the region, but blustery NNW winds will persist into
the evening hours.

Cronce

&&

.MARINE...
Issued 240 AM CST Tue Jan 13 2026

Gusty west to southwest winds are expected across the lake today,
as low pressure deepens across southwestern Ontario. A Small
Craft Advisory is in effect for the nearshore. By tonight, that
low will deepen to 29.1 inches and will push east into western
Quebec.

As that low deepens and moves east it will push a strong, Arctic
cold front down Lake Michigan this evening into tonight. Northwest
winds will rapidly increase to gale force behind the front, with
gales continuing into Wednesday evening. Gale Warnings are in
effect for all of Lake Michigan, including the nearshore waters.
Moderate to occasionally heavy freezing spray is expected during
this time as well.

By late Wednesday night high pressure of 30.3 inches will build
south across the upper Mississippi Valley, and will eventually
move across the lake on Thursday, bringing lighter winds. Winds
will briefly turn westerly to southwesterly Thursday evening and
night, before another strong cold front sweeps across the region
early Friday.

Boxell

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 3 AM
     Wednesday.

     Gale Warning...LMZ643-LMZ644-LMZ645-LMZ646...3 AM Wednesday to
     9 PM Wednesday.

     Gale Warning...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-
     LMZ565...midnight Wednesday to midnight Thursday.

     Gale Warning...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
     LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-
     LMZ878...3 AM Wednesday to midnight Thursday.

&&

$$

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