Sheboygan, Wisconsin 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

865
FXUS63 KMKX 032017
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
317 PM CDT Sat May 3 2025

.KEY MESSAGES...

- Patchy frost is possible tonight for inland areas.
  Alternatively, patchy fog may develop.

- Generally dry on Sunday. Onshore flow will keep temperatures
  colder near the lake.

- Increased rain chances Sunday night into Monday morning, then
  dry weather likely for the rest of the week. Turning warmer.

&&

.SHORT TERM...
Issued 315 PM CDT Sat May 3 2025

Tonight through Monday:

Strong high pressure drifts eastward from Ontario to Quebec
Canada throughout the period, with a weaker satellite high
pressure lingering over Wisconsin and the western Great Lakes.
Meanwhile, closed low pressure wobbles between West Virginia and
Ohio. This pattern favors a light north to northeast breeze,
faster during the daytime hours and slower at night. This will
also keep daytime high temps cooler in far eastern WI.

For the rest of this afternoon, a 15% chance of a sprinkle of
rain west of Madison, looking less likely given the lack of any
signatures on Radar at the moment. For Tonight, a possibility of
patchy frost inland from Lake Michigan, with forecast lows
around 35 degrees, light and variable winds inland (light
northerlies may persist by the shoreline) and mostly clear skies
(though scattered /broken clouds will approach southeastern WI
towards daybreak Sunday). Hence, I`d diagnose the highest frost
potential along and west of the Kettle Moraine. With forecast
dewpoints hovering at or slightly above the freezing mark in
most areas, it will be possible for patchy fog to develop and
inhibit the frost formation. But, if we remain fog free and
clear skies for long enough, the potential for patchy frost is
there. Warmer low temperatures are forecast for Sunday and
Monday night.

A plume of moisture wrapping around the occluded low pressure
southeast of us merits a 30-60% chance of rain Sunday night,
tapering off into Monday morning. Highest chances are in
southeastern WI, tapering into east-central and south-central
WI. This is likely to leave Madison and areas westward dry. The
remainder of the forecast period (for all areas) is also looking
dry.

Sheppard

&&

.LONG TERM...
Issued 315 PM CDT Sat May 3 2025

Monday night through Saturday:

Long story short: drier and noticeably warmer. Another closed
upper-level low is expected in the 500-300mb pattern mid to late
next week (crossing the middle / southern Mississippi River
Valley), which is likely to perpetuate the dry weather pattern.
We are likely to see a few days with daytime highs in the low
70s inland, cooler by Lake Michigan due to periods of synoptic
north to northeast winds, as well as light and variable winds
(with a localized lake-breeze responding to the warmer
temperatures inland).

Sheppard

&&

.AVIATION...
Issued 315 PM CDT Sat May 3 2025

Lake Michigan shoreline clouds are finally clearing out, leading
to some VFR. Further inland we have 2,500 to 4,000 ft cumulus
clouds, leading to patches of VFR and MVFR ceilings. These
conditions continue through early this evening, when the cumulus
clouds erode and leave us with mostly clear skies for the
majority of the overnight hours. Light north to northeast winds
subside tonight, then ramp back up throughout Sunday.

For early Sunday morning, scattered to broken clouds approach
once again, likely well over the 3,000 ft VFR threshold for most
areas, though the cool / moist breeze off lake Michigan could
lead to some lowered ceilings in southeastern WI. Patchy fog is
also possible predawn Sunday for inland terminals, though
confidence is too low for inclusion in TAFs.

Sheppard

&&

.MARINE...
Issued 315 PM CDT Sat May 3 2025

Nearshore Waters:
For zones south of North Point Light in Milwaukee, a Small Craft
Advisory is in effect through 7 PM this evening due to lingering
waves. Small craft conditions are possible again Sunday PM into
Sunday night due to steady north winds and building waves.

Open Waters:
High pressure around 30.0 inches will expand across the Western
Great Lakes today, strengthening to around 30.1 inches. This high
pressure will sit over the western Great Lakes region into early
next week. Low pressure around 29.7 inches centered over Ohio and
West Virginia will wobble back westward at times through Monday,
maintaining northeasterly to northerly winds across Lake
Michigan, with occasional gustiness across the southern half
through the weekend. Occasional showers and patchy fog will also
be possible.

Sheppard

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory...LMZ645-LMZ646 until 7 PM Saturday.

&&

$$

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