NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 310458
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1158 PM CDT Sat May 30 2026

.KEY MESSAGES...

- Mostly dry weather under high pressure expected through
  Wednesday. Fire weather concerns may increase early in the
  week. Cooler by Lake Michigan with a lake breeze each day.

- An unsettled weather pattern is expected for late next week.

&&

.SHORT TERM...
Issued 1157 PM CDT Sat May 30 2026

Rest of Tonight through Tuesday:

Light east winds overnight will transition to southeast by late
morning as high pressure sits over the Upper Great Lakes and
low pressure starts to develop in the Northern Plains. A broad
area/long line of thunderstorms that currently stretches from
eastern Montana to western Nebraska and central Kansas will
progress east-northeast overnight into Sunday morning along the
nose of the low level jet and a mid level shortwave trough.

There is a small chance (20%) that the outflow boundary from
this storm complex could fire off more storms in Iowa Sunday
afternoon that could make it into southwest WI Sunday night. In
addition, the upper level feature (weak vorticity advection) is
producing light rain/sprinkles over MN this evening and that
forcing is going to translate over WI Sun evening, so we may
need to increase precip chances. Overall the forcing for storms
is weak for WI, but with the daytime heating and a subtle
moisture return of dewpoints in the lower 50s, the envirnoment
could support some ongoing/decaying storms. If anything makes it
here, it would quickly diminish as it treks east through
southern WI due to the dry air and high pressure in control.

A similar scenario is possible for Monday. But also on Monday,
the upper low sitting over the northeast will swing a trough
into Michigan. This will push colder, lake-cooled air from east
to west across southern WI Monday morning (back door cold
front). This one does not look as strong as the one today
(Saturday), but we can still plan for a steady easterly wind and
cooler temperatures. Tuesday winds will be lighter but with
similar temperatures.

Cronce

&&

.LONG TERM...
Issued 1157 PM CDT Sat May 30 2026

Wednesday through Saturday:

The high will begin to shift eastward Wednesday, so inland temps
closer to 85 are expected, but there will still be a lake
breeze. With winds shifting to the southwest on Thursday, the
lake breeze will be much weaker/delayed, so highs will range
from the upper 80s inland to the upper 70s lakeshore.

The shifting weather pattern should allow for some much-needed
rain to return to southern WI late in the week. There is still
a lot of uncertainty here, so the extended forecast will
continue to feature general chances for storms (20 to 40%) for
the whole period. We will have to wait a few more days for
timing and rainfall amounts to become clearer.

The pattern is a little complicated and therefore uncertain in
the extended. A potent mid level shortwave trough will track
along the U.S./Canadian border Wed night and Thu (speed is very
different between models). Meanwhile, a weak shortwave is
expected to ripple from the southern Plains into the Upper
Midwest and help "feed" moisture into that US/Canada low and
bring a chance (20-40%) of rain to southern WI Thu nt. If there
are timing differences with the northern low and the southern
Plains shortwave, then the rain may not pan out for us or be
very light.

However, it looks like there will be another round of these
shortwaves colliding over the Upper Midwest again Friday night
into Saturday, and therefore another chance for rain. We are
going to be very warm and relatively humid (dewpoints in upper
50s) from Friday through Sunday. This will be conducive for
thunderstorms with any forcing we can get from shortwaves. While
this does not look like a really great setup for severe storms,
we will have to watch for the potential for a few at times.

Overall, we should see some rain between Fri and Sun but the
models seem to be producing too much QPF (precip) at this time.

Cronce

&&

.AVIATION...
Issued 1157 PM CDT Sat May 30 2026

VFR through the TAF period with high clouds overhead. Winds
will gradually decrease through the night and be lighter
tomorrow out of the southeast. Expect the lake breeze to
temporarily cause a brief uptick in the winds.

Cronce

&&

.MARINE...
Issued 1157 PM CDT Sat May 30 2026

High pressure over the Upper Great Lakes will strengthen to
around 30.2 inches overnight and continue to dominate the weather
pattern through Tuesday. Lighter winds are expected Sunday. Then
breezy easterly winds will return Monday into Monday night before
weakening for Tuesday. Winds are to become more southerly on
Wednesday as the high pressure breaks down and exits the region
while low pressure develops over the Plains. Look for increasing
southerly winds Thursday as low pressure of 29.7 inches crosses
the Northern Plains.

Cronce

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None
LM...None

&&

$$

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