Sun Prairie, Wisconsin 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

993
FXUS63 KMKX 250110 AAA
AFDMKX

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
810 PM CDT Sun May 24 2026

.KEY MESSAGES...

- A Dense Fog Advisory is in effect for the nearshore waters
  north of North Point Lighthouse and all of the open waters
  until middle morning on Memorial Day. Patchy dense fog may
  occur close to the Lake Michigan shore.

- Mostly dry this week, with the only precipitation coming with
  a small chance (around 20 percent) later tonight into Monday
  morning (mainly further west) and a chance (25 to 35 percent)
  on Wednesday.

- Warm temperatures in the 80s are expected for Memorial Day
  into Wednesday. Highs in the upper 80s are forecast on Tuesday.

&&

.UPDATE...
Issued 810 PM CDT Sun May 24 2026

Patchy dense fog may occur close to the Lake Michigan shore
tonight into middle morning on Memorial Day, if it moves onshore
from the lake. See Marine section for more information on the
Dense Fog Advisory over Lake Michigan.

There are mainly small chances (20 to 30 percent) for some
showers and a few storms to move into western portions of the
area overnight into Monday morning. The main area of warm air
advection and the low level jet axis should remain far enough to
the west to keep most of this activity there. CAMs seem to
generally support this, but some do have some weakening showers
moving into the far western areas later tonight or early Monday
morning.

Otherwise, mostly clear skies tonight should give way to some
middle level clouds overnight into Memorial Day. There may be
diurnal cumulus clouds as well in the afternoon hours on
Memorial Day. Light southeast to south winds tonight should
become southwest on Memorial Day, with a southeast lake breeze
for areas near the lake in the afternoon. Highs should reach the
middle 80s Monday for most of the area, turning cooler near the
lake.

Wood

&&

.SHORT TERM...
Issued 140 PM CDT Sun May 24 2026

Tonight through Tuesday night:

Some moisture aloft with some shortwave energy as well as a
strengthening LLJ will trigger some showers and storms to the
northwest of the CWA tonight, toward central MN. These will
gradually track east overnight into Monday morning. CAMs
indicate that some of the showers/weak storms will enter the
western CWA. However, as this pushes east is will impinge on
drier air for much of the column with decreasing forcing,
particularly from the LLJ. Thus it appears as though any linger
precip to the west will quickly dissipate as it pushes into a
much drier air mass to the east. Perhaps some showers and even a
rumble of thunder in the western CWA but will likely dissipate
by around Madison. This will leave a very quiet rest of the day
Monday with highs climbing to the 80s for much of southern WI.

Monday night we will start to move into an upper level ridge
setup which will bring us very warm temperatures for Tuesday
with modest southwest flow on the backside of a surface high.
There will likely be some precip in the midwest region,
primarily focused along a warm front to he north. If we see any
precip it would most likely during the evening and night
timeframe for both Monday night and Tuesday night as a result
of some better low level moisture in these timeframes. The
better chance of the 2 will be Tuesday night as a developing
high over the UP may shunt the warm front a tad south enough to
potentially bring it into play for the northern parts of the
CWA. Chances continue to remain limited for this timeframe
regardless but a slight uptick for Tuesday night. The upper
levels will definitely suggest drier conditions and thus
anything Tuesday night would be very front and low level
moisture dependent.

Kuroski

&&

.LONG TERM...
Issued 140 PM CDT Sun May 24 2026

Wednesday through Sunday:

Into the day Wednesday if we see the front has been pushed south
enough it may very well introduce precip chances across southern
WI with the developing high to the north. It should be mentioned
that conditions aloft remain unfavorable given the upper ridge
overhead however, even the low level moisture environment is not
great. I remain skeptical of what large scale models are showing
for Wednesday as this is a very dry general environmental signal
with very limited forcing mechanisms as well. But Wednesday
definitely remains the best chances for the week for precip and
storms.

Thursday and Friday remain in the same underlying pattern with
large scale ridging overhead and stronger surface high pressure
overhead which will keep things dry for both days. Into the
weekend conditions may remain dry but uncertainty will increase
as the ridge moves to the east and breaks down. Currently models
suggest high pressure to the north may remain in place keeping
the region dry but given the increased messiness of forcing in
the upper levels it makes for uncertainty as if the high breaks
down then precip may become much more likely. Thus the weekend
while currently trending drier has some concern for precip
chances given upper level trends.

Kuroski

&&

.AVIATION...
Issued 810 PM CDT Sun May 24 2026

Patchy dense fog may occur close to the Lake Michigan shore
tonight into middle morning on Memorial Day, if it moves onshore
from the lake. Kept any mention of fog out of the terminals near
Lake Michigan for now, but there could be a period of 2 to 5
mile visibility that occurs at times.

There are mainly small chances (20 to 30 percent) for some
showers and a few storms to move into western portions of the
area overnight into Monday morning.

Otherwise, mostly clear skies tonight should give way to some
middle level clouds overnight into Memorial Day. There may be
diurnal cumulus clouds as well in the afternoon hours on
Memorial Day.

Light southeast to south winds tonight should become southwest
on Memorial Day, with a southeast lake breeze for terminals near
the lake in the afternoon.

Wood

&&

.MARINE...
Issued 810 PM CDT Sun May 24 2026

High pressure around 30.2 inches developing over the lake
tonight will bring modest south the southwest winds. As the high
develops, dense fog will continue to spread across the lake. A
Dense Fog Advisory is in effect tonight into middle morning on
Memorial Day for all of the open waters of Lake Michigan, as
well as the nearshore waters north of North Point Lighthouse.
Patchy dense fog may occur south of there.

The high pressure system will push to the east on Memorial Day,
but will keep precipitation mostly away from the lake. There may
be small chances for showers or a storm over the northern part of
the lake later in the day into Monday night, with a warm front in
the vicinity.

Some chances for showers and storms are forecast later Tuesday
into Wednesday, as the front sags back south as a cold front. High
pressure around 30.3 inches is expected to build toward eastern
Hudson Bay Tuesday into Wednesday, which may help push the cold
front southward across the region.

Kuroski/Wood

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Dense Fog Advisory...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-
     LMZ565-LMZ567-LMZ643-LMZ644-LMZ669-LMZ671-LMZ673-LMZ675-
     LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878
     until 10 AM Monday.

&&

$$

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