Sun Prairie, Wisconsin 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

979
FXUS63 KMKX 121456
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
956 AM CDT Thu Jun 12 2025

.KEY MESSAGES...

- An Air Quality Advisory is in effect through 3 PM CDT this
  afternoon from Fond du Lac, Dodge, Jefferson, and Rock
  Counties westward.

- Periodic shower and thunderstorm chances across central to
  southwestern Wisconsin through this afternoon.

- Additional chances for more scattered showers Friday and
  Saturday. There will be breaks/lulls in the rain.

&&

.UPDATE...
Issued 956 AM CDT Thu Jun 12 2025

Stationary front just south of the region keeps steady lift
across southern Wisconsin through today. Smoke through the
atmosphere this morning appears to be inhibiting thunderstorm
development for the time being, with the better chances moving
in this afternoon and evening across central to southwestern
Wisconsin. Smoke has also managed to work its way to the surface
inland from Lake Michigan, with the DNR issuing an Air Quality
Advisory from Fond du Lac, Dodge, Jefferson, and Rock Counties
westward through 3 PM CDT this afternoon. Smoke will clear out
as thunderstorms develop and the front sags farther southward.

MH

&&

.SHORT TERM...
Issued 347 AM CDT Thu Jun 12 2025

Today and Tonight:

While there has been a lull in thunderstorm activity this
morning across southern Wisconsin, rain continues to funnel in
from the west. Storms continue to develop and fire along 850mb
frontogenesis and WAA in northern Iowa and stream east along the
front. The sfc front is currently along the WI/IL border and
will stay stagnant across the state boundary through today.
CAPE, instability, and shear are all low to zero across southern
Wisconsin, which is quickly decaying all storms/showers that
move in.

Mid level WAA will again kick in to our west and push
the mid level front northward. As this boundary pivots north, so
to will the rain/storm potential. With the sfc front to our
south and a solid deck of clouds overhead, the southern
Wisconsin environment will struggle to recover and there is not
any triggers for convection expected to move through. This
means that any rain we get is coming from Iowa and Minnesota
(where there is better instability and lift). With the mid
level boundary moving northward its likely (60-80%) that
southern counties and eastern counties remain dry through today
and into Friday afternoon. Should we actualize that 20-40%
chance for isolated showers to develop across the area the main
driver will be diurnal heating and good moisture. Either way,
not anticipating any stronger storms.

Heading into Friday morning guidance is suggesting another push
of mid level WAA moving northeast across northern Iowa and into
southwest/west central Wisconsin during the early morning hours.
Should we get this wing of WAA, there will be a good chance for
showers and a few thunderstorms to develop along it and continue
northeast. Otherwise mostly dry weather is expected through much
of the day Friday as the sfc front will be to our south and the
mid level support (baroclinic zone) will be to our north.
Friday night into early Saturday morning an inverted trough is
expected to swing through the region providing a good force of
lift to trigger another round of showers and storms. There is
some uncertainty on track and how strong this inverted trough
will be so kept POPS around (20 to 35%). While we don`t have
great chances for rain the next couple days the chances are non
zero, so bring a jacket/umbrella if your out and about. When
thunder roars go indoors.

Patterson

&&

.LONG TERM...
Issued 347 AM CDT Thu Jun 12 2025

Saturday through Wednesday:

With the 850mb baroclinic zone sitting over central WI and then a
subtle surface trough dropping through southeast WI, there is
uncertainty about precip chances on Saturday. To add to that
uncertainty, a weak upper trough will still be lingering over the
IL and Ohio River Valley area. Southern WI may be in the warm
sector for a time on Saturday, and mid level lapse rates would be
steep enough to allow for some instability, but enough forcing
would be in question for isolated showers and thunderstorms. A
few showers could develop along the weak cold front dropping in
from the northeast Saturday afternoon, although the moisture
source and overall synoptic forcing will be minimal.

Surface high pressure will take hold Sunday and Monday so our
weather should be quiet. Temperatures will continue to be slightly
below normal Sunday, ranging from the upper 60s near the lake and
upper 70s well inland. Expect temps to be a notch warmer Monday as
the upper level ridge nudges closer.

The GFS tries to develop a storm complex over ND on the top of
that ridge and race it through MN and central/southern WI Monday
night. The ECMWF hints at this potential complex but diminishes it
by the time it gets here.

A shortwave trough or series of them is then expected to track
across the Northern Plains Tuesday into Wednesday. This could
bring a few rounds of showers and thunderstorms to southern WI,
but timing and intensity remain very uncertain.

Cronce

&&

.AVIATION...
Issued 956 AM CDT Thu Jun 12 2025

VFR conditions continue through today into tonight, with
potential for a shallow low-level cloud deck around 1000 ft to
develop late tonight into Friday morning and lifting by midday
Friday. Smoke will produce local reductions in visibility in
south-central to southwestern Wisconsin this afternoon, with 5
to 6 mile visibility expected at times at JVL and MSN.

Rain showers are expected to redevelop this afternoon across
southwestern to central Wisconsin, with isolated thunderstorms
within these showers. Thunder chances diminish after sunset,
with light showers potentially lingering near Lake Michigan.

Expect easterly winds throughout today, with gusts near 20 kt
at Lake Michigan terminals. Winds shift to become northeasterly
tonight, then easterly again on Friday. Gustiest conditions near
the Lake through Friday.


MH

&&

.MARINE...
Issued 347 AM CDT Thu Jun 12 2025

Low pressure in Ontario will continues east into the northern New
England States today as stationary front sits across the far
southern lake. This stationary front will remain over the far
southern portions of the lake through Saturday. Light to moderate
northeast to east winds are expected for areas north of this frontal
boundary. Areas south of the front can expect light southeast winds.
This afternoon into tonight northeast winds will again approach
Small Craft Advisory levels with gusts of 20 knots possible.
Rain and storms will be possible across mid lake this afternoon
and evening.

This front will drift southward and clear the lake early Saturday as
low pressure moves into the southern Great Lakes Region from the
Rockies. Light to north to northeast winds are expected across the
entire lake Saturday and Sunday once the front has cleared.
Additional chances for rain Friday and Saturday.

Patterson

&&

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

$$

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