NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 120455
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1155 PM CDT Sat Apr 11 2026

.KEY MESSAGES...

- Warm and humid conditions are forecast Sunday and last through
  much of the new week. Intermittent showers and thunderstorms
  are expected during this period. Severe storms and heavy rain
  will be possible at times. Rivers are expected to rise with
  some flooding possible.

- Gale Watch for the north half of Lake Michigan late Sunday
  afternoon into early Monday morning. Areas of dense fog will
  be possible at times over the lake from Monday morning
  through the end of the week due to a relatively mild and moist
  airmass over the cold waters of Lake MI.


&&

.SHORT TERM...
Issued 1154 PM CDT Sat Apr 11 2026

Tonight through Monday night:

Low pressure around 994 mb over ern MT will track into ND tnt,
while a swly low level jet of 45-60 kt continues to shift ewd
across WI. The low to mid level warm, moist advection and
frontogenesis is supporting the showers and isold storms over
srn WI at this time with limited coverage toward the IL border.

The low pressure area will then track to the arrowhead of MN on
Sunday with its warm front quickly shifting nwd across srn WI
from 12-15Z Sunday. Some scattered showers and storms will
likely continue in the morning as the frontal passage occurs,
with perhaps greater coverage toward central WI as a weak
shortwave trough tracks through the region. Despite what may be
widespread cloud cover, temps should still reach around 70F
within the warm sector with dewpoints possibly reaching 60F.
Wind gusts of 30-35 mph are forecast.

A shortwave trough and its own sly 50 kt low level jet will then
approach from the srn Great Plains for the mid to late
afternoon and through the evening. Tall, skinny, surface based
CAPE around 500 J/KG will be present with rain chances around
60-90 percent east and south of MSN, lesser chances to the north
and west. The severe storm probability will remain very low,
but cannot completely rule out damaging winds via momentum
transfer if a stronger storm could develop.

The trailing cold front from the low over Ontario will then
stall over central WI on Monday with subtle shortwave ridging
aloft. Sly winds will continue to maintain a warm and humid
airmass with perhaps some breaks in the cloud cover in the
afternoon. Middle to upper 70s is forecast at this time. A weak
shortwave trough will then track from the central Great Plains
across central WI Mon nt. This will initiate a wave of low
pressure and the nose of a strong low level jet over said
region. The warm sector will be strongly capped but right along
and north of the front, convective initiation and severe
convection is likely. There are differences among the models on
the aforementioned features and its certainly possible srn WI
could see numerous storms, some severe, if a more southerly
solution occurs.

Gehring

&&

.LONG TERM...
Issued 1154 PM CDT Sat Apr 11 2026

Tuesday through Saturday:

A stationary front will reside in the vicinity of srn WI for
Tue-Wed with possible weak vorticity maximums aloft that could
set off new rounds of convection. A more organized shortwave
trough will then approach from the sw Wed nt and pass on Thu
providing more certainty for convection. Yet another stronger
upper trough and sfc trough will move out of the Great Plains
and into the wrn Great Lakes for Fri nt-Sat. In summary,
multiple rounds of showers and storms are forecast from Tue-Sat,
with a few inches or more of rain possible. River rises are
expected with some flooding possible. Some severe storms will
likely occur at times.

Gehring

&&

.AVIATION...
Issued 1154 PM CDT Sat Apr 11 2026

Areas of MVFR Cigs developing tnt from south central WI to
central WI as a warm front approaches from the south. Showers
are likely at times including isolated storms. The MVFR Cigs
will become more widespread Sunday afternoon when additional
showers and storms track into se WI from the south. LLWS
developing late this evening and lasting a few hours beyond
sunrise Sunday via a sly low level jet of 45 kt. Widespread Cigs
then falling below 1 kft Sunday evening. LLWS may redevelop over
far ern WI as well.

Gehring

&&

.MARINE...
Issued 1154 PM CDT Sat Apr 11 2026

Low pressure around 29.4 inches will track across the northern
Great Plains to northeast Minnesota from tonight into Sunday
evening, then develop toward Hudson Bay late Sunday night. This
will bring breezy south winds to all of Lake Michigan, but with
the potential for gales over the north half late Sunday afternoon
into early Monday morning. A Gale Watch is now in effect.

Winds will weaken later Monday morning as the low quickly moves
away and the trailing cold front stalls over northern Lake
Michigan. Then, passing low pressure systems along the stalled
front will lead to intermittent showers and thunderstorms through
the middle of the week. Areas of dense fog will likely occur at
times due to a relatively mild and humid airmass over the cold
waters.

Gehring

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 4 AM
     Monday.

     Gale Watch...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...5 PM
     Sunday to 3 AM Monday.

&&

$$

Visit us at weather.gov/milwaukee

Follow us on Facebook, X, and YouTube at:
www.facebook.com/NWSMilwaukee
www.x.com/NWSMilwaukee
www.youtube.com/NWSMilwaukee