205
FXUS63 KMKX 202315
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
615 PM CDT Sun Sep 20 2026

.KEY MESSAGES...

- A prolonged period of high swim risk conditions continues
  into Tuesday at all Lake Michigan beaches, and may need to be
  extended into Wednesday evening.

- Dry weather and below normal temperatures are expected for
  much of the upcoming week.

&&

.UPDATE...
Issued 607 PM CDT Sun Sep 20 2026

A few isolated sprinkles linger across the area, but previous
forecast remains on track with lingering clouds and breezy
northeasterly winds.

Wagner

&&

.SHORT TERM...
Issued 1251 PM CDT Sun Sep 20 2026

This afternoon through Monday night:

Light rain will linger near the WI/IL border into early
afternoon, winding down by mid/late afternoon as a mid-level
trough exits to the east. Plenty of clouds will hang around the
remainder of the day into Monday between the departing system
and the next approaching shortwave from the southwest. Latest
guidance shows increasing mid and high level moisture as the
wave approaches and then moves through Monday into Monday night.
There is expected to be a lot of dry air in the lower levels
though, due to the influence of strong surface high pressure
centered near the Ontario/Quebec border. Could see a few
sprinkles from Madison westward, but otherwise dry weather is
expected tomorrow into tomorrow night. Temps tomorrow will be
several degrees below normal given the cooler airmass and
expected mostly cloudy skies.

DDV

&&

.LONG TERM...
Issued 1251 PM CDT Sun Sep 20 2026

Tuesday through Sunday:

Strong high pressure centered just north of the Great Lakes
will very gradually shift eastward Tuesday through the end of
the week. A cooler and much drier airmass is expected across
southern Wisconsin through at least mid-week under the
influence of the high and an upper level troughing pattern.
Below normal high and low temps are anticipated through mid-
week.

Upper level ridging will attempt to nose into the area from the
west later in the week and into the weekend, which should allow
temps to return to around normal. Surface high pressure will
linger across the Great Lakes into the weekend, which is
expected to largely keep conditons dry for southern Wisconsin.

DDV

&&

.AVIATION...
Issued 607 PM CDT Sun Sep 20 2026

Seeing some breaks in the clouds this evening resulting in MVFR
ceiling between 1.5-3kft toward the WI/IL border with more
broken VFR with swaths of MVFR ceilings toward I-94 corridor and
northward. Expect ceilings condition bouncing between VFR/MVFR
levels tonight with breezy northeasterly winds. Eventually
expecting gusts along the lakeshore to ease, but still looking
breezy behind the cold front overnight into Monday morning.
Otherwise, breezy northeasterly winds look to pick up and
persist for Monday. Some lower ceilings may linger along the
WI/IL border Monday morning, but ceilings are expected to lift
from north to south as high pressure builds down into the Great
Lakes region for the start of the week.

Wagner

&&

.MARINE...
Issued 1251 PM CDT Sun Sep 20 2026

Low pressure around 29.8 inches will move from central Illinois
into the Ohio Valley today into Monday. Meanwhile, high
pressure around 30.4 inches over western Ontario today will move
eastward through Monday, reaching Quebec by Monday night. The
high will then largely remain in place into mid-week, while
strengthening to around 30.7 inches. Gusty northeast winds are
expected today into tonight, becoming east and remaining gusty
Monday into Wednesday. A few gale force gusts may occur today
into Monday, mainly over southern portions of the lake. Building
waves are expected over western portions of the lake today into
the middle of the week. Lighter easterly winds should then
linger for Thursday into Friday, as the high pressure system
slowly moves farther east.

DDV

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ052-WIZ060-WIZ066-WIZ071-WIZ072
     until 7 PM Wednesday.

LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 7 PM
     Wednesday.

&&

$$

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