028
FXUS63 KMKX 140429
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1129 PM CDT Sun Sep 13 2026

.KEY MESSAGES...

- Widespread showers and scattered thunderstorms are forecast
  Monday night into Tuesday morning. Locally heavy rain and
  urban and small stream flooding are possible.

- Gales are expected Monday night into Tuesday morning across
  the Lake Michigan open waters, as increasing southeast to
  south winds develop. A Gale Warning has been issued for the
  open waters of Lake Michigan, and for the nearshore zones
  north of North Point Lighthouse. A Small Craft Advisory is
  also in effect for late Monday afternoon into early evening,
  extending through the night south of North Point Lighthouse.

- A High Swim Risk is expected from the Sheboygan County beaches
  south to Kenosha County Beaches from late Monday afternoon
  into Tuesday morning. A Beach Hazards Statement is in effect.

&&

.SHORT TERM...
Issued 1129 PM CDT Sun Sep 13 2026

Overnight through Tuesday:

Skies have cleared out and high pressure will move over the
area overnight into early Monday morning. Light to calm winds
will allow for good radiational cooling conditions overnight.
This should bring chilly lows in the lower to middle 40s over
most of the area, with lows around 50 degrees close to the
lakeshore.

CAMs seem to continue to support some showers and a few storms
moving east northeast into south central Wisconsin by middle to
late afternoon into the early evening, perhaps into east
central Wisconsin by late afternoon or early evening. This is
with the focused warm air advection push and the leading edge of
the moisture advection with the low level jet. Will keep some
chances (20 to 40 percent) in the forecast for now. Highs Monday
should reach the lower 70s in most areas, as southeast winds
increase.

Still looks like later Monday evening into early Tuesday
morning should be the main period for showers and some storms,
as the low level jet veers over the area and low level
frontogenesis with the frontal boundary pushes southeast into
the area. Precipitable water values remain high, up to 2.00
inches, with possible training of this activity bringing locally
heavy rainfall potential. Urban and small stream flooding are
also possible given the setup.

This activity should gradually shift southward into northern
Illinois by late morning or early afternoon, as the low level
jet weakens and the low level frontogenesis shifts southward as
well. May see a period of low clouds for the rest of Tuesday
with humid conditions. Highs Tuesday are still forecast to reach
the middle to upper 70s, though may end up lower if the low
clouds linger through the rest of the day.

A High Swim Risk and Beach Hazards Statement remain in effect
from later Monday afternoon until midday Tuesday, as the
combination of gusty south southeast winds and building waves
brings hazardous conditions to area beaches. Stay out of the
water, and avoid dangerous areas like piers and break walls.

Wood

&&

.LONG TERM...
Issued 1129 PM CDT Sun Sep 13 2026

Tuesday night through Sunday:

Models and ensembles suggest high pressure should move east
across the Western Great Lakes region Tuesday night into
Wednesday. The northeast winds with the high may limit any
chances for showers across the area during this time. Ensemble
members are mostly still showing measurable rainfall, but they
may not be seeing this drier trend yet. For now, kept chances
for showers (30 to 70 percent) for mainly Wednesday, but these
may need to be cut back in later forecasts if this drier look
continues.

Some warm air advection tries to sneak back into the area
Wednesday night into Thursday, though it is not very strong and
may lack moisture if another high to the north shunts any
precipitation with this system further to the south. Ensemble
members continue to show measurable rainfall for this period,
but may not be catching onto this possible drier trend. For
now, kept the relatively high chances (50 to 80 percent) for
showers and a few storms for now. This may also need adjusting
downward in later forecasts.

A more organized low tracks through southern Wisconsin or
northern Illinois Saturday, with possibly another system for
later in the weekend. Ensemble members remain fairly wet with
measurable rainfall during this period, so will keep the 30 to
70 percent chances for now. Temperatures through the week and
into the weekend will depend on clouds and precipitaion trends,
so kept NBM values for now until better confidence can be found.

Wood

&&

.AVIATION...
Issued 1129 PM CDT Sun Sep 13 2026

Skies have cleared out and high pressure will move over the
area overnight into early Monday morning. Light to calm winds
are expected.

The high will gradually move east of the area Monday into Monday
evening, with southeast winds gradually increasing in strength.
Southeast gusts of 15 to 20 knots should occur Monday
afternoon, with south to southwest gusts of 20 to 25 knots
Monday night into Tuesday morning.

Middle to high clouds should move into the area Monday. There
may be a round of showers that moves into western and
northwestern parts of the area during the afternoon, though it
may be delayed until Monday evening.

Ceilings should gradually lower to around or below 1000 feet
AGL later Monday night into Tuesday morning, as the showers and
some thunderstorms move into the area.

May see some low level wind shear conditions develop Monday
evening into early Tuesday morning, with south to southwest
winds of 40 to 50 knots at 2000 feet AGL.

Wood

&&

.MARINE...
Issued 1129 PM CDT Sun Sep 13 2026

North winds will gradually ease overnight into Monday morning,
as high pressure around 30.3 inches moves across the lake.

Winds will then increase and veer to south southeast Monday
afternoon and night, becoming south into Tuesday, as low
pressure around 29.3 inches moves from southern Manitoba through
northern Ontario. Gales are expected Monday night into Tuesday
morning. A Gale Warning has been issued for Lake Michigan.

A Small Craft Advisory is in effect later Monday afternoon into
early evening for the nearshore waters of Lake Michigan, for
building waves and increasing south southeast winds. A Gale
Warning is in effect for the nearshore waters north of North
Point Lighthouse from middle Monday evening into early Tuesday
morning, as south southeast to south gales to 35 knots are
expected. The Small Craft Advisory continues south of there
until early Tuesday morning. Winds and waves may remain above
Small Craft Advisory levels through the rest of Tuesday morning.

Periods of showers and thunderstorms will accompany the
developing low from as early as Monday evening into Tuesday.

Winds will trend north to northeast Tuesday night into
Wednesday, as high pressure around 30.3 inches moves into the
region. North to northeast winds may linger into the rest of the
week, as the high slowly moves to the east of the region.

Wood

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ052-WIZ060...4 PM Monday to 1 PM
     Tuesday.

     Beach Hazards Statement...WIZ066-WIZ071-WIZ072...4 PM Monday
     to 7 AM Tuesday.

LM...Gale Warning...LMZ080-LMZ366-LMZ565-LMZ567-LMZ643-LMZ644-
     LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-
     LMZ872-LMZ874-LMZ876-LMZ878...9 PM Monday to 7 AM Tuesday.

     Gale Warning...LMZ261-LMZ362-LMZ364-LMZ563...9 PM Monday to 1
     PM Tuesday.

     Small Craft Advisory...LMZ643-LMZ644...4 PM Monday to 9 PM
     Monday.

     Small Craft Advisory...LMZ645-LMZ646...4 PM Monday to 7 AM
     Tuesday.

&&

$$

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