NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 021809
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
109 PM CDT Sun Aug 2 2026

.KEY MESSAGES...

- Breezy northeast winds will lead to high waves and dangerous
  currents at Lake Michigan beaches today into tonight. A Beach
  Hazards Statement is in effect through 1 AM CDT Monday
  morning for all Lake Michigan beaches. Stay out of the water!

- Next chances for thunderstorms Tuesday night through Wednesday
  night. A few periods of strong storms cannot be ruled out,
  but timing and impacts are not yet clear.

&&

.SHORT TERM...
Issued 110 PM CDT Sun Aug 2 2026

Rest of Today through Tuesday afternoon:

High Swim Risk conditions remain in place for Lake Michigan beaches
across all of southern Wisconsin today, finally improving late
tonight. A Beach Hazards Statement is in effect through 1 AM CDT
Monday. Stay out of the water and away from dangerous areas like
piers and breakwalls!

The northeast breeze continues across southern WI this afternoon,
remaining gusty along the Lake Michigan shoreline. High pressure
will continue to build into the region from the north, leading to a
gradual decrease in cloud cover this afternoon and decelerating
winds tonight. Clear skies and calm winds will make favorable
conditions for radiational cooling in the Baraboo and WI River
Valleys late tonight, likely leading to fog in these areas through
early Monday morning.

Skies should remain mostly clear Monday through Tuesday morning,
with dry weather through the period. Light and variable winds on
Monday should allow a weak lake breeze to form over eastern WI. As
high pressure shifts east towards the Ohio River Valley and Mid
Atlantic CONUS on Tuesday, winds turn southwest and accelerate,
spreading the warmth further east and boosting daytime highs into
the mid 80s. Clouds then begin to build into the region from NW to
SE Tuesday afternoon as a cold front approaches.

Sheppard

&&

.LONG TERM...
Issued 110 PM CDT Sun Aug 2 2026

Tuesday evening through Sunday:

Deep low pressure over Hudson Bay Canada will drag a SW to NE
oriented cold front into the Midwest on Tuesday. The front should
bisect WI by Tuesday afternoon, with ensemble output for CAPE south
of the boundary generally between 1,000 and 2,000 joules (locally
higher) and a downward trend of instability later in the evening
into the overnight hours. 500mb flow along the front should be out
of the WSW around 30kt, closer to the instability axis SW around
20kt, keeping the effective bulk shear under 35 kt. With the
frontal convection and shear generally arriving too late to tap
into the full compliment of the diurnal instability, no
organized severe weather threat is expected. 20-40% chances for
showers and weak thunderstorms reach the northwest half of the
CWA Tuesday evening, with more widespread 65-75% chances
holding off until late Tuesday night through Wednesday as the
right-entrance of an upper jet streak gives convection a boost.
Wind shear may increase to levels that permit strong to severe
storms (40-50 kt) Wednesday afternoon and evening, with some PVA
ahead of an approaching shortwave trough timed to arrive in the
evening. Despite the efforts of the shear and trigger
mechanism, the broad synoptic lift and overnight / morning
frontal convection could keep the skies mostly cloudy on
Wednesday and limit instability.

Precip chances (30-60%) continue into Wednesday night along the
frontal zone in southern WI. Post-dawn Thursday morning through
Friday is now looking mostly dry as high pressure builds into
the region. Deepening low pressure over the northern Great
Plains would then allow precip chances and slightly above normal
temperatures (perhaps highs in the mid 80s and modestly humid)
to return to our region for the weekend.

Sheppard

&&

.AVIATION...
Issued 110 PM CDT Sun Aug 2 2026

Lingering low stratus clouds over southeastern WI will
gradually break apart into diurnal cumulus clouds and lift to
around 3,500 ft this afternoon, clearing out this evening.
Continued dry weather and VFR conditions are then expected
through the TAF period and into Tuesday. The only exception
would be the potential for some inland fog to develop late
tonight through early Monday morning, mainly in river valleys
and low-lying marshy areas of southwestern WI.

Breezy north-northeast winds along the Lake MI shoreline will
gradually decelerate tonight. Light and variable winds expected for
inland areas on Monday, allowing a light easterly lake breeze to
develop over eastern WI.

Sheppard

&&

.MARINE...
Issued 110 PM CDT Sun Aug 2 2026

Breezy north winds and high waves are expected today and this
evening over central and southern Lake Michigan. This will occur as
low pressure around 29.7 inches near Ohio moves slowly into the
Lower Great Lakes and Mid Atlantic CONUS, while a ridge of high
pressure around 30.0 inches stretches from James Bay to Lake
Superior to the Upper Mississippi River Valley. Winds will
gradually diminish late tonight. High pressure around 30.0
inches then builds across Lake Michigan on Monday and slowly
moves toward the Lower Great Lakes Monday night. Winds remain
light and variable through this time. Next chances for
thunderstorms return Tuesday night through Wednesday night as a
weak front moves southward through the region.

Sheppard

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ052-WIZ060-WIZ066-WIZ071-WIZ072
     until 1 AM Monday.

LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 1 AM
     Monday.

&&

$$

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