NWS-Milwaukee/Sullivan Forecast Discussion
FXUS63 KMKX 222258
AFDMKX
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
558 PM CDT Mon Jun 22 2026
.KEY MESSAGES...
- A High Swim Risk is in effect for Lake Michigan beaches in
Racine and Kenosha counties this afternoon and evening, with a
Moderate Swim Risk for Milwaukee county. Keep out of the
water and away from dangerous areas like piers and breakwalls!
- Chances for thunderstorms late Tuesday night through Wednesday
evening. A Marginal Risk for severe thunderstorms late Wed
afternoon and evening.
- Slightly below normal temps continue through Friday with a
strong warming trend early next week.
&&
.UPDATE...
Issued 558 PM CDT Mon Jun 22 2026
High pressure is slowly building in from the Northern Plains and
should be overhead of Wisconsin Tuesday. Diurnal cumulus clouds
will remain across inland areas until sunset then they should
dissipate. Fog will still be possible for areas north and west
of Madison tonight. Under the clear skies, light winds and moist
low levels it may be possible for some locally dense fog in
low lying areas (ie: river valleys and marshes). Widespread
dense fog is not currently expected. No major changes to the
forecast.
Patterson
&&
.SHORT TERM...
Issued 220 PM CDT Mon Jun 22 2026
Tonight through Thursday night:
A north to south sfc ridge will slowly move across srn WI tnt-
Tue AM, reaching Lake MI in the afternoon. Low level instability
will once again lead to sct-bkn cumulus clouds in the
afternoon. For early Tue AM, areas fog, locally dense may form
in the river valleys west of Madison.
For Tue nt, a well organized shortwave trough will track into
nrn MN and wrn Lake Superior from Canada with its sfc low moving
into nw WI. The warm front and associated swly low level jet of
25 kt will focus over srn and central WI. Fairly widespread
showers (60-80 percent) and isolated thunderstorms will reach
along and west of a line from Mineral Point to Madison to
Sheboygan by 12Z Wed. The warm, moist advection and associated
showers and isolated storms are expected to continue ewd on Wed.
The weak sfc low around 1010 mb may track as far south as
central WI then ewd across the lake Wed nt. A weak cold front
will pass Wed nt but the wind fields and sfc convergence remains
weak. Only isolated to scattered showers and storms are
expected to develop later in the afternoon and evening after the
warm frontal precipitation has exited. However, strong deep
layer shear of 45-50 kt is expected in conjunction with MLCAPE
of 1000-1500 J/KG. Thus there is a Marginal Risk for a severe
storm or two. On Thu, the main upper wave will finally exit the
nrn Great Lakes with 500 mb height rises over the region. The
srn portion of a sfc ridge will build into srn WI late in the
day and Thu nt. Another pleasant day in the 70s is forecast.
Gehring
&&
.LONG TERM...
Issued 220 PM CDT Mon Jun 22 2026
Friday through Monday:
A shortwave trough will approach from the west during the day on
Fri then move across WI and nrn IL Fri nt. There are 20-40
percent chances for showers and isolated storms with this upper
wave. Afterward, high amplitude ridging is expected over the
Great Lakes for the weekend into early next week. A gradual warm
frontal passage will bring 30-50 percent chances for showers and
storms with some uncertainty in the timing of the front.
Eventually, hot and humid conditions will take hold some time
early next week but with continued chances for showers and
storms, as srn WI may be on the west side of the ridge axis and
in the vicinity of an intermittent swly low level jet stream.
Gehring
&&
.AVIATION...
Issued 558 PM CDT Mon Jun 22 2026
Largely VFR conditions are expected through the period. Diurnal
cumulus clouds around 6 kft are expected to diminish/dissipate
near sunset this evening. Then skies will be mostly clear
through the rest of the night. For areas north and west of MSN
(Madison), there will be a chance for fog to develop tonight
into Tuesday morning. Fog could become dense in river valleys,
widespread dense fog is not expected. MVFR to IFR visibilities
will be possible for terminals in these areas (1-3 SM). For any
terminals in the Wisconsin or Baraboo River Valley, visibilities
could drop down to a 1/2 mile. Any fog that develop should burn
off short after sunrise. Diurnal cumulus is expected to develop
again Tuesday afternoon around 4-6kft.
North to northeast winds this evening will diminish tonight
becoming light and variable. The light and variable winds are
expected through Tuesday afternoon. With the light winds, a lake
breeze is expected to push inland and switch winds to easterly.
By Tuesday night, south to southwest winds will set up across
the state.
Patterson
&&
.MARINE...
Issued 220 PM CDT Mon Jun 22 2026
Modest northerly winds over the southern portion of the lake will
gradually become light tonight as high pressure approaches. A
surface ridge of 30.2 inches will then slowly move across Lake
Michigan for Tuesday afternoon and evening with light and variable
winds expected. By Wednesday, the high pressure will exit to the
southeast and low pressure around 29.9 inches will track from
northwest WI to across northern or central Lake Michigan
Wednesday night. As the low approaches, modest southerly winds
will develop on Wednesday, then shift west to northwest late
Wednesday night and Thursday after the low passes. The winds will
remain light the remainder of the week. A Small Craft Advisory
continues until 9 PM CDT south of North Point Lighthouse due to
3 to 5 foot waves.
Gehring
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ071-WIZ072 until 9 PM Monday.
LM...Small Craft Advisory...LMZ645-LMZ646 until 9 PM Monday.
&&
$$
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