NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 202224 AAA
AFDMKX

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
524 PM CDT Wed May 20 2026

.KEY MESSAGES...

- A Beach Hazard Statement is in effect from this afternoon
  through early Thursday afternoon for a High Swim Risk at
  beaches in Milwaukee, Racine, and Kenosha Counties.

- Expect a gradual warming trend through the Memorial Day weekend.

- Rain chances return Friday afternoon and night (40-70%), with
  lower chances through the holiday weekend.

&&

.UPDATE...
Issued 524 PM CDT Wed May 20 2026

Mid and high level clouds will increase from west to east this
evening into tonight, especially across the northern half of the
forecast area. Otherwise, quiet weather is expected and the
forecast looks on track for the evening and overnight hours.

DDV

&&

.SHORT TERM...
Issued 126 PM CDT Wed May 20 2026

This afternoon through Thursday:

Diurnal cumulus clouds developed quickly this morning. The wind
direction became northeast to east quicker than previously
forecast (much earlier than any models suggested) due to the
cold lake accelerating the lake breeze.

Expect the clouds to gradually lift and thin out this afternoon
as drier air mixes in. Clearing near the lake is also expected
with the lake breeze pushing inland.

The surface high pressure will slide into the Upper Great Lakes
this afternoon and then sit over us through Thursday night.
Meanwhile, a mid level shortwave that is currently over
Nebraska will track through southern WI tonight through Thu
afternoon. Look for mid level clouds to spread into southern WI
overnight. Cannot rule out a few sprinkles during the day
Thursday during the time of the more robust portion of the
shortwave, but dry air will dominate below 10kft.

Easterly winds will continue this period, although the lakeshore
winds are expected to shift more northeast Thursday afternoon
after the passage of that shortwave. The persistent onshore
winds will allow for high waves to build along the lakeshore.
The Beach Hazards Statement for Milwaukee, Racine and Kenosha
counties start time was moved up to 3 PM this afternoon and
extended in time to Thursday at 1 PM.

Cronce

&&

.LONG TERM...
Issued 126 PM CDT Wed May 20 2026

Friday through Wednesday:

A broad low pressure trough setting up over the Plains and the
gradually departing Great Lakes high will allow for an
increasing pressure gradient over southern WI Friday. The
steady/higher onshore winds will create an uptick in the waves
once again, so another Beach Hazards Statement for a high swim
risk will be needed early Friday morning through Saturday
morning.

That broad upper trough will develop into two distinct surface
lows on Friday; one over SD/NE and one over IL/IN. Models have
been a little indecisive about these surface lows (due to the
uncertain nature of upper lows), but it is important to note
that the precip chances for southern WI Friday afternoon/night
will depend on the strength/track of the IL/IN low. We have
fairly high chances in the forecast right now (60-80%, highest
east). There is some concern that dry air in the low levels
could inhibit the more widespread precip from reaching the
ground.

That upper trough will push into northern WI by mid-late
Saturday morning which will end our precip chance. However,
there may be some lingering precip from an additional upper
trough that could track into southern WI during the day Sat, but
this would be light and short-lived.

Our forecast is currently mostly dry for Sunday & Monday, but
there are enough ripples in the upper level flow that there
could be a few light showers possible. The bottom line is that
Memorial Day weekend will not have any complete wash-outs for
those with outdoor plans, and there will be a warming trend to
the temperatures (reaching 80s by Monday for inland areas).
However, expect a lake breeze each afternoon.

Beyond Monday, it looks like southern WI could be getting into a
wetter pattern, but there are some indications that the moisture
would only return to MN and IA and not as far east as WI/IL.
Stay tuned. Temperatures look above normal.

Cronce

&&

.AVIATION...
Issued 524 PM CDT Wed May 20 2026

Mid and high level cloud will gradually increase this evening
into tonight, with mostly cloudy skies expected Thursday as an
area of warm air advection aloft moves through. Despite the
forcing from the warm air advection, dry weather is expected
tomorrow due to very dry conditions in the lowest 8-10 kft. Not
out of the question for a few sprinkles, but most locations will
likely remain dry. Northeast winds 5-10 knots through tonight
will become more easterly on Thursday, except for near Lake
Michigan where winds may remain from the northeast.

DDV

&&

.MARINE...
Issued 126 PM CDT Wed May 20 2026

Winds will becoming northeasterly for the whole lake by this
afternoon as high pressure builds into the Upper Great Lakes
region and then lingers into Thursday.

Gusty northeast winds will persist through midweek, especially
over the southern half of the lake, and with building waves
along the western lakeshore. High pressure continues to build to
as it lifts northeastward across Ontario and Quebec Friday
through the weekend with easterly winds continuing across Lake
Michigan. Expecting winds to increase during this timeframe due
to a broad low pressure trough setting up over the Plains.

A Small Craft Advisory is in effect south of the North Point
Light from this afternoon through early Thursday afternoon due
to high waves from persistent easterly winds. There should be a
6-8 hour lull in the 3-5ft waves Thursday afternoon/evening
before higher winds and therefore higher waves return Thu nt-Fri
nt. We will probably just issued one long S.C.Advy to account
for this.

Cronce

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ066-WIZ071-WIZ072 until 1 PM
     Thursday.

LM...Small Craft Advisory...LMZ644...10 PM Thursday to 10 PM Friday.

     Small Craft Advisory...LMZ645-LMZ646 until 10 PM Friday.

&&

$$

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