NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 200429
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1129 PM CDT Sun Jul 19 2026

.KEY MESSAGES...

- The Wisconsin DNR has issued an Air Quality Advisory for all
  of Wisconsin that remains in effect until Noon CDT Monday.
  Lingering wildfire smoke will lead to unhealthy air quality.

- Severe storms are possible late Monday afternoon through
  Monday evening. All severe hazards are possible, with an
  Enhanced (level 3 out of 5) threat level. There is some
  uncertainty regarding the placement and coverage of these
  storms.

- There is a High Swim Risk for area beaches in Ozaukee and
  Sheboygan County beaches Monday afternoon. Life threatening
  waves and currents are expected in High Swim Risk areas. Stay
  out of the water, and away from dangerous areas like piers,
  breakwalls and river outlets.

&&

.SHORT TERM...
Issued 1122 PM CDT Sun Jul 19 2026

Today through Monday:

Visibility has improved marginally this evening with much of the
area reporting visibility above 5 miles. Some of the thicker
wildfire smoke has moved inland and is currently northwest to
west of Madison and into North Central Wisconsin. As the night
goes on, wildfire smoke is anticipated to clear out and
conditions will improve, though some visibility restriction to 6
miles is expected through noon on Monday. With the wildfire
smoke lingering, an Air Quality Advisory stays in effect until
Noon Monday.

Gusty south winds will drive high waves and rip currents at
beaches in Ozaukee and Sheboygan Counties Monday Afternoon.
Swimming is not advised.

Attention then turns to the threat for severe
weather on Monday. Currently a cluster of thunderstorms is
ongoing over the North Dakota and South Dakota border region.
How this cluster of thunderstorms evolves through the overnight
hours will heavily determine where severe weather will set up on
Monday.

As the overnight hours progress, it is expected that this
cluster of thunderstorms will grow upscale and broaden as the
low level jet interacts with the complex over Minnesota. CAMs
then show this thunderstorm complex potentially riding SE along
the Mississippi River valley during the pre and post dawn hours
on Monday. While the complex is expected to weaken during the
morning, 1500 J/kg of MUCAPE may support some strength as it
clips southwest Wisconsin. Some small hail and gusty winds may
occur. This thunderstorm complex is likely to put out an outflow
boundary that will limit the eastern extent of the better
surface moisture and limit where better return flow will set up
during the day on Monday. This evening’s CAMs have somewhat
pulled back on the idea that there will be widespread supercells
over southern Wisconsin and they have favored a more western
solution where storms would clip the western half or
southwestern corner of our CWA. These storms would still likely
be supercellular, and capable of all hazards, owing to effective
shear that will be greater than 40 knots, steep lapse rates, and
low level curvature in the hodographs. The wave aloft is also
still potent with broad diffluence and strong speed aloft that
will promote storm strong lift. But, the severe weather threat
would be more contained to a limited area of our CWA.

Two other scenarios that could play out is that the stratiform
rain from whatever thunderstorm complex rolls through in the
morning would contribute to stability over the region which
would skunk severe weather potential late in the day. Yet
another scenario could be that this thunderstorm complex over
the Dakotas dies, Monday morning return flow is unabated, and we
see widespread supercells over southern Wisconsin. Radar trends
will be monitored through the night to see how this
thunderstorm complex plays out. HRRR and RRFS solutions favor
the scenario in the above paragraph. If this scenario were to
pan out, storms would get going as soon as 4:00 PM and then
linger into the evening hours before moving southeast of the
area ahead of an approaching cold front.


CMiller

&&

.LONG TERM...
Issued 1017 PM CDT Sun Jul 19 2026

Tuesday through Saturday:

Synopsis: Cool advection will begin in earnest in the low levels on
Tuesday as Monday evening's cold front continues into the Ohio River
Valley. Cold advection will be further augmented by a secondary
northerly wind shift/cold frontal feature during the afternoon
hours, which will act to draw an air mass from the Hudson Bay
vicinity into southern Wisconsin for the middle part of the week.
The passing secondary surface boundary could trigger a few pop-up
thunderstorms during the peak heating of the day on Tuesday, with
east-central and southeast Wisconsin being most favored for activity
at this time. High pressure will build from the northern Great
Plains into the western Great Lakes Wednesday through Thursday,
maintaing a cooler and drier weather pattern. The high will shift
east Friday into Saturday, allowing for southerly winds and steadily
climbing surface temperatures during the conclusion of the period.
Increasing humidity will eventually accompany the rising
temperatures, though its arrival will lag behind that of the warmer
air temperatures. Widespread muggy conditions will thus hold off
until Saturday night or the daytime hours Sunday.

Tuesday afternoon: Will be monitoring for a few pop-up thunderstorms
as a secondary wind shift/cold front pulls south through the area.
Development of activity will be contingent upon sufficient low level
moisture behind Monday's initial cold front, which as of this
forecast appears likely to be in place. East-central and southeast
Wisconsin are currently most favored for activity, given maximized
low level lift from the passing surface boundary and any afternoon
lake breeze. Severe weather potential is low in any thunderstorms,
though an isolated storm with stronger wind gusts can't be entirely
ruled out. Will continue to refine favored precip corridors and
hazards potential over coming forecasts.

Quigley

&&

.AVIATION...
Issued 1033 PM CDT Sun Jul 19 2026

Wildfire smoke has generally exhibited an improvement over the
eastern half of the CWA while visibility restrictions still
exist over the western part of the CWA, particularly northwest
of Madison. As the night goes on, visibility restrictions from
Smoke should improve though 5 to 6 statute miles of visibility
may linger in spots through the morning hours on Monday. Along
with the thicker smoke over the northwestern part of the CWA
some ceilings have also been seen ranging from 3000 to 4000
feet. These should also improve as wildfire smoke clears up
tonight.

As the night goes on, high clouds will spread in ahead
of approaching thunderstorms from Minnesota. These
thunderstorms should approach southwestern Wisconsin during the
post dawn hours tomorrow, generally exhibiting a weakening
trend as they head southeast. However, these storms still may
be strong enough to produce some small hail and gusty winds.
There will be a break during the late morning through the Mid
afternoon before additional thunderstorms may develop from the
late afternoon into the evening. Some strong to severe storms
are expected. Winds will be southwesterly after a period of
light and variable winds tonight. Southwest winds will be gusty
Monday afternoon. Gusts between 20 to 25 knots are anticipated.


CMiller

&&

.MARINE...
Issued 1126 PM CDT Sun Jul 19 2026

Wildfire smoke currently overspreads Lake Michigan, with areas of
denser smoke reducing visibility to around 1 nautical mile at
times. A Marine Dense Smoke Advisory is in effect across Lake
Michigan into early Monday morning.

High pressure will continue to exit southeastward tonight, with
low pressure tracking southeastward across Manitoba and Ontario
Canada into Monday. South to southwest winds build across the
lake tonight, becoming gusty into Monday. A few gusts to gale
force will be possible Monday afternoon and evening over the
northern half of the lake. Strong to severe thunderstorms will
also be possible Monday afternoon through Monday night across
the lake.

A cold front crosses the lake Monday night into Tuesday morning.
Winds veer northwest and become gusty again as it passes. Winds
veer due north later Tuesday into Tuesday night with gusts to
gale force possible.

CMiller

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ052-WIZ060...1 PM Monday to 7 AM
     Tuesday.

LM...Small Craft Advisory...LMZ643-LMZ644...1 PM Monday to 7 AM
     Tuesday.

     Small Craft Advisory...LMZ645...1 PM Monday to 1 AM Tuesday.

&&

$$

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