NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 190559
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1259 AM CDT Sun Jul 19 2026

.KEY MESSAGES...

- The Wisconsin DNR has issued an Air Quality Advisory for all
  of Wisconsin into Monday morning, as wildfire smoke moves
  southward into the area tonight and lingers, contributing to
  lower visibilities and unhealthy air quality.

- High Swim Risk conditions are expected at southern Wisconsin
  beaches in Ozaukee County and southward tonight into early
  Sunday morning.

- Severe storms are possible mainly Monday afternoon and
  evening. All severe hazards are possible during this time.
  There is some uncertainty with a possible first round of
  storms may affect the airmass recovery for a potential second
  round.

&&

.SHORT TERM...
Issued 1239 AM CDT Sat Jul 18 2026

Current Overnight through Sunday:

Smoke continues to push inland over southern Wisconsin tonight.
The densest smoke is located northeast of a line from Kenosha
to Wisconsin Dells. As the overnight hours progress, the smoke
should push all the way west to the Mississippi River Valley and
maintain its density as it gets trapped in subsidence from a
high pressure center moving over the state. This will cause the
smoke to persist through Sunday until winds come around to South
and southwesterly as the high pressure center exits east
towards the lower Great Lakes region late Sunday afternoon into
Sunday night. In the meantime, expect visibility restrictions
and haziness from the smoke as well as unhealthy AQI over the
region. An air quality advisory is out until noon Monday.

Otherwise lows tonight will be in the upper 50s to low 60s with
highs in the low to mid 80s.

A Beach Hazard Statement continues for all lakeshore counties
except Sheboygan. Swimming is not advised at Lake Michigan
beaches until the hazard endsat 7am.

CMiller

&&

.LONG TERM...
Issued 1239 AM CDT Sat Jul 18 2026

Monday through Friday:

There remains a significant amount of uncertainty regarding the
severe weather threat for Monday as CAMs that are within range
show significant west to east spread regarding where
thunderstorms will track through Wisconsin and the upper
Mississippi River Valley region. However, one thing to note is
that there will be a strong aloft ridge over Iowa that will
effectively work to cap thunderstorm activity. CAMs have
repeatedly forecasted thunderstorms to run into ridges this
summer only for these storms to die or ride the ridge in
reality. Conceptual models suggest that these thunderstorms
should ride the edge of the ridge and track into southern
Wisconsin rather than diving south into Iowa and the cap as some
models forecast. The 00z HRRR captures this well, tracking
thunderstorms along the ridge's edge into southern Wisconsin.
To some extent the RRFS also has this as well. If these
solutions were to verify, storms would hold off until late
afternoon and evening and the potential for supercells/MCS would
occur. Hodographs look straight, which would favor hail. the
environmental kinematics show great venting and wind speed aloft
which would suggest that any MCS that rolls through would be
forward propagating and capable of high winds. QLCS tornadoes
also cant be ruled out, given that 0 to 3km shear will be
greater than 30 knots in magnitude. Still, some of the far
Western solutions cant be completely ruled out. If this
solution were to be verified, storms would propagate SE in
either Iowa or along the Mississippi River Valley, leaving much
of southern Wisconsin under stratiform rain Monday. This would
dampen a severe weather threat. Model trends will be watched
through Sunday for better agreement. Beyond, quiet weather
returns as a Canadian high pressure sinks south into the upper
Great Lakes region midweek. Temperatures also look cooler, with
highs on Tuesday in the low 80s, upper 70s on Wednesday, and
low 80s on Thursday. Conditions will remain dry during this
time. Slight chances for thunderstorms may return on Friday as a
warm front lifts NE over the region.

CMiller

&&

.AVIATION...
Issued 1239 AM CDT Sat Jul 18 2026

Smoke will linger and continue to spread West overnight.
Lakeshore locations will likely see anywhere from 2 to 4
statute miles of visibility overnight. Well inland locations may
be in the 3 to 5 statute mile range. While there will be some
high clouds overnight, the smoke will create MVFR to low VFR
ceilings over southern Wisconsin. These conditions should
continue through much of the day tomorrow, with some marginal
improvement Sunday afternoon due to daytime mixing. Winds will
be light and variable overnight. Becoming light in northeasterly
Sunday.

CMiller

&&

.MARINE...
Issued 1257 AM CDT Sat Jul 18 2026

Wildfire smoke has returned to Lake Michigan this evening and may
become dense once again. The smoke is expected to reduce
visibility to 1 nautical mile at times, and a Marine Dense Smoke
Advisory is in effect across Lake Michigan into early Monday
morning.

Gusty northwest winds have come around to north to northeast
and will quickly taper off over the next few hours, as high
pressure moves over the northern Great Lakes. Northeast to
light and variable winds are then expected Sunday into Sunday
night.

Gusty south to southwest winds may then develop Monday into
Monday night, with gusty west to northwest winds possible into
the middle of next week. A few southerly gales are possible
Monday afternoon and evening, with a few northwest gales possible
Tuesday night into Wednesday.CMiller

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ060-WIZ066-WIZ071-WIZ072 until 7
     AM Sunday.

LM...Small Craft Advisory...LMZ643 until 2 AM Sunday.

     Small Craft Advisory...LMZ644-LMZ645-LMZ646 until 7 AM Sunday.

&&

$$

Visit us at weather.gov/milwaukee

Follow us on Facebook, X, and YouTube at:
www.facebook.com/NWSMilwaukee
www.x.com/NWSMilwaukee
www.youtube.com/NWSMilwaukee