064
FXUS63 KMKX 210031 AAA
AFDMKX

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
731 PM CDT Mon Jul 20 2026

.KEY MESSAGES...

- Severe storms are possible this evening, as scattered storms
  develop along a cold front to the northwest and move east
  southeast into and through the area. All severe weather
  hazards are possible. However, it remains in question how
  much of the area may see this activity.

- There is a High Swim Risk for area beaches in Ozaukee and
  Sheboygan Counties into tonight. 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.

&&

.UPDATE...
Issued 731 PM CDT Mon Jul 20 2026

Still watching scattered convection developing along the cold
front from north central to west central Wisconsin early this
evening. This will be the area where any potential severe storms
moves comes from this evening, with an east southeast general
frontal motion and a more southeast storm motion if any
supercells can develop.

However, it remains in question how much of the area may see
this activity, as CAMs suggest that convection may remain more
scattered versus a solid line or broken line. The northern parts
of the area may have a better shot at seeing severe storms,
given current trends with the location of the storms. Will
continue to monitor trends into this evening.

There is 2500 to 3000 or greater J/kg of mean layer CAPE ahead
of the front into western portions of the area. There is 50 to
60 knots of 0 to 6 km bulk shear and 20 to 25 knots of 0 to 1 km
bulk shear over the area as well. Thus, there is plenty of
support for severe storms and potentially significant severe
storms including supercells and bowing segments. Stay weather
aware into this evening.

Will also keep the High Swim Risk and Beach Hazards Statement
going into tonight for Sheboygan and Ozaukee County beaches.
Waves of 3 to 4 feet should linger this evening, before
subsiding later tonight.

Wood

&&

.SHORT TERM...
Issued 1200 PM CDT Mon Jul 20 2026

Late Afternoon through Tuesday night:

The current expectation is for the WAA induced convection to push
out over the next hour or so allowing for a period of sun to
bring recovery of the environment to the area, with the recovery
northwest of the CWA already ongoing. This important due to
west central WI likely being the the general initiation location
for storms later this afternoon/early evening. A few models
point toward some more isolated storm initiation mid to late
afternoon but models have trended down on this likely due to the
impact of the morning convection and the likelihood that there
would not be enough recovery time behind the WAA related
convection this morning. However, models have trended in the
other direction for the convection potential into the evening.

While perhaps underselling the morning convection a tad, models
have generally caught on to the true trend in the morning
activity and thus we have been able to trust their output a bit
more. The conditions set up for the front associated with the
low pushing through the northern Great Lakes to be the initiator
of convection from eastern IA up to the UP of MI. In addition,
a strengthening LLJ into the evening will increase low level and
deep layer shear with models indicating an enlarged hodograph
with 200-300 m2/s2 0-3km SRH and 50-70kts of deep layer shear.
While uncertainty exists in the afternoon recovery, it looks
likely for NE IA, SE MN and west central WI, where initiation
is expected to occur, to have had much of the day to recover
with areas further southeast likely having reduced instability
but plenty of instability nonetheless. In the area of
initiation, dewpoint climbing to mid 70s with upwards of 5000
J/kg of SBCAPE is expected (4000 J/kg MLCAPE) with decreasing
instability further southeast but still plenty.

All hazards with this event are possible including strong
tornadoes, large hail and damaging winds. The way models portray
this event unfolding is suggestive of widespread initiation but
when that occurs usually there are just a few storms which
generally take over while others gets suffocated by the
stronger storms environment. If this plays out this way the area
of concern will shrink but there would be significantly
heightened concerns for those in the path of those stronger
storms.

Storms will likely clear out of the area just after midnight
with little to no weather concerns overnight as the front will
have pushed through. High pressure will however hold back a bit
into Tuesday as the low pressure system sticks around and may
even bring a backdoor cold front during the day Tuesday which
may yield some light showery activity. However by Tuesday night
the high pressure will start to build in from the west with
quieter conditions expected. However, the higher pressure may
start to usher back in some smoke to southern WI.

Kuroski

&&

.LONG TERM...
Issued 1200 PM CDT Mon Jul 20 2026

Wednesday through Monday:

High pressure will push over souther WI and northern IL for
Wednesday and stick over the area through at least Thursday
while gradually drifting east and gradually weakening through
Friday. There is at least some potential for convection Friday
and Saturday but this appears unlikely at this time given a bit
more activity aloft. However, chances increase late weekend and
early next week as lower pressure swings in. Uncertainty
increases for this period but looks to be the best chance for
precip and storms in the extended. Timing will determine any
storm concerns for this but too early to tell at this time.

Kuroski

&&

.AVIATION...
Issued 731 PM CDT Mon Jul 20 2026

Still watching scattered storms developing along the cold front
from north central to west central Wisconsin early this
evening. This will be the area where any potential severe storms
moves comes from this evening.

It remains in question how much of the area may see this
activity, as storms may remain more scattered versus a solid
line or broken line. The northern parts of the area may have a
better shot at seeing severe storms, given current trends with
the location of the storms. Will continue to monitor trends into
this evening. Any storms will bring locally reduced visibility
and ceilings, along with strong winds and large hail.

Gusty southwest winds are expected this evening, becoming west
later tonight and weakening somewhat, before veering northwest
and becoming gusty again Tuesday morning. These winds will
remain through the day, then veer north and weaken somewhat
again Tuesday evening. Given the winds into Tuesday morning,
will leave out mention of low level wind shear for now.

Should see ceilings clear out later tonight after the cold front
moves through, with scattered to broken clouds around 3500 to
4500 feet AGL developing with daytime heating on Tuesday.

Wood

&&

.MARINE...
Issued 731 PM CDT Mon Jul 20 2026

Low pressure tracking southeast through southern Ontario will
drag a cold front across the lake tonight. Gusty south to
southwest winds ahead of the front are expected, with a few gale
force gusts possible this evening over the northern half of the
lake.

Strong to severe thunderstorms will also be possible through
tonight across the entire lake. Winds will veer northwest behind
the cold front and remain gusty Tuesday morning. Winds then veer
due north later Tuesday into Tuesday night, with a few gusts to
gale force possible. Heading into Wednesday, winds are expected
to diminish, becoming light and variable by Wednesday night as
high pressure builds into the Great Lakes region.

Kuroski/Wood

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ052-WIZ060 until 7 AM Tuesday.

LM...Small Craft Advisory...LMZ643-LMZ644 until 7 AM Tuesday.

     Small Craft Advisory...LMZ645 until 1 AM Tuesday.

&&

$$

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