NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 100018
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
718 PM CDT Thu Jul 9 2026

.KEY MESSAGES...

- Isolated showers and thunderstorms are expected through the
  evening with the passage of a weak cold front. Brief gusty
  winds and locally heavy rainfall are possible.

- Patchy dense fog possible tonight across all of southern
  Wisconsin, with the most widespread fog potential near Lake
  Michigan.

- Hot and muggy conditions return early next week.

&&

.UPDATE...
Issued 718 PM CDT Thu Jul 9 2026

The majority of storms have sunk south of the WI/IL border, but
a few storms may continue along the lake breeze boundary and in
a convergence zone draped across Columbia to Waukesha Counties.
These storms would have the main concerns of gusty winds and
locally heavy rainfall. After storms end tonight, expecting
light and variable to calm winds and falling temperatures with
remnant moisture at low levels to bring fog potential to all of
southern Wisconsin tonight. Some areas may become dense,
especially near Lake Michigan.

MH

&&

.SHORT TERM...
Issued 154 PM CDT Thu Jul 9 2026

This afternoon through Friday night:

Scattered showers and isolated thunderstorms are ongoing along
the weak cold front over central WI. The front will slowly move
swd and reach the IL border by 23-00Z, but slightly quicker for
the counties adjacent to Lake MI as the front accelerates down
the lake. Meanwhile a shortwave trough over nw IA will track
across far srn WI this evening. Thus expected scattered showers
and storms to slowly develop from north to south into the
evening, ending by late evening. MLCAPE around 1500 J/KG, DCAPE
over 1000 J/KG, and effective shear around 20 kts can support a
few strong storms. In addition, high 0-3 KM CAPE in combination
with sfc vorticity along the front will result in brief funnel
clouds with initial updrafts.

Nely winds and a slightly cooler and drier airmass can be
expected for Fri-Fri nt as a ridge of high pressure extends
south from Ontario into WI. Near normal temps and humidity is
forecast.

Gehring

&&

.LONG TERM...
Issued 154 PM CDT Thu Jul 9 2026

Weekend through Thursday:

A warming trend is expected as a large and strong upper ridge
first extends from the Desert SW into the nrn Great Plains this
weekend, then re-orients itself west to east from WY through
the Great Lakes early next week. Sfc ridging will remain over
srn WI and prevent high dewpoint air from advecting into the
region until Tue. High temps will warm through the 80s during
this time approaching 90F for well inland next week. Lake
breezes will develop each day so cooler near the lake. At this
time, maximum heat index values of lower to middle 90s are
forecast next week.

Gehring

&&

.AVIATION...
Issued 718 PM CDT Thu Jul 9 2026

VFR conditions are expected to prevail through the evening away
from Lake Michigan terminals. Near Lake Michigan, a layer of
marine low clouds between 800 and 1500 ft will move in this
evening. Fog around 2-3 SM visibility will develop late tonight
with some areas becoming dense (as low as 1/2 SM). Fog will burn
off after sunrise, with clouds rising to VFR by midday.
Expecting light northeasterly winds to develop Friday morning and
continue throughout the day into the overnight hours.

MH

&&

.MARINE...
Issued 154 PM CDT Thu Jul 9 2026

Light to modest north winds over the northern half of the lake
will slowly move south today, shifting winds in the southern half
of the lake from southerly to northerly. Some fog may develop at
times during this period, with patchy dense fog possible, as
relatively warm, moist air remains over the cooler lake waters.
Winds will remain north to northeast on Friday, as high pressure
around 30.0 inches builds into the the region from the north. The
high should shift southeast over the weekend, which should
continue to bring light to modest winds.

Gehring

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...None.
&&

$$

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