109
FXUS63 KMKX 120850
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
350 AM CDT Sun Oct 12 2025

.KEY MESSAGES...

- Low clouds will linger through the morning.

- Chance (20-30%) of light showers Overnight into Monday.

&&

.SHORT TERM...
Issued 350 AM CDT Sun Oct 12 2025

Today through Monday:

Low clouds are the main story for today. Widespread low clouds
are present over southeast Wisconsin and portions of south
central WI. The western edge is just west of Madison at this
time. The clouds were originally formed due to the cool air over
the relatively warm lake (lake effect). As winds shifted to the
southeast overnight, they pushed the low clouds inland. In
addition, warm air advection began just above the surface helped
to trap the moisture and low clouds beneath a dry layer in the
mid levels. We can expect increased mixing in the low levels
during the day, so the low clouds should become more scattered
and probably diminish this afternoon as drier air takes hold.

There is a chance of light rain tonight. A low pressure trough
(oriented north to south) approaching from the Northern Plains
will reach the western Wisconsin border around midnight and
slowly cross the state overnight through Monday afternoon. The
reason for the slow movement is that the parent low is way up in
Manitoba and will be occluding during this time. As a result,
the trailing cold front will be weakening as it crosses southern
WI.

The period when the synoptic forcing and moisture line up
at all levels will be brief for us, and it looks like it will be
between 2 AM and Noon Monday. The NAM is the most optimistic
for deep moisture, while most of the other models have some dry
air in the low levels to overcome or too much upper level dry
air. The meso model forecast reflectivity show a n-s band of
light rain tracking across southern WI from 1 AM to 8 AM. While
the precip will be light, I increased the chance for rain across
all of southern WI to the 20-30% range.

The frontal boundary and therefore the light rain chances may
linger over southern WI through Monday afternoon. Depending on
when the clouds clear, temperatures could reach the lower 70s
for inland areas. But if the clouds hang on through the
afternoon, then highs will only be in the upper 60s.

Cronce

&&

.LONG TERM...
Issued 350 AM CDT Sun Oct 12 2025

Monday night through Saturday:

500 mb cluster analysis shows a ridge axis lingering over the
region for most of next week, with continued positive anomalies.
High pressure at the surface should slide southeast into the
region Tuesday into Wednesday. There may be passing vorticity
maxima at 500 mb during this period that may bring some clouds and
showers, though the air column is fairly dry below the middle
levels on forecast soundings. Ensembles are not showing much in
the way of measurable precipitation either during this period, so
PoPs may need to be lowered in later forecasts. Temperatures look
to be near or a little above seasonal normal values.

Warm air advection later in the week may bring enough moisture
into the area to bring some chances (20 to 40 percent) for showers
and perhaps a few storms at times. Temperatures should trend
upward by Friday, with above normal temperatures lingering into
next weekend, supported by ensemble trends.

Wood

&&

.AVIATION...
Issued 350 AM CDT Sun Oct 12 2025

Low clouds with bases around 3000 feet spread from the
lakeshore into much of southern WI overnight. They should begin
to lift to 3500 ft and break apart after daybreak as southeast
winds increase and drier air mixes into the region. The low
clouds should clear this afternoon and higher clouds will make
their way into the region tonight.

Tonight, there is a chance (20-30%) of light rain showers along
a north- south oriented cold front that will march across
southern WI between 1 AM and 8 AM. Light rain shower chances may
linger in southeast WI into Monday afternoon. Cloud bases
associated with these showers should remain VFR, but any pockets
of steadier rain could bring ceilings down to 2000 ft at times.

Cronce

&&

.MARINE...
Issued 350 AM CDT Sun Oct 12 2025

High pressure over eastern Canada will remain in place today,
while a low pressure trough crosses North Dakota. Between these
systems, breezy southerly winds are expected over Lake Michigan
today through Monday afternoon. Winds will shift to the west
Monday afternoon behind the associated cold front. High pressure
will then move across the Upper Great Lakes region Tuesday
through Wednesday.

A Small Craft Advisory remains in effect for waves 4 to 6 feet
due to persistent onshore winds from mid morning through Monday
afternoon. A few wind gusts up to 25 kt will be possible today.
The southern Nearshore zone from Winthrop Harbor to Wind Point
remains without an Advisory, but we may need to add it for a
shorter period from late tonight into Monday due to the
orientation of the shoreline near Wind Point.

Cronce

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory...LMZ643-LMZ644...10 AM Sunday to 1 PM
     Monday.

&&

$$

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