Markesan Wisconsin Weather Forecast Discussion

086
FXUS63 KMKX 070839
AFDMKX
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
339 AM CDT Tue Oct 7 2025
.KEY MESSAGES...
- Lingering showers through daybreak, but exiting between 7-9
  AM CDT this morning.
- Dry and cooler with a return to near normal/seasonal temps
  today through Thursday.
- Widespread frost development expected for areas along and
  northwest of HWY-151 overnight into early Wednesday morning,
  thus a Frost Advisory is in effect.
&&
.SHORT TERM...
Issued 336 AM CDT Tue Oct 7 2025
Today through Wednesday:
Showers continue early this morning along the 700mb
frontogenesis band, but expecting this activity to push out of
the area and over Lake Mich by 12-14z. Associated cloud cover
with this activity will follow a similar trend but may linger
and extra hour or two before fully clearing. Otherwise, expect
cooler and drier conditions through the afternoon as high
pressure begins to build down from the Canadian Plains into the
Upper Midwest. Temps this afternoon will be in the mid to upper
60s with a few locations cracking 70F not out of the question.
However, as high pressure slides further east into WI overnight,
clear skies and light winds will contribute to much cooler
temps. Looking at overnight lows dipping into will fall into the
40s along the lakeshore areas and mid to upper 30s for inland
areas. Coldest temps in the mid 30s look to occur in low lying
areas mainly along and northwest of HWY-151. Thus conditions are
primed for areas of frost to develop and have elected to issue
a Frost Advisory for Sauk, Columbia, Marquette, and Green Lake
counties late tonight into Wednesday morning. Other inland areas
surrounding the current advisory may still see some frost
development, but expecting coverage to be more patchy.
The center of the high pressure will be overhead of WI by
Wednesday, which will bring light and variable winds, along with
even cooler daytime temps in the lower 60s. Given the
subsidence from the high, expecting a dry forecast across
southern WI, but given north- northeasterly winds off of Lake
Michigan cannot rule out a few lake effect induced clouds and
maybe even a few stray sprinkles for far southeastern WI (mainly
lakeshore areas of Milwaukee, Racine, and Kenosha counties).
Wagner
&&
.LONG TERM...
Issued 336 AM CDT Tue Oct 7 2025
Wednesday night through Monday:
Temperatures will be cool again Wed night with high pressure
overhead, but not quite as low as tonight. For comparison, the
EC Ens has a prob of the min temp less than 40F at 90-100% in
Marquette County Tue night, and only 70-80% Wed night (only
around 30% near Wisconsin Dells). The GFS Ens has a similar
idea. There still may be patchy frost in areas toward central
WI, but confidence is lower.
Southerly winds will kick in Thursday morning as the surface high
moves off to the east and a weakening low pressure trough approaches
from the Northern Plains. Temperatures will gradually warm into the
mid 60s Thu and upper 60s Fri. Showers are possible along the front
as it crosses WI Thursday night or Friday morning. There may
actually be a trailing shortwave trough on Friday. Forecast precip
chances are low Thu- Fri due to the model variability and weaker
overall forcing.
A more amplified upper trough will approach from the Northern Plains
on Sunday. This could give us shower and thunderstorm chances Sunday
night into Monday. This will also bring in higher temps again. The
GFS ens has a 70 to 90% chance of exceeding a +10F temp anomaly on
Sunday (the ECMWF Ens has 40-60% chance).
Cronce
&&
.AVIATION...
Issued 336 AM CDT Tue Oct 7 2025
Scattered showers linger across southern WI early this morning
bringing MVFR along with a few pockets of IFR flight conditions for
southeastern terminals. Expect these lower ceilings and brief
drops in visibility associated with the showers to continue
through daybreak, but is expecting to push out over Lake
Michigan between 12- 14z. Otherwise, expect clearing skies and
light north-northwesterly winds through the afternoon ahead of
an approaching high pressure working its way down into the
Upper Midwest. VFR conditions will then prevail through the end
of the periods as high pressure moves overhead of WI by
Wednesday morning with more light and variable winds.
Wagner
&&
.MARINE...
Issued 336 AM CDT Tue Oct 7 2025
Breezy north to northwesterly winds across southern half of the Lake
this morning will gradually spread back north across the rest
of the open waters through the afternoon as high pressure begins
to build in from the Plains today. Looking at the center of the
high pressure to move across WI Wednesday and settle over the
Great Lakes Region through the second half of the week. Expect
increasing, southerly winds to return Friday and into the
weekend as the high pushes further east.
Wagner
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Frost Advisory...WIZ046-WIZ047-WIZ056-WIZ057...3 AM Wednesday
     to 9 AM Wednesday.
LM...None.
&&
$$
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

NWS MKX Office Area Forecast Discussion