Monticello, Wisconsin Weather Forecast Discussion

376
FXUS63 KMKX 060901
AFDMKX
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
401 AM CDT Mon Oct 6 2025
.KEY MESSAGES...
- On and off showers chances across southern WI today (20-80
  percent) along with a few isolated thunderstorms this
  afternoon, mainly for southeastern WI.
- Cooler, more seasonal and closer to normal temperatures
  return Tuesday into Thursday.
&&
.SHORT TERM...
Issued 357 AM CDT Mon Oct 6 2025
Today through Tuesday:
Slow moving cold front is beginning to push into the
northwestern portion of the CWA early this morning. However,
the shower activity along and ahead of it is weaken as there is
limited upper-level support to maintain it at this time. Thus
looking at scattered light showers for areas along and northwest
of HWY-151 through day break. Additionally given this weakening
trend in the morning shower activity, the lull in showers is
looking increasingly more likely through the morning hours and
current PoPs may be a bit too aggressive. This also would mean
central portions of the CWA may miss out on much of the
rainfall. However, the lack of morning activity would allow for
the environment to recover quicker and build up more
instability (500-750 J/KG of SBCAPE) this afternoon, thus
supporting better thunderstorm potential across south eastern
WI.
Still not expecting any stronger storms given how displaced the
line would be from the favorable upper-level dynamics, but
still cannot rule out a very localized potential given the
strong low- level/surface frontogenesis along with meager 0-3
km shear values around 30 kt. Again this potential is and
remains very low, but if a stronger storm did happen to develop,
gusty winds are likely the main concern given steeper low-level
lapse rates along with low- level shear vectors remain fairly
parallel with the frontal boundary. However, cannot rule out
the non-zero chance (given a few similarities to the Oct event
we saw a few years ago) to see a weak spin up within this broken
line of showers/storms, especially if there is a bulge within
the line if stronger/deeper storms develop and if the 0-3 kt
shear vectors turn more perpendicular to the front`s orientation
as some models such as the HRRR hint at briefly. Again mainly
expecting a broken line of showers and a few isolated rumbles of
thunder across southern WI this afternoon, but it is still
worth mentioning if all the aforementioned factors align, the
non-zero chance of a stronger storm or two to keep an eye out
for this afternoon.
Otherwise, the cold front will slide through the area by this
evening and cooler and drier airmass will works its way
southeastward this evening and overnight. Looking at more
seasonable temps tonight into Tuesday with lows in the mid 40s
to lower 50s and highs topping off in the 60s. Tuesday will be
drier with lighter winds as high pressure begins to build into
the Upper Midwest.
Wagner
&&
.LONG TERM...
Issued 357 AM CDT Mon Oct 6 2025
Tuesday night through Sunday:
Upper level ridging will take hold on the Northern Plains and
the exiting upper low will allow for surface high pressure to
sit over the Upper Great Lakes Tuesday night through Wednesday
night. This will allow for clear skies and calm/light winds, and
therefore cooler nights. As the high moves in from Upper
Michigan Tue nt, a cold front will drop through southern WI
(back door cold front). With 925mb temps dropping to 6 to 8C,
overnight lows will have a chance to drop into the upper 30s
inland from Lake Michigan. Highs Wednesday will be in the mid
60s which is around normal for this time of year. Wed nt will be
another cool night with lows around 40 inland.
Winds will become southerly on Thursday with return flow around
the high, and a warming trend will return. A shortwave trough
is expected to track across the Northern Plains and cross WI
Thursday evening. This may give us a brief round of showers.
Depending on the speed of that shortwave, the small chance of
showers could linger into Friday. Expect high pressure to
dominate the region for Saturday and give us a warm anD dry
weekend once again with high temperatures well above normal.
Cronce
&&
.AVIATION...
Issued 357 AM CDT Mon Oct 6 2025
Cold front will be pushing through southern WI today bringing
scattered off and on shower chances this morning and additional
chances along with a few rumbles of thunder this afternoon,
mainly for southeastern WI. With any shower activity expect to
see periods of lower ceilings and brief drops in visibility
resulting in MVFR flight conditions and locally lower IFR
conditions, especially if any taller/deeper storms develop.
Otherwise, will see lighter southerly winds turn more west then
north with the cold frontal passage through the afternoon
evening. High pressure and VFR conditions will build in across
southern WI overnight into Tuesday.
Wagner
&&
.MARINE...
Issued 357 AM CDT Mon Oct 6 2025
As low pressure tracks across Hudson Bay region through the
day, its associated cold front will make its way down across
Lake Michigan. Expect lighter south- southwesterly winds ahead
to turn northerly behind the cold front passage and exit
southern Lake Michigan by this evening. High pressure builds into
the Upper Midwest Tuesday and settles over the Great Lakes
Region through midweek resulting in lighter, varying winds.
Increasing southerly winds return for the end of the week as the
high pressure gradually slides further east.
Wagner
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...None.
&&
$$
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NWS MKX Office Area Forecast Discussion