Elm Grove, Wisconsin Weather Forecast Discussion

102
FXUS63 KMKX 170335
AFDMKX
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1035 PM CDT Tue Sep 16 2025
.KEY MESSAGES...
- Patchy fog will be possible overnight into Wednesday morning
  for low-lying river valleys and along the Kettle Moraine.
- Above normal temps for inland areas Wednesday with highs in
  the 80s.
- Rain chance trend continues to be later, but there remains a
  20-50 percent Friday and into the weekend.
&&
.UPDATE...
Issued 1015 PM CDT Tue Sep 16 2025
Patchy fog looks to be developing again across northwestern
portions of Lake Michigan where water temps are colder and
dewpoints highers. The overall pattern has not changed much over
the last couple of days so its possible that more fog will
develop and advect southward across the lake. Low lying areas
inland will also be at risk for some patchy fog to develop with
dewpoints in the low 60s to upper 50s. No major changes to the
forecast.
Patterson
&&
.SHORT TERM...
Issued 315 PM CDT Tue Sep 16 2025
Tonight through Wednesday night:
Quieter pattern continues tonight into Wednesday as southern WI
sits on the backside of the surface high meandering across
Quebec. Looking at overnight lows in the upper 50s to lower 60s.
Expect the calm winds overnight to pair with linger surface
moisture to once again bring a bout of patchy fog across the
area. Low- lying areas such as the Wisconsin River Valley and
low areas along the Kettle Moraine look to be the most
susceptible to seeing fog development overnight into Wednesday
morning. Again coverage looks patchy/spotty, but cannot rule out
isolated pockets of visibilities dipping below 1 mile at times
through daybreak.
Otherwise, Wednesday is not looking too dissimilar to today
other than slightly more winds and temps a few degrees warmer as
we sit under the upper-level ridge. 12z HREF as well as the
morning run of the NBM progs a greater than 70 percent chance
across much of southern WI (exception being along the immediate
Lakefront) to see daytime temps exceed 80F. While there is a
potential to see warmer temps up to and even exceeding 85F
Wednesday afternoon as seen with the over performing temps this
afternoon, the best potential (40-60 percent chance) exists for
areas along and northwest of HWY-151. Would not be out of the
realm of possibility to even see 90F for northwestern portion of
the CWA. By Wednesday night, expect to see more easterly winds
across the area as the mid-level trough across the Central
Plains creeps further eastward.
Wagner
&&
.LONG TERM...
Issued 315 PM CDT Tue Sep 16 2025
Thursday through Tuesday:
By Thursday we begin to see the upper-level ridge pattern begin
to break down as the Central Plains cutoff low/trough meanders
slowly eastward with a warm front extending into the region.
Meanwhile a low further north toward the Hudson Bay Region
associated cold front stretches southward across Upper Midwest
and will interaction with the the Central Plains system. These
combine frontal features look to result in cooler conditions
Thursday. Thus looking at not as warm of temps, but still in the
upper 70s to lower 80s highs on Thursday. Models have been
trending slower of the progression of this cutoff low/trough and
rain chances continue to delay the onset timing later into
Friday now as the system breaks down more as it works its way
into our neck of the woods. This looks to coincide with a
southward push of the frontal features along with a push of
colder airmass behind it with a surface high traversing across
Ontario.
This frontal feature does look to linger around the region
heading into the weekend and with a series of mid-level
shortwave troughs passage. Thus, will maintain lower end 20-40
percent chance of showers and a few rumbles of thunderstorm
through the weekend. Given the uncertainty of this pattern, it
does not look to be a complete washout for the weekend at this
time, but will need to be monitored. Otherwise, temps look
closer to normal this weekend with highs in the 70s and lows in
the 60s.
Wagner
&&
.AVIATION...
Issued 1015 PM CDT Tue Sep 16 2025
IFR to VFR conditions are expected through the period. Tonight
into Wednesday morning there is a potential for more patchy fog
to develop in low lying areas and along Lake Michigan. Any fog
coming off the lake is expected to mainly be across the northern
half of the lake from roughly Sheboygan (SBM) northward. For
both inland areas and marine fog visibilites are expected to be
around 1-4 SM. Any fog that does develop should burn off shortly
after sunrise.
Beyond this VFR conditions are expected through the period.
Mostly clear to partly cloudy skies are expected. The partly
cloudy skies will be mostly limited to western Wisconsin. Dry
conditions are expected. Light and variable winds will remain
through the period.
Patterson
&&
.MARINE...
Issued 315 PM CDT Tue Sep 16 2025
The back edge of the high pressure centered over Quebec will
meander around and just east of Lake Michigan through Wednesday.
Expect light southeasterly winds under this pattern as a low
pressure continues to slowly lift into the Hudson Bay region
through today. Given the warm pattern and lighter winds, cannot
rule out a few areas of fog each night through midweek. Winds
are then expected to increase a bit and shift more easterly for
the second half of the week as another area of low pressure
develops across the Central Plains. Will see a mix of east to
northeasterly winds later Thursday into Friday with a warm front
stretched across the lake as a the low pressure is progged to
lift northward into the Upper Midwest. Will see stronger winds
up to around 25 kt into the weekend and small craft conditions
may develop at times.
Wagner
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...None.
&&
$$
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NWS MKX Office Area Forecast Discussion