Plainfield, Wisconsin Weather Forecast Discussion

025
FXUS63 KGRB 252324
AFDGRB
Area Forecast Discussion
National Weather Service Green Bay WI
624 PM CDT Thu Sep 25 2025
.KEY MESSAGES...
- Patchy dense fog late tonight into Friday morning. More fog
  possible Friday night into Saturday morning.
- An extended period of low-impact weather is forecast through
  next Thursday. Above average temperatures are expected during
  this time. Greatest chances (40-70%) of highs reaching 80 will
  be Saturday and Monday.
&&
.DISCUSSION...
Issued at 153 PM CDT Thu Sep 25 2025
Fog took a while to diminish, but skies have turned partly to mostly
sunny this afternoon. Sharp, yet moisture starved, cold front is
noted from northwest Ontario to northern MN. This front swings
across the western Great Lakes tonight into Friday morning.
Soundings point to shallow moisture increasing in the 900mb-800mb
layer with weak lift, so kept the sprinkles tonight over the
north. Patchy fog again late tonight, though a bit more wind with
the front moving through may limit the coverage. Best chances seem
to be from north-central to central WI, though per HREF
probabilities for sub 2 mile vsby, coverage and extent of very low
visibilities look lower than last night/this morning.
Once the front drops across the area, increasing moisture in
lowest 3kft and northeast winds will result in partly to mostly
cloudy skies through mid afternoon with the most clouds and even a
few sprinkles closer to the Bay of Green Bay and Lake Michigan.
Clouds begin to thin out by midday north, but elsewhere, it is not
looking as nice and sunny of a day as it did previously. High
temps will slip a few degrees from today, with readings in the mid
to upper 60s north and near the bay/lake, and into the lower 70s
over central WI. Another round of fog is possible Friday night
into Saturday morning based on model vsby, MOS guidance and an
overall favorable profile shown in forecast soundings.
Beyond Friday, the stretch of dry and seasonably warm weather is
expected to last through at least next Wednesday as areas of high
pressure passing across the Great Lakes keep rain chances at bay.
Small pops are showing up in the forecast beginning next Thursday,
but based on latest trends from recent guidance and ensembles,
chances of much rain may even hold off until Friday or Saturday.
Highs through the period will be in the mid to upper 70s most
days, with chances of reaching 80 degrees the highest on Saturday
(40-60% chance - greatest Fox Valley) and Monday (50-70% chance -
greatest central WI). Coolest nights will be Friday night and
Saturday Night over northern WI when readings drop into the lower
40s, though cooler readings in the upper 30s are possible, as we
saw this morning in isolated fashion. Pattern will continue to
favor late night/early morning fog, some nights with more
widespread lower vsby than others.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 624 PM CDT Thu Sep 25 2025
A boundary will slide south overnight with westerly winds
becoming northerly and eventually northeasterly into Friday.
Upstream observations and satellite imagery late this afternoon
show broken mainly mid/high clouds near and behind the boundary.
These will progress across the region overnight into Friday.
The HREF indicates the highest probabilities (>60%) for a period
of MVFR ceilings across parts of central WI into the Fox Valley
Friday morning, although the NBM shows somewhat lower
probabilities (~40%).
With the front dropping south and the RAP indicating flow
remaining around 20 kts around 1 kft overnight, confidence is
low for fog development at TAF sites overnight, but patchy fog
could not be ruled out, especially across central/north-central
WI sites early Friday. Limited visibility restrictions to MVFR
for KRHI, KAUW, and KWCA given current trends.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WI...None.
MARINE...None.
&&
$$
DISCUSSION...JLA
AVIATION...JM

NWS GRB Office Area Forecast Discussion