Navarino, Wisconsin Weather Forecast Discussion

114
FXUS63 KGRB 270316
AFDGRB
Area Forecast Discussion
National Weather Service Green Bay WI
1016 PM CDT Fri Sep 26 2025
Updated aviation portion for 06Z TAF issuance
.KEY MESSAGES...
- An extended period of low-impact weather is forecast through
  next Friday. Above average temperatures are expected during this
  time, with the best chance of highs reaching or exceeding 80
  degrees occurring on Saturday and Monday.
- Patchy fog and low clouds expected late tonight into early
  Saturday.
- Patchy frost possible in north central WI late Saturday night
  into early Sunday.
&&
.DISCUSSION...
Issued at 318 PM CDT Fri Sep 26 2025
Low clouds associated with a weak cold front will continue to
erode over the southern part of the forecast area late this
afternoon, and most of the cloud cover should be gone by sunset.
There is potential for some fog development tonight. Model
visibility forecasts favor fog in our southwest counties, though
surface and boundary winds are lightest and most supportive of fog
in eastern WI. The western part of the forecast area (C/NC WI)
should be more prone to low stratus development, due to boundary
layer flow increasing to 15 to 25 knots overnight. Bottom line is
that patchy fog and low clouds are expected, but widespread dense
fog is not.
A cold front will move through the forecast area on Saturday,
accompanied by a narrow band of clouds, but no precipitation.
WAA and compressional heating ahead of the front will boost highs
into the 70s and lower 80s in most areas. Gusty SW-W winds will
also occur. High pressure builds into the region in the wake of
the front, with clear skies, light winds and a dry air mass
supportive of cool overnight temperatures Saturday night. Have
lowered the blended models Min temps into the middle 30s in parts
of north central WI, where patchy frost is possible overnight into
early Sunday.
Another cold front drops south across the region Monday night,
with Canadian high pressure ridging across the region through the
rest of the week. This will result in slightly cooler, but still
above normal temperatures mid-week, and continued dry conditions
through the end of the week. Winds will pick up a bit out of the
southeast Wednesday night into Thursday, leading to possible
marine concerns (Small Craft Advisories) on Lake Michigan,
especially south of Two Rivers.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1015 PM CDT Fri Sep 26 2025
Aviation forecast focus continues to revolve around the potential
for low ceilings and fog tonight. A band of low clouds, currently
situated between 2000-3500 ft over east-central WI, continues
linger late this evening, but have finally started erode over past
hour. These clouds lead to below normal confidence regarding fog
potential overnight.
THROUGH 12Z SATURDAY...
Predominantly VFR conditions are expected to prevail at the start
of the period for most terminals. However, as we head into the
07-09Z time frame, there is a potential for IFR visibilities and
LIFR ceilings to develop. Confidence is highest from MFI to Y50,
which is the corridor with most support from model guidance.
Confidence is lower over the central and east-central WI TAF
sites due to either increasing southwest winds late (AUW/CWA) or
pre-existing clouds (GRB, ATW, MTW). Stuck with continuity for
those terminals, as the forecast was already conservative to
begin with. MTW and CWA continue to have the greatest potential
for a brief period of LIFR flight conditions. SFC WNDS will be
light and variable initially, becoming SW at 3-5 KT overnight.
AFTER 12Z SATURDAY...
Any fog or low stratus is expected to burn off between 13Z and
15Z (8-10 am local time), with conditions improving to VFR across
all terminals. As a cold front moves through the region during
the afternoon, a period of SCT to BKN low clouds between 2500-4000
ft AGL is possible, which may result in brief MVFR cigs. SFC WNDS
will become W/NW at 10-15 KT with some gusts possible behind the
frontal passage. No significant aviation hazards are expected
during the afternoon. Most terminals will see SKC sky conditions
return by 21Z Sat thru 03z Sun.
OUTLOOK...
No significant weather events impacting aviation are anticipated
for Sunday.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....Kieckbusch
AVIATION.......MPC

NWS GRB Office Area Forecast Discussion