Alvin, Wisconsin Weather Forecast Discussion

888
FXUS63 KGRB 290250
AFDGRB
Area Forecast Discussion
National Weather Service Green Bay WI
950 PM CDT Sun Sep 28 2025
Updated aviation portion for 06Z TAF issuance
.KEY MESSAGES...
- An extended period of dry and low-impact weather is forecast
  through the next week. Above to much above average temperatures
  are expected during this time frame.
&&
.DISCUSSION...
Issued at 239 PM CDT Sun Sep 28 2025
High pressure and a very dry air mass (PWAT of 0.42 inch on the
12z GRB RAOB) have resulted in sunny skies across the forecast
area this afternoon. The sunshine, combined with light south
winds, allowed temperatures to warm into the lower to middle 70s
at most locations.
With the very dry air mass in place, only expecting patchy ground
fog development late tonight into early Monday morning. Have
continued to side with the cooler guidance for low temperatures,
with readings ranging from the upper 30s/lower 40s in the cool
spots of north central WI, and 40s to lower 50s elsewhere. Another
mostly sunny day is anticipated on Monday, with southwest winds
boosting highs into the upper 70s to middle 80s. A weak cold front
drops south across the region Monday night, with greater
potential for patchy/areas of fog as a shallow cooler air mass
arrives and winds become light from the east to northeast.
Canadian high pressure will ridge across the Great Lakes region
through the rest of the week, and will be slow to shift east due
to the blocking influence of a couple tropical systems in the
western Atlantic. The frontal passage will bring a minor cooling
trend mid-week, followed by much above normal temperatures into
the early part of the weekend. Dry conditions persist through at
least Saturday or Saturday night, followed by a chance of showers
as a slow-moving cold front arrives for the late weekend and early
part of next 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 950 PM CDT Sun Sep 28 2025
No significant changes to the previous forecast. High confidence
in VFR conditions for all terminals (KGRB, KATW, KMTW, KAUW, KCWA,
KRHI) through the period. A dry airmass and high pressure will
result in clear skies and light winds.
The only potential for sub-VFR conditions is some patchy ground
fog toward sunrise Monday. The risk is very low for most sites,
but KRHI and perhaps KMTW have a slightly higher chance for a
brief period of IFR or MVFR visibility between 08Z and 12Z.
Otherwise, expect clear skies and calm winds overnight, becoming
E/NE at 5-10 KT on Monday afternoon.
OUTLOOK...
MVFR/IFR conditions possible late Monday night into Tuesday
morning due to fog/low stratus, but these conditions are after the
06Z TAF period.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....Kieckbusch
AVIATION.......MPC

NWS GRB Office Area Forecast Discussion