Mosinee, Wisconsin Weather Forecast Discussion

709
FXUS63 KGRB 061204
AFDGRB
Area Forecast Discussion
National Weather Service Green Bay WI
704 AM CDT Sat Sep 6 2025
Updated aviation portion for 12Z TAF issuance
.KEY MESSAGES...
- Rain ending early this morning. Isolated to scattered showers
  this afternoon and evening.
- Near-record cold maximum temperatures are possible today. Frost
  potential Monday morning. Temperatures warming next week, but
  remaining below normal.
- Chances for rain and a few storms Monday night into Tuesday
  night.
&&
.DISCUSSION...
Issued at 415 AM CDT Sat Sep 6 2025
Precipitation Trends...What started out as a small area of rain
associated with mid-level f-gen from a passing shortwave overnight,
has expanded into a widespread area of rain over the forecast area
early this morning. This area of rain will continue to track east
with the shortwave this morning, exiting eastern WI around 8 AM.
Based on trends and observations, locations could see up to a third
of an inch with this area of rain.
After a break in the rain activity this morning, another mid-level
shortwave looks to bring isolated to scattered shower activity this
afternoon into this evening due to the added support of daytime
heating. While the potential is very low, cannot rule out a rumble
of thunder at times within these showers given a couple hundred J/kg
of CAPE and steeper mid-level lapse rates arriving in the late
afternoon/evening, but severe weather is not expected. The shower
activity will decrease into the evening with the loss of daytime
heating, but may linger in far northern WI overnight due to
continued cyclonic flow.
Surface high pressure will gradually build into the area on Sunday,
bringing an end to the shower activity. The high will depart Sunday
night and bring return flow with warmer, moist air into the Upper
Mississippi Valley on Monday. By Monday night, a shortwave will
slide into the Upper Mississippi Valley and combine with the return
flow/moist air and bring the next chance for showers and potentially
thunderstorms to the region through midweek. A ridge of high
pressure will then build into the region for the remainder of the
week, keeping conditions dry.
Temperatures/Frost Potential...The abnormally cold airmass will
remain over the area this weekend, resulting in well below normal
temperatures. Several sites over the past 2 days have set new record
low maxes, with the potential to do so again today (Saturday). See
the climate section for more details about records. The addition of
the surface high moving over the area Sunday into Monday, may allow
frost to develop in portions of the forecast area Sunday night into
Monday morning with forecast lows in the mid 30s to low 40s. The
potential for frost late tonight into Sunday morning has decreased
due to the potential for clouds and/or enough wind in the boundary
layer to prevent decoupling. The return flow early next week will
allow temperatures to rise into the 60s and low 70s, but remain
below normal.
&&
.AVIATION...for 12Z TAF Issuance
Issued at 703 AM CDT Sat Sep 6 2025
Lingering SCT to BKN VFR clouds will be ending this morning
followed by a brief period of clearing. Clouds will increase late
this morning into early this afternoon with diurnally driven
isolated to scattered rain showers developing this afternoon into
this evening. VFR conditions are expected with these showers.
Given the isolated to scattered nature of the showers, it is too
difficult to determine the exact timing/location. Decided to
include a PROB30 group of -SHRA with the best window at each TAF
site. Anticipate later shifts will make amendments or include
TEMPO groups as necessary. The shower activity will end by late
this evening with some clearing expected.
&&
.CLIMATE...
Issued at 415 AM CDT Sat Sep 6 2025
The unseasonably cold airmass will bring one more opportunity for
potentially setting a new record low maximum temperature for today
(9/6). Here is a look at the current records and forecast values
for Green Bay, Rhinelander, and Wausau.
Green Bay
Date           Record Low Max       Forecast High
----           --------------       -------------
9/6              58F(1965)               60F
Rhinelander
Date           Record Low Max       Forecast High
----           --------------       -------------
9/6              55F(1956)               56F
Wausau
Date           Record Low Max       Forecast High
----           --------------       -------------
9/6              56F(1965)               57F.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....Kruk
AVIATION.......Kruk
CLIMATE........Kruk/Bersch

NWS GRB Office Area Forecast Discussion