Middle Inlet, Wisconsin Weather Forecast Discussion

272
FXUS63 KGRB 150347
AFDGRB
Area Forecast Discussion
National Weather Service Green Bay WI
1047 PM CDT Sun Sep 14 2025
Updated aviation portion for 06Z TAF issuance
.KEY MESSAGES...
- Areas of fog, locally dense, will impact travel late tonight
  into early Monday.
- Mainly dry through Tuesday, with a chance of showers and
  thunderstorms returning Wednesday and continuing into the
  upcoming weekend.
- Temperatures about 10 to 15 degrees above normal through mid-
  week, with a significant cool down expected late this week into
  the weekend.
&&
.DISCUSSION...
Issued at 413 PM CDT Sun Sep 14 2025
Fog Trends...Fog is expected to develop again tonight and linger
into Monday morning. Overall, the 12z models came in with lower
probabilities for widespread dense fog across the forecast area, but
continue to focus on far northeast WI with the greatest potential.
Based on forecast soundings, the decrease in coverage appears to be
caused by "too strong" of winds in the boundary layer. That being
said, anticipate far northeast WI will see dense fog develop, with
patchy dense fog likely occurring in other locations in eastern WI.
Central and north-central WI may see patchy fog, but it will less
likely be dense. Any fog will burn off a few hours after sunrise.
Precipitation Trends...A strong ridge of high pressure will keep dry
conditions in the forecast through at least Tuesday. As the ridge
sags/shifts eastward on Tuesday/Tuesday night, a shortwave to the
north will attempt to bring a boundary and a 15-35% chance of
showers and storms to the UP and northern WI sometime between
Wednesday and Thursday. Meanwhile, models indicate an upper-level
trough developing over the Northern/Central Plains during this time,
which looks to be the main driver for any precip potential late this
week and into the weekend. Until the evolution of this trough
becomes clearer, low chances for precip will remain in the forecast
through the weekend.
Temperatures...The ridge of high pressure will continue to usher in
above normal temperatures through midweek, with highs mainly in the
upper 70s to mid 80s. Despite the above normal temperatures, they
will be far from nearing any records. With the pattern change
expected later this week, temperatures will cool back down to near
or slightly below normal with highs in the mid 60s to low 70s.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1047 PM CDT Sun Sep 14 2025
VFR conditions will prevail late this evening, then attention
will turn to the low cloud and fog potential overnight into
Monday morning. Conditions not as favorable as last night for
widespread clouds/fog. Latest SREF/HREF probabilities have trended
down, now in the 40-60% for VSBY under a mile over far northeast
WI, with lower probabilities under 40% at the TAF sites. Keeping
some fog still seems warranted with the light winds and clear
skies, so will continue to include some MVFR fog at GRB/ATW. Will
keep a lower VSBY in a TEMPO group at RHI, where ground fog is a
little more likely. Will not include fog at AUW/CWA as
probabilities are lowest in this area, but can`t rule out a
little ground fog early Monday morning. Finally, some lake fog may
impact MTW. Will need to monitor fog trends and adjust as needed
through the night.
Any fog will burn off/lift by 13-14z Monday, with VFR conditions
expected the rest of the day. Winds will be light mainly out of
the southeast/east overnight, then increase to around 10 kts on
Monday. LLWS is possible overnight across north central WI as
winds at 1000 ft will be ~25 kts.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....Kruk
AVIATION.......Bersch

NWS GRB Office Area Forecast Discussion