Seneca Cors, Wisconsin Weather Forecast Discussion

482
FXUS63 KGRB 292301
AFDGRB
Area Forecast Discussion
National Weather Service Green Bay WI
601 PM CDT Mon Sep 29 2025
Updated aviation portion for 00Z TAF issuance
.KEY MESSAGES...
- Areas of fog, locally dense, will impact the region tonight into
  early Tuesday morning. The fog may result in locally hazardous
  travel conditions for the early morning commute on Tuesday.
- Dry conditions prevail through at least Friday, with a chance
  of showers and isolated thunderstorms arriving Friday night into
  Saturday, and continuing at times through Monday.
- Above to much above normal temperatures anticipated through the
  next week.
&&
.DISCUSSION...
Issued at 243 PM CDT Mon Sep 29 2025
Mostly sunny skies covered the region this afternoon, with
temperatures ranging from the middle 70s near Lake Michigan to the
upper 70s and lower 80s elsewhere. The latest surface analysis
showed a Canadian cold front sagging south through northern
Minnesota and northern Lake Superior.
A weak back door cold front will drop south across the region
tonight, with greater potential for areas of fog and patchy dense
fog as a shallow cooler air mass arrives and winds become light
from the east to northeast overnight. The fog could pose localized
travel hazards for the Tuesday morning commute. Lows are expected
to drop into the upper 40s to middle 50s in most areas.
Canadian high pressure will ridge across the Great Lakes region
through the rest of the work week, and will be slow to shift east
due to the blocking influence of a couple tropical systems in the
western Atlantic. Tonight`s cold frontal passage will bring a
minor cooling trend mid-week, followed by much above normal
temperatures for the end of the work week and the weekend.
Dry conditions persist until Friday night or Saturday, when a
chance of showers and isolated thunderstorms arrive in conjunction
with a weakening cold front. Another more significant cold front
is expected to move through late Sunday night into Monday, so
periodic showers and isolated storms should continue into early
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 00Z TAF Issuance
Issued at 600 PM CDT Mon Sep 29 2025
High confidence in areas of IFR/LIFR conditions developing
overnight. A backdoor front will introduce a shallow, cool, and
moist airmass, creating favorable conditions for fog and low
stratus.
VFR conditions this evening will deteriorate after 06Z as fog
develops and spreads from east to west. Areas of IFR/LIFR
conditions in both visibility and ceilings are expected through
sunrise. Confidence of IFR/LIFR flight conditions is highest over
central and east-central WI (KGRB, KATW, KMTW, KAUW, KCWA) where
dewpoints have crept up into the upper 50s to lower 60s this
afternoon. Conditions will improve to VFR between 13Z and 14Z
Tuesday as fog dissipates. VFR is expected for the remainder of
the afternoon with light E/NE winds.
Outlook...
VFR conditions are expected to continue into Tuesday night.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....Kieckbusch
AVIATION.......MPC

NWS GRB Office Area Forecast Discussion