826
FXUS63 KGRB 291742
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1242 PM CDT Thu Oct 29 2026

Forecast discussion for routine morning forecast issuance

.KEY MESSAGES...

- Spotty light rain (20-50% chances) for Halloween. Rainfall
  amounts less than 0.05 inch. Despite the rain, high temperatures
  will remain slightly above normal in the 50s.

- Low pressure brings widespread showers (60-80%) and gusty winds
  early next week, peaking on Election Day. At least 0.50 inch
  rain for most. Chances for rain lingers much of next week as
  the low slowly exits east.

- Above normal temperatures continue until late next week.

&&

.DISCUSSION...
Issued at 1241 PM CDT Thu Oct 29 2026

High pressure brings cooler temperatures through Friday. Fog risk
tonight looks low as some wind will keep low-levels mixed enough.
Could have a bit more patchy ground fog Saturday morning, though
increasing clouds from the south may restrict radiational cooling
needed for that.

Spotty light rain for Halloween...Deep trough set up over the
eastern Pacific sends a southern stream trough toward the western
Great Lakes on Saturday. Not much surface reflection as the
departing high holds. However, looking at soundings there is a
moist profile below 10kft with weak lift forecast, suggesting
that though chances of measurable rain (0.01") will be under 50%,
drizzle or very light trace amounts of rain may occur beneath a
mostly cloudy sky. Ensembles support this idea showing 30-60%
chance of seeing at least a trace of rain, greatest over central
Wisconsin. But, not looking at any kind of washout for outdoor
activities. Even with the clouds and some rain, high temperatures
will still reach the mid to upper 50s which even though cooler
than lately, will be above average.

Stronger system with widespread rain early next week...After some
dry weather returning Sunday into start of Monday, larger scale
troughing shifts across the plains and moves into the Great
Lakes-Ohio Valley. Surface low is well agreed upon from ensembles
from ECMWF, GFS, and Canadian to track across northern Ohio
Valley, placing Wisconsin in regime that will bring periods of
rain from late Monday through Wednesday as the system slowly
crosses. Peak of rain and gusty winds will be Tuesday, Election
Day, but unsettled weather will be slow to unwind the rest of the
week behind the departing low. Chances for exceeding 0.50 inch
rain Monday Night through Tuesday are up to 70%, while chances for
exceeding 1.00 inch are up to 40-60%. Higher end projections take
rainfall to 1.5 to 2.0 inches. Certainly looks like a soaking
rain at times. Dynamics may be strong enough for some embedded
thunder as the initial warm air advection rain arrives on Monday
night.

Temperatures will remain above normal the next week, though a bit
of a cooldown (temperatures returning to around normal) occurs
late next week after the low pressure system passes by. Available
long range guidance points to above normal temperatures through
most of November. Official forecast for meteorological winter (Dec
through Feb) also favors above normal temperatures which is right
in line with the ongoing very strong El Nino.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1241 PM CDT Thu Oct 29 2026

Skies will be mostly clear into tonight, except at RHI where SCT-
BKN MVFR stratocu will linger on edge of more widespread cloud
field. Late tonight through midday Friday, the stratocu will
diminish at RHI, but as this occurs a swath of SCT-BKN mid-level
altocu (100-120) will spread across all the TAF sites, along with
some cirrus.

WNW-NW winds will remain gusty (up to 23 kts) through 22z-24z.
Tonight into Friday will feature NW winds around 5 kts as high
pressure builds in from the northwest.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION.....JLA
AVIATION.......JLA

NWS GRB Office Area Forecast Discussion