796
FXUS63 KGRB 051941
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
241 PM CDT Sun Oct 5 2025

Forecast discussion for routine afternoon forecast issuance

.KEY MESSAGES...

- Gusty winds along with the very warm temperatures will keep
  increased fire weather potential in the area this afternoon.

- Rain chances return this evening through Monday night. Total
  rainfall mainly less than 0.50 inch. 20-40% chance of seeing up
  to 0.5 inch in parts of central WI.

- Turning much cooler early this week, with a frost or freeze for
  portions of central WI to northern WI Tuesday night.

- Conditions hazardous to small craft through Monday morning.

&&

.DISCUSSION...
Issued at 241 PM CDT Sun Oct 5 2025

Short Term...Tonight and Monday

Precipitation: Latest surface and satellite analysis shows the
cold front still stretched over Minnesota, with scattered shower
activity working its way across portions of western Wisconsin. As
we progress towards the evening, the front will continue its slow
movement into the region, with some scattered showers likely
(60-80%) across central and north-central Wisconsin by the late
evening. Rain then crosses the area overnight, with around 6-12
hours of on and off showers at any one location before the front
arrives in eastern Wisconsin near the Lake Michigan shoreline and
Fox Valley. This could leave a few of the most eastern areas still
dry by early Monday morning, but rain will follow up shortly
after. Any scattered shower activity is expected to continue in
portions of east-central Wisconsin through the day Monday before
tapering off during the evening. Thunder is not expected at this
time, as minimal instability is present to support any convection.
Rain amounts will therefore be relatively light at any given time,
but amounts approaching a quarter of an inch are possible (50-70%
chance) due to the longer period of on and off rain. A few areas
in central Wisconsin may see amounts closer to half an inch
(30-50% chance), but this will likely be more localized.

Elevated Fire Weather: Fire weather conditions remain a concern
for the afternoon, ahead of the rain. Relative humidity readings
in the afternoon around 35-40%, warm temperatures, and gusty winds
will keep the potential for power line fires in place.
Fortunately, fall fuels remain suboptimal for fire at this time,
which will help tamper the threat.

Boating Hazards: Small Craft Advisories are in effect into Monday
for Lake Michigan and the Bay of Green Bay due to gusty south
winds and high waves. On Lake Michigan, waves are expected to
build to 4 to 8 feet this evening. A Small Craft Advisory is in
effect for the Bay of Green Bay for gusty winds of 25 to 30 knots
and waves of 3 to 5 feet. Once winds shift towards the northwest
late in the day on Monday, boating conditions should improve.

Long Term...Monday Night Through Sunday

Behind the cold front from the short term forecast will come a
period of cooler weather for the middle of the week. The main
weather concern accompanying the colder temps will be the
potential for a widespread frost/freeze Tuesday night, and frost
again Wednesday night.

Temperatures...
Cooler air set to arrive behind the cold front from Monday will
bring in cooler temperatures for the region for much of the work
week. Expect highs to be in the 60s through Friday, with a slow
warm up in the works to bring highs back towards the lower 70s by
the weekend. Overnight temperatures will also be impacted, with
widespread frost likely for Tuesday night as low temperatures get
into the lower to middle 30s for much of central and north-central
WIsconsin. Areas closer to the Fox Valley and Lake Michigan
shoreline may yet stay in the upper 30s, keeping them frost free.
Additional frost is possible Wednesday night but will likely see
less areal coverage as temperatures begin slowly moderating once
again.

Precipitation...
A weak disturbance could bring another round of precipitation
through the region around the end of the work week, but
probability of significant precipitation remains low. Guidance
suggests less than a ten percent chance of exceeding a quarter of
an inch of rain.

The relatively extended period of dry weather could bring in some
fire weather concerns by the end of the week as fuels dry out
ahead of the next round of warmer weather next weekend.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1245 PM CDT Sun Oct 5 2025

Primary aviation concern for the period will be the passage of
cold front, which will bring a period of LLWS and rain to the
region into Monday.

Ahead of the front, VFR conditions will continue through the
afternoon, but winds will remain gusty at all locations. As the
cold front moves in during the evening, expect rain to cross from
west to east, impacting northern and central Wisconsin first
before heading east by around daybreak. This initial onset will be
accompanied by a period of LLWS up to around 30-40 knots. The rain
will still mostly retain VFR ceilings for the evening and
overnight, but could see ceilings fall to MVFR in the morning
hours as the rain moves off to the east. Kept thunder out of the
TAF at this time, as confidence was too low to make an inclusion
in the forecast.

&&

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

&&

$$

DISCUSSION.....Uhlmann/ - Default -
AVIATION.......Uhlmann