Forecast Discussion for GRB NWS Office
148
FXUS63 KGRB 130552
AFDGRB
Area Forecast Discussion
National Weather Service Green Bay WI
1252 AM CDT Tue Oct 13 2026
Updated aviation portion for 06Z TAF issuance
.KEY MESSAGES...
- Chance for widespread soaking precip arrives late this week,
though there is still some uncertainty regarding amounts and
timing.
- Temperatures will cool through the week, bottoming out on Friday
then slowly warming this weekend into early next week.
&&
.DISCUSSION...
Issued at 1145 PM CDT Mon Oct 12 2026
Showers and embedded thunderstorms will exit the region early
Tuesday morning as a low pressure system lifts northeast through
the western Great Lakes. Behind this departing low temperatures
will be a lot cooler Tuesday; ranging from around 60 across the
north to around 70 across east-central Wisconsin. Although the
weather is mainly expected to be dry until the next system arrives
later in the week, a weak mid level shortwave will bring a slight
chance (10-20%) for light showers Tuesday night.
A larger phasing system is expected towards the end of the week
as southern and northern streams merge. Phasing systems generally
have much uncertainty in terms of timing but some general
agreement has come into alignment with the most recent forecast
cycles. Rain will start sometime in the late morning to afternoon
hours on Thursday then cross the region into the overnight hours.
How long the system remains around on Friday remains uncertain
and will depend largely on whether the phasing occurs overhead or
to our east. After some possible showers Friday morning, things
look to dry out at least by Friday afternoon. Recent model runs have
backed off a bit on the snowflakes as the system winds down. This
system will also bring a period of windy conditions for Friday,
especially across the Door Peninsula.
Behind this departing low a large area of high pressure will build
back into the region, which will bring dry weather for the weekend
into early next week. The high will also allow temperatures to
slowly warm through early next week, as highs recover back into
the 60s.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1244 AM CDT Tue Oct 13 2026
Isolated showers and storms will exit far northeast WI by 08z.
Otherwise, variable conditions persisted across the area, with
VFR conditions across portions of central and east-central WI
with IFR conditions across the north and along the bay and
Lake Michigan. Where conditions are in the VFR category now
should fall into the MVFR/IFR conditions overnight as low
pressure and an associated cold front moves across the region.
CIGS will gradually rise Tuesday morning with conditions rising
into the VFR category by afternoon. Gusty west to northwest
winds can be expected with gusts of 20-25 mph between 14z-21z
Tuesday. Winds will ease towards sunset Tuesday afternoon.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....Kurimski
AVIATION.......Eckberg
NWS GRB Office Area Forecast Discussion