186
FXUS63 KGRB 022330
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
630 PM CDT Fri Oct 2 2026

Updated aviation portion for 00Z TAF issuance

.KEY MESSAGES...

- Areas of frost north of Hwy 29 late tonight into Saturday
  morning. Frost Advisories and Freeze Warnings have been issued.

- More frost will be possible at times across northern Wisconsin
  Sunday night through early next week. Greatest chance for a
  widespread frost/freeze event will be Sunday night.

- Chance of showers (30-70%) north of highway 29 late Saturday
  afternoon into Sunday morning. Otherwise mainly dry through
  middle of next week.

&&

.DISCUSSION...
Issued at 1138 AM CDT Fri Oct 2 2026

Frost/freeze potential into early next week...Frost/freeze still
on track for tonight. Light winds, clear skies with high pressure
drifting overhead and PWATs down to 0.30 inch point to min temps
bottoming out. MOS guidance typically does well on these type of
nights and shows readings in the mid-upper 20s for sites in Vilas
toward IMT. Converted the Frost Advisory to Freeze Warning along
U.P. border and continued the Frost Advisory elsewhere north of
highway 29. Mid-high clouds increase late from the west, which
may allow for temps steadying out late tonight.

After a reprieve on Saturday night, next chance for another
widespread frost/freeze is Sunday night into Monday morning,
with temperatures in the mid 30s even sneaking down toward the
Fox Valley. Chance of seeing temps less than 33F are 40-80% Sunday
night and again on Monday night. Expect more frost/freeze headlines
to be issued during this time.

Dry pattern ahead...Rain chances over the course of the extended
will be sparse, with next chances for light rain arriving
late Saturday afternoon into Saturday evening. Transient
shortwave energy will accompany the passage of a clipper-like low
over the upper Midwest Saturday evening and night, generating
isentropically forced showers for areas mainly north of Hwy 29.
Though low chance, MUCAPEs as high as 500J/kg into northwest WI
late Saturday could support a rumble of thunder surviving into
far northern WI early Saturday evening. Abundance of low level
dry air will result in a meager 20-30% chance for receiving 0.25"
of QPF through Sunday morning. Otherwise, high pressure will be
the main driver of the synoptic pattern through at least the
middle of next week, bringing abnormally dry weather from the
Plains to the Midwest. This does not bode well for northern
Wisconsin where D2 (Severe) to D4 (Exceptional) drought conditions
exist. Next chances for more widespread rain don`t arrive until
Wednesday, though if this week is anything to go by, high pressure
could end up putting up a good fight. Latest deterministic models
have backed off on these chances compared to what was shown before.

&&

.AVIATION...for 00Z TAF Issuance
Issued at 625 PM CDT Fri Oct 2 2026

VFR conditions should prevail through Saturday morning. Across
northern WI, areas of frost are expected late tonight into early
Saturday morning. The next chance of rain arrives Saturday morning
over far northern WI, with even better chance of rain Saturday
afternoon across the north. For locations across east-central WI,
the rain will not arrive until late afternoon and more likely
during the evening. Significant difference on the arrival of
MVFR or lower CIGS late Saturday afternoon and night, thus
lower confidence in the CIGS at KRHI late tomorrow afternoon.
Rain will exit the area late Saturday night.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Freeze Warning from 11 PM this evening to 7 AM CDT Saturday for
WIZ005-011>013.

Frost Advisory from 11 PM this evening to 7 AM CDT Saturday for
WIZ010-018>021-073-074.
&&

$$

DISCUSSION.....JLA/Goodin
AVIATION.......Eckberg

NWS GRB Office Area Forecast Discussion