023
FXUS63 KGRB 031115
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
615 AM CDT Sat Oct 3 2026

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Areas of frost expected north of Hwy 29 through this morning.
  Frost/freeze headlines remain in effect.

- Chance of showers (40 to 80%) across the north late this morning
  through tonight. Otherwise, mainly dry through at least the
  middle of next week.

- Areas of frost will be possible at times across northern
  Wisconsin both Sunday and Monday nights. Greatest chance for a
  widespread frost/freeze event will be Sunday night.

&&

.DISCUSSION...
Issued at 115 AM CDT Sat Oct 3 2026

Frost/freeze potential... Temperatures have dipped down into the
low to mid 30s within headline areas early this morning under
mostly clear skies and light winds. With several hours yet for
cooling to occur, current thinking is that headlines remain on
track. However, with mid clouds knocking on our door, will have to
see whether or not temperatures end up steadying out. Otherwise,
next frost/freeze chances will be Sunday night and Monday night
following brief reprieve tonight. NBM showing 40 to 80% chance
for temperatures below 33 degrees mainly along the Upper Peninsula
border for both nights, with pretty slam dunk signal for below 36
degrees. As such, expect additional headlines to be issued for
both periods.

Rain chances... CAMs continue to trend slightly earlier with rain
chances today through Sunday as WAA increases ahead of clipper-
like low to the north. Scattered showers are now progged to
arrive to central and north-central Wisconsin late this morning
with initial push of WAA, filling in later this afternoon and
evening in proximity to approaching front. QPF amounts have
likewise increased, with probabilistic guidance now showing a 20
to 40% chance for receiving 0.5" of QPF north of Hwy 29.
Regardless, not expected to be drought busting for areas that
desperately need soaking rain. Both NAM-NEST and ARW try to
generate lake effect showers along the Lake Michigan shoreline
early this morning, though remain doubtful that these will come to
fruition due to lingering dry air.

Ridge of high pressure will continue to be the main driver of the
synoptic pattern through the extended, with most recent suite of
ensemble runs nearly wiping out precip chances during the mid-
week timeframe. Beyond that, not seeing any strong signals for
organized systems through at least the middle of the month. With
frost/freeze headlines already in play, this may result in
increasing fire weather concerns over the next several weeks due
to current drought status and increasing fine fuels.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 600 AM CDT Sat Oct 3 2026

Mid clouds increase from the west ahead of spotty shower chances
this morning. Low confidence in showers occurring, though have
included PROB30 mention of SHRA at RHI from 14 to 18Z. Greater
chances for rain at all terminals then arrive late this afternoon
through this evening. Have tried to refine rain arrival into the
02 to 06Z timeframe for the east central sites, with heavier rain
filling in across AUW, CWA, and RHI during this time. Cigs may
drop down to MVFR across central and north-central Wisconsin late
tonight, though rain should continue falling from a mid deck at
the east-central sites.

Winds will be mainly out of the south through this evening,
gusting between 15 and 20 knots at all sites. Winds then veer to
northwesterly by Sunday morning. LLWS may affect RHI, AUW, and CWA
at times after 00Z Sunday as 850 mb winds increase.

&&

.MARINE...
Issued at 115 AM CDT Sat Oct 3 2026

Increasing gradient winds will result in conditions hazardous to
small craft developing along Lake Michigan nearshore waters north
of Sturgeon Bay this evening into Sunday morning. Southwest winds
will be sustained at around 10 to 20 knots, with gusts to 25
knots. Waves will build between 3 and 6 ft, highest near Death`s
Door.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Freeze Warning until 7 AM CDT this morning for WIZ005-011>013.

Frost Advisory until 7 AM CDT this morning for WIZ010-018>021-
073-074.
&&

$$

DISCUSSION.....Goodin
AVIATION.......Goodin
MARINE.........Goodin

NWS GRB Office Area Forecast Discussion