227
FXUS63 KGRB 151915
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
215 PM CDT Thu Oct 15 2026

Forecast discussion for routine afternoon forecast issuance

.KEY MESSAGES...

- Ongoing, widespread rain this afternoon and evening, becoming
  scattered overnight into Friday. Probabilities for 1 inch or
  greater range from 60 to 90%.

- Northwest winds increase on Friday, with gusts between 30 and 40
  mph, and a 30% probability that lake shore counties could
  receive gusts to 45 mph. Gale force gusts are expected across
  marine zones.

- A Freeze Watch has been issued for Friday night as temperatures
  are likely to fall into the upper 20s in locations away from
  Lake Michigan.

&&

.DISCUSSION...
Issued at 214 PM CDT Thu Oct 15 2026

Precip...Small adjustments/increases in QPF over the next 24
hours, otherwise forecast remains similar to the previous update.

Moisture plume associated with sfc low/shortwave in the central
Plains has been spreading northeast today and resulted in onset of
widespread rain across central and northeast WI. Expect steady
rain to continue this afternoon and evening, followed by rain
becoming scattered overnight as two energy areas phase across the
Great Lakes and move east. Lingering low-level moisture and
trailing surface trough will keep widely scattered rain and
drizzle in the forecast throughout Friday morning, and into the
afternoon for the east. Event total rain amounts will range from
approximately 0.75 to 1.10 inches, with probabilities of exceeding
1 inch of rain now ranging from 60 to 90%. Most of this will
occur before 06Z/Fri, with around 0.20 inch or less after that
time.

Wind...As northern and southern stream lows approach from the
northwest and southwest, then phase just east of WI, expect
tightening pressure gradient to result in strong north to
northwest winds on Friday. Gusts of 30 to 35 mph are forecast area
wide. Potential for wind gusts reaching 45 mph are greatest near
the lake shore, where this is a small potential for wind-related
headlines. However, right now the probability of exceeding 45 mph
gusts stands around 30%. See MARINE section for additional wind
information.

Temperatures...Cold front associated with northern stream low will
usher in a cooler batch of air for a couple days. Clouds and wind
will keep temps in the mid 30s and 40s tonight, but clearing skies
and lights winds on Friday night will allow readings to fall below
freezing in most locations. Probabilities range from 40 to 80% for
a hard freeze, lows of 28 degrees or cooler, away from the lake
shore counties. Therefore, a Freeze Watch was issued for all
counties where the growing season continues, aside from Door
County. Temperatures quickly start to rebound on Sunday with highs
back in the 60s for several days.

Next week...High pressure will result in low impact weather into
at least the middle of next week, with temperatures AOA normal,
little to no precip chances until at least Thursday, and light
winds.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1226 PM CDT Thu Oct 15 2026

Flying conditions will continue deteriorating to primarily IFR
for the rest of today and tonight, with some improvement to MVFR
late in the TAF period on Friday morning.

Ongoing widespread rain will move northeast into the rest of
northeast WI over the next 1-2 hours; and then persist for the
afternoon and evening, leading to low cigs and vsbys. Temporary
dips to LIFR over the next 12 hours with cigs right around the 500
ft threshold.

Rain transitions to scattered to isolated coverage after 06Z/Fri,
but low cigs and vsby remain. Improvements to MVFR occur around or
after 09Z/Fri as ceilings rise and patchy fog clears out, but as
this occurs NW winds increase, with gusts up to 30 kts. LLWS is
also present at 2kft for central and north-central WI on Friday
morning.

&&

.MARINE...
Issued at 214 PM CDT Thu Oct 15 2026

Gradient winds on the back edge of the departing surface low ramp
up Thursday night into Friday morning, putting us solidly within
northwest flow and CAA regime. Deep daytime mixing will tap into
45 to 50 knot winds at 850 mb Friday afternoon, which will result
in a brief window for gale force gusts over all marine zones
through Friday evening. NBM probabilistic guidance continues to
show a healthy signal (60 to 90%) for gusts exceeding 34 kts,
highest along the Lake Michigan nearshore waters south of
Kewaunee. Waves build 7 to 10 ft on the Lake and 4 to 7 ft on the
Bay during this time, subsiding Friday night as winds shift to
more westerly and the pressure gradient eases up. Gale Warning
remains in effect.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Freeze Watch from late Friday night through Saturday morning for
WIZ020-030-031-035>040-045-048>050-073-074.
&&

$$

DISCUSSION.....KLJ
AVIATION.......KLJ
MARINE.........Goodin/KLJ

NWS GRB Office Area Forecast Discussion