274
FXUS63 KGRB 031121
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
521 AM CST Tue Nov 3 2026

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Periods of rain, gusty winds, and a few rumbles of thunder
  continue through Thursday, with the heaviest periods of rain
  coming now through this evening.

- Above normal temperatures continue through Thursday, falling to
 normal to end the week.

&&

.DISCUSSION...
Issued at 1048 PM CST Mon Nov 2 2026

Periods of Rain Through Thursday... A large low pressure system will
continue to spin over the region through mid-week keeping on an off
rain chances in the forecast through Thursday. The heaviest periods
of rain are expected overnight into Tuesday as southerly winds have
brought ample moisture (PWATS above the 99th percentile of
climatology) to the region. As winds start to take on more of a
westerly component Wednesday gulf moisture will get cut off from the
region, however, light on and off showers will likely linger at
least through Thursday as forcing associated with the low pressure
system continues over the region. There is a low-end (~5%) for a few
weak thunderstorms to develop this afternoon, and again Wednesday
afternoon as weak elevated instability builds over the region.

Despite the prolonged period of rain this week, a complete washout
is not expected, as showers  will be on and off through Thursday.
Thus far radar estimate show around 0.3-0.7 inches of rain have
fallen north and west of the Fox Valley with around 0.2 inches haven
fallen the Fox Valley and along the lakeshore. The probability of
an addtioanl 1 inch of rain through Thursday us about 20-30% across
northern WI with lower percentages further south. However, depending
on which areas see some convective elements mix in each afternoon
(i.e. thunder), some localized areas may get closer to two inch
rainfall. Dry conditions do finally return Friday and Saturday but
another short-wave may bring a few showers back on Sunday.

Temperatures...
The surge of warm and moist air will keep high temperatures above
normal the next couple of days, with 60s forecast for much of the
region. The influx of warmer air may also bring some new record
high minimum temperatures for some sites on Tuesday. A slow drop
is then expected for the latter part of the week with highs getting
back to the upper 40s to lower 50s and overnight lows falling back
into the 20s to 30s.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 521 AM CST Tue Nov 3 2026

A prolonged period of poor flying conditions is expected through
the TAF period as a large low pressure system spins over the
region. An expansive status deck is firmly in place across the
region with IFR/LIFR conditions at all terminals. These low CIGs
will likely remain through much of today and tonight. There may
be brief periods this afternoon where CIGs improve to MVFR across
eastern WI; however, conditions will likely deteriorate again
this evening. Along with the low CIGs expect on and off rain
showers through tonight that will bring periods of MVFR to IFR
VSBYs. There is a low end (~5%) chance for a few rumbles of
thunder this afternoon; however, confidence in any thunder is too
low to include with this TAF issuance.

Winds will be fairly gusty through the TAF period, with south to
southeasterly gusts up to 20-25 kts through tonight. Gusty winds
just above the surface will bring a period of LLWS this morning as
well as tonight to the TAF sites.

&&

.MARINE...
Issued at 1048 PM CST Mon Nov 2 2026

A prolonged period of gusty south to southeast winds and large
waves on the bay and Lake Michigan will continue into Wednesday. A
Small Craft Advisory remains in for the Lake Michigan nearshore
waters through Wednesday evening. A few gale force gusts are
possible today on Lake Michigan, mainly south of Algoma. The Small
Craft Advisory has also been expanded to the Bay through this
evening.

Winds will shift to the north on Thursday, possibly gusting to
near 25 kts as the system departs to the east.

&&

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

&&

$$

DISCUSSION.....GK
AVIATION.......Kurimski
MARINE.........GK

NWS GRB Office Area Forecast Discussion