Forecast Discussion for GRB NWS Office
947
FXUS63 KGRB 021753
AFDGRB
Area Forecast Discussion
National Weather Service Green Bay WI
1153 AM CST Mon Nov 2 2026
Updated aviation portion for 18Z TAF issuance
.KEY MESSAGES...
- Periods of rain, gusty winds, and a few rumbles of thunder from
late this afternoon through Thursday, peaking tonight through
Tuesday evening.
- Probabilities to reach or exceed 1 inch are 65-95% north and
west of the Fox Valley, and 40-60% in the Fox Valley east to
Lake Michigan from Monday afternoon through Wednesday afternoon.
- Above normal temperatures continue through Thursday, falling to
normal to end the week.
&&
.DISCUSSION...
Issued at 1047 PM CST Sun Nov 1 2026
Periods of Rain Through Thursday...Quiet and dry conditions remain
overnight with clouds increasing ahead of a developing low
pressure system, currently over the Central Plains. This system is
expected to bring periods of light to moderate rain, gusty winds,
and a few rumbles of thunder this afternoon/evening through
Thursday. Southerly flow will usher in well above normal PWATs of
around 1.5-1.6 inches (99th percentile of climatology) this
evening through Tuesday evening, when the biggest surge of
moisture is expected. PWATs and rain intensity decrease Tuesday
night through Thursday, as low-level winds gradually turn
westerly, cutting off Gulf moisture. A few rumbles of thunder from
elevated storms are possible at times, mainly on Tuesday, given a
couple hundred J/kg of MUCAPE, but strong/severe storms are not
expected.
Despite the prolonged period of rain this week, a complete washout
is not expected. However, drought stricken areas across northern WI
could see some relief as probabilities for 1 inch or more of rain
are 65-95% for locations north and west of the Fox Valley, with 40-
60% in the Fox Valley east to Lake Michigan late this afternoon
through Wednesday afternoon. The probability for 2 inches continues
to decreased slightly with NBM prob now forecasting 20-50% for
locations north and west of the Fox Valley. Additional periods of
light rain are expected after Wednesday afternoon through Thursday.
Dry conditions are expected to finally return by Friday, however,
another short-wave may bring periods of rain back to the area next
weekend.
Temperatures...Above normal temperatures are expected through
Thursday, falling to normal on Friday through the weekend (highs in
the upper 40s to low 50s) following the prolonged rainy system.
Tuesday will be the warmest day with highs in the mid to upper 60s,
but the cloud cover and rain may cause slightly lower temperatures.
A few sites may be near/set new record high minimum temperatures on
Tuesday, November 3.
&&
.AVIATION...for 18Z TAF Issuance
Issued at 1153 AM CST Mon Nov 2 2026
An extended period of rain showers moves into the region this
afternoon and evening, bringing widespread MVFR to IFR conditions
for the afternoon hours, before ceilings drop to IFR/LIFR
overnight. Ceilings will likely not see much improvement through
the morning hours on Tuesday. Rain will also impact visibility at
times, with periods 2-4SM visibility likely. Can`t rule out a
rumble of thunder this evening, but confidence on location wasn`t
high enough to include at any terminal this TAF issuance.
Winds will be fairly gusty through the TAF period, with south to
southeast gusts up to 20-25 kts through the end of the current TAF
period.
&&
.MARINE...
Issued at 1047 PM CST Sun Nov 1 2026
A slow moving low pressure system will move across the Great Lakes
tonight into Wednesday morning, bringing a prolonged period of gusty
south to southeast winds and large waves on the bay and Lake
Michigan. A Small Craft Advisory has been posted for the Lake
Michigan nearshore waters from this afternoon through Wednesday
evening. A few gale force gusts are possible Tuesday on Lake
Michigan. The Small Craft Advisory may need to be expanded to cover
the Bay as well.
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.......Uhlmann
MARINE.........GK
NWS GRB Office Area Forecast Discussion