NWS-Green Bay Forecast Discussion
FXUS63 KGRB 291130
AFDGRB
Area Forecast Discussion
National Weather Service Green Bay WI
630 AM CDT Wed Apr 29 2026
Updated aviation portion for 06Z TAF issuance
.KEY MESSAGES...
- Chance (25 to 50%) of showers today and Thursday, with rainfall
totals generally under a quarter inch through the weekend.
- Minor flooding persists on the Wolf River and Winnebago system.
Water levels should gradually recede as the week progresses due
to a lack of significant rainfall.
- Below normal temperatures expected through the weekend.
Frost/freeze potential toward the end of the week.
&&
.DISCUSSION...
Issued at 1117 PM CDT Tue Apr 28 2026
Radar continues to show weak returns percolating across northeast
Wisconsin early this morning, though any evidence of showers
making it to the surface remains well off to our south. Chance
showers (25 to 50%) then return later this morning into this
afternoon as shortwave energy and attendant surface wave pivot
over the Great Lakes. A rumble or two of thunder would not be out
of the question this afternoon due to meager daytime instability
(100 to 300 J/kg MUCAPE), though remains unlikely.
The remainder of the week will be characterized by afternoon
shower chances as a blocking upper low sits and spins over Quebec,
bringing a train of shortwaves to the Great Lakes within
northwest flow regime. However, QPF should easily be held down to
a quarter of an inch or less each day. No thunder is expected due
to a lack of instability. Some CAA snow flurries cannot be ruled
out Thursday afternoon as 850 mb temps drop between -4 and -8C,
though will remain unimpactful. Weak high pressure then builds in
for the weekend, before a potent cold front brings more widespread
precip chances early next week.
Temperatures... Expect temperatures to remain below normal through
the end of the week as a cold Canadian airmass streams into the
Midwest. Highs will read primarily in the 40s and 50s during this
time. Frost/freeze concerns then come into play toward the end of
the work week as lows fall into the mid 20s to mid 30s. Will
likely necessitate headlines across portions of central Wisconsin
to the lakeshore, where the growing season/greenup have begun.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 102 AM CDT Wed Apr 29 2026
SCT to BKN low clouds and light rain continue to stream into
northeast Wisconsin early this morning, with localized MVFR cigs
observed. Chance (25 to 50%) showers persist through this
afternoon, with lowering and thickening cigs remaining possible.
However, any drops to MVFR will likely be brief as showers pass
over a terminal. A rumble or two of thunder wouldn't be out of the
question this afternoon due to weak instability, though have
withheld PROB30 mention in the TAFs due to low confidence. Shower
chances then come to an end from west to east by around 04Z.
Otherwise, winds will be sustained out of the north/northwest at
around 5 to 10 knots, gusting between 15 and 20 knots this
afternoon.
&&
.HYDROLOGY...
Issued at 1117 PM CDT Tue Apr 28 2026
Minor flooding remains limited to the Wolf River basin and the
Winnebago system, and is forecast to continue through the middle
to end of the week per RFC guidance. With a notable lack of
significant rainfall in the forecast, river levels should be
allowed to gradually recede through the weekend, with hydro/flooding
concerns becoming little to none by early next week. However,
those living near rivers or streams should continue to monitor the
latest river forecasts.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....Goodin
AVIATION.......Goodin
HYDROLOGY......Goodin
FXUS63 KGRB 291130
AFDGRB
Area Forecast Discussion
National Weather Service Green Bay WI
630 AM CDT Wed Apr 29 2026
Updated aviation portion for 12Z TAF issuance
.KEY MESSAGES...
- Chance (25 to 50%) of showers today and Thursday, with rainfall
totals generally under a quarter inch through the weekend.
- Minor flooding persists on the Wolf River and Winnebago system.
Water levels should gradually recede as the week progresses due
to a lack of significant rainfall.
- Below normal temperatures expected through the weekend.
Frost/freeze potential toward the end of the week.
&&
.DISCUSSION...
Issued at 1117 PM CDT Tue Apr 28 2026
Radar continues to show weak returns percolating across northeast
Wisconsin early this morning, though any evidence of showers
making it to the surface remains well off to our south. Chance
showers (25 to 50%) then return later this morning into this
afternoon as shortwave energy and attendant surface wave pivot
over the Great Lakes. A rumble or two of thunder would not be out
of the question this afternoon due to meager daytime instability
(100 to 300 J/kg MUCAPE), though remains unlikely.
The remainder of the week will be characterized by afternoon
shower chances as a blocking upper low sits and spins over Quebec,
bringing a train of shortwaves to the Great Lakes within
northwest flow regime. However, QPF should easily be held down to
a quarter of an inch or less each day. No thunder is expected due
to a lack of instability. Some CAA snow flurries cannot be ruled
out Thursday afternoon as 850 mb temps drop between -4 and -8C,
though will remain unimpactful. Weak high pressure then builds in
for the weekend, before a potent cold front brings more widespread
precip chances early next week.
Temperatures... Expect temperatures to remain below normal through
the end of the week as a cold Canadian airmass streams into the
Midwest. Highs will read primarily in the 40s and 50s during this
time. Frost/freeze concerns then come into play toward the end of
the work week as lows fall into the mid 20s to mid 30s. Will
likely necessitate headlines across portions of central Wisconsin
to the lakeshore, where the growing season/greenup have begun.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 102 AM CDT Wed Apr 29 2026
SCT to BKN low clouds and light rain continue to stream into
northeast Wisconsin early this morning, with localized MVFR cigs
observed. Chance (25 to 50%) showers persist through this
afternoon, with lowering and thickening cigs remaining possible.
However, any drops to MVFR will likely be brief as showers pass
over a terminal. A rumble or two of thunder wouldn't be out of the
question this afternoon due to weak instability, though have
withheld PROB30 mention in the TAFs due to low confidence. Shower
chances then come to an end from west to east by around 04Z.
Otherwise, winds will be sustained out of the north/northwest at
around 5 to 10 knots, gusting between 15 and 20 knots this
afternoon.
&&
.HYDROLOGY...
Issued at 1117 PM CDT Tue Apr 28 2026
Minor flooding remains limited to the Wolf River basin and the
Winnebago system, and is forecast to continue through the middle
to end of the week per RFC guidance. With a notable lack of
significant rainfall in the forecast, river levels should be
allowed to gradually recede through the weekend, with hydro/flooding
concerns becoming little to none by early next week. However,
those living near rivers or streams should continue to monitor the
latest river forecasts.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....Goodin
AVIATION.......Goodin
HYDROLOGY......Goodin