NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 271102
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
602 AM CDT Wed May 27 2026

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Isolated to scattered thunderstorms are possible this afternoon
  and early this evening across the area. A few storms could
  become strong to severe with damaging winds and small hail.

- Above normal temperatures for the next week, with highs mainly
  in the upper 70s and 80s.

- Conditions hazardous to small craft are expected tonight for
  the Lake Michigan nearshore waters south of Sturgeon Bay.
  Boaters should exercise caution on the bay of Green Bay this
  evening.

- There is a high risk for rip currents tonight for beaches along
  Lake Michigan in Manitowoc County.

&&

.DISCUSSION...
Issued at 1256 AM CDT Wed May 27 2026

The front that brought last evenings shower and thunderstorm will
stall and remain as a semi-stationary front across central
Wisconsin today. This front will be the impetus for additional
showers and thunderstorms as a mid level shortwave dives south
through the western Great Lakes later today. SBCAPEs this
afternoon are expected to be 1500 to 2500 J/kg with a bit better
bulk shear values around 30 knots. Recent CAMs runs are a bit more
generous with coverage of showers and thunderstorms with the
shortwave in the vicinity of the semi-stationary front; therefore,
will raise POPs across the entire region, especially given how
todays front overperformed. The severe weather potential is
similar with a marginal risk for strong to severe storms given the
decent instability and better shear values. DCAPE values around
1000 J/kg indicate damaging winds would be the main threat with
the best CAPE thickness just below the hail growth zone,
indicating only small hail is expected from the stronger storms.
Per the previous shift, adjusted highs down several degrees as we
will be on the north side of the aforementioned front with similar
highs carried over from that shift.

The front should then move south as a cold front through the rest
of Wisconsin this evening, which will usher in a period of dry
weather across the region late in the week and continuing through
early next week as high pressure builds in across the Great Lakes.
Other than Thursday, when temperatures will be around normal,
readings will rise above normal into early next week, with highs
in the mid 70s to mid 80s. The warmest day will be Friday when
highs could approach or hit 80 degrees. Despite the Canadian high
settling overhead, temperatures at night, even in northern
Wisconsin, will remain above 40 degrees.

A period of gusty north-northeast winds this evening will bring a
period of high waves and strong rip currents to Manitowoc County.
Therefore, a Beach Hazards Statement has been issued from this
evening through early Thursday morning.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 559 AM CDT Wed May 27 2026

Patchy IFR to LIFR visibilities have developed over north-central
WI from Merrill to Manitowish Waters early this morning. These
lower visibilities should mix out by 13-14z with daytime heating.

Then a stalled front over the Upper Peninsula will sag south
across the area this afternoon. Widely scattered showers and
storms are expected to accompany the front. Previous forecast
indicated the most favorable time period for showers or storms at
area terminals using prob30 groups. While minor timing changes
were made, confidence that showers and storms will impact the
terminals is generally lower than 30% based on latest model trends.
Brief gusty winds will be possible in any showers that develop.

As the front passes by early this evening, gusty northeast winds
are likely to develop for a 3-6 hour period. Gusts up to 25 kts
will be possible over the northeast WI terminals (KGRB, KATW,
KMTW). These gusts should subside after 05-06Z Thu.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Beach Hazards Statement from this evening through late tonight
for WIZ050.
Small Craft Advisory from 9 PM this evening to 3 AM CDT Thursday
for LMZ542-543.
&&

$$

DISCUSSION.....Kurimski
AVIATION.......MPC