NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 170350
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1050 PM CDT Tue Jun 16 2026

Updated aviation portion for 06Z TAF issuance

.KEY MESSAGES...

- Showers and storms end by evening. Most storms will produce
  small hail and gusty winds. An isolated storm could produce
  quarter sized hail over eastern WI.

- Another round of showers and storms are expected for Wednesday
  (80-100% chance). A few strong storms with small hail and gusty
  winds may occur. Moderate to heavy rainfall will have a 60-80%
  chance of exceeding 1 inch of rain.

- Below average temperatures in the 60s and 70s through the week.

&&

.DISCUSSION...
Issued at 303 PM CDT Tue Jun 16 2026

Active weather continues through late this week. Temperatures will
remain below normal.

Into this evening...Compact, tightly wrapped up shortwave trough
crosses the region. Instability has built sufficiently to result
in strong to severe storms early this afternoon with 0.5 inch to
1.0 inch hail, especially with such low freezing levels. Lack of
shear well under 20 kts means main storm mode will be pulse type.
Showers and storms will exit eastern WI after 6-7p.

Wednesday...
Another, stronger shortwave drops towards the region on Wednesday,
bringing another round of showers and storms. The track of the
accompanying surface low is expected to remain over southern
Wisconsin which should keep warm front and more unstable air south
of the area, and greatly limit the overall severe potential. That
said, some overrunning moisture from the surface warm front
combined with some surface heating and sufficient shear will
still support at least embedded storms. Best potential for any
stronger storms will be from central to east-central Wisconsin,
mainly south of highway 10. Heavy rainfall will also be possible
with any convection. There is a Marginal Risk of Excessive
Rainfall stretching across central to east-central Wisconsin and
southwards as well.

Rest of the forecast period...Another brief round of scattered
(20-30% chance) showers will be possible on Thursday, driven
primarily by strong surface heating. Convective support will be
relatively minimal, so expect impacts from any scattered showers
to be minimal. After this, the only chance for more widespread
active weather would be Saturday night into Sunday, when another
larger system enters western Great Lakes. Greatest risk for rain
appears to be setting up for Sunday instead of Saturday.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 909 PM CDT Tue Jun 16 2026

VFR flying conditions prevail overnight, with cigs lowering
Wednesday morning prior to cold frontal passage. Expect
widespread MVFR and even IFR conditions to work their way east
during this time, lasting through the end of the TAF period. SCT
showers and storms are forecast Wednesday morning through
Wednesday evening, with heavy rain, gusty winds, and up to 1" hail
possible with any stronger storms during the afternoon. Vsbys may
lower into MVFR or IFR territory if heavy rain or a stronger
storm were to move over a terminal. However, have withheld mention
of thunder in the TAFs this far out due to low confidence in
storm coverage and placement.

Post-frontal winds ramp up and shift to the southeast Wednesday
afternoon, gusting between 20 and 25 knots. Locally higher gusts
will be possible with any convection.

&&

.MARINE...
Issued at 303 PM CDT Tue Jun 16 2026

S to SE winds increase Wednesday afternoon before shifting to NE
as sfc low passes by to the south. Waves build sufficiently enough
that a Small Craft Advisory and Beach Hazards Statements will
eventually be needed. The higher waves will linger into Thursday
morning, before winds shift offshore to the NW.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Beach Hazards Statement from Wednesday afternoon through
Thursday morning for WIZ022-040-050.
&&

$$

DISCUSSION.....JLA
AVIATION.......Goodin
MARINE.........JLA