NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 021117
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
617 AM CDT Thu Jul 2 2026

.KEY MESSAGES...

- Peak afternoon heat indices will range from the mid to upper 90s
  for east-central and far northeast Wisconsin today. Heat indices
  gradually decrease into the holiday weekend.

- Periodic chances for showers and thunderstorms through the
  holiday weekend. A few storms may become strong to severe late
  this afternoon into late this evening capable of producing
  damaging winds and hail.

&&

.DISCUSSION...
Issued at 301 AM CDT Thu Jul 2 2026

Precipitation/Thunder Chances...A mid-level shortwave and stationary
boundary lying across the region early this morning has been
producing a large area of rain with embedded thunderstorms.
Upstream, additional thunderstorms have fired along the boundary
across west-central WI. These thunderstorms will continue track
eastward early this morning, impacting locations along the border of
our forecast area and NWS Milwaukee's forecast area, mainly with
heavy rainfall. With PWATs still around 2 inches and additional
rainfall of 1-3 inches still possible with these storms, didn't make
any changes to the Flood Watch that remains in effect until 10 AM
for central and east-central WI. These showers and storms will
gradually come to an end/move south of the area later this morning.

For the remainder of today through the holiday weekend, the forecast
area will remain under a zonal flow, but several embedded mid-level
shortwaves (some weak, some stronger) are expected to bring
additional rounds of showers and storms at times. For the remainder
of today, most guidance indicates conditions will be dry with the
boundary staying just south of the forecast area. However, cannot
rule out the potential for the boundary to sit somewhere along our
southern forecast area border, keeping the potential for strong to
severe thunderstorms in place with 1000-2000 J/kg of CAPE and deep-
layer shear of 30-40 kts during the late afternoon into the late
evening. If strong to severe storms develop, damaging winds, hail,
and heavy rainfall will be the main concerns. Models have the next
shortwave/ripple bringing showers and storms to the area sometime on
Friday, with slightly better agreement Friday afternoon/evening.
Depending on if these storms develop over the area, a few may be
strong or severe with damaging winds being the main concern. Models
continue to indicate a slightly stronger shortwave moving across the
area sometime between late Friday night through Sunday. While there
is agreement for this system to bring heavy rainfall, the severe
potential will depend on the exact timing and placement of the
surface low associated with it.

Beyond Sunday global ensembles and ML models continue to trend
toward a drier period through the first half of next week.

Temperatures...Above normal temperatures will remain in place
through at least Friday with highs in the mid to upper 80s today and
low to mid 80s on Friday, and dew points still ranging from the mid
60s to mid 70s. A few spots may near 100 degree heat index values
today, but given how sparse this is forecast, decided not to issue
any heat headlines. With temperatures and dew points slightly
decreasing for Friday through the holiday weekend, will continue to
monitor the need for additional heat headlines, but the likelihood
is decreasing.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 617 AM CDT Thu Jul 2 2026

Showers will exit central into east-central Wisconsin through
mid-morning. Patches of IFR/MVFR stratus this morning,
especially across central into north-central Wisconsin, will
give way to VFR conditions with some diurnal cumulus and
mid/high clouds.

Confidence is low with evolution of additional storms this
afternoon and evening. Overall, the highest storm chances appear
to be across southern Wisconsin. However, there is at least low
(10-40%) chances for storms, especially late this afternoon
after 02.21Z, into tonight. These trends will be refined in
subsequent updates as confidence in storm evolution increases.

Otherwise, there are low chances (20-40%) for patchy low
stratus or fog development (MVFR to IFR) late tonight, mainly
over central into north-central Wisconsin. Confidence was not
high enough to include in the TAFs for this update.

&&


.GRB WATCHES/WARNINGS/ADVISORIES...
WI...Flood Watch until 10 AM CDT this morning for WIZ020-030-031-
     035>040-045-048>050-074.
MARINE...None.

&&

$$

DISCUSSION...Kruk
AVIATION...JM