261
FXUS63 KGRB 032322
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
622 PM CDT Wed Jun 3 2026

Updated aviation portion for 00Z TAF issuance

.KEY MESSAGES...

- Elevated fire weather conditions this afternoon due to low
  relative humidity, above normal temperatures, and increasing
  winds.

- Showers and storms return Thursday, lasting into the weekend.
  Limited potential for a strong storm on Thursday. Better Chance
  for a couple stronger storms Friday afternoon.

- Above normal temperatures persist for the next week. Chance
  (50-60% for central Wisconsin) for highs in the low 90s by the
  middle of the week. This will bring potential for heat related
  impacts.

&&

.DISCUSSION...
Issued at 226 PM CDT Wed Jun 3 2026

Rain/storm chances...
The large upper ridge that has held dry weather in place is set to
diminish and depart eastwards over the next couple days, allowing
for a strong moisture return off the Gulf the next couple of days.
Although moisture will begin to push into the region by Thursday
morning, remain somewhat skeptical on how much rain will reach
the surface by noon due to how dry air near the surface is during
this period. As the moisture plume sags more eastwards through
the day, would expect shower and thunderstorm activity to still
gradually spread across the region with some scattered shower
activity (20-30%) arriving in the Fox Valley by the evening.
Moisture influx then continues into Friday, with precipitable
water values expected to exceed 1.5" during the day. This combined
with some better instability and mid-level forcing could bring
some heavier rainfall to the region during the afternoon and
overnight into Saturday. Probabilistic guidance brings 50-70%
chance of exceeding half an inch of rainfall for most of the
region, but is more skeptical of exceeding an inch, staying closer
to around 20-30% only across central Wisconsin. Would expect
these higher end values to be limited to areas that see convection
during the afternoon and/or overnight hours, which may make the
higher rain totals fairly localized.

In terms of strong or severe storm potential the next few days,
overall storm strength on Thursday appears fairly limited.
Instability values will be slow to rise with the moisture still
inbound. Minimal shear and little upper forcing will be present,so
any storms will largely depend upon upstream development before
moving eastwards into our region. This type of development would
make wind the primary concern and largely be limited to portions
of central to north-central Wisconsin. Some shower activity could
continue overnight but any stronger storm potential should
diminish fairly quickly. Friday will have better potential for
some stronger storms during the afternoon as a shortwave will
cross the area during the afternoon and bring a period of better
convergence and support aloft to portions of central to east-
central Wisconsin. Shear values will also be greater, with around
30-40 knots of bulk shear. Cloud cover from earlier rain may be a
limiting factor in instability returning however, and CAPE
profiles are generally long and narrow, which is not typically
conducive to strong updrafts. Still, with lingering boundaries
from prior convection possible as well as the aforementioned upper
support in the afternoon, could see a stronger storm or two
develop, with some hail and/or wind concerns in the afternoon to
evening hours. A similar situation appears to unfold for Saturday,
but with less focused upper support. As a result, would expect
diurnal instability to produce a cumulus field during the
afternoon and evening hours, resulting in some scattered showers
and a few thunderstorms. Much like Friday, instability may again
be hampered by overnight convection, but if this clears early then
a few additional thunderstorms may be possible.

Temperatures... Temperatures will remain steady in the upper 70s
to mid 80s (around 5 to 10 degrees above average) over the course
of the next week as a warming ridge dominates the Midwest. Highs
peak in the mid to upper 80s in/around the Fox Valley and into
far northeast Wisconsin on Thursday, though the chances for a
90 degree reading remain low this week(10 to 20%). Shower/storm
timing and associated cloud cover may also mitigate temperatures.
Dewpoints will read comfortably in the mid to upper 50s during
this time, resulting in a low heat risk of 1 out of 4. Greater
potential for heat-related impacts will come late this weekend
into early next week as upper flow re-amplifies and building heat
ridge/Hudson Bay high set us up under southerly flow regime. Early
looks at probabilistic guidance suggest around 40-60% chance of
seeing 90 degrees in central Wisconsin. Ample moisture transport
from an open Gulf will likewise cause dewpoints to rise into the
60s, which would put us under a level 2 out of 4 (moderate risk)
for heat- related impacts early next week.

&&

.AVIATION...for 00Z TAF Issuance
Issued at 622 PM CDT Wed Jun 3 2026

VFR conditions will prevail tonight. Thursday conditions will
generally remain VFR, however, periods of MVFR conditions are
possible with a round of showers moving into the region.

Band of scattered cirrus will continue to pass over the region this
evening. As low and mid level moisture begins to advect into the
region cigs will gradually start to lower Thursday morning. A series
of short-waves, currently over the Dakotas, will arrive to the
region late Thursday morning kicking off a round of showers for the
afternoon. Shower coverage will likely be isolated to scattered
through the afternoon (18-24Z). As any showers pass over a terminal
brief MVFR conditions will be possible. For now have left TS out of
the TAFs as instability will be limited, however, there is a low-end
change for a few isolated thunderstorms during the afternoon.

With the increasing southwest flow, marginal wind shear conditions
will push into north-central WI after 06z. Therefore added LLWS to
the RHI TAF for a brief period early Thu morning.

Southwest winds will increase on Thursday with gusts 15 to 20 kts
starting after 14-15Z.

&&

.FIRE WEATHER...
Issued at 226 PM CDT Wed Jun 3 2026

Dry weather and low relative humidity readings will keep elevated
to near critical fire weather potential in place through the
evening hours tonight. The greatest areas of concern will be along
the sandy soil regions, especially in northeastern Wisconsin near
the Upper Peninsula border where RH values in the afternoon are
expected to continue to linger around 18 to 25% through the
afternoon. Fortunately, winds concerns will remain marginal during
this period, but will retain the SPS to message the fire weather
concerns for dry fuels and low relative humidity through the
evening. Active weather possible the next couple of days will help
bring some relief to the fire weather concerns for the region.

&&

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

$$

DISCUSSION.....Uhlmann
AVIATION.......GK
FIRE WEATHER...Uhlmann

NWS GRB Office Area Forecast Discussion