286
FXUS63 KGRB 230403
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1103 PM CDT Wed Apr 22 2026

Updated aviation portion for 06Z TAF issuance

.KEY MESSAGES...

- Dry weather is forecast through Thursday afternoon, which will
  continue the gradual drop on area rivers.

- Rain and thunderstorms are expected Thursday evening into
  Friday. The potential for severe weather is low, but a brief
  window for strong wind gusts exists early Thursday evening,
  mainly for central and north-central WI. Heavy rainfall may
  accompany any thunderstorms with a 20-55% chance of exceeding 1
  inch of rain.

- Another round of rain and thunderstorms is forecast late Sunday
  into early Tuesday. Heavy rainfall is also possible with this
  system, with a 20-50% chance of exceeding an inch of rain.

&&

.DISCUSSION...
Issued at 304 PM CDT Wed Apr 22 2026

Another mostly clear day across the area with temperatures in the
mid 60s to low 70s away from the bay and Lake Michigan where
readings were closer to 60 degrees. Clouds increase tonight into
Thursday, with a shift to southerly flow bringing in warmer air.
Highs on Thursday will be the warmest of the week, in the mid 70s
to low 80s, aside from near the bay and lake where highs will be
in the 50s to low 60s. Dew points/moisture also increases
Thursday, which will lead to higher afternoon RHs than the past
couple days, in the upper 30s and 40s.

The rain and thunderstorm potential for late Thursday into Friday
has increased over the past day. Arrival in the western GRB
counties is about 6 hours earlier, closer to 00Z/Fri, at which
time CAMs are indicating a broken line of rain and storms
approaching from the west. With the earlier arrival time there is
still 1000-1200 J/kg of MUCAPE, although the profile remains
long, skinny. SPC has included much of the area in the `marginal
risk` for Thursday. Given the earlier timing, a very isolated
strong to severe wind threat exists for a couple hours in the
early evening, then expect the threat will wane as instability
lowers. Pwats are similar to previous forecasts in the 1.2 to 1.4
inch range, meaning locally heavy rain will be possible within any
shower or thunderstorm. NBM probabilities have increased to a
20-55% chance for more than 1" of rain from Thursday evening
through Friday. But 2" probabilities are still around 15% or less,
primarily for central WI. Given the dry stretch of weather so far
this week, current projections indicate 1.0 to 1.5" of rain would
bring subtle river rises, but river levels/forecasts to do not
see any big differences until there is more than 2" of rain within
that basin.

Lingering/redeveloping showers with isolated thunderstorms will
end Friday afternoon, followed by another stretch of dry weather
through the weekend with temperatures slightly above normal.

Looking ahead, trends continue to show another low pressure system
bringing rain and thunderstorms to the area Sunday night through
early Tuesday. Probabilities of exceeding 1" of rain are around
20-50%.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1057 PM CDT Wed Apr 22 2026

High clouds will move across the region early in the TAF period.
Low clouds (MVFR) moving through central IA are expected to make
a run at the TAF sites early Thursday morning, and should be most
persistent at CWA/AUW/RHI. Daytime heating should cause ceilings
to rise back to VFR before mid-day. There is a small chance of
showers or a thunderstorm at the western TAF sites toward 00z/Fri,
with more numerous showers and embedded thunderstorms arriving in
the mid to late evening.

Light to moderate E-SE winds will continue overnight, then become
stronger from the SE-S on Thursday. Gusts to 25 to 30 kts are
possible, especially over NC/C WI. LLWS also develops overnight,
primarily impacting north central WI and the RHI TAF site between
06z-14z/Thu, then subsiding late in the morning.

&&

.HYDROLOGY...
Issued at 304 PM CDT Wed Apr 22 2026

Minor to moderate flooding continues on many rivers. Most of the
river levels have crested, and with a prolonged stretch of dry
weather anticipated through Thursday, water levels should
gradually subside through the week.

Those living near rivers should continue to monitor the latest
Flood Warnings and statements from the National Weather Service
in Green Bay.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION.....KLJ
AVIATION.......Kieckbusch
HYDROLOGY......KLJ

NWS GRB Office Area Forecast Discussion