956
FXUS63 KGRB 301108
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
608 AM CDT Thu Jul 30 2026

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Chance (20 to 40%) for showers or storms today, mainly north of
  Highway 29. No strong storms are expected.

- Wildfire smoke may reach the surface at times today and
  tonight. Minor visibility restrictions and a drop to moderate
  air quality is expected.

- Greater chances (40 to 60%) for showers and storms return
  Friday into Friday night. No severe weather is expected.

&&

.DISCUSSION...
Issued at 140 AM CDT Thu Jul 30 2026

Rain/storm chances...Some CAMs are still picking up on a signal
for pop-up showers or storms (20 to 40% chance) north of Highway
29 today due to weak instability. However, generating a shower or
storm will be difficult due to lack of forcing and smoke aloft.
Overall, most areas should stay dry with upper ridging firmly in
place.

Better chances for a more widespread wetting rain will come on
Friday as a potent shortwave spins up a surface low over the
northern Plains. Current long-range solutions show more of a
glancing blow to our southern tier of counties where higher PWATs
(1.5 to 1.75") are holed up closer to the low, though mid-range
guidance shows pockets of heavier rainfall occurring with better
instability and skinny CAPE profiles Friday afternoon. Given the
more glancing blow, the threat for excessive rain this run appears
to have fallen from previous forecasts along with the chance for
rain, which currently stands at 40-60%. Convective activity
should remain fairly limited due to weak shear (< 20 knots). High
pressure then builds into the weekend, foretelling of a drier
forecast into early next week.

Smoke...GOES satellite imagery shows a plume of elevated wildfire
smoke in place over Wisconsin with high pressure in place across
the southern Great Lakes. Subsident airmass is expected to bring
some of this smoke to the surface at times, which should become
more widespread today. Air quality is forecast to fall into the
moderate (yellow) category during this time, with minor reductions
in visibility possible. Worth noting is that overall air quality
impacts are not expected to be as drastic as earlier in the month.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 546 AM CDT Thu Jul 30 2026

VFR conditions will prevail across the region through the TAF
period. A plume of wildfire smoke drifting over the area may
slightly reduce surface vsbys, but they should remain VFR based on
upstream trends. There is also a 20-30% for showers to impact RHI
today from upstream activity sinking south from Upper Michigan;
however, minimal aviation impacts are expected. Winds will be
under 10 knots through Thursday afternoon.

Beyond the TAF period a more widespread round of showers and
thunderstorms is expected to move across the region Friday,
possibly bringing periods of MVFR conditions.

&&

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

&&

$$

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

NWS GRB Office Area Forecast Discussion