817 

FXUS63 KGRB 050341

AFDGRB



Area Forecast Discussion

National Weather Service Green Bay WI

1041 PM CDT Thu Jun 4 2026



Updated aviation portion for 06Z TAF issuance



.KEY MESSAGES...



- An Air Quality Advisory is in effect for portions of northeast

  and east-central WI until 11 pm this evening. 



- There is a 40-70% chance of showers and storms from late this 

  afternoon into Friday morning. 



- Additional storms are expected again Friday afternoon and

  evening. Some of the storms could become strong or severe with

  damaging winds and large hail. The highest risk of stronger

  storms will be from 4 pm to 10 pm. 



- Increasing heat and humidity will result in the heat index

  climbing into the 90s at most places later next week.



&&



.DISCUSSION...

Issued at 151 PM CDT Thu Jun 4 2026



Another warm afternoon with temperatures in the lower to 

middle 80s. The relative humidity dropped to 25 to 35% away from

the bay and lake. Meanwhile, scattered showers and thunderstorms

developed across western Wisconsin over the last hour or two. 



The scattered showers and storms are expected to move into north-

central and central WI between 3 pm and 6 pm. Brief heavy rain,

gusty winds and small hail are possible with the stronger storms.  

The showers and storms are then expected to spread eastward into

northeast and east-central WI around or shortly after midnight. 

There is still a lot of uncertainty in the extent of the 

precipitation later tonight into Friday morning across east-

central WI due to differing model solutions. On Friday, a weak

cold front will move across the area bringing another round

of showers and thunderstorms Friday afternoon and evening. 

Bufkit soundings indicated 800-1,200 of CAPE and 0-6 km 

shear values of 30-35 knots to support the potential for

stronger/severe storms. It all may come down to how

much clearing takes places Friday morning into the afternoon.



Otherwise, there is a small chance of isolated storms across

east-central WI Saturday afternoon. The next widespread chance

of showers and storms will be Monday afternoon into Tuesday.

Stronger storms will be possible during this time frame.



Later next week, heat and humidity will build across the region

with temperatures well above normal for early June. By late in

the week, many locations will experience heat index values into

the 90s, and possibly a few locations hitting the triple digits. 

The intense heat could cause a few roads/highways to buckle.



&&



.AVIATION...for 06Z TAF Issuance

Issued at 1041 PM CDT Thu Jun 4 2026



Band of showers along a frontal boundary extending from north-

central WI back toward central IA continues to slowly move east late 

this evening. As this boundary shifts east overnight and as showers 

move over any terminals expect brief periods of MVFR conditions. As 

the showers dry up in central and northern WI overnight period of 

IFR status and patch fog is possible. Have cigs dropping to 600-

700ft for the pre-dawn hours at AUW, CWA, and RHI. Conditions should 

gradually improve Friday morning as cigs rise. 



Another round of thunderstorms is likely (60-70%) Friday afternoon 

and evening as a cold front drops south across the region. Have 

framed out forecast arrival window for those thunderstorms will 

PROB30 groups at all TAF sites, generally between 22-04Z. Main 

hazards with these storms will be strong wind gusts and cloud to 

ground lightning.



&&



.GRB WATCHES/WARNINGS/ADVISORIES...

Beach Hazards Statement until 1 AM CDT Friday for WIZ022-040-050.

&&



$$



DISCUSSION.....Eckberg

AVIATION.......GK