FXUS63 KGRB 042300

AFDGRB



Area Forecast Discussion

National Weather Service Green Bay WI

600 PM CDT Mon May 4 2026



Updated aviation portion for 00Z TAF issuance



.KEY MESSAGES...



- Warm and breezy through early this evening with low relative

  humidities and elevated fire weather conditions. 



- Wind gusts 35 to 40 mph expected across central to eastern

  Wisconsin through early this evening. 



- A line of showers and thunderstorms (20-30% chance) could 

  develop late this afternoon across the southern Fox Valley and 

  lakeshore. Stronger storms could produce wind gusts 40-50 mph.

 

- Temperatures fall below normal for the rest of the week. Risk 

  for Frost/Freeze Headlines ramps up beginning Tuesday night.



&&



.DISCUSSION...

Issued at 1251 PM CDT Mon May 4 2026



Breezy and warm conditions are expected through early this evening

as a cold front continues moving through the region. CAMs show a 

thin line of showers and thunderstorms developing across the far 

southeastern portion of the area, including the southern Fox 

Valley east to the lakeshore. However, much of the area should 

for the most part escape unscathed with no rain from this cold 

front. In fact, the recent CAMs runs develop this line just 

outside of our area or just the extreme southeastern portion of 

our area. Therefore, lowered POPs a notch with the highest amount 

only 30% instead of 40% given the lower probability of seeing rain

from this front. If storms do develop, inverted-V soundings

indicate gusty winds of 40-50 mph will be possible. Given the

synoptic winds are already gusting to 30 to 40 mph, it won't take

much to push winds just a bit higher. Any activity would quickly 

move southeast out of the area; therefore, the window for this 

isn't particularly large and only a few hours.



Gusty winds will continue this evening behind the cold front and

slowly subside throughout the night. Winds should die down below

20 mph sometime around or shortly after midnight.



Cooler weather is then expected for the rest of the week with

temperatures just below normal for this time of year. Daytime

temperatures will mainly be in the 50s, with 40s closer to the

lakeshore. The cooler temperatures will bring the risk for

Frost/Freeze potential during this period, with the highest

potential Tuesday night through Thursday night. Temperatures will

then rebound to around normal for this time of year by the

weekend, with a low risk for additional Frost/Freeze headlines.



Conditions are expected to mainly be dry for the rest of the 

week; however, there will be small (10% chance) for an isolated 

shower Tuesday and Wednesday as shortwaves rotate around the upper

level trough located across the Great Lakes region. There is a 

better chance (20-30%) for showers on Thursday as a more vigorous 

shortwave dives southeast with a bit more moisture in the column.

Mainly dry conditions are then anticipated late in the week into

the early part of the weekend, with a low (10-20%) chance for

showers late in the weekend.



&&



.AVIATION...for 00Z TAF Issuance

Issued at 600 PM CDT Mon May 4 2026



Early this evening, a cold front is exiting the NE WI lakeshore.

Scattered showers and storms continue to develop south and east of

KMTW, but lighter activity north to Washington Island is likely 

no intense than just sprinkles. Winds continue to gust from 20 to 

30 kts across the region.



For tonight, expectations are for showers to exit the NE WI lakeshore

by 00z. As winds veer to the west- northwest, the gusts will take

some time to subside and likely remain in the 20 to 25 kt range 

until 02-05z. Then winds will gradually subside overnight to 10-15

kts. 



Conditions will remain VFR as skies gradually clear from 

northwest to southeast behind the departing cold front. Cloud

bases will remain above 6 kft until the clearing occurs.



After a period of mostly clear skies overnight, fair weather 

clouds will pop with daytime heating on Tuesday. Coverage will be 

highest north and west of the Fox Valley, but ceilings will likely

be above 4.5 to 6 kft. West-northwest wind gusts to 20 kts can be

expected on Tuesday afternoon.



&&



.GRB WATCHES/WARNINGS/ADVISORIES...

None.



&&



$$



DISCUSSION.....Kurimski

AVIATION.......MPC