FXUS63 KGRB 271117

AFDGRB



Area Forecast Discussion

National Weather Service Green Bay WI

617 AM CDT Mon Oct 27 2025



Updated aviation portion for 12Z TAF issuance



.KEY MESSAGES...



- Mainly dry conditions will persist through Thursday, courtesy of

  dominant Canadian high pressure. Rain chances Tuesday are

  minimal, as dry air should inhibit the eastward extent of the 

  rain. 



- A Small Craft Advisory is in effect from 7 pm Monday to 7 am

  Wednesday for the nearshore waters of Lake Michigan from Rock

  Island to Sheboygan. Persistent east to southeast winds of 10 

  to 20 knots with gusts to 30 knots will create waves of 4 to 7 

  ft, resulting hazardous conditions for small craft.



- High temperatures will generally be near or slightly above 

  normal all week



- High uncertainty exists for the timing of the next rain chance

  late in the week due to an upcoming pattern shift.



&&



.DISCUSSION...

Issued at 346 AM CDT Mon Oct 27 2025



Patchy fog (not as widespread as yesterday morning) was noted 

across portions of northeast Wisconsin early this morning,

generally from Clintonville and Shawano north to near Iron

Mountain. There was a wide range in temperatures early this 

morning ranging from 30 at Oconto to 47 at Manitowoc. 



Any lingering fog should burn off a few hours after sunrise, with

mostly sunny skies with highs in the middle 50s to around 60 this

afternoon. An approaching low-pressure system on Tuesday is 

expected to bring increasing cloudiness to the region. Latest 

model trends suggest the rain will hit a brick wall due to the dry

Canadian high pressure system in place. We have very low 

confidence that any meaningful rain will make it into central or 

northeast Wisconsin, with the system likely shunted to the south

Tuesday night into Wednesday. Highs on Tuesday will be in the 

50s. High temperatures today and Tuesday has been raised a few 

degrees due to the cool bias in the MOS guidance. 



Dry weather will hold firm through Wednesday and Thursday as the 

high pressure remains entrenched. The weather pattern undergoes a 

significant shift beginning Friday, as the upper-level ridging 

breaks down and transitions to a more progressive west-northwest 

flow. This change introduces significant uncertainty regarding the

timing of the next organized precipitation. Models suggest a 

chance for rain late Friday or over the weekend, but details are 

unclear. Temperatures are expected to remain near or slightly 

above normal throughout the period, and current guidance suggests 

highs may be slightly too cool and could be increased in later 

updates.



On Lake Michigan, winds and building waves prompted the issuance

of a Small Craft Advisory from 7 PM Monday until 7 AM Wednesday 

morning for the nearshore waters. On the bay, confidence was lower

in meeting Small Craft criteria, thus held off on issuing for

the bay at this time. Day shift will need to take another look

at this.



&&



.AVIATION...for 12Z TAF Issuance

Issued at 611 AM CDT Mon Oct 27 2025



Patchy dense fog and IFR or lower CIGS continue to expand across

north-central WI this morning. Have highlight the KRHI taf as the

site was down to 1/4 mile in freezing fog. Any patchy fog will 

burn off by 14z-15z this morning. Gusty southeast winds are 

expected this afternoon as VFR conditions prevail. Winds will 

diminish late this afternoon with some low clouds could develop 

again after 07z, especially for locations near the lake and Bay. 

A system moving into the plains will spread rain towards the area 

Tuesday afternoon and night, but it is not expected to reach the 

area. VFR conditions expected on Monday. 



&&



.GRB WATCHES/WARNINGS/ADVISORIES...

None.



$$



DISCUSSION.....Eckberg

AVIATION.......Eckberg