Marine Weather and Tide Forecast for Sister Bay, WI

DISCUSSION
Issued at 350 PM CDT Tue Apr 22 2025

On and off precipitation is expected through the week, with rain showers and thunderstorms in the mix. Today's rain has departed as the coinciding forcing weakened and moved northeast.
Dry weather is expected overnight into Wednesday morning. There will also be light winds and partial clearing, which could lead to fog formation. Fog will generally be patchy, but locally dense areas with visibility less than 1 mile are possible, especially in low- lying areas.

A cold front approaches central Wisconsin Wednesday afternoon and slowly moves east/southeast through the area Wednesday and Wednesday night. Aside from the front, there is not a lot of broad scale forcing yet, making any showers and storms more diurnally driven.
By mid- afternoon, forecast MUCAPE values are in the 200-800 J/kg range and bulk shear of 50-60kts. CAMs have backed down a bit on the coverage, showing more widely scattered precip on Wednesday afternoon and overnight. Due to the CAPE and shear, any thunderstorms could produce some small hail or strong winds, but severe storms are not anticipated.

Precipitation becomes more widespread from Thursday into Friday morning as a surface low tracks south of the area along the front, along with added support from the RRQ of the upper jet, and and shortwave. There is little to no CAPE forecast, so while cannot completely rule out any thunder, will generally be looking at rain throughout Thursday and Friday. It will be more light to moderate, with amounts ranging from about 0.25 to 1.00 inches, highest in central WI. The probability of exceeding 1" of rain in central WI is around 20-30%. Therefore, flooding potential will be low.

In addition to the rain, winds will be stronger on Friday and Friday night, with northeast gusts up to 30 mph. Winds will be strongest across the Fox Valley and east-central WI.

High pressure will lead to dry and quiet weather Saturday and most of Sunday. Another system could bring rain and thunderstorms early next week.

AVIATION
for 18Z TAF Issuance Issued at 1258 PM CDT Tue Apr 22 2025

A band of rain showers continues to move off to the northeast early this afternoon. Kept a mention of light showers in central/north-central WI TAF sites, and GRB for another 30 to 60 minutes until the rain fully clears out.

A mix of VFR/MVFR cigs will follow behind the rain, along with a brief period of SE wind gusts to ~15 kts.

Partial clearing and light winds are expected overnight. This will allow for some fog formation. Guidance is mixed on how dense/low vsby will be late tonight. A couple hours of IFR vsbys are possible, with fog quickly dissipating after sunrise.

VFR conditions return for Wednesday morning, through the 18Z TAF period. Scattered rain showers and thunderstorms are forecast Wednesday afternoon and overnight.

GRB WATCHES/WARNINGS/ADVISORIES
None.