Marine Weather and Tide Forecast for Green Bay, WI

DISCUSSION
Issued at 246 AM CDT Fri Mar 13 2026

Today...

The ongoing clipper system will continue to bring snowfall across the region through the morning hours before quickly departing in the afternoon hours. Early morning observations show rain beginning to mix in across portions of central Wisconsin to east- central Wisconsin, with snow predominantly only on grassy and raised surfaces but struggling to get on roads. Therefore, will leave these areas free of winter weather headlines for now.
Further north, snow has shown better accumulation, especially for areas north of a line from Wausau to Oconto. Moderate to occasionally heavy snowfall remains in these areas and is forecast to continue, adding up to 3 to 5 inches to many areas. The main change for the winter headlines will be upgrading Door County to a Winter Storm Warning, primarily for the northern portions of the County and Washington Island, which will see an increase in overall snowfall on the backside of the passing clipper as winds shift to the northeast. Probabilistic guidance suggests a 70-80% chances of exceeding 5 inches for this northern area, which combined with the increased winds up to 45 mph during this period, will likely see heavier impacts, thus the upgrade.

Wind-wise, morning observations show decent mixing with gusts up to 25 to 40 mph at times across portions of our area. These winds will shift to the northeast through the morning and likely see some increases up to 35 to 50 mph at times by the mid to late morning hours and last into the afternoon (40-60% chance at any one location). Thus, no changes expected to the Wind Advisory at this time. Fortunately, the main core of winds aloft, which have been observed to bring 50 to 60 mph wind gusts to the surface in Iowa overnight, will likely miss our area to the south, bringing the stronger gusts to areas of northern Illinois and southern Wisconsin.

Weekend System...

A major winter storm is expected to impact the region starting Saturday night and lasting into Monday, bringing widespread travel disruptions and impacts to most of northeastern Wisconsin. The long residence time, ample moisture drawn all the way from the Gulf, and significant dynamic forcing will all serve to bring some impressive, possibly even record setting snowfall to the region.
Probabilistic guidance remains near 70-100 percent for over a foot of snowfall, with a corridor of 40-70% for two feet of snowfall over the course of the 36 to 48 hours. This would also make for some locally even higher amounts in the areas of the strongest snowbands. The main uncertainty that has crept into this forecast will be along the southern edge of the snowband where soundings suggest the warmth and moisture aloft may be sufficient for sleet and possibly some freezing rain. This would reduce snow totals for portions of the Fox Valley and eastwards to the lakeshore areas in east- central Wisconsin, but areas further north and west will still see higher amounts. It also bears mentioning that even "reduced snowfall" for this system is still around or over a foot of snow; all things are relative.
Accompanying the snowfall will be a period of strong wind gusts, with guidance suggesting widespread 80%+ of exceeding 35 mph gusts at times. Combining these factors increases the potential for blizzard and possibly whiteout conditions at times Sunday through Monday, which will bring widespread travel disruptions. The main question that remains is where these conditions will align best, given the aforementioned changes on the southern end. All said, expect travel to become extremely difficult to impossible Sunday into Monday, so now is the time to make alternate arrangements.

AVIATION
for 12Z TAF Issuance Issued at 651 AM CDT Fri Mar 13 2026

Poor flying conditions continue across the region this morning as active weather continues to bring IFR ceilings and visibility to the northwoods. Further south, from a line from Wausau to Green Bay, precipitation has transitioned to a light rain, which has helped bring some MVFR conditions to the region. However, strong winds will move in as winds shift to the west and then the northwest by the afternoon with periodic gusts up to 35 to 40 knots. The highest winds will be around in the mid to to late morning before slowly decreasing through the afternoon hours. Better flying conditions then finally arrive late tonight into Saturday, as skies clear and winds subside.

GRB WATCHES/WARNINGS/ADVISORIES
Winter Storm Warning until 1 PM CDT this afternoon for WIZ005- 010>013-018>022-073.

Winter Storm Watch from Saturday evening through Monday afternoon for WIZ005-010>013-018>022-030-031-035>040-045-048>050- 073-074.

Winter Weather Advisory until 1 PM CDT this afternoon for WIZ030- 031-074.

Wind Advisory until 6 PM CDT this evening for WIZ035>040-045- 048>050.