Marine Weather and Tide Forecast for St. Francis, WI

SHORT TERM
Issued 201 PM CDT Thu Oct 15 2026

Tonight through Friday night:

Widespread rain will continue into this evening, as surface low pressure clips the southeast forecast area ahead of a strong approaching trough. It still looks like the northwest half of the forecast area will wind up with the higher rainfall totals given the low track, with upstream radar adding confidence to this scenario.

Rain chances will be lower overnight tonight into early Friday morning as the surface low pulls away, with scattered showers then expected by mid-Friday morning and into the afternoon as the strong trough swings through. Blustery north winds are expected by Friday afternoon behind the trough. Gusts to 30 knots are likely, with a few gusts to 35 knots possible towards Lake Michigan. High temperatures tomorrow will will be well below normal, only rising to about 50 by the afternoon.

Decreasing clouds and winds Friday night will allow for temps to drop quite a bit, as the colder airmass behind the departing system continues to settle into the area. Overnight lows may drop below 30 across much of the southern Wisconsin away from Lake Michigan. A Freeze Watch is in effect for these areas. At the very minimum, most (if not all) locations across the forecast area will likely see a round of frost.

DDV

LONG TERM
Issued 201 PM CDT Thu Oct 15 2026

Saturday through Thursday:

High pressure is expected to largely be in place across the region this weekend into the middle of next week. A prolonged period of mainly dry weather is thus likely during this period.
Temperatures should gradually warm over the span of these few days, as southerly low level winds develop while upper level ridging nudges into the area. Above normal temps are likely by mid-week.

DDV

AVIATION
Issued 201 PM CDT Thu Oct 15 2026

Widespread rain along with lower ceilings and visibilities will continue into this evening. Rain chances will be lower overnight into Friday morning, though lower ceilings will linger.
Scattered showers are then expected later Friday morning and into the afternoon.

Light easterly winds this afternoon will become west/northwest from west to east this evening behind low pressure moving through the area. Stronger north winds are then expected Friday, with gusts to 30 knots likely, with a few gusts to 35 knots possible towards Lake Michigan.

DDV

MARINE
Issued 201 PM CDT Thu Oct 15 2026

Two areas of low pressure are progged to merge over the Great Lakes region into a single low pressure later today into tonight and deepen to around 29.4 inches as it shifts into the eastern Great Lakes through Friday. Expect a northerly wind shift to ramp up and increase to gales and nearing storm force at times Friday on the backside of the departing low pressure while a strong high pressure around 30.7 inches builds to the west. A Gale Warning remains in effect for all of the open waters of Lake Michigan Friday morning into Friday night.

Widespread rain is expected this afternoon into tonight, with a few thunderstorms possible over the southern open waters. Lake effect showers & a few thunderstorms may linger into Friday along the back side of departing low pressure. A few waterspouts are possible in the Friday showers/thunderstorms, particularly over the southern half of Lake Michigan.

As the high sinks toward the Ohio River Valley on Saturday, strong low pressure around 29.0 inches will develop in northern Manitoba through the weekend. The tight pressure gradient may bring southwest gales to Lake Michigan on Sunday.

DDV

MKX WATCHES/WARNINGS/ADVISORIES
WI
Freeze Watch
WIZ046-WIZ047-WIZ051-WIZ052-WIZ056-WIZ057- WIZ058-WIZ059-WIZ062-WIZ063-WIZ064-WIZ065-WIZ067-WIZ068- WIZ069-WIZ070...1 AM Saturday to 9 AM Saturday.

LM
Gale Warning
LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563- LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779- LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...10 AM Friday to 1 AM Saturday.

Gale Warning...LMZ643-LMZ644-LMZ645-LMZ646...10 AM Friday to 10 PM Friday.

Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 10 AM Friday.