Marine Weather and Tide Forecast for Cornucopia, WI

DISCUSSION
Issued at 241 AM CDT Sat May 17 2025

Vertically stacked low continues to slowly move eastward this morning, currently centered over northwest WI. Light rain showers continue to rotate around the system, pushing onshore over the northern portion of the North Shore, with activity near and west of Hwy 53 moving southward. Showers continue today and tonight as the system slowly pulls away from the area.
Northerly flow will reinforce cooler air over the Northland, with highs 10-20 degrees below normal this weekend. Overnight lows will cool into the 30s tonight, with low 30s in the Arrowhead. For Sunday morning, will be issuing a Freeze Watch for portions of Lake and Cook counties, and a Frost Advisory for Southern Cass and Crow Wing counties. If wind speeds trend downward or skies clear, those products might need expanding.
For Monday night, a more significant area will fall below 30 degrees, and expect more widespread freeze headlines.

Ridging builds into the area early next week, with a push of drier air southward from central Canada. Trended dewpoints down Monday and Tuesday afternoons, dropping minimum RH values in the low 20s for most of northeast MN and portions of northwest WI. Breezy easterly winds of 10-15kts are expected those afternoons. Strongest winds will be off the lake over areas around the Twin Ports, where moisture will also be a bit higher.
Another nearly vertically staked low system will move eastward across the Mid Mississippi River Valley early next week. The Northland remains on the northern side of the system, and latest guidance shows a more dominant dry airmass over the area, preventing significant moisture advection northward. Will keep low rain chances across the southern portions of the area, through mid week, for now. Would not be surprised to see these chances lowered over the next couple days. Temperatures do warm through the week, with highs in the 60s for most of the area by Thursday, and lows in the upper 30s and 40s.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
Issued at 641 AM CDT Sat May 17 2025

A stacked low pressure system will continue to rotate eastward over the Great Lakes Region today, as high pressure builds toward the Northland from the west. On the west side of this low, light rain showers will continue to pivot over the area, ending from west to east through the day. Low level moisture remains high and expect a mix of IFR and MVFR cigs to remain over forecast terminals through the day. Cannot rule out LIFR cigs tonight.

Breezy northwest winds increase this morning, with gusts of 23-28kts through the day. Winds shift more northerly tonight and diminish to 5-10kts.



MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/
Issued at 241 AM CDT Sat May 17 2025

Off and on light rain showers continue through tonight. Winds through this afternoon will be northwesterly at 10 to 15 knots with gusts to 20 knots for most of the South Shore, and up to 25 knots for the Twin Ports and up the North Shore where Small Craft Advisories remain in effect. Winds then diminish a bit and become easterly Saturday night and Sunday. Winds of 5 to 15 knots will be seen on Sunday, with some gusts to 20 knots along the South Shore and at the head of the Lake. A period of stronger easterly winds is expected for next week starting on Monday which may lead to conditions hazardous to small craft.

For the open water discussion, refer to the NWS Marquette Area Forecast Discussion at weather.gov/mqt.

DLH WATCHES/WARNINGS/ADVISORIES
MN...Freeze Watch from this evening through Sunday morning for MNZ012-021.
Frost Advisory from 1 AM to 9 AM CDT Sunday for MNZ033-034.
WI...None.
MARINE...Small Craft Advisory until 7 PM CDT this evening for LSZ140.
Small Craft Advisory until 4 PM CDT this afternoon for LSZ141>145.