Marine Weather and Tide Forecast for Little Sturgeon, WI

DISCUSSION

UPDATE...Issued at 936 PM CDT Thu May 15 2025

The line of storms just exited northeast WI. Scattered showers with a few lightning strikes are still ongoing over north central WI due to continued vorticity advection with the spinning closed low that is now over eastern North Dakota.

The southwest winds are gusty upstream with that lobe of vorticity pushing into central WI, which is due to momentum transfer. It looks like winds will taper off through the overnight hours with weaker mixing. But as soon as the sun rises, expect the gusty winds to kick in once again.

Previous Discussion...Issued at 304 PM CDT Thu May 15 2025

The Rest of this Afternoon through Friday Night:

A broken line of cellular storms has broken out, currently from Eau Claire down to Madison WI. This is line is expected to develop further and ramp up in intensity this evening. Hail and gusty winds are expected, owing to SBCAPE around 2500 J/kg amid effective shear around 40 knots. A couple tornadoes also look possible, given effective SRH values around 200 m2/s2 over much of NE WI, and an effective warm front parked from the Fox Valley up through Marathon and Lincoln County. The peak timing for storms looks to be from 5pm through 8pm this evening as the broken line moves northeast. A Tornado Watch is out from now through 10pm over much of our CWA

Storms will quickly move through and a dry punch aloft will clear out skies fairly quickly behind the storms. There will be a bit of a lull overnight, but tomorrow, enhanced mixing will lead to gusty southwest winds with some scattered gusts to 40 mph. A secondary shortwave pivoting around an upper level low and lingering moisture will squeeze out some more scattered thunderstorm activity in the afternoon. Very dry low levels and the high based nature of the storms will cause the potential for gusty winds with any storms that get established enough in the environment.

Saturday through Wednesday

The upper low will linger into Saturday. Cooler conditions are expected due to clouds and the cooler air aloft and highs will top out in the low to mid 60. Diurnally driven scattered showers may occur through the day. This upper low should move east on Sunday, restoring relative high pressure, but clouds will likely linger along with cooler temperatures as winds will come around to northeasterly. By late in the extended period, a large low pressure system is expected to approach the upper Midwest Monday into Tuesday, bringing a prolonged period of showery rain and clouds to the area. Winds will remain northeasterly off of the lake, keeping our CWA cool with highs in the 50s.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
Updated at 1050 PM CDT Thu May 15 2025

While strong thunderstorms have departed late this evening and a lull in the weather is expected overnight, expect flight conditions to deteriorate on Friday as low pressure slowly crosses the region.

South to southwest winds will become strong and gusty by mid to late Friday morning with gusts of 30 to 35 kts likely. These gusty winds will diminish on Friday evening.

Low level wind shear will likely develop across the region late tonight and continue through Friday morning.

Scattered showers and thunderstorms are forecast to develop on Friday afternoon. A few strong storms are possible that could produce wind gusts in excess of 45 kts.

Ceilings are forecast to fall to MVFR on Friday evening with another round of showers moving across the region.



MARINE
Updated at 936 PM CDT Thu May 15 2025

A small craft advisory continues into tonight. The southeast winds are switching to southwest. There should be a period of gusty southwest winds overnight, but lower confidence in them occurring over the lakeshore vs. inland. Therefore, we will probably allow the Small craft advy expire. We will need another small craft advisory for tomorrow as gusty southwesterly winds are expected to become gusty during the daytime hours.

GRB WATCHES/WARNINGS/ADVISORIES
WI...None.
MARINE...Small Craft Advisory until 1 AM CDT Friday for LMZ522.
Small Craft Advisory until 11 PM CDT this evening for LMZ542- 543.