Marine Weather and Tide Forecast for Old Mill Creek, IL

UPDATE
Issued 950 PM CST Sun Dec 8 2024

Warm air advection will continue into the overnight hours, with winds shifting south to southwest, as low pressure moves from southeast Minnesota to Door County. Moisture advection in the low levels should also occur per forecast soundings, and should allow for patchy light drizzle over mainly southeast Wisconsin overnight. The area is on the northern edge of some differential CVA from a shortwave to the south as well. Temperatures will continue to slowly rise into the 40s overnight as well.

The cold front will push through the area by middle morning Monday, with the winds shifting to the west and pushing out the low clouds and any patchy drizzle. Gusty west southwest winds should then occur through the rest of the day, with mild highs in the middle to upper 40s.

Wood

SHORT TERM
Issued 306 PM CST Sun Dec 8 2024

Tonight through Monday night:

Southern WI is very mild this afternoon with temperatures topping out in the lower to mid 50s under full sunshine. The 850mb warm front is pushing into northern WI. Weak low pressure that is currently over the southern Mississippi River Valley will lift into IL overnight as an upper low weakens and tracks there as well. There is a lot of low level moisture with the weak surface low, so there is increasing confidence that some of it will brush southeast WI during the overnight hours. Given the depth of the moisture and some added synoptic lift from vorticity advection aloft and warm air advection in the low levels, there should be low clouds and some patchy drizzle over portions of south central and southeast WI. Reduced visibility down to 3 miles is possible as well, but dense fog is not expected given the non-zero winds.

Another surface low tracking across northern MN tonight will phase with this weaker low over eastern Upper Michigan Monday morning and park there for the remainder of the week. Westerly winds will develop over southern WI Monday afternoon and usher in cooler (polar) air Monday night on brisk west to northwest winds.

Cronce

LONG TERM
Issued 306 PM CST Sun Dec 8 2024

Tuesday through Sunday:

Tuesday, polar air will become entrenched across southern Wisconsin, with northwesterly winds remaining breezy. A shortwave along the edges of an arctic high will bring the next wave of even colder air Wednesday night into Thursday, with the shortwave producing chances (20-40%) of snow showers across southern Wisconsin Wednesday. Arctic high pressure settling in behind the shortwave will bring Wednesday night lows in the single digits above zero to the single digits below zero, with gusty northwesterly winds continuing and bringing wind chill values in the negative teens to negative 20 degrees.

Arctic high pressure and highs in the lower teens are expected Thursday, with wind chills in the negative single digits throughout the day. Winds shift southerly again Thursday night as high pressure continues its press eastward and low pressure develops in the lee of the Colorado Rockies. Expect temperatures to slowly warm into the weekend ahead of this next system ejecting and pressing northeastward. Chances for precipitation (20-40%) develop ahead of the system on Friday along a warm frontal feature, as well as within the system itself into the weekend. That being said, ensemble modeling indicates differences in phasing between a northern Plains clipper and the Colorado low, resulting in differences between precipitation placement and system strength. Confidence remains low in specifics at this time, but fairly high confidence exists for a period of precipitation during the weekend.

MH

AVIATION
Issued 950 PM CST Sun Dec 8 2024

Low level wind shear conditions should linger until around midnight CST, with southwest winds around 35 knots at 2000 feet AGL across the area.

Winds are expected to shift south to southwest overnight, as low pressure moves from southeast Minnesota to Door County.
Moisture in the low levels should allow for patchy light drizzle over mainly southeast Wisconsin terminals overnight, including Milwaukee, Kenosha and Waukesha. Ceilings should drop to as low as around 1000 feet AGL overnight into early Monday morning.

The cold front will push through the area by middle morning Monday, with the winds shifting to the west and pushing out the low clouds and any patchy drizzle. Gusty west southwest winds should then occur through the rest of the day.

Wood

MARINE
Issued 950 PM CST Sun Dec 8 2024

Weak low pressure around 29.5 inches over southeast Minnesota will reach Door County by early Monday morning, then drift into eastern Upper Michigan Monday afternoon. South to southeast winds will increase overnight, then become west Monday in the wake of the low. Broad and weak low pressure around 29.8 inches will sit over the Upper Great Lakes through Wednesday night.

Colder air will spill into the region Monday night, with much colder, Arctic air moving in Wednesday morning. A few gale force gusts are possible Wednesday night into Thursday morning, as the low strengthens slightly to around 29.7 inches over northern Lower Michigan. Freezing spray and lake effect snow are expected.
High pressure around 30.6 inches will settle over the Upper Midwest Thursday into Friday, then continue to drift away over the weekend.

A Small Craft Advisory may be needed Monday later Monday afternoon into Monday night north of North Point Lighthouse, for gusty west southwest winds. Winds and waves may reach these levels again Wednesday into Wednesday night, as Arctic air moves into the region on gusty northwest winds.

Wood

MKX WATCHES/WARNINGS/ADVISORIES
WI...None.
LM...None.