textproduct: Milwaukee/Sullivan

KEY MESSAGES

- A period of light rain (55-75% chance) will lift through southern Wisconsin Thursday night into Friday morning.

- Becoming even cooler Friday into this weekend, with additional precip chances (50-70%) arriving Saturday into Sunday. Some accumulating snow can't be ruled out.

UPDATE

Issued 1019 PM CST Tue Nov 4 2025

Low pressure in central Minnesota this evening will continue to track east into north central Wisconsin tonight. Clouds have moved in across the state this evening and should remain through much of the night. Rain showers along some mid level WAA and along the LLJ have started across northern Wisconsin. This area of rain should expand a bit further southward in to central Wisconsin overnight. However, the chance for Fond du Lac and Sheboygan counties to get clipped by any light rain showers has decreased below 10%. The better lift and support looks to remain north of our CWA through tonight.

Patterson

SHORT TERM

Issued 244 PM CST Tue Nov 4 2025

Tonight through Wednesday night:

It looked like sunshine was a sure bet for the afternoon, but the mid level warm air advection prevailed and produced more clouds than anticipated. As a result, the temperatures only got into the mid-upper 50s (not quite 60) for most areas and winds remained non-gusty. However, in southwest WI as the clouds cleared out, gusts up to 23 mph developed, and temperatures rose quickly into the lower 60s.

A mid level shortwave trough tracking across the Northern Plains will have a developing resultant surface low that tracks across central WI tonight. Ahead of the low, the strong low level jet (LLJ) and warm air advection will lead to continued mid and high level clouds over central and southern WI. The better chance (up to 60%) for rain will be over far northern WI and the U.P., but light rain or sprinkles may clip Fond du Lac and Sheboygan counties as the LLJ (and associated lift) ramps up this evening.

As the low exits toward northern Lower Michigan Wednesday morning, a weak cold front and gusty northwest winds will spread into southern WI. Mixing up to 3000 ft, which is not that deep, will still tap into fairly strong winds up to 35 mph. Drier air is expected to overtake the region Wednesday afternoon, and skies will clear fairly quickly behind the system. High pressure ridging in right behind it will allow for calm winds and a cool night Wed nt, with lows in the upper 20s to around 30.

Cronce

LONG TERM

Issued 244 PM CST Tue Nov 4 2025

Thursday through Tuesday:

The wind direction will quickly flip around to the south on Thursday as our next ripple in the mid level flow approaches from the Northern Plains. Yet again, we will see a period of gusty southerly winds Thursday afternoon and evening. This time, light rain is expected all along the warm air advection area from southern IL through northern WI. Amounts will be light (around 0.10 inch), and there is still uncertainty about everyone getting some rain as there will be dry air in the layers of atmosphere at times. Basically, it does not look like there will be a specific time period where the entire column is saturated.

The surface low will cross Lake Superior Friday afternoon and the associated cold front and west- northwest winds will slide into southern WI. The pressure gradient will be weaker with this system (compared to the one tomorrow), but the air will be colder behind it. Friday night lows will be just below freezing, with a potential for spots with an early development of clear skies and light winds to bottom out in the upper 20s. There is a chance that clouds could fill in earlier than expected with the next approaching system, so that would limit our cooling.

Low pressure will deepen as it tracks across central IL Saturday afternoon or evening due to a digging upper trough. This is a classic type system that brings a fairly narrow swath of higher precipitation along the northwest side of its path where the frontogenesis is strongest. The exact track of this low will waffle north and south between model runs over the next several days, so be ready for forecast changes. This system will be drawing cold air aloft (-2 to -9C) into its back side (northwest) which is coincident with the higher precip amounts. Higher rates will allow for more rapid cooling from the top down, so accumulating snow is a real possibility. It just might be in northern IL rather than southern WI, so we will keep an eye on this.

Outside of the main axis of precip, expect a rain/snow mix on the northern fringe, and rain near the lake. Onshore winds off the 55 degree lake will likely keep us all rain there. Expect brisk northerly winds Saturday night, along with flurries. Another extension of the upper low will be cross the Upper Great Lakes Sunday, which will keep us mostly cloudy with a chance of flurries or sprinkles through Monday. Lows will be solidly around 20 degrees Sunday night and Monday night inland from Lake Michigan.

Cronce

AVIATION

Issued 1019 PM CST Tue Nov 4 2025

LLWS is expected this evening into early tonight,roughly 2 AM,with 45 kts at the top of the column (2 kft). There will be some initial directional shear as southerly sfc winds differ from the westerly to northwest winds aloft. Sfc winds will back to westerly over the next few hours and winds will increase as the LLJ moves in. Speed shear is by far the bigger concern with lighter winds near the sfc and stronger aloft. The LLWS will end Wednesday morning as northwest increase and become gusty at the sfc. Wednesday morning through Wednesday evening gusts of 30 to 35 MPH will be possible. As we head into Wednesday night winds will diminish becoming light and westerly.

Otherwise largely VFR conditions are expected are expected through the period. Far northern Sheboygan and Fond du Lac could get the only instant of MVFR ceilings around 3 kft. These MVFR ceiling should largely be contained to the areas that are getting light rain overnight/early morning. Since this could largely remain to our north confidence on any MVFR ceilings is low.

Patterson

MARINE

Issued 244 PM CST Tue Nov 4 2025

A brief period of gusty south to southwest winds is expected over Lake Michigan this evening as low pressure crosses Northern Wisconsin. With the strong warm air advection aloft, the mixing should not be deep enough to tap into the strong low level jet of up to 45 kt, so not expecting gales at the lake surface.

Winds will become northwest behind the surface low and associated cold front Wednesday morning. A few gale force gusts will be possible during the early Wednesday afternoon hours, especially in the mid and southern open lake areas.

No change to the Small Craft Advisory that runs from this evening through Wednesday evening.

The next potential for southerly gales for the Open Waters is Thursday night. This is due to low pressure crossing northern Minnesota and Lake Superior. Brisk northwest winds will ensue behind the low Friday afternoon and evening, but gusts are expected to remain below gale force. Brisk northwest winds will persist through Monday as broad low pressure sits over the Upper Great Lakes and a high builds in to the central Plains.

Cronce

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 6 PM Wednesday.