textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Gusty north northeast winds overnight will bring in colder temperatures into Friday. Lake effect clouds near the lake are expected into Friday morning as well.

- There are at least slight chances (around 20 to 30 percent) for snow showers Friday afternoon, with the highest chances toward Sheboygan.

- Elevated fire weather conditions are possible this weekend, with gusty winds and very low relative humidity values.

- Warmer temperatures are expected by later this weekend into Monday.

- Trending toward active weather next week, with multiple chances for showers and thunderstorms Monday night through Wednesday.

SHORT TERM

Issued 1247 AM CDT Fri Mar 27 2026

Overnight through Monday:

The gusty north northeast winds have scoured out a lot of the low clouds over areas away from Lake Michigan, with some high clouds still pushing east northeast through the region. These winds have also brought a band of lake effect low clouds into the lakeshore areas, and should linger overnight into Friday morning.

Cold air advection will continue into Friday morning, with lows overnight into the middle to upper 20s. Highs Friday should rebound into the lower to middle 40s, but will feel more like the 30s with the north northeast winds into the morning, though they will gradually decrease and shift northwest by midday. They will become gusty again in the afternoon, reinforcing the 30s wind chills.

There is still at least a slight chance (around 20 to 30 percent) for snow showers to occur over far northern and northeastern portions of the area Friday afternoon. This is a result of a strong 500 mb vorticity maximum with good differential CVA pushing through the area. Forecast soundings have steep lapse rates in the low levels, with some moisture toward the 850 mb level and a little instability developing with peak heating.

CAMs and most deterministic models are dry for this period in that area, though the HRRR does try to bring some very light QPF into the far northeast parts of the area by 00Z Saturday. For now, left in PoPs around 20 percent or so for Friday afternoon.

Any heavier snow showers that may develop could bring a quick dusting to a few tenths of an inch of snow accumulation, though pavement temperatures may be too warm and most of this may melt. It does not look like a snow squall situation, as there is very little if any low level frontogenesis response moving through the area. This period will continue to be monitored.

High pressure will pass by to the southwest Friday night and southeast of the region Saturday. This will bring increasing south to southwest winds into the area Saturday into Sunday, as the pressure gradient tightens somewhat. This should result in warm air advection with warming temperatures this weekend, along with decent low level mixing and dew point/relative humidity drops each afternoon. Thus, elevated fire weather conditions may occur.

Highs in the middle to upper 40s Saturday should rise into the 60s for Sunday. The winds may allow for the warmer temperatures to reach the Lake Michigan shore each day, except for areas toward Port Washington and Sheboygan where south winds may keep onshore flow going.

The warm air advection should linger into Monday, with highs possibly into the upper 60s or lower 70s well inland. There may be easterly flow that develops Monday, if the warm front stays to the south of the area, so temperatures closer to the lake are far more uncertain, per ensemble members and NBM. Dew points should start to rise somewhat by Monday, which should bring relative humidity values up.

Wood

LONG TERM

Issued 1247 AM CDT Fri Mar 27 2026

Monday night through Thursday:

This whole period features a more active weather pattern, with multiple chances for precipitation. Very warm weather is expected on Tuesday, followed by a cool down to milder conditions (though with a high degree of uncertainty) for the middle of next week.

Ensembles depict a low pressure system tracking eastward across the Dakotas Monday night, passing either overhead or further north in Wisconsin later Tuesday or Tuesday night. Ensemble IQRs for Tuesday's daytime high temperature remain relatively tight and well into the 70s for inland areas, suggesting high confidence in very warm weather from the surface WAA ahead of the low.

Depending on the exact trajectory of the low, we could see inland highs in the mid 70s (or even upper 70s), with either a stiff southerly breeze (shoreline highs in the 60s) or stiff southwesterlies (shoreline and Milwaukee metro reach 70s as well). In either case, roughly 50 percent rain chances for Monday night (WAA aloft/warm front), Tuesday (warm front/warm sector convection), and Tuesday night (cold front) are appropriate.

With that level of warmth/moisture return, we wouldn't be surprised to see some thunder with that as well, and as the track of the system becomes clearer, we'll assess whether we could be looking at some strong/severe storms. GEFS potential for greater than 1000 Joules/kg of CAPE on Tuesday is sitting at roughly 50 percent (highest further southwest in Wisconsin) with significant variability from one member to the next.

Cold advection ensues as the low pressure departs, likely leaving a cooling trend (milder temperatures) for Wednesday and Thursday, followed by a gradual warm-up. Beyond that, predictability is incredibly low from Wednesday onwards. The only common thread from ensemble guidance is a chance for an additional slower-moving low pressure system (perhaps a Colorado low) to track northeastward towards our region mid or late next week, delivering additional precip chances. Rain would easily be the dominant solution for precip type, due to the antecedent warmth, with potential for thunder in the (uncertain) event of a potent moisture return/deeper low pressure.

Sheppard

AVIATION

Issued 1247 AM CDT Fri Mar 27 2026

The gusty north northeast winds have scoured out a lot of the low clouds over areas away from Lake Michigan, with some high clouds still pushing east northeast through the region. These winds have also brought a band of lake effect low clouds with 1500 to 2000 foot AGL ceilings into the lakeshore terminals, and should linger overnight into Friday morning. Ceilings should become more VFR category by Friday afternoon, then clear out Friday night.

The gusty north northeast winds overnight will gradually decrease Friday morning and shift northwest by midday. They will become gusty again in the afternoon, before gradually weakening in the evening.

There is still at least a slight chance (around 20 to 30 percent) for snow showers to occur over far northern and northeastern portions of the area including Sheboygan Friday afternoon. For now, left mention out of the Sheboygan TAF due until more confidence in snow showers affecting that site is gained.

Any heavier snow showers that may develop could bring a quick dusting to a few tenths of an inch of snow accumulation, though pavement temperatures may be too warm and most of this may melt.

Wood

MARINE

Issued 1247 AM CDT Fri Mar 27 2026

Strong high pressure around 30.8 inches will move from the southern Canadian Prairies into the Northern Plains overnight. Ahead of the high, strong north northeast winds will linger across Lake Michigan into early Friday morning. A Gale Warning remains in effect through early Friday morning across the southern two thirds of the lake, and the nearshore waters, for widespread gales of 35 to 40 knots. A few gales to 35 knots may occur in the northern third of the lake. Winds will gradually diminish Friday morning, as the high moves into the Upper Midwest.

High pressure will continue to move southeastward on Friday, with northwesterly winds developing as it passes to the south Friday night. Winds will gradually back to southerly into Saturday afternoon, as low pressure around 29.7 inches develops in the lee of the Colorado Rockies. Winds may shift to the north and northeast on Monday, as a warm front sets up to the south of the region.

Winds and waves may increase late Monday into Monday night, lingering Tuesday into Thursday, with Small Craft Advisory conditions possible at times.

Wood

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...Gale Warning...LMZ080-LMZ366-LMZ565-LMZ567-LMZ643-LMZ644- LMZ645-LMZ646-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779- LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 until 5 AM Friday.