textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Area of light drizzle and light freezing drizzle will continue to shift east across southern portions of the area early this morning. They are weakening as they encounter dry air to the east, but slick spots may still occur in areas at or below freezing.

- Temperatures are trending well above normal through the end of the week.

- Additional periods of rain are forecast Wednesday night into Thursday (about 40 to 70 percent chances) and Friday into Saturday (80-plus percent chances). Some thunderstorms are possible in each round of rain.

UPDATE

Issued 555 AM CST Tue Mar 3 2026

The area of light drizzle and light freezing drizzle will continue to shift east across southern portions of the area early this morning, as 700 mb frontogenesis response works with some moisture in the 850 mb to 700 mb layer. There is still some dry air below 850 mb, which appear to be helping to weaken this area as it shifts east. Will continue to keep this in the forecast until middle morning, when temperatures rise above freezing and the frontogenesis response shifts east of the area. There still may be some slick spots that occur in areas at or below freezing, as well as elevated and untreated surfaces, for the next few hours.

Low clouds may move north into southern portions of the area for a time this morning, before retreating southward this afternoon. Highs should reach into the middle 40s inland, with highs around 40 near the lake.

Clearing should push into the area this evening, as weak high pressure develops over the area. Patchy fog is possible in northern parts of the area later tonight into early Wednesday morning. As temperatures drop below freezing, may see some slick spots develop in low lying areas with the fog/freezing fog. Lows should drop into the middle to upper 20s tonight.

Wood

SHORT TERM

Issued 1159 PM CST Mon Mar 2 2026

Tonight through Thursday:

Synopsis/Mesoanalysis: High pressure is centered off the Northeast coast late this evening, with an affiliated surface ridge entrenched across the majority of the state. Evident in regional radar, a narrow area of light rain is ongoing over northern Iowa. Said rainfall is being driven by an area of upper divergence & accompanying warm advection & frontogenesis in the 850-700 mb layer. The precip will attempt to work east-southeast into the area late tonight/early Tuesday morning as its affiliated forcing mechanisms move toward southern Lake Michigan. How far east the precipitation reaches remains uncertain given lingering low level dry air affiliated with the aforementioned surface ridge, though locations generally along and south of a Wisconsin Dells - Waupun - Port Washington line standing the best chances of seeing light precipitation during the 3-9 AM time frame. Some light freezing rain is possible at the onset of precipitation, particularly from Monroe - Madison - Wisconsin Dells and points east. A light glaze of ice can't be ruled out on untreated surfaces in any locations experiencing light freezing rain, though any icing will be quick to melt as temperatures rise following sunrise. Budget a few extra minutes of time if planning to be on the roads early Tuesday morning. Precip will quickly wrap up by late Tuesday morning, with dry conditions continuing through most of the day Wednesday. The next disturbance will slowly move in Wednesday night through Thursday, bringing the next chances for rain & perhaps a few thunderstorms to southern Wisconsin.

Late Tonight into Tuesday morning: Will be closely monitoring incoming precip as it attempts to work into the area. Low level dry air will prove to be a limiting factor on precip reaching the surface, particularly outside of the narrow zone of enhanced lift being provided by upper divergence & 850-700 mb warm advection and frontogenesis. Expect that said forcing mechanisms will remain south of a Wisconsin Dells - Waupun - Port Washington line. Have updated precip probabilities to account for ongoing radar trends, with areas in the southwest corner of the CWA having the greatest potential of seeing light precipitation. Have maintained mentionable but lower precip probabilities moving east of I-39, where the influences of dry air could become an even bigger limiting factor on the eastward progress of precip. Due to periods of clear skies through the first half of the evening, surface temps have become cool enough to support some initial freezing rain or freezing drizzle along & east of a Monroe - Madison - Wisconsin Dells line. Thus can't rule out some very light icing of untreated surfaces in these locations in the event precip reaches the ground. Continue to expect that any related impacts would remain below Special Weather Statement/Winter Weather Advisory thresholds, but will nevertheless be monitoring trends through the predawn hours.

Tuesday night into Wednesday morning: Will be monitoring for some patchy fog/frost potential with skies clearing out and surface winds remaining light. Given a very shallow near-surface moist layer, could see more frost than fog, but can nevertheless rule out some visibility reductions in some spots. Have thus inserted mentions in the evening forecast update. Will need to monitor temperature trends in the event fog becomes more favored, as sub-freezing surface temperatures would lead to some patchy freezing fog & slick spot potential on untreated surfaces.

Wednesday evening into Thursday: The next disturbance will gradually move in, leading to increasing rain chances across the region. Global deterministic & ensemble guidance is beginning to converge on a disturbance track across the southeastern half of the area, which is translating to likely precip probabilities southeast of a Monroe- Madison-Sheboygan line with chance probabilities further northwest. Do continue to see some weak instability in LREF forecasts, so a few embedded thunderstorms remain possible with rain occurring during the late Wednesday - Thursday time frame. Not expecting any strong/severe hazards, though some cloud to ground lightning and brief heavy downpours would be possible in any embedded thunderstorms. Anticipate measurable rainfall accumulations, with probabilistic guidance indicating ~40-70% chances of 0.25" or greater over the southeast half of the area with lighter totals further northwest.

Quigley

LONG TERM

Issued 1159 PM CST Mon Mar 2 2026

Thursday night through Monday:

Weak shortwave ridging will briefly take hold Thu nt in the wake of the shortwave trough. Stratus clouds will likely linger and cannot rule out patchy drizzle.

An upper low over the Intermountain West Thu nt will then eject newd as an open shortwave trough to the Mid MO River VAlley or srn MN by 12Z Sat. The sfc low will track into the same region by 00Z Sat with a warm front extending ewd along the WI and IL border. The GEFS is more amplified with this low pressure area than the Ens ECMWF, but both are expected to bring sufficient warm, moist advection and lift for widespread rain (80-90 percent) Fri afternoon and night. The sfc warm front will pass nwd Fri nt while low pressure tracks through wrn and nrn WI, likely reaching Ontario Sat AM. The cold front will then pass on Sat, likely in the morning. Overall the timing and evolution of this system could change to some degree, but a mild and wet period is still likely. High temps in the 50s and 60s are forecast.

Afterward an active quasi-zonal polar jet stream over srn Canada will then result in strong low pressure tracking ewd across far nrn Ontario on Sunday. This will support dry swly winds and warm advection over srn WI with continued mild temps. A dry cold front will then pass Sun nt with high pressure for Mon.

Gehring

AVIATION

Issued 555 AM CST Tue Mar 3 2026

The area of light drizzle and light freezing drizzle will continue to shift east across southern portions of the area early this morning. There is still some dry air in the low levels, which appear to be helping to weaken this area as it shifts east. Will continue to have light drizzle mentioned at most terminals until 15Z, with PROB30 mentions for light freezing drizzle. There still may be some slick spots that occur in areas at or below freezing for the next few hours.

Low clouds with ceilings dropping to 1500 to 2500 feet AGL should move north into southern portions of the area for a time this morning, before retreating southward this afternoon. Light east to southeast winds should become north to northeast by later this afternoon.

Clearing should push into the area this evening, as weak high pressure develops over the area with light winds. Patchy fog is possible in northern parts of the area later tonight into early Wednesday morning. As temperatures drop below freezing, may see some slick spots develop in low lying areas with the fog/freezing fog, but will keep mention out of terminals for now. Winds should become east to southeast on Wednesday, with mostly sunny skies.

Wood

MARINE

Issued 1159 PM CST Mon Mar 2 2026

1000 mb low pressure is centered over the Hudson Bay this evening, with 1040 mb high pressure positioned off the coast of the northeastern United States. Placement of the two surface features is resulting in generally south to southeasterly breezes across the open waters of Lake Michigan. Winds will lighten from the second half of the overnight through Tuesday morning as a small area of 1022 mb high pressure attempts to develop over the western Great Lakes. An upper disturbance is forecast to cross southern Lake Michigan late tonight into Tuesday morning, bringing chances for light rain or freezing rain to the southern half of Lake Michigan.

Light south to southwesterly winds will continue across the northern half of Lake Michigan through Wednesday, while winds shift out of the east further south in response to developing 1012 mb low pressure in the middle Mississippi River Valley. Said low will likely pass just to the south of Lake Michigan Wednesday night into Thursday, allowing for northeast winds to become established across the entirety of the open waters. Rain showers will spread north across the open waters in response to the approaching/passing low Wednesday afternoon through Thursday. A few thunderstorms are possible over southern Lake Michigan Wednesday afternoon & evening. Severe weather is not anticipated.

1000 mb low pressure remains forecast to develop in the central Great Plains Thursday night, and is expected to be somewhere between the Upper Mississippi River Valley & northern Wisconsin by Friday evening. Said low will move near or just north of northern Lake Michigan Friday night into Saturday morning, quickly moving into Quebec by Saturday evening. South to southwest winds will thus steadily increase ahead of the developing & approaching low Friday afternoon into Saturday morning, ultimately veering westerly Saturday afternoon. Winds will be gusty at times during the Friday- Saturday time frame, with a few gales possible Friday night into Saturday morning. It remains uncertain if any gales would be widespread enough to warrant headlines. Widespread rain and embedded thunderstorms will accompany the approaching/passing low Friday through Saturday, with strong or severe storms not anticipated at this time.

Isolated to widely scattered thunderstorms are possible in nearshore zones ahead of approaching/passing low pressure systems Wednesday afternoon & evening, and once again Friday into Saturday. Not currently expecting widespread strong or severe storms in either round of activity. Winds & waves will approach Small Craft Advisory thresholds Friday night through Saturday morning, with trends being monitored for possible headlines in later forecasts.

Quigley

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...None.