textproduct: Milwaukee/Sullivan

KEY MESSAGES

- A mix of light rain and light snow is forecast overnight (30 to 60 percent chances) in south central Wisconsin, with some light freezing rain mixed in over areas mainly north of Madison. Any light ice accumulation would be on elevated surfaces. - Milder temperatures return on Wednesday, with widespread showers (around 85 percent) forecast late Wednesday afternoon during the passage of a cold front. A few rumbles of thunder possible.

- Another round of showers with a few storms (50 to 80 percent) should occur Thursday night, followed by an active weather pattern of warmer temperatures and more showers and storms Sunday into Monday.

SHORT TERM

Issued 120 PM CDT Tue Apr 7 2026

Tonight through Friday night:

Tonight, on the backside of the high pressure with low pressure across the upper Central Plains, expect a system to push through overnight into Wednesday morning. The system will be dominated by a weak upper level shortwave with strong low to mid level WAA with plenty of moisture in the mid to upper levels. Thus precip appears likely across much of southern WI for a period overnight into Wednesday morning. This appears likely to start pushing in around midnight. Moisture in the low levels will be the biggest detriment to any precip as areas, particularly to the east (closer to the high pressure), where the low level dry air may be substantial enough to limit the precip potential. However, it is generally expected to bring some precip to most of southern WI. The question then becomes what precip should we expect.

Given cooler temps aloft as this system initially pushes in the very front of the system may in fact be light snow, but given the WAA aloft a fairly significant warm nose will develop. While WAA aloft will create a warm nose the general WAA at the surface will raise temps at the surface to around or just above freezing. Toward central WI this may bring a period of freezing rain given cooler surface temps but given warmer conditions and lighter rain ice accumulations would be light and likely only on elevated surfaces. Elsewhere, temps at the surface will likely warm up above freezing making this largely just a rain event for most of the CWA. Precip will likely push out by around mid morning with clearing skies in to the day Wednesday.

The developing low out to the west will begin to push in Wednesday afternoon with the base of the low around the central US/Canada border. This low will drag a cold front through the region Wednesday evening/night with plenty of support from the a shortwave aloft as well. Precip may begin as early as the late afternoon with precip ahead of the front but the majority of it will occur Wed evening into the overnight hours primarily along the front. A tiny bit of instability may yield a rumble of thunder or two but for the most part this is expected to be moderate rain showers for a few hours in any given area with rain pushing out by Thursday morning.

With the front out of the area Thursday morning expect higher pressure to push in behind it, though this will be fairly short lived. Thursday during the day is expected to remain dry but by Thursday evening expect a warm front to lift north into the area based from a weak low pressure developing in lee of the Rockies into the central Plains. A shortwave aloft, strong WAA on the nose of the LLJ in the low to mid levels with a moist column suggest a very high chance for precip Thursday night with a slug of rain expected. The best chances (75+%) will be for the southern portions of the CWA with lesser chances (40-70%) toward central WI. Thunder looks unlikely given the profiles suggesting very limited instability but we cannot rule out a rumble of thunder, especially if the warm front lifts any farther north than currently expected. Precip will generally push out sometime Friday morning as high pressure nudges in from the northwest, shoving the front back to the south. High pressure will continue to push east but will strengthen into the central Great Lakes region keeping us dry. East wind off the lake from the high pressure will keep us fairly cool, however.

Kuroski

LONG TERM

Issued 120 PM CDT Tue Apr 7 2026

Saturday through Tuesday:

High pressure is expected to bring quiet weather through the daytime hours Saturday. High clouds will likely increase during the day as the high begins to exit to the east, with light southeast winds also expected on the back side of the high. High temps will be a couple to few degrees above normal under the light southerly low level flow, mildest in the west away from Lake Michigan.

Southerly low level flow will continue Saturday night through at least Monday per 12Z models, which will result in even milder conditions late weekend into early next week. Highs into the low to mid 70s are likely for Sunday and Monday. Additionally, expect periods of warm advection aloft and increasing moisture as a couple of shortwaves roll through. This will bring multiple rounds of shower/storm chances Sat night through Monday. Could see some stronger storms Monday or Monday night as the low and associated cold front move through, though confidence in low strength/timing/placement is not high at this time given variations among the latest model solutions. Plus, this period is several days out, so plenty of time for the finer details to change.

Kept precip chances going Tuesday as the low slowly exits the region, with cooler temps arriving on the back side of the low for mid-week.

DDV

AVIATION

Issued 120 PM CDT Tue Apr 7 2026

Clear skies and light winds are expected through the rest of the day. Look for winds to become southerly this evening as mid level clouds begin to spread in from the west. A period of snow/freezing rain/sleet is possible during the overnight hours, mainly north of Madison to West Bend between 1 and 4 AM (08-11Z). A brief and very light wintry mix is possible south of there. Ceilings and visibility are expected to remain VFR during the precip, but conditions may briefly become MVFR.

Kuroski

MARINE

Issued 120 PM CDT Tue Apr 7 2026

High pressure around 30.6 inches has moved across central Lake Michigan lowering winds generally across the lake. Low pressure around 29.5 inches will then track along the Northern Plains/Canadian border tonight and Wednesday, then track north of Lake Superior Wednesday night into Thursday morning. This will result in breezy southerly winds over Lake Michigan on Wednesday with gale force gusts up to 40 kt. A Gale Warning is in effect for the northern three quarters of the lake. A Gale Warning is also in effect for a period Wednesday for the northern nearshore zone with the rest of the nearshore in a Small Craft Advisory.

Much weaker north winds will then take hold by Thursday afternoon into Friday as high pressure around 30.4 inches slowly moves through the region. Breezy southerly winds return toward early next week as a stronger system pushes in from the west.

Kuroski

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...Small Craft Advisory...LMZ643...4 AM Wednesday to 9 AM Wednesday.

Gale Warning...LMZ643...9 AM Wednesday to 7 PM Wednesday.

Gale Warning...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ868-LMZ870-LMZ872- LMZ874...7 AM Wednesday to 4 AM Thursday.

Small Craft Advisory...LMZ644-LMZ645-LMZ646...4 AM Wednesday to 4 AM Thursday.