textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Scattered to numerous showers (40 to 70 percent chance) should move east through the area this evening. Isolated to scattered thunderstorms (20 to 30 percent chance) may occur, especially north of I-94. A stronger storm or two may produce hail and gusty winds north of Madison.

- There are chances for showers (20 to 60 percent chance) Sunday into Sunday evening, highest south. Thunderstorms look unlikely to occur. Northeast winds with dry low level flow may limit shower chances in the area, so expect more refinements to the precipitation forecast.

- Chances for showers and thunderstorms at times toward the middle to later portions of next week.

UPDATE

Issued 655 PM CDT Fri Jun 19 2026

Dry air and forcing not aligning has been the main driver for lack of organized develop this evening. The better forcing and support remains to the northwest in central WI where the base of the shortwave trough and instability line up better. While chances for showers south of the west to east extent of I-94 look light and sporadic, still could see some thunderstorm develop over the next couple of hours for our central and east central WI counties as the trough swings eastward through the evening. While unlikely at this point, still not completely out of the realm of possibility to see a stronger storm or two move into the northern fringes of the CWA capable of producing hail and localized gusty winds. However, the later arrival paired with the drier air may limit the coverage keeping any of the more organized/stronger activity isolated. Chances quickly diminish this evening as drier airmass quickly settles in behind this system and chances end by 04-06z.

Wagner

SHORT TERM

Issued 211 PM CDT Fri Jun 19 2026

Late This Afternoon through Saturday night:

A 500 mb shortwave trough will shift southeast toward the area into early evening, then shift through the area this evening into later tonight. A weak surface low should shift southeast through northern Wisconsin and to the east during this period, with warm air advection ahead of it in the low levels across southern Wisconsin. There is a low level jet nose pointing east into the area as well late this afternoon into this evening.

These features should help bring scattered to numerous showers (40 to 70 percent chance) eastward through the area during this time. There should be up to 500 J/kg of mean layer CAPE in western and northwestern parts of the area to allow for isolated to scattered thunderstorms (20 to 30 percent chance) to occur as well. This is mainly skinny mean layer CAPE with deep layer bulk shear of 40 to 50 knots.

Thus, may see hail and gusty winds with a stronger storm or two mainly northwest of Madison into early evening. Otherwise would see some cloud-to-ground lightning risk with any storms. Storms may have a tougher time pushing further east during the evening, as instability weakens, but kept 20 to 30 percent chances for thunder in these areas for now. This activity should exit overnight.

Gusty west northwest winds should gradually weaken into this evening, becoming more southwest overnight into Saturday morning as the low moves east of the region. Should see some clearing out of the clouds later tonight as well. Lows in the lower to middle 50s are expected.

High pressure should build into the area Saturday, bringing mainly dry conditions. Some CAMs are suggesting a few showers may occur in northeast Wisconsin, but think the airmass will be too dry in the area for any showers. Gusty northwest winds are anticipated Saturday, with highs in the middle 70s. The high should continue to bring dry conditions for Saturday night, with lows in the lower to middle 50s.

Wood

LONG TERM

Issued 211 PM CDT Fri Jun 19 2026

Sunday through Friday:

Low pressure is expected to shift eastward from the Central Plains into central Illinois Sunday, then east northeast into Ohio Sunday night. There is a 500 mb shortwave trough that may weaken as it shifts east across Iowa into northern Illinois Sunday. There has been an ensemble trend with keeping the better or even most of the QPF in northern Illinois, as dry northeast flow in the low levels may limit precipitation chances in northern and even southern portions of the area. For now, will leave the 30 to 60 percent chances in the forecast, but look for continued refinements to the precipitation forecast as we get closer to Sunday.

Gusty northeast to north winds later Sunday into Monday morning may bring a high swim risk to beaches along Lake Michigan, as the low pressure system moves east southeast of the region. A Beach Hazards Statement may eventually be needed.

500 mb cluster analysis suggests a general trough may linger over the region for the middle to later portions of next week, with below normal 500 mb heights. This may lead to several vorticity maxima rotating through the region at times, with perhaps some surface low development and weak instability. For now, will leave in 20 to 30 percent chances for showers and storms at times during this period. Temperatures look to remain somewhat below seasonal normal values, but still rather comfortable for this time of year.

Wood

AVIATION

Issued 655 PM CDT Fri Jun 19 2026

Outside of some scattered light showers and an isolated thunderstorm for central WI terminals that may briefly bring lower ceilings and visibility through the evening, VFR conditions are expected to prevail through the period as high pressure builds in overnight through Saturday. Expect southwest winds this evening to shift more westerly through Saturday and pick up in the afternoon as this evening's system pushes further east with light and variable winds return by Saturday night.

Wagner

MARINE

Issued 211 PM CDT Fri Jun 19 2026

Winds will turn south this afternoon, as weak low pressure around 29.8 inches approaches the lake. It crosses northern portions of the lake later tonight with nearly calm winds, with southwest to west winds developing further to the south. Generally light winds are expected Saturday into Saturday night with high pressure around 30.0 inches moving through.

Low pressure around 29.5 inches should track eastward from the central Great Plains on Sunday, reaching central Illinois early Sunday evening, then into Ohio by Monday. East winds overspread Lake Michigan Sunday, becoming gusty over southern portions of the lake and turning northeast later Sunday into Sunday night. Winds turn north and remain gusty into Monday, particularly over southern portions of the lake. At this time, winds look to remain below gale force over southern portions of the lake.

Lighter winds return Tuesday and Wednesday, as high pressure around 30.1 inches builds into the region.

Wood

MKX WATCHES/WARNINGS/ADVISORIES

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