textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Well above normal temps will continue through Friday with the exception of near the lake on Wednesday.

- Next chances (60-80%) for showers and thunderstorms late Thursday night and Friday, then again early next week.

SHORT TERM

Issued 307 PM CDT Tue Apr 21 2026

Tonight through Thursday:

The showers and storms have shifted to the south and east as the low to mid level thermal ridge and moisture ridge moves away. A weak and decaying, dry cold front will then pass from north to south across the region from late this afternoon into the evening. Much later at night, areas of fog may form over far srn WI as the front stalls over nrn IL.

High pressure over Ontario and the nrn Great Lakes Wed AM will shift toward the lower Great Lakes, while upper ridging moves into the Upper MS River Valley. Ely winds will become ssely with warm advection beginning once again. High temps will range from 50s at the Lake MI beaches to middle to upper 70s over south central WI. The sly winds will continue to bring warm temps into Thu as a n-s sfc trough and cold front moves ewd across the Great Plains. High temps will be near 80F.

Gehring

LONG TERM

Issued 307 PM CDT Tue Apr 21 2026

Thursday night through Tuesday:

For late Thu nt and Fri a shortwave trough will lift from the central Great Plains into WI, while the cold front slowly passes. Thus 60-80 percent chances for showers and scattered storms are forecast. A weak high pressure area will then pass on Sat followed by increasing sely winds and warm advection for Sunday ahead of cyclogenesis over the central Great Plains.

The low pressure area and associated shortwave trough is then expected to lift newd into WI on Mon, with another round (50-60 percent) of showers and storms.

Gehring

AVIATION

Issued 307 PM CDT Tue Apr 21 2026

VFR conditions this afternoon and evening. Areas of BR and fog (Vsbys of 1SM to 5SM, locally less possible) may then form over far Srn WI as a front stalls over nrn IL early Wed AM. The fog and any low stratus should then burn off by late morning with VFR conditions returning.

Gehring

MARINE

Issued 307 PM CDT Tue Apr 21 2026

Light to modest south winds will shift to light north to northeasterly tonight, as a weak cold front passes and high pressure moves across Ontario and the northern Great Lakes. Scattered strong thunderstorms will affect far southern Lake Michigan this afternoon.

The high over the northern Great Lakes will then shift to the lower Great Lakes on Wednesday. Light northeast to east winds on Wednesday will then become southeast Wednesday night and increase Thursday into Friday, as strong low pressure around 29.2 inches develops in the northern Plains.

A Small Craft Advisory may be needed north of North Point Lighthouse from late Thursday afternoon into Friday morning.

Gehring

MKX WATCHES/WARNINGS/ADVISORIES

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