FXUS63 KMKX 201927 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 227 PM CDT Sat Jun 20 2026 .KEY MESSAGES... - Rain is looking likely from Madison to Milwaukee and south to the IL border for Sunday afternoon and evening. Around one half inch of rain is expected toward the IL border. - Showers likely with chances for thunderstorms Tue nt-Wed. - Below normal temps continue for much of the new week. && .SHORT TERM... Issued 227 PM CDT Sat Jun 20 2026 Tonight through Tuesday: There is just a slight chance for a brief shower over east central WI late this afternoon and early evening due to low level instability. Otherwise a weak surface ridge will pass tnt followed by increasing clouds toward sunrise as a shortwave trough moves into the middle MO Rvr Valley. This shortwave trough will track into north central IL by 00Z Mon then to nrn Ohio by 12Z Mon. Its sfc low will track slightly to south of the upper wave and gradually fill. There is still some disagreement among the deterministic models and CAMs on the track of the low, but confidence is increasing on the nrn extent of the rain shield reaching a line from Madison to Milwaukee for Sun afternoon and evening. Mid level warm, moist advection, frontogenesis, and PVA will focus over far srn WI. Rain chances of 60-90 percent are forecast over far srn WI with only 20-30 percent chances for MQT, Green Lake, FLD, and Sheboygan Counties. Around one half inch of rain is expected toward the IL border. Nely winds will follow in the wake of the low on Mon with any broken stratocumulus ending Mon AM, although sct high clouds could occur into the afternoon with the passage of a weak shortwave trough to the south. A north to south sfc ridge will then slowly move across srn WI Mon nt-Tue. Below normal temps, but pleasant temps, will continue through this period. Gehring && .LONG TERM... Issued 227 PM CDT Sat Jun 20 2026 Tuesday night through Saturday: A slow moving shortwave trough and weak sfc low will then track from srn Canada across the Great Lakes for Wed-Thu. Rain chances of 50-90 percent will begin Tue nt and last into Wed. Thunderstorms will be possible during this time. Lingering precipitation is then possible Thu followed by high pressure for Thu nt-Fri. Yet another shortwave trough and a return to sly flow and warm advection will approach for Sat with more chances for showers and storms. Gehring && .AVIATION... Issued 227 PM CDT Sat Jun 20 2026 VFR conditions today into Sun AM. Sct-bkn035-050 cumulus will dissipate early this evening. Clouds will then increase early Sun AM with rain developing from late Sun AM into Sun evening from Madison to Milwaukee south to the IL border. MVFR Cigs and Vsbys are expected with the rainfall. Gehring && .MARINE... Issued 227 PM CDT Sat Jun 20 2026 Generally light winds are expected tonight into Sunday morning as high pressure around 29.9 inches moves across Lake Michigan. Low pressure around 29.6 inches should then track eastward from the central Great Plains, reaching central IL early Sunday evening, then into Ohio by Monday. Light east winds overspread Lake Michigan Sunday afternoon, becoming breezy northeast winds over the southern portions of the lake later Sunday into Sunday night. Lighter winds return late Monday evening into Tuesday as high pressure around 30.1 inches builds into the region. A Small Craft Advisory may be needed on Monday due to breezy nnely winds and high waves from Sheboygan to Winthrop Harbor. Gehring && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...None. && $$ Visit us at weather.gov/milwaukee Follow us on Facebook, X, and YouTube at: www.facebook.com/NWSMilwaukee www.x.com/NWSMilwaukee www.youtube.com/NWSMilwaukee