NWS Milwaukee Forecast Discussion
737 FXUS63 KMKX 192258 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 558 PM CDT Wed Aug 19 2026 .KEY MESSAGES... - Patchy dense fog may occur overnight into early Thursday morning across parts of south central Wisconsin. - Dry and pleasant conditions through Thursday with drier air in place. - Shower/storm chances return Thursday night into Friday. && .UPDATE... Issued 559 PM CDT Wed Aug 19 2026 Lake breeze has initiated very isolated showers and storms in southeastern Wisconsin, with storms dissipating quickly as lake breeze influence moves inland and storms drift toward Lake Michigan. Expecting any impacts to remain minimal. Overnight, patchy fog with a few areas of locally dense fog are possible under mostly clear skies and calm winds. MH && .SHORT TERM... Issued 151 PM CDT Wed Aug 19 2026 Tonight through Friday night: High pressure over the region is expected to slowly shift to the southeast into Thursday, as northwest flow at 500 mb lingers. This will bring a period of dry conditions with light winds. There may be patchy fog overnight into early Thursday morning in parts of south central Wisconsin, with patchy dense fog possible in low lying areas. Lows tonight should drop into the lower to middle 50s, with highs Thursday in the lower 80s. Modest warm air and moisture advection in the low levels should push into the area Thursday night into Friday, as winds shift to the south and southwest. Weak low pressure moving east southeast through the region should bring a cold front through the area on Friday, exiting to the southeast Friday night. There is a modest shortwave trough that may move through the area Friday, though some models wash this feature out. Thus, most of the upward vertical motion is in the low levels. Forecast soundings are showing tall skinny mean layer CAPE with modest deep layer bulk shear of 20 to 25 knots. This should bring generally showers with widely scattered thunderstorms later Thursday night and Friday. Kept 50 to 70 percent chances for the showers west to east during this period, with the chances for thunderstorms in the 20 to 40 percent range. The southeast parts of the area would have better chances for storms, with more daytime heating to tap into. Not seeing much in the way of strong to severe storms at this time, but will continue to monitor its potential in later forecasts. High pressure should start to build into the area Friday night, which should dry things out. Wood && .LONG TERM... Issued 151 PM CDT Wed Aug 19 2026 Saturday through Wednesday: Quiet and dry weather is expected to linger through the weekend and early next week. Persistent upper-level northwesterly flow along a ridge, combined with a surface high pressure system over the Great Lakes region through Tuesday, favors these conditions. High temperatures are predicted to be near normal for the season, sitting in the upper 70s to lower 80s range, with dewpoints in the lower 60s. The next chance for precipitation is Wednesday (20 to 30 percent), as a surface low and accompanying cold front move through the area. Zawlocki && .AVIATION... Issued 559 PM CDT Wed Aug 19 2026 VFR conditions and light winds expected this evening, with an easterly lake breeze across southeastern Wisconsin. Overnight, winds become near calm and patchy fog will develop. Visibilities in the 1-4 SM range are expected. Patchy dense fog (1/4 SM or less) is possible in low lying areas such as river valleys. Thursday morning, a return to VFR conditions as fog lifts rapidly and winds become south-southwesterly. A southeasterly lake breeze is expected for Lake Michigan terminals. Winds then remain southwesterly through the overnight hours while cloud cover increases. Still expecting VFR conditions to persist. MH && .MARINE... Issued 151 PM CDT Wed Aug 19 2026 Light to modest winds are expected tonight into Thursday, as high pressure around 30.0 inches tracks through the western Great Lakes region. As the high exits to the southeast later Thursday into Thursday night, south to southwest winds will develop. Gusty southwest winds, as well as shower and thunderstorm chances, return Friday into Friday night, as low pressure around 29.8 inches moves across the region and drags a cold front through. Gusty winds will shift to the northwest later Friday night into Saturday after the front moves through. High pressure around 30.2 inches moving into the region later in the weekend may help maintain gusty north winds. Wood && .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