Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
247 FXUS63 KMKX 190614 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 114 AM CDT Wed Aug 19 2026 .KEY MESSAGES... - Areas of fog, locally dense, are expected through sunrise. - Dry and pleasant conditions through Thursday with drier air in place. - Shower/storm chances return Thursday night through Friday. Quiet weather is expected for the weekend. && .SHORT TERM... Issued 114 AM CDT Wed Aug 19 2026 Rest of Tonight through Thursday: With dewpoints still in the lower 60s in southern WI and the rain- cooled air, fog developed quickly this evening once the rain ended. The reason for the fog is that the actual front is still in central WI near Green Bay and Stevens Point. We can see on satellite that the fog focused over the Rock River Valley but is slowly drifting eastward. With webcams and automated observing stations showing spotty dense fog and sometimes stratus, I opted to issue a Special Weather Statement rather than a Dense Fog Advisory for now and keep an eye on satellite/obs trends. The Wisconsin River Valley area is also at risk for areas of dense fog overnight. The drier air mass will finally get through southern WI today (Wed), but it will take the whole day for areas along and south of I-94 due to no overall forcing to push the front all the way through quickly. We can expect light winds that become northerly in the afternoon, with the exception of the lakeshore seeing onshore winds from a lake breeze. High temperatures will be in the upper 70s under partly cloudy skies with diurnal cumulus clouds. Low temperatures tonight will be in the 50s. Thursday will be another nice day, weather-wise. However, a shortwave trough and potential area of thundeRstorms will approach from central MN. If it holds together, there could be showers and a few storms in southern WI early Friday morning. Cronce && .LONG TERM... Issued 114 AM CDT Wed Aug 19 2026 Friday through Monday: A broad upper trough will set up over Ontario and Hudson Bay over the weekend. Friday afternoon looks similar to the environment from yesterday (Tue) where warm, moist advection helped increase our instability during the day and a shortwave also crossed the area. While it probably will not be do that same degree, it still could be enough for showers and a few storms to develop over southern WI. The focus is the main question; an outflow boundary or lake breeze may help storm development within that environment. Showers/storms will be possible until the weak cold front comes through Fri afternoon or evening. Shower chances could actually linger into Saturday if the cold front takes its time getting through southern WI (again). The ECMWF is showing this slower frontal movement. By Sunday, we will be in a weather pattern with northwest flow aloft and several shortwave troughs tracking across the Upper Midwest. This pattern can bring a round of showers/storms every other day or two. Sunday and Monday weather looks quiet with high pressure dominating the Upper Great Lakes. Highs in the mid-upper 70s each day. Cronce && .AVIATION... Issued 114 AM CDT Wed Aug 19 2026 A mix of fog and stratus (with VLIFR ceilings) developed within the Rock River Valley shortly after the rain ended last evening. It is expanding eastward now and affecting KUES and KMWC. This may toward sunrise as drier air starts to move in. Elsewhere, fog is less dense and an area of high clouds is spreading in from northern IA, so expect patchy fog overnight. Look for diurnal cumulus clouds with bases around 5000 ft today and light winds. Look for a lake breeze to develop this afternoon. Patchy fog is not as probable later tonight due to drier air in place. Cronce && .MARINE... Issued 114 AM CDT Wed Aug 19 2026 Light northerly winds will become more variable today as high pressure around 30.0 inches tracks through the western Great Lakes through Thursday. Southwesterly winds and thunderstorm chances return later Friday as another system drags a cold front across the Upper Great Lakes region. High pressure is expected over the region this weekend. Cronce && .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