Day 4 of Milwaukee, WI (KMKE)

 Dropped to 37F by 06z, but mysteriously didn’t get any lower than that despite clear skies and calm winds. While KMKE is known to be a hot spot, this is still weird and perhaps just the draw of luck as just about every other station in the vicinity dropped to 35F or lower, many of them even 33F or lower. As the sun rose, temperatures rapidly warmed up in the morning, even faster than expected, before the lake breeze got going late in the morning. The lake breeze slowed the warm up, but it still reached 55F. 

 

Apparently yesterday was just a cold outlier. The warmer temperatures probably also led to the lake breeze being a bit stronger, with a max of 14 kt. Tonight, the lake breeze induced easterly winds will continue and not switch to a land breeze due to synoptic-scale easterly winds developing. This will minimize any cooldown with the winds off Lake Michigan whose water temperature is still in the lower 50s F. Mostly sunny skies tomorrow will lead to some warm up, but the same wind off the lake will lead to less of a warm up with cooler temperatures than inland. However, the wind will be lighter and air mass will be warmer, leading to still warmer temperatures than today. Since the lake water temperature changes much more slowly than the land surface, the temperature gradient along the lakeshore will be stronger than today, which could lead to a tricky forecast especially looking at maps. There is quite a bit of model disagreement, with HRRR and NAM 3-km being cooler. NAM 3-km is likely too cool due to it showing too many low-level clouds, though there could be some (but not a lot of) low-level clouds due to moisture coming off the lake. Interestingly, the low will likely occur at the end (Saturday 06z) when the wind weakens and shifts to a land breeze, mitigating any lake influence.