Humidity levels finally start dropping across Minnesota

Following more storms Monday, Minnesota finally transitions into a much cooler and less humid weather pattern.

Monday’s forecast

The state started warmer than average again Monday morning, with a few 40s northeast, most of the state in the 50s, and 60s south and west. 

Highs also stay warm, with almost all of the state making it back into the lower 80s, although it stays significantly cooler near Lake Superior.

Minnesota remains under a warm, humid, southerly flow again through the day. Under those conditions, much of the state sees cloudy skies again Monday, and there have already been a couple isolated showers and storms in northern and central Minnesota Monday morning.

Drier air does finally push in from the northwest Monday afternoon, meaning skies begin to clear and the humidity starts to lower in northwestern Minnesota during the afternoon. 

Meanwhile, with eastern and southern Minnesota still in the humid air mass, showers and storms are likely, especially in the afternoon through early overnight period. 

Some of those storms may become severe, with high winds and large hail as the primary risk.

Dew points drop

The drier air northwestern Minnesota sees Monday continues to spread across Minnesota Tuesday. 

Dew point is a measurement of moisture in the atmosphere that indicates the air temperature needed for saturation which is also 100 percent relative humidity. The higher the dew point, the more humid it tends to feel.

Recently, Minnesota has experienced a very tropical air mass with dew points in the 60s and even 70s. This is why it has felt so sticky recently. 

As the drier air spreads across Minnesota Wednesday, it drops dew points from the sticky 60s to much more comfortable 40s (and even lower for parts of northern Minnesota by Wednesday). 

Here is that forecast contrast Tuesday morning as the drier air moves across the state:

Extended forecast

Humid air also is also not able to warm and cool as quickly as dry air. The new, drier air mass that returns to Minnesota also cuts off the recent warm flow, and with the air being drier, the state starts getting larger day to night temperature swings again.

Following 70s and 80s Tuesday, the cooler weather drops highs into the 50s north and 60s south already Wednesday despite sunshine. Another round of showers and storms is forecast for Thursday. 

That returns clouds across the state, which drops even more of Minnesota into the 50s. Meanwhile, overnight temperatures cool into the 30s north and 40s south Thursday and Friday mornings.

Here is that dramatic temperature swing expected for the Twin Cities:

It finally looks like highs return to more seasonable levels just in time for the holiday weekend. Average highs as of May 24 range from the upper 60s north (cooler by Lake Superior) to low 70s south, with the Twin Cities at 72.

Programming note

You can hear my live weather updates on Minnesota Public Radio at 7:49 a.m. Monday through Friday morning.