Instant meteorological Summer: 90s and severe storm risk Tuesday

Happy meteorological summer 2020.

Meteorologists and climatologists designate the months of June through August as meteorological summer in the northern hemisphere. We now enter the three warmest months of the year in Minnesota on average.

Instant summer

The weather maps are in perfect sync with the start of meteorological summer in Minnesota. A warm humid air mass blew in Monday. Highs reach the 80s Monday, with the year’s first 90-degree temperatures arriving across southern Minnesota Tuesday.

This tropical air mass features our first real high dew point episode in Minnesota this year. Dew points are rising through the sticky 60s Monday in southern Minnesota. The moisture pools from the southern Twin Cities metro area Tuesday, where dew points may reach the tropically steamy 70-degree mark in some locations.

Enhanced severe risk

A low-pressure system will cut into the steamy air mass across Tuesday. That brings the highest risk level so far this year for southern Minnesota from NOAA’s Storm Prediction Center.

A slight risk covers central Minnesota just south of St. Cloud. A more serious enhanced risk covers southern Minnesota, basically from the Twin Cities south to the Iowa border.

The biggest threats Tuesday are large hail over 2-inches in diameter and damaging winds over 60 mph.

Twin Cities: Evening rush hour storms?

The highest risk window for storms in the Twin Cities area appears to be between 5 and 8 p.m. Tuesday evening. NOAA’s HRRR model captures the essence of storm clusters popping in the late afternoon just west of the Twin Cities, and moving through during the early evening hours.

Stay alert Tuesday for possible, even likely severe weather watches and warnings Tuesday afternoon and evening.