Updraft® - Minnesota Weather News

Isolated thunderstorms now; hottest weekend of summer ahead

Afternoon air mass thunderstorms; season's first 90-degrees temperature likely this weekend.

Forecast high temperatures Sunday
Forecast high temperatures Sunday
National Oceanic and Atmospheric Administration

It’s a classic summer week in Minnesota. For many, this may be the best weather week of summer so far. Highs in the 80s, with tolerable dew points in the 60s and a few isolated afternoon pop-up thundershowers? Warm lakes to play in? Does summer get much better in Minnesota?

Burntside solstice sunset
Summer solstice sunset at Burntside Lake near Ely in 2015.
Paul Huttner | MPR News

Our classic summer weather pattern features mostly clear mornings. As the sun rises up and begins to heat the ground, lumpy cumulus clouds begin to form in the morning. The cloud towers billow in the afternoon sky. Finally they achieve shower and thunderstorms status as they begin to drop isolated rain shafts earthward.

Such is the process of air mass thunderstorms on summer afternoons. Welcome to Minnesota’s mini-Miami summer climate regime.

The National Oceanic and Atmospheric Administration’s FV3 model captures the essence of the pattern again Tuesday afternoon. Watch the isolated showers pop up and drift slowly southeast once again on Tuesday. The forecast model loop below runs between 1 p.m. and 11 p.m. Tuesday.

NOAA FV3 model
Finite-Volume Cubed-Sphere Dynamical Core model between 1 p.m. and 11 p.m. Tuesday
NOAA, via Tropical Tidbits

Highs Tuesday will run in the 80s once again:

Forecast high temperatures Tuesday
Forecast high temperatures Tuesday
NOAA

A few more air mass thundershowers may pop up again Wednesday, then mainly dry and hotter weather expands into the upcoming weekend.

A drippy fetch of tropical moisture is ready to surge north into Minnesota later this week. Dew points will hit 70 degrees as soon as Thursday or Friday, and could peak near 80 degrees by Sunday afternoon across southern Minnesota.

NOAA’s Global Forecast System model shows the tropical moisture plume between Friday and Sunday:

NOAA GFS model
Global Forecast System model dew point output between 7 a.m. Friday and 7 p.m. Sunday
NOAA, via Tropical Tidbits

We’ll likely record our first 90-degree temperature of the year in the Twin Cities on Saturday and/or Sunday:

Forecast high temperatures Sunday
Forecast high temperatures Sunday
NOAA

The warmest temperature so far in 2024 at Minneapolis-St. Paul International Airport is 89 degrees on June 16.

Remember last year we sweltered through 33 days of 90-degree heat in the Twin Cities. The average is 13 days.

Stay tuned.