Stalled frontal boundary focus for multiple rounds of storms

A nearly stalled frontal boundary will be the focus for multiple rounds of storms through Friday. Heavy rain is possible especially Thursday night for southern Minnesota. 

An unsettled and active pattern develops Wednesday through Friday 

Hopefully you soaked up a bit of sun Tuesday as we’re in for an unsettled stretch with heavy rainfall potential.

Clouds will increase Wednesday with spotty showers and isolated thunder for southern Minnesota. More organized thunderstorms will develop midafternoon and track east through the evening hours for mostly the southern half of the state.

We’ll also have some hazy skies with elevated wildfire smoke occasionally drifting around the state. Some air quality sensors will report “orange” or “unhealthy for sensitive groups” levels at times.

There’s just a marginal risk (level 1 of 5) of some isolated severe storms in the southernmost counties of the state Wednesday afternoon and evening.

Temperatures will be a bit cooler — mostly in the 70s — for highs across Minnesota Wednesday afternoon, but temperatures will be much warmer south of the stalled front in Iowa and Nebraska and along the Minnesota-Iowa border.

That nearly stationary frontal boundary will continue to be the focus for spotty showers and thunder into Thursday especially close to the front, but the main action we’re monitoring is Thursday evening into Friday morning.

An upper-level disturbance combined with an accelerating low-level jet stream (winds at about 4,000 feet above the ground) will push moisture up and over that boundary to produce widespread showers and thunderstorms that could produce heavy rainfall. 

Rainfall will exceed 2 inches in many locations for central and southern Minnesota with locally higher amounts certainly possible, if not likely. 

There’s a slight risk of excessive rainfall Thursday into Thursday night. A slight risk means at least a 15 percent chance of rainfall exceeding flash flood guidance within 25 miles of a point within the yellow area.

There’s also a marginal risk (level 1 of 5) of isolated severe storms for the southern half of the state Thursday afternoon and evening, but the main threat will be south as Minnesota sees a mostly heavy rain threat.

We will be cool Friday, with lingering clouds and morning showers keeping temperatures mostly in the 60s. The weekend looks mainly dry though clouds will linger Saturday, keeping temperatures on the cooler side of normal as well. 

Next week will bring warmer temperatures but also another round of potentially active weather. At least we have no immediate concerns for drought in central and southern Minnesota.