Mixed weather bag ahead

Our weather will offer a little something for everyone in the next 48 hours.

Look for a mix of clouds and sun today as a warm front approaches from the south. The front is already generating widespread showers in Iowa, and they will gradually spread north into Minnesota through tonight. The best rain chances favor southeast Minnesota.

(Image: Twin Cities NWS)

Rainfall totals will be impressive in Iowa, where some multi-inch totals could fall. This system grazes southeast Minnesota with some decent rain totals that could amount to half an inch or more in some spots. Here’s the latest three-day quantitative precipitation forecast from the National Oceanic and Atmospheric Administration’s Weather Prediction Center.

Image: NOAA/WPC

Notice the solid band of rainfall that stretches from Iowa all the way to Mexico. Some of the moisture from this system is remnant moisture from former Tropical Storm Ingrid getting sucked north into the system.

Warm front ahead

Take a look at the GOES visible satellite from Tuesday morning. You can see the increase in clouds, and the southerly wind flow setting up ahead of a warm front in Iowa.

(Image: NOAA via College of Dupage)

The return to southerly flow will boost temps, but mostly tomorrow as the warm front kicks through. Here’s NOAA’s North American Mesoscale Model’s take on the southerly flow, which will shift back to northwest again with a trailing cold front Thursday evening.

(Image: NOAA)

Temps respond nicely tomorrow after the frontal passage — 80s anyone?

(Image: NOAA)

Longer range temperature roller coaster

Why is September known for more rapid weather changes in Minnesota? Longer nights in the Arctic mean colder air.

The jet stream moves back south from Canada, and that brings weather systems in more rapidly now. Warm summery air lingers south, but colder air is now pooling to the north. The series of passing fronts creates a kind of push-pull temperature pattern. Here’s a look at the European Centre for Medium-Range Weather Forecasts model output for the next week. Another cold front drops temps Friday, then we warm up again this weekend.

(Image: Norwegian Meteorological Institute via Weatherspark)