Weekend in the 70s; rain, possible thunderstorms ahead

We’re gradually warming up across Minnesota this week, but let’s fast-forward to the weekend.

Southerly winds will pump much warmer air into Minnesota this weekend. Highs will push the 70-degree mark once again in southern and western Minnesota by Saturday afternoon.

By Sunday, the thermal ridge will push into Minnesota. That’s the warmest tongue of air embedded in southerly flow patterns ahead of advancing low-pressure systems. Most forecast models suggest at least mid-70s Sunday afternoon for much of southern Minnesota.

Keep in mind forecast models often underestimate temperatures in extreme situations.

I won’t rule out more widespread 80-degree temperatures in southern Minnesota and possibly the Twin Cities Sunday. But with fading October sun angle and intensity, many of us will probably top out in the upper 70s Sunday — good enough for one more semi-summery autumn weekend.

The average high temperature in the Twin Cities this weekend is 55 degrees., so temperatures will be near 20 degrees above average Sunday afternoon.

An inch of rain coming?

It’s still too early to be confident about rainfall coverage and totals this weekend, but Wednesday’s forecast models continue to be encouraging that a decent soaking is possible for big parts of Minnesota.

The National Oceanic and Atmospheric Administration’s Global Forecast System model continues to show a potent low-pressure system tracking through the eastern Dakotas into northwestern Minnesota Sunday into Monday.

This scenario would produce widespread rain and possibly some thunderstorms Sunday night.

The European Centre for Medium-Range Weather Forecasts model is typical of solutions that crank out more than 2 inches of rain around the Red River Valley, with an inch or more possible from the Twin Cities northward.

Let’s see how the forecast models handle the storm track over the next few days.

Stay tuned.