Periods of rain and thunderstorms this weekend; heaviest rain to the south

Updated at 3 p.m.

Periods of rain and thunderstorms will continue Saturday and Saturday night in most of Minnesota and western Wisconsin. Far northwestern Minnesota may see little or no rain this weekend.

Scattered showers and thunderstorms are also possible on Sunday, especially in the southern half of Minnesota and on into western Wisconsin.

How much rain?

The highest weekend rainfall totals, 1.5 to 2.5+ inches, are expected from the southern third of Minnesota eastward into Wisconsin. Even higher (3 to 4”) totals are possible in areas that see training thunderstorms, which move over the same area again and again like railcars of a train moving along a track.

One forecast model shows the highest weekend rain totals in the far southern two tiers of Minnesota counties. Another forecast model shows the heaviest weekend rain totals in the southern three tiers of Minnesota counties and creeping into the far southern part of the Twin Cities metro area.

Areas that see heavy rain could see some flooding. Here’s the discussion of that flooding potential from the NWS La Crosse office:

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3 p.m. update

The NWS has issued a flood watch for much of south-central and southeastern Minnesota and portions of Wisconsin and northeastern Iowa from 10 p.m. this Saturday to 10 a.m. Sunday:

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You can hear updated weather information for Minnesota and western Wisconsin on the Minnesota Public Radio News network, and you can see updated weather info on the MPR News live weather blog.

Severe weather outlook

Widespread severe weather is not expected Saturday or Saturday night.

The National Weather Service Storm Prediction Center shows a marginal risk (shaded dark green) of severe weather Saturday and Saturday night in roughly the southern third of Minnesota, including the Twin Cities metro area, plus parts of Wisconsin and northern Iowa:

Marginal risk means that an isolated severe thunderstorm is possible.

The Storm Prediction Center updates their severe weather outlook every few hours.

Temperature trends

Saturday highs will range from the upper 60s in parts of far northwestern Minnesota to 80s in the southeast. Portions of west-central and southwestern Wisconsin could top 90. Saturday afternoon dew points will be in the steamy 70s from the Twin Cities metro area into southeastern Minnesota and parts of western Wisconsin, with sticky 60s in much of central and southwestern Minnesota.

Sunday high temperatures will be mainly in the 60s in northern Minnesota, with 70s elsewhere:

Sunday afternoon dew points will be in the comfortable 40s and 50s to the north, with sticky 60s in the metro area and southern Minnesota:

Back to forecast high temps, Twin Cities metro area highs are projected to reach the mid to upper 70s on Monday, followed by lower 80s Tuesday, mid 80s Wednesday and Thursday and upper 80s on Friday. It may be rain-free most of the work week.

Temperatures may be warmer than normal next weekend and into the start of the following week. The NWS Climate Prediction Center shows a strong tendency for above-normal temperatures in the upper Midwest from August 13 through August 19:

Weather nugget

Minneapolis-St. Paul International Airport tallied just 1.18 inches of rain in the entire month of July and 1.13 inches of rain in June. That’s very dry. The Twin Cities 30-year average is more than 4 inches of rain in each of those months.

Programming note

You can hear my live weather updates on MPR News at 7:35 a.m., 9:35 a.m. and 4:39 p.m. each Saturday and Sunday.