Showers mainly southern Minnesota for Labor Day; heavy rain possible Tuesday

Strong high pressure continues to be locked in place over the mid-Atlantic states this Monday morning. A plume of tropical moisture from the Gulf of Mexico is streaming clockwise around the periphery of the high, across Texas then north to Kansas and northeast across soggy Iowa to southern Wisconsin.

Severe storms will be possible in western North Dakota.

Storms have been widespread across Iowa already early Monday morning.

Some showers and thunderstorms are edging into far southern Minnesota.

As we go through Labor Day, I expect quite a few showers and thunderstorms to break out across southern Minnesota. Some storms are likely to creep as far north as the Twin Cities metro area by late Monday afternoon or during the evening.

Meanwhile, northern Minnesota will be treated to a holiday of sunshine with comfortable temperatures and dew points. Highs should be mainly in the 70s statewide. The Twin Cities should warm to about 79.

Widespread rain and possible flooding on Tuesday

A northward surge of energy and moisture will ramp up the showers and storms Monday night and spread them across much of the state. Some storms likely will diminish Tuesday morning as the nocturnal low level jet stream weakens, but expect rainfall to increase significantly later in the day.

The atmosphere will be pumped with much more precipitable water than is normal for September. Repeated heavy rains from showers and thunderstorms training one behind the other might cause flash flooding from Tuesday through Tuesday night. Local rainfalls in excess of four inches are possible with repeated storms. Parts of southeastern Minnesota that have absorbed significant rains recently could be the most susceptible to flooding.

Severe storms are also a possibility for Tuesday-Tuesday night, but the risk area is just marginal:

High temperatures on Tuesday should be mainly in the 70s again.

Much drier conditions later in the week

Forecast models are calling for that cold front to make a welcome push southeastward on Wednesday and allow cooler,  much drier Canadian air to drain southward across the state. Note the lovely blue H of high pressure over Saskatchewan.

We should see a lot of dew points in the 50s and even 40s beginning on Wednesday and continuing through at least next weekend.

Tropical Storm Gordon?

Tropical Cyclone Seven is dropping large areas of heavy rain on southern Florida this morning. It is forecast to strengthen into Tropical Storm Gordon as it crosses the Gulf of Mexico in the general direction of the Mississippi River delta. Such a track would bring heavy rain to coastal areas of Louisiana, Mississippi and Alabama by Wednesday. A tropical storm warning has been posted along the Gulf Coast in dark blue.