We’ve had a cool but pleasant day ahead of what is going to be a stormy night in much of KELOLAND. A low pressure system is going to move west through east through Nebraska over the next 24 hours, pushing rain and possibly strong storms into KELOLAND.
The storms bring a couple of concerns to us in KELOLAND. First is the enhanced risk of severe thunderstorms in SW South Dakota in the form of hail and strong winds.
The other possibility of heavy rainfall. Much of KELOLAND, including Sioux Falls, can expect an average of half an inch to an inch of rainfall – beneficial rainfall for most of us because we are short of moisture. But there is the possibility that slow moving storm cells moving over the same ground a few times may produce some excessive rainfall (flash flooding). The greatest risk of this is near Yankton and along the lower Missouri River valley.
Otherwise, we have cold air coming. Tonight will become breezy, from the east, with lows dropping into the upper 40s with widespread rain and thunderstorms.
Tomorrow we’ll continue with showers and thunderstorms, mainly in Sioux Falls and SE KELOLAND closer to the Nebraska storms. A brisk NE wind will draw in cold air, and temperatures will fall tomorrow morning. Afternoon highs will only be in the upper 40s in the north to the mid 50s in Sioux Falls and SE KELOLAND.
Friday will be a quiet day, but with an easterly breeze it is going to be much colder than normal. Highs will only be in the upper 50s to low 60s.
The holiday weekend will start mostly cloudy and cool with some rain showers, mainly on the light side. Saturday will be in the low 60s, about ten degrees colder than normal for Memorial Day weekend. Sunday will be a little warmer in Sioux Falls and the SE with lingering showers. Skies should be brighter to the north and west, where it will warm back to the low 70s.
Monday (Memorial Day) will be warmer, though there could still be a few showers around. Highs will be in the low to mid 70s.
Tuesday (June 1) will be warmer, near-normal, in the 70s. A warming trend begins on Wednesday, in the mid 70s to low 80s.
It looks like the warming trend will continue through the first weekend of June, with many locations getting into the 80s.