Cloud cover will continue to increase across KELOLAND, as a warm front will be followed by a cold front. Winds have picked up as a result. A strong south wind is warming Sioux Falls and SE KELOLAND through the 70s into the 80s. The NW winds are holding temperatures in the 70s in western South Dakota. Rain showers are increasing from west to east.
Tonight we could have some stronger thunderstorms in Sioux Falls and SE KELOLAND as the cold front approaches and changes winds to the northwest. But the most likely location of severe weather continues to be in NW Iowa into SW Minnesota, an area still rated a slight chance for severe storms by the Storm Prediction Center. Sioux Falls and the I-29 corridor is still considered a marginal risk for severe weather.
Overnight, with those showers and thunderstorms passing through, we’ll have a northwest wind shifting to the west, dragging cloud cover along with them. Lows will be in the 40s, a little cooler in western South Dakota where cloud cover will break up.
Tomorrow we could have a few lingering showering in the morning. Otherwise Friday will be dominated by incoming cool air. With a brisk NW breeze, highs will be more than 20 degrees colder than today in places like Sioux Falls. Highs will only be in the upper 50s to low 60s. Rapid City will have a tough time reaching 50.
Saturday will be very cool. Morning lows will dip to the mid 30s in northern and western South Dakota, in frost territory. Friday afternoon will be mostly cloudy and chilly, with highs in the low to mid 50s with a north wind preventing any kind of warmup.
After a chilly morning on Sunday – frost not out of the question as temperatures dip into the mid 50s in most of KELOLAND – clouds will break up a bit Sunday afternoon. We’ll call it partly cloudy. Highs will only reach the upper 50s to low 60s.
Monday will be mostly cloudy and cool. Temperatures will still be about ten degrees colder than normal, in the low 60s. We have widespread showers in the forecast both Monday and Tuesday, but they won’t bring much water. It looks like those showers will only give us a few tenths of an inch.
Showers may linger into Wednesday in Sioux Falls, while clouds break up from west to east. Then the anticipated warming trend kicks in, especially from Thursday on. In fact, forecast models are giving us a very warm Memorial Day weekend. Even Sioux Falls looks like it will reach the mid 80s.