Southerly winds today have led to warmer than average conditions across KELOLAND, with temperatures in the upper 70s to mid-80s. Dry air aloft has resulted in clear skies with a few spotty cumulus clouds, but overall it has been a warm, sunny, quiet day with winds around 10-15 mph.
Tonight winds will pick up and shift from south to northwest as a cool front comes through. Precipitation chances are low with the dry air aloft. However current models suggest a good chance of rain in Aberdeen with the possibility of thunderstorms around the midnight hour. The Storm Prediction Center has rated NE South Dakota a slight risk for severe thunderstorms. The Black Hills could also see a few showers.
Tomorrow will be warm in Sioux Falls and SE KELOLAND, with a high in the low 80s under partly cloudy skies ahead of an incoming cool front. Northern and western KELOLAND will be cooler, mostly in the 70s. It could be our last dry day for a while – though Rapid City could see some late-day showers.
Thunderstorms will begin Friday, with a chance of thunderstorms in the morning – but more likely late in the day and Friday night. Temperatures will be cooler – in the 60s to low 70s – with cloud cover and an east wind. We expect a warm front to come north from Nebraska during the day, sparking late day thunderstorms. They could be strong, and much of central and eastern KELOLAND will have a slight risk of severe thunderstorms Friday afternoon and night.
The weekend – all weekend – looks cloudy, breezy, cooler, and very wet. Most of the area will get more than an inch of rainfall during the weekend. Some places – including Sioux Falls and eastern KELOLAND – might get a couple inches. There will also be a brisk easterly wind drawing in colder air, so weekend temperatures will cool from the 50s and 60s on Saturday to the 40s and 50s for highs on Sunday. Sunday morning we could have some snow mixed in with the rain. Rapid City could see an inch of snow, a little more in the Black Hills.
Next week also looks like it will start cool and rainy. The severe threat for early next week seems to have decreased a little for next Tuesday and Wednesday, as current models have put the low pressure system further to our east. However, we are still in a position to see significant rainfall. Highs will return to near-normal mid-May readings for the rest of the week.