Sioux Falls, SD
Thunderstorms are heading east and north of Sioux Falls after dumping heavy rain and areas of hail. Brandon, Mitchell, Springfield, and Waubay all picked up hail during the overnight. We are expecting a break in the storms this morning into the early afternoon.
More storms will develop late in the afternoon along the main cold front from north-central Nebraska into south-central SD. Much of eastern SD is included in a moderate risk of severe weather. Hail, damaging winds, and tornadoes will be possible with these developing storms. The storms will be discrete supercells in the beginning, and then transition to a squall line through the evening as the storms move closer to Sioux Falls, with high winds the main threat after 8pm. There could be a few isolated storms ahead of the main line, but the atmosphere will be mostly capped, limiting that threat at this time. We will be monitoring all of these ingredients closely and I would expect a tornado watch for portions on the moderate risk area by late this afternoon.
Look for the storms to end after midnight, with strong west winds developing tomorrow. A high wind watch is in effect for much of northern KELOLAND where winds could gust over 50mph. Highs will a little cooler tomorrow with drier air moving back into KELOLAND.
That trend won’t last long with storms returning Wednesday night and Thursday morning, some of which could be severe again. I do expect more warm and humid weather the rest of week, which means scattered storms could develop again this weekend.