The upper level ridge of high pressure that has controlled our atmosphere the last few days will weaken and be replaced with an upper level trough this weekend. This has brought us thunderstorms today as these upper level winds change from the south to the north. And once the upper level winds switch fully to a north to northwest flow, it looks to stay that way until next weekend. That means we won’t see the hot temperatures, like we’ve had the last few days, return until next weekend at the earliest.
We’ve had scattered showers and thunderstorms around eastern SD today. Nothing has been severe in KELOLAND but to the north, they’ve already had severe storms. As the night goes on, a cold front will continue to march eastward, so we’ll continue to hold on to shower and thunderstorm chances through the evening and overnight. The bulk of the stronger storms are more likely to happen late this afternoon and evening.
As the passing cold front moves into eastern SD late this afternoon, thunderstorms that do develop may become strong to severe in the very warm atmosphere. The main threat from these severe storms will be hail with a secondary concern for strong wind gusts. The Storm Prediction Center has issued a Marginal risk for severe weather in the east with a Marginal risk for heavy rain that would cause localized flooding also in the east.
Temperatures tonight will cool to the 40s and 50s with the storms weakening after midnight.
Much cooler air will be in place on Sunday. Afternoon temperatures will be in the 60s to lower 70s with leftover morning clouds and rain moving on, leaving behind sunshine in the afternoon. Some brief showers are possible over the Black Hills during the heat of the day.
Monday will continue the pleasant weather with highs mostly in the mid to upper 70s underneath mostly sunny to sunny skies and a generally light wind.
Tuesday brings the next chance for passing rain. Highs will be cooler, in the low to mid 70s, in response to the extra cloud cover and reinforcing shot of cool air. The rest of the week looks dry with continued highs in the 70s. Late next week and next weekend, we’ll see highs bounce back to the upper 70s to 80s.