The front came through overnight, switching the winds to the northeast and pushing the humidity out. But the humidity has been replaced by wildfire smoke from Canada. Unlike recent days – the smoke has dropped from cloud level down to the ground. There is a noticeable smoke odor in Sioux Falls. The thickest smoke has been east of the James River, and it is even impacting visibility – diminishing our sunshine.
Temperatures are probably being held back by the smoke as well. Afternoon temperatures have been close to 15 degrees cooler than yesterday, with that NE wind and smoky air.
Tonight we will have an area of rainfall develop in western South Dakota and then spread to the east overnight. Rainfall could be moderate or even heavy in western and south central South Dakota, but little or nothing in northeast South Dakota. Tonight’s lows will be in the low 60s.
Tomorrow will be cloudy and rainy for much of KELOLAND, though it looks like NE South Dakota will get little or nothing out of this system as it moves to the east and southeast. Showers and thunderstorms are in the forecast for western and southern KELOLAND, though the risk of any severe weather looks pretty low. Temperatures will be sharply cooler, with highs only in the mid 70s – to perhaps the low 80s in the NE which looks like it will miss out on the rainfall. There will be a southeast breeze feeding moisture into the system.
As far as rainfall amounts: It looks like a band of 1/2” to 1” rainfall will set up in central and SE KELOLAND as the energy drifts to the southeast. That is what a combination of models is suggesting, though another model we trust even gives Sioux Falls around an inch of rainfall. There is general agreement that rainfall amounts will be heavier in Nebraska.
The Weather Prediction Center also has southern KELOLAND as a marginal risk for excessive rain, meaning rainfall could be locally heavy enough to produce flash flooding rainfall.
Saturday will be mostly sunny in SE KELOLAND, with skies clearer in the north and west. Highs will be near-normal for the last day of July, in the mid 80s. Sunday, the first day of August, will be sunny with temperatures in the low to mid 80s.
We’ll keep temperatures in the low 80s in SE KELOLAND and the mid to upper 80s in the rest of the area on Monday and Tuesday.
As temperatures start to warm in the middle of the week, we may see some scattered thunderstorms. It also looks like we’ll be warmer for the following weekend (August 6-7-8), though not the excessively hot temperatures like we’ve seen this week.