Summer Hangs On: Storms likely late Thursday and Friday
A nearly stationary trough will be on the move later this week, and the crossing will bring unsettled weather to South Dakota
- Today will be sunny and dry, with temperatures for the most part in the 60s and 70s across the region. A nice, relatively cool day!
- Dry and clear conditions will continue moving into Wednesday evening and Thursday morning
- Some areas Tuesday afternoon got put through the ringer wind-wise, but otherwise we avoided most flooding and hail threats yesterday
- Buffalo, SD took the cake with a 72 mph wind gust!
- Thursday will see warmer temperatures in the 70s and 80s across the region, but that’s not the whole story
- We’ll see a tale of two cities (or states rather) as we move through the next 72 hours
- Wednesday will feature drier air with dew points in the 30s and 40s across the region (with a few 20s near the Big Horns)
- This won’t last though, as our nearly stationary trough out West that has been keeping the West coast cool fights its way East and into our region.
- Our dew points climb into the mid 60s out towards the South Dakota plains, which in September is a decent show of force
- Even Rapid city and the higher elevations of the Black hills could see moisture levels reach mid 50s and 60° dew points.
- This is plenty of surface moisture given that the upper atmosphere is starting to cool off given our slowly decreasing daylight.
- Late Thursday evening we have a chance for some isolated strong storms to pop up, given the mentioned conditions beforehand
- The Storm Prediction Center so far has a Marginal (1/5) risk for strong storms for us, but that will undoubtedly shift before tomorrow is here
- Forecast guidance models are not all the impressive, given the ingredients and dynamics at play.
- Keep in mind (if you’re looking at the radar image posted) This is what was shown for Tuesday as well, and we got a decent windstorm out of those storms!
- This means we could be surprised by a few boomers in the hills Thursday night into Friday, I believe the ingredients and dynamics supports such a scenario
- Friday is a whole different ball game, with plenty of evidence and clues towards a possible severe weather event towards Central South Dakota
- Eastern portions of our area, basically Black Hills Eastward, should keep a close eye on Friday as things could shift westward before all is said and done.
- 3 days out, the storm prediction center already has a Slight (2/5) risk for strong to severe weather from the Black Hills, East.
- This will undoubtedly go through a few adjustments, but the trend has been upward, not the other way around.
- Impacts could include large hail, damaging winds and even a few isolated tornadoes. We’ll keep you all updated as this forecast develops
Anybody that lives in South Dakota in September and comments “boy this is pretty unsual” ought to look at the record books for this month. Our highs and lows have the capability of being ridiculous, from the 100s to the 20s. September is a naturally volatile time of the year as warmer air masses fight to retain control of the Northern Plains as cooler air shifts South. With these transitions, comes unsettled weather. Friday is worth watching, but that’s it at this point. We’ll have more updates tomorrow as this system approaches! Be safe out there – Brant