We have a very, very busy forecast over the next 3-5 days, so lets start with Saturday and work our way through the timeline… piece by piece… region by region. This is HIGHLY curious meteorological event – but it’s not a dire one. Let’s break it down.
- Saturday is going to be Hot, dry, and at times breezy through the afternoon and evening.
- Wear the sunscreen, drink plenty of water, treat it like a mid-July afternoon.
- The National Weather Service in Billings, MT and Rapid City, SD have issued Red Flag Warnings for large portions of our region until 8 PM this evening.
- The three big issues – low relative humidity, hot temperatures and breezy West/Northwest Winds in the afternoon.
- Don’t drive into tall grass, dispose of cigarettes properly, all of those good practices and we’ll keep our first responders and firefighters at home with their family.
- By keeping our region fire-free, we get to send help to firefighters out west – who need supplies, rest, and most importantly reinforcements. Keep up the good work.
- Temperatures across the region will be on the hotter side, with Pine Ridge and areas south/east of the Black Hills seeing those triple digits.
- Sunday will be tamer temperature-wise, but with breezy conditions starting to pick up from the Northwest with a little more energy.
- A few 90s will be possible Sunday, but overall high 70s and a wide spread of 80s looks more likely.
- Notice winds won’t be outrageous Sunday, but they will be persistent and steady from the West and Northwest through Sunday evening.
- Sunday evening will show the first signs of trouble, with temperatures dropping into the evening into the 40s and 50s.
- Widespread showers will start to push in from the North and Northwest.
- Now, generally any energy that comes from the Northwest doesn’t bring lots of moisture and computer models tend to overdue precipitation… so why are we thinking something is up for Monday and Tuesday?
- The infamous Colorado Low: The Jet stream takes a Nose dive into the Central Plains, kicking off a closed off low pressure system right on the front range.
- This has been spurred on by a stout ridge of high pressure pushing into the Gulf of Alaska – If you ever want to look on the horizon for potential trouble – watch the jet stream over this important region. Warm temperatures in Alaska usually means unsettled weather for our region. The stronger the ridge, the more likely the Black Hills will see something gnarly down the line.
- With that counter clockwise spin of the low pressure system in Colorado, the conveyor belt will bring Easterly and Southeasterly winds into the region – which will pump gulf moisture into our region.
- To boot, we have Canadian High pressure setting up to our northeast – which will further reinforce Easterly winds and pump more cool air into the Black Hills.
- The proof is in the pudding – A steady Easterly/northeasterly wind will be evident Monday morning as our Colorado low becomes more organized.
- Widespread showers will continue to meander southwards as energy and moisture fill into the region Monday morning going into the lunch hour.
- I think there will be a chance for a few rumbles of thunder with the approaching system – there’s a good amount of energy being whipped up in the atmosphere.
- By Monday afternoon, the Big Horn Mountains and the higher elevations of the Black Hills could see a back and forth mix between steady rain and snow.
- This snow will be the heavy, wet flakes associated with Late Spring, early Fall systems where temperatures hover close to 32° – so don’t be surprised to see bursts of heavy snowfall at times.
- Also…. thunder snow could be in the cards as well.
- This trend continues late into Monday and Early Tuesday morning, with on and off snow showers through the Black Hills and Bighorns, with everyone else seeing a blustery, steady rainfall.
- Breezy conditions will continue through Monday into Early Tuesday as well – so things WILL be on the chilly side regardless if you’re seeing snow or not.
- By 6 AM Tuesday, dry air will begin encroaching into the Black Hills Region, cutting off the moisture supply and bringing cooler, drier conditions.
- Rain/snow showers will continue for the higher elevations.
- By noon Tuesday, showers are wrapping up while a steady, chilly breeze will continue to dry things our and cool things off towards Tuesday evening.
- This is important – temperatures Tuesday night into Wednesday morning are expected to be in the lower 30s across most of the area – this is expected to lead to widespread frost.
- Make sure to bring in pets and cover sensitive plants – this early frost could be widespread enough to cut the growing season short for some… we’ll monitor temperature trends closely.
- Always, always the big question – “How much snow are we talkin’.. and where?”…. So far models have been pretty consistent that the lower elevations will see little to nothing. The Big Horns and the higher elevations of the Black Hills are the only spots looking to receive any sort of accumulations.
- To boot, any accumulations that do occur will mostly be on grassy surfaces, deck railings, trees, etc. – the ground it just too darn warm for significant accumulations to gather, stick, and cause travel impacts on raods. Remember we’re going to be in the 90s in the Black Hills today!
- Having that said – could we have some slick spots? Yes. The Bighorns are looking to see heavy enough accumulations (in the possible 6-12″ range) that some roads could temporarily become covered.
- Snow could be heavy at times in the Black Hills, and this could lower visibility. Remember that wet roads are slick too! Just take it easy, and there shouldn’t be much problem getting around.
- If I had to throw money on it, I think the Northern Hills could see a wet, compact 2″-4″ of snow with some areas seeing locally higher amounts. NOW…. if colder air arrives sooner, and moisture leaves later…. yes we could be talking more than that.
- With snow arriving so early in the season – there’s so, so many factors that could throw this system out of whack – leading to an all rain event – or even a huge reduction in potential rainfall amounts across the region. As annoying as it is… we’ll know much more about specific impacts by Sunday and particularly Monday morning.
- Could we end up with a winter weather advisory?…. maybe.
- If the forecast looks busy, its because it is. Sunday night is when things really get going, and we could see impacts all the way through Wednesday morning.
- Out of this entire event, there is one impact that should take precedence over any other – Frost.
- Tuesday night into Wednesday’s frost potential is very much real, and could have actual impacts on our growing season, and could require actual preparations if the forecast holds true.
- Otherwise we’re looking at a potentially historic weekend are far as numbers are concerned… but not as far as travel impacts are concerned.
I’ve received several messages, of concerned residents about this upcoming system. “…. this feels alot like Atlas…” – I’m here to assure you, without a shred of doubt, that this won’t be anything close to an Atlas event. We may not even see winter weather advisories out of this event, let alone a winter storm warnings. This isn’t even in the same universe of discussion.
Now, having said that, I won’t ever admonish or disparage any person asking me if we’re looking at an Atlas-type event back in 2013. We’re talking about a horrible event – something that ruined lives and had impacts that still echo even 7 years later. Even if I have to assure a thousand people every single time there’s snow in the forecast that this isn’t Atlas – I’m ok with that. Atlas was a traumatizing event for many, and to ask the question is prudent and acceptable. We have to realize however, what a biblical event we’re talking about here. There’s a good chance all of us will live our entire lives and never see anything like that ever again – possibly even our children’s lives – and that’s great news.
With that said – this Labor Day weekend storm is not even close folks
We are in a very sensitive time of the year – there’s lots of financial impacts to a significant early snowfall, early frost, you name it – so we’ll be sure to stay up to date with these upcoming systems through Halloween and Thanksgiving. We have a strong hurricane system already in the works, with La Nina setting up in the Pacific Ocean. Dusting off the record books, we find that years with La Nina and strong hurricane seasons have traditionally led to colder, wetter winters for the Northern Plains. Traditionally speaking…. not gospel by any stretch of the imagination.
The BIG story here should be the wonderful, plentiful moisture that we could be receiving out of this system. We need it, we asked for it, we’re getting it. It’ll be cool and blustery for a few days, with even a few inches of snow to brag about to our family members in Texas and Florida – but that’s about it. We’ll keep an eye on the frost potential for Tuesday night into Wednesday – but otherwise we’re talking about a highly curious, high moisture, low impact event.
Now………. if we DO receive any measurable snowfall in Rapid City on Labor Day… it’ll be the earliest recorded snowfall in recorded history. So… if you’re into the numbers game – this is a game worth watching. Grab the popcorn, grab some fuzzy socks and your favorite blanket – and enjoy.
Stay safe out there.