Hold onto your beanies—our first extreme temperature drop and the first accumulating snow of the season is coming soon for much of Colorado. And it’s safe to say most Coloradans are pumped (sorry, warm-weather lovers).
Weather models like the North American Model (NAM), Global Forecasting System (GFS) and the European Center for Medium-Range Weather Forecasts (ECMWF, or simply, the Euro) have been hinting at an anomalously strong cold front pushing through the region. All models are currently showing an abrupt temperature change happening Wednesday night with frozen precipitation soon after.
It’s typical to see snow in October here in Denver, so this storm shouldn’t be much of a surprise. Denver averages a little more than 4 inches of snow each October. In the last two years, Denver has seen its first snow on October 6 and October 9, respectively, and the average first date of snow for Colorado is October 18.
Huge temperature swings and major weather changes—as we’re expecting from Wednesday to Thursday—is also normal for Colorado. But that doesn’t mean the 50-degree swing won’t come as a shock for residents who have grown accustomed to the warm and sunny fall weather we’ve been having.
So, what should you expect from the first winter blast of the season? Here’s what you need to know:
How much snow are we going to get?
Denver is forecast to get between 2 and 5 inches of snow from Wednesday night to Friday morning, with the bulk of the snow accumulating during the daylight hours on Thursday. There could be a few convective (think summer thunderstorm) snow bands that form and that would result in higher amounts of snow in some locations. The mountains should get between 4 and 8 inches, while the Eastern Plains will see between a trace and 2 inches of the white stuff. And yes, the snow in the mountains will aid resorts in getting snow coverage on the slopes in advance of opening days, but it won’t be enough on its own. Manmade snow will still be necessary to make up the additional snow needed for certain resorts to open this month.
When can we expect the temps to drop?
The cold is going to hit abruptly. High temperatures through Wednesday are supposed to be in the mid-70s to low-80s. A strong cold front will move through Wednesday evening/night, which will drop temperatures significantly. If the forecast is correct, we can expect to see a 50-degree drop (or more) in just 12 to 18 hours, as highs on Thursday are only expected to reach the low to mid-30s. Overnight lows heading into Friday will be even colder, dropping to the upper teens (stay tuned to see if we hit a record low, which looks probable).
It’s likely we’ll see a “hard freeze”—a time period where temperatures stay at or below 32 degrees for several hours. Denver is currently under a freeze alert for Wednesday night/Thursday morning when temperatures are forecast to drop into the 20s. That means you should prepare irrigation systems and plumbing for freezing temperatures. Our first freeze in Denver typically occurs around October 6, which puts this week’s cold blast within a few days or normal. Of course, areas in the mountains will be even colder, with higher elevations reaching sub-zero temperatures by Friday morning.
What will be the impact of the storm?
Main roads, highways, and interstates throughout the metro area should be OK throughout the storm—just wet. But with that said, wet roads plus freezing temperatures is a recipe for black ice, so be cautious, especially during the Thursday evening commute. And you might want to give yourself some extra time to get where you need to go, as the shock of seeing snow falling is likely to cause some slowdowns on the road on Thursday. Less travelled and less sunny roads may become snow covered at points through the day.
Considering that most leaves are still on the trees throughout the metro area, beware that we could see issues with limbs breaking and causing damage to power lines. However, we don’t expect widespread strong winds to accompany this storm, so power outages will not be a huge concern, only a possibility.
Even with the significant temperature drop, this is a pretty typical autumn weather pattern for Colorado—sunny and warm one day, snowy and cold the next, before returning to sunshine once again. By Friday, although temperatures will stay about 20 degrees colder than normal for the afternoon, we’ll be back to sun-filled skies, and by the weekend, this first storm will be a distant memory, as temps return to the pleasant 60s.