Colorado Weather Forecast | Sep. 10–19, 2021
Record heat into Saturday, isolated thunderstorm chances this weekend, less smoke, cold front on Tuesday, hot and dry to end next week.
Summary
- Record high temperatures today, hot into Saturday.
- Weak shortwave providing moisture and lift to bring isolated thunderstorm potential to northern Colorado on Saturday and Sunday.
- Smoke is mixing out, much less smoke by the weekend.
- Stronger cold front on Tuesday, better moisture, snow level could drop to 12,000ft., however, minimal snow accumulation is expected.
- Quick warming trend into the end of next week, generally dry, another system around Sunday.
Discussion
Blue skies are starting to peek out over Colorado as more southwesterly winds aloft mix out some of the heavier smoke from the past couple days. We should have much less smoke for the weekend and at least for the next few days.
It’s oppressively hot out there, at least for this time of year. Yesterday, Denver broke its record high temperature for September 9th by a decent margin, topping out at 96 degrees Fahrenheit (in 2020, Denver set a record lowest high temperature of 31 degrees on the same day!). Another high temperature record has fallen today, with 97 degree temperatures at the airport easily beating out the previous record of 93 degrees.
Even the mountains are experiencing some scorching temperatures.
You can thank a huge heat dome for the current heat wave:
The center of high pressure located near the Texas panhandle has been moving east, which has been bringing cleaner air into the state via southwesterly flow — and much warmer temperatures.
This ridge will start to break down over the weekend, with a weak shortwave impacting the area by later on Saturday.
This comes with a decent dose of moisture that will stick around through the weekend.
However, expansive high pressure over the region will minimize the amount of instability in the atmosphere, reducing the potential for afternoon thunderstorms. Still, the shortwave should introduce enough dynamics to put isolated afternoon storms in the forecast for both Saturday and Sunday, with the best chances in northern Colorado.
Unfortunately, this wave doesn’t look to do much to knock high temperatures down, with guidance still showing highs in the mid 90s for Denver on Saturday and low 90s on Sunday. There may be some respite for areas that pick up a few storms, however.
The story remains the same through Monday — another round of isolated afternoon thunderstorms for northern Colorado, and highs in the 90s for the Plains. But respite is on the horizon in the form of a stronger mid-atmospheric wave which should push through the region on Tuesday.
This wave looks to knock a pretty decent cold front into the state on Tuesday:
This will drop high temperatures below average, with ensembles hinting at highs in the low 70s at best for Denver!
Near and above treeline, temperatures will be knocked into the 40s and possibly just above freezing overnight.
The snow level could dip below 12,000ft. in the early morning hours of Wednesday.
If we look a bit higher at 13,000ft., we can see the potential for snow accumulation on Tuesday.
This likely wont amount to anything more than a dusting of heavy wet snow, though.
Still, it’s hard to ignore a little bit of snow showing back up in the grids.
Regardless of snow, this isn’t exactly a frigid air mass, so lightning is still the primary concern, with northern Colorado and areas near the Divide at highest risk on Tuesday afternoon.
This likely wont put a dent in our precipitation deficit either. Most of Colorado has experienced abnormally dry conditions over the past month, except parts of the Western Slope (luckily enough).
After Tuesday we see high pressure quickly rebuilding, though we wont get back into heatwave territory until next Friday or Saturday.
Still, it will feel like summer again from next Thursday to Saturday, and drier air will work its way into the state which will keep thunderstorm potential pretty minimal. By next Sunday we see another wave impacting the state — cooler temperatures and better precipitation chances — and some hope for a pattern change, though a stronger more wintry signal isn’t showing up until around September 24th to 26th.
More on that later, enjoy the weekend!
Authors
Frequent updates, graphics, and general stoke:
Twitter / Instagram / Facebook: @highpointwx
Website and app with automated, high-resolution forecasts for mountains, climbing areas, and ski resorts (+ backcountry) with elevation switcher, uncertainty visualization, and more:
https://highpointwx.com
If you enjoy our forecasts and/or website, please consider becoming a Patron to help keep the lights on. Thank you!
