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Colorado Weather Forecast | Sep. 20–26, 2021

First real snow chances of the year tonight and Monday morning, weak system later in the week, otherwise dry and warm.

Hello everyone, we’re back to cover some exciting weather in the future. I [Thomas] spent the past week doing some alpine climbing and finishing the 14ers, and am just now seeing the buzz about our first winter-ish storm slated for tonight.

A decent trough is getting into position over the northern Rockies:

This has put the jet stream over Colorado.

Strong winds associated with the jet have been battering the mountains, especially along the Divide, with the RTMA showing gusts of 50–70mph this morning and some downsloping Chinook winds reaching the urban corridor.

A colder air mass is present west of the Divide, with some of the higher terrain dipping below freezing this morning. Berthoud Pass recorded a low of 32 degrees and a wind gust of 52mph.

Some precipitation associated with the leading edge of this system pushed through the mountains overnight, with some light snow accumulation at high elevation. Here’s the Aspen Highlands Roundshot cam from this morning:

The main event is yet to come, with a stronger gust front pushing from northwest to southeast through the state around midnight, and temperatures dropping strongly behind it. Precipitation behind the cold front will fall as snow above 9,000ft, with the snow level dropping even a bit further, but likely after the precipitation has wrapped up. This front will also push some smoke into Colorado.

Southern Colorado will feel less of an impact from this cold front, in addition to the metro area, which will be warmed by downsloping winds (this will also reduce or eliminate the chance of seeing any precipitation overnight). However, high temperatures across the northern Colorado high plains will only top out in the high 60s and low 70s on Monday, which is a decent cool off.

Models disagree pretty significantly on the potential for snow tonight, with the NAM3km model swinging for the fences (a foot of snow along the Divide) — but most global models are showing just a dusting. The Blend is coming in at 0–2" for most mountains in central and northern Colorado, with the highest potential along the Divide and in the Park Range, which seems correct to us.

Looking at probabilities, it’s likely most northern mountains will get at least a dusting, with the central mountains in the running too:

However, chances drop significantly for snow accumulations higher than an inch:

We just have such a short window of lift and moisture that it seems unlikely that significant snow will fall for more than a few hours, and the NAM is showing its typical bias for holding significant precipitation over ridgelines long after any decent forcing and moisture has passed, so we don’t think its forecast for higher snow totals is correct.

After a much cooler day on Monday, most of the state will warm a bit into Tuesday before returning to drier, warmer conditions on Wednesday thanks to a strong ridge quickly rebuilding behind the trough:

Winds will also die down after Tuesday as the jet moves away from our region.

The exception is the Front Range, which will see a reinforcing shot of colder air and light precipitation on Monday night / Tuesday morning.

Another, weaker wave could impact us on Thursday / Friday. We’d probably see a weak, fairly dry cold front push down the Front Range and drop high temperatures by 5 degrees or so, with minimal impacts in the mountains.

Ridging returns for the coming weekend, with dry and warm conditions. After that, there is no strong signal for any sort of significant storm, with warm and dry conditions likely prevailing into the start of October.


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Weather forecasts and articles for the recreating in the Colorado high country — mountains, ski resorts, and crags.

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Highpoint Weather Forecasting Team

Highpoint Weather Forecasting Team

The Highpoint Weather forecasting team — weather nerds who like to play outside.

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