Colorado Daily Snow

Heads up, there may be fresher snow! Read the latest Colorado Daily Snow

By Joel Gratz, Founding Meteorologist Posted 5 years ago September 28, 2018

Early October will be action packed

Summary

Following dry weather on Friday and Saturday, Sunday could bring afternoon and evening showers. Then the remnants of Hurricane Rosa should bring a lot of moisture to Colorado with mostly rain on Tuesday and Wednesday (October 2-3) and showers could continue through the end of the week. The longer-range forecasts now show a chance for the first cold storm of the season (snow!) perhaps around October 5-6 or more likely closer to October 8-10.

Short Term Forecast

This is the final Friday of September, and like most September days around here, it is a sunny and beautiful day across the mountains of Colorado. The visible satellite image shows no clouds over the mountains and a thick blanket of low clouds over the eastern plains. Temperatures are warm over the mountains but cold over the plains with readings in the 40s.

The rest of Friday will be clear and warm over the mountains and the clouds will stick around for a lot of the day over the plains.

Saturday will be gorgeous everywhere will warm temperatures, no precipitation, and high cirrus clouds.

On Sunday, we might see a few showers over the western mountains late in the day and in the evening.

Extended Forecast

The 4-15 day forecast looks like it will be action-packed, so let’s get to it.

The big story will be that the moisture from Hurricane Rosa will track toward Colorado.

Right now, it looks like the best chance for a lot of precipitation in Colorado will be on Tuesday and Wednesday.

But how much precipitation?

The latest American GFS model shows 1-2 inches of rain for most areas. That is significant rain in 24-48 hours.

How about the latest European model forecast? It keeps the heaviest precipitation to the western edge of Colorado.

However, we know that we shouldn’t look at only one forecast from one model.

Below is the average precipitation forecast from 51 versions of the European model. It covers most of the western mountains with more than 1 inch of precipitation.

Breaking that down further, let’s look at the forecast for Crested Butte, roughly in the middle of Colorado’s mountains.

Each horizontal line in the chart below shows the precipitation forecast from one of the 51 versions of the European model.

You can see that by October 5, the end of the week, highlighted in red, roughly half of the model versions show more than one inch of precipitation. And the rest of the model versions show at least some precipitation with about 25% showing 0.5-1.0 inches of the rest showing fewer than 0.5 inches.

Because multiple models agree, and model versions of the same model agree, we should now have pretty high confidence for moderate to heavy rain next Tuesday and Wednesday.

How about snow?

Unfortunately, the remnants of Hurricane Rosa will not just bring lots of moisture but also warm air. Any snow during October 2-3 should be confined to the very highest elevations, above most ski areas.

If we're patient, though, we will have a better chance for snow by the end of the week, around October 5-6 or so.

And, I have some good news beyond that.

As we head toward October 8-10, the average of 21 versions of the American GFS model show a cold and stormy weather pattern near Colorado.

Even better, the average of 51 versions of the European model show the same thing.

Thus, even though October 2-3 will feature mostly rain, it’s possible that we could finally see our first colder storm of the season during the following week.

Thanks for reading … next update on Monday, October 1!

JOEL GRATZ

Announcements

OpenSummit

We have an iPhone app that provides detailed weather forecasts for your hiking, biking, and climbing adventures. OpenSummit now includes forecasts for 1,000 of the highest and/or notable summits and hiking areas across the United States. Download OpenSummit (iPhone only)

Upcoming Presentations

* October 18 in Colorado Springs
* October 25 in Golden
* November 7 in Boulder
* Early November in Summit County
* November 28 in Vail
* December 5 in Denver

Geography Key

Northern Mountains
Steamboat, Granby, Beaver Creek, Vail, Ski Cooper, Copper, Breckenridge, Keystone, Loveland, Abasin, Winter Park, Berthoud Pass, Eldora, Rocky Mountain National Park, Cameron Pass

Along the Divide
Loveland, Arapahoe Basin, Winter Park, Berthoud Pass

East of the Divide
Eldora, Echo, Rocky Mountain National Park, Cameron Pass

Central Mountains
Aspen, Sunlight, Monarch, Crested Butte, Irwin, Powderhorn

Southern Mountains
Telluride, Silverton – north side of the southern mountains | Purgatory, Wolf Creek – south side of the southern mountains

About Our Forecaster

Joel Gratz

Founding Meteorologist

Joel Gratz is the Founding Meteorologist of OpenSnow and has lived in Boulder, Colorado since 2003. Before moving to Colorado, he spent his childhood as a (not very fast) ski racer in eastern Pennsylvania.

Free OpenSnow App