While the leaves are beginning to turn at our lower elevations - snow is already coating our higher summits.
Several of your have sent me photos of your recent adventures and asked me whether the summer hiking season is over - or if the snow that's fallen will melt.
So let's take a look.
First: where the snow is now.
Rocky Mountain National Park and the northern mountains have the most snow. Above 12,000 feet in these zones, many peaks have about 6" or slightly more (though some of this is already melting).
In the central mountains there are patches of snow and ice above 12,500 feet, with the most consistent coverage in the northern Sawatch approximately on a line near and north of Leadville.
In the southern mountains, the snow level is also about 12,500 feet but the snow is very patchy. You're most likely to find it in cracks and sheltered sections of the terrain that get little sunlight.
Regardless of range: we're still in the time of year where a good amount of the snow will melt.
The main things you need to pay attention to for the rest of the fall season are the freezing level, and the aspect (e.g. side) of the mountain you're hiking on.
The freezing level is the height in the atmosphere the temperature is at 32 degrees. Above this height, air continues to get colder - so this represents the height above which snow won't melt.
Of course, that's not the only way snow can disappear. Sublimation is the direct transition of snow into water vapor, skipping the liquid phase entirely - which is possible when strong sunlight hits the snow.
This is where the aspect - or side - of the mountain you're on play a role. The sun is at its highest angle when its in the south. Snow will more efficiently evaporate on east, south, and west facing slopes as a result. Northerly facing slopes get the least solar energy, and are likely to hold onto snow relatively well for the rest of the year.
It's unlikely you'll find completely clear trails for the rest of the fall season - but the freezing level will move well back above the tops of our highest peaks many times in the next few weeks.
You can use our forecasts on News5 and KOAA.com to see when the next snowfall event will be in the high country.
You can also use this website to see the freezing level for any major peak in the state. To interpret the graph, compare the arrow indicating the top of the peak, to the line. When the line is below the arrow, the freezing level is below the summit. Pay attention to mornings in particular. If the freezing level was below the summit overnight but above during the day - you're likely to encounter black ice.
____
Have a question or story idea you would like the First Alert 5 Weather team to consider? Email: weather@koaa.com
Watch KOAA News5 on your time, anytime with our free streaming app available for your Roku, FireTV, AppleTV and Android TV. Just search KOAA News5, download and start watching.
