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Colorado snowmelt kickstarts after early spring heat

snow cover colorado 4.9.2021
Posted at 2:32 PM, Apr 09, 2021
and last updated 2021-04-09 16:32:36-04

So far this April, the high temperature in Colorado Springs has been above average every day. Record high temperatures were recorded on April 4th and 5th, reaching 79 degrees each day.

While this early spring warmth has been a delight to get outside and enjoy, our mountain snowpack reacted accordingly.

Warm weather leads to a sharp drop

Since March 31st, the mountains have seen between 8 to 15 inches of snowmelt.

Early season snowmelt will first saturate the soil and then later in the season, the excess will run off into rivers and streams. Most of this first round of melting likely absorbed into the soil or evaporated, with little change to most river and reservoir levels.

This is an occurrence that is becoming more common. According to the EPA, April snowpack in Colorado has reduced 20-60% since the 1950s.

What an early-season melt can mean

For Colorado as a whole, the snowpack peaked on March 28 at 14.6 inches of liquid equivalent. The median peak is April 8 at 16.8 inches.

Snowpack water equivalent in Colorado from NRCS

For the Arkansas river basin, the peak was on March 30th at 12 inches this year, the median is April 5 at 12.2".

Snowpack water equivalent in the Arkansas River basin from NRCS

Snow amount hasn't been a huge concern for the Arkansas, Rio Grande, and South Platte basins as we have stayed near average all winter. More concern remains for western slope river basins which are falling further behind on snowpack.

But, an early and fast melt of an average snowpack can lead to issues later in the year.

A slow melt will allow for more runoff into the dry and hot summer months which can suppress wildfires. A slow melt can also keep the soil saturated for longer helping agriculture and water supply in general. This safety net is not there when the snow melts too fast or too soon.

Beyond the snow

A healthy snowpack can help with drought conditions, forest health and is a vital source of Colorado water. But that is only half of the story. Spring and summer rain is the main water source for the year for the plains.

In 2020, the snowpack was above average, but snow evaporation, a dry spring, and hot dry summer led to a horrific wildfire season.

A good sign on the horizon, cooler weather is ahead for mid-April, which at the very least will slow the melt. At most it will may replenish the snowpack we have lost so far.