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Denver was the center of snowfall bull’s-eye. Here’s the science behind the rare occurrence.

The latest snowstorm was the largest of the season so far, and also featured a rare Denver bull’s-eye.

Widespread snow totals of 8 to 14 inches covered the entire metro area in a fresh blanket of white, resulting in treacherous road conditions and a tedious clean-up process.

The official observation at Denver International Airport, which usually is a poor representation of Denver snowfall, was also an impressive 9.6 inches. It was the biggest snowstorm in the city since Apr. 16-17 2016, when 12.1 inches was recorded. It is also now the 7th largest February snowstorm in Denver since records began in 1874.

Leading up to the storm, the snowfall looked to largely be driven by upslope winds. In this area, the upslope flow refers to winds that blow from the Eastern Plains, westward and uphill toward the mountains. Such a scenario typically results in snowfall getting maximized close to the foothills, while the I-25 corridor gets lighter amounts, and DIA ends up with close to nothing.

Several factors caused this storm to overperform region-wide, and ultimately surprise many metro area residents upon waking up Thursday morning.

The upslope flow became established Wednesday afternoon, as expected. However, a boundary set up very close to the Denver metro in the evening, which separated southeasterly winds to the south of it and northeasterly winds to the north of it. The result was a lot of converging air at the surface near Denver.

After air converges at the surface, it is forced to rise. Forcing air to rise like this is an efficient way of creating and enhancing precipitation.

Another meteorological process called “frontogenesis” was occurring higher up in the atmosphere. Much colder air was plunging down from the north, while the milder air from earlier this week tried to hold its ground. This can also focus heavy snow bands over the area where the temperature contrast is largest. In this case, Denver was the sweet spot once again.

By combining these two factors with a favorable placement of the jet stream 30,000 feet in the sky, the stage was set for a wallop.

Intense bands of snow remained nearly stationary Wednesday evening after developing. These bands dropped one to three inches of snow per hour, for several hours. They hit every part of the metro area throughout the duration of the storm, including the airport.

Denver’s February snowfall total now stands at 13.5 inches, solidifying the city’s third straight snowier-than-normal February. The seasonal snowfall total sits just below 34 inches, which is right on track with the long-term normal through the end of February.

It is also a good time for the annual reminder that March is typically Denver’s snowiest month of the year. This large February snowstorm may have only been an appetizer of what still lies ahead.

Ben Reppert is a meteorologist with WeatherNation TV.

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