This storm had a little bit of everything. Rain, snow, fog, drizzle, and oh yeah... SLEET! We had crazy sleet in Colorado Springs Saturday night. As I mentioned, I have never seen it sleet that hard or for that long in all my time in Colorado. In the Midwest and in the Plains, sleet is far more common. One storm I worked in Sioux City, Iowa, dropped 4 inches of sleet and it shut everything down. Around here though, we see graupel more often than sleet. The dynamics that make sleet usually don't occur around here for a long enough time to sustain it. Saturday night was a different story. It was raining lightly and had been doing so, before it turned to sleet around 7:15pm. Rapid rising motion brought some cooler air down close to the surface and the rain changed to sleet and didn't have time to melt back into rain before hitting the ground. There was also some dry air present above the ground and that promoted evaporative cooling which changed the rain to sleet and was able to maintain it. Mind you the whole time it was sleeting, the temperature was just above freezing .Below is a rough schematic of how it more commonly works in the Midwest and Plains.
SLEET: This occurs when snowflakes, ice crystals or ice pellets melt into raindrops on the way down. That is, they fall into warmer air on their way toward earth. But, as they continue toward the ground, they fall back into air that is below freezing. Yes, sometimes it's warmer up in the sky than it is down here on the ground. If the cold air near the ground is substantial enough, the melted drops freeze into sleet before they get to us.
When the atmosphere saturated completely and the dry air was replaced, the sleet changed over to snow. Took a long time though and you may not see that happen again for quite some time...
Overall, the storm wasn't a huge one, but did produce some decent amounts. Areas around Denver picked up 8 to 12 inches and seemed to have the most widespread significant accumulations. Southern Colorado was a bit more spotty...as usual.
If you guys have additional snow totals to report, you can always do so by posting here or emailing them to: firstname.lastname@example.org
Here's to a quiet week of weather...
Chief Meteorologist Brian Bledsoe