The area around campus was littered this morning with small, spongy, ball-shaped snow pellets that fell over night. They are indeed fully recyclable.
Most clouds are comprised of a mixture of ice crystals and supercooled cloud droplets. Supercooled means that the droplets are below freezing, but remain in the liquid phase. Graupel is a type of snow pellet that forms as an ice crystal falls and collects these supercooled cloud droplets, which freeze on contact. This leads to the formation of a ball or lump shaped snow pellet.
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| Source: Parkerjh, Wikipedia Commons |
What was up with the PM2.5 bump last night/this morning?
ReplyDeletehttp://www.airquality.utah.gov/aqp/trend_charts/getData.php?id=slc
My theory is that we had moderately bad air, the stuff over the lake was worse, and it got pushed by Hawthorne with this little storm?
Thanks for the heads up. I just looked at the PM2.5 time series and it did exhibit some strange behavior. The flow did switch from SW to NW as the trough came through. What is odd is how it dropped around noon. Perhaps there was a some gunky air over the lake, it got swept in with the trough, but eventually cleaner air replaced it? It's tough to say given the lack of AQ data upstream.
DeleteJim,
ReplyDeleteLooks like low-density and nearly round pellets - so I'd tend to call then snow pellets. I don't know if there's a density criteria for graupel, which tends to be more dense than snow pellets because of its faster growth rate. Just my guess.
Bob