I woke up to a dusting of snow yesterday morning as a cold front plowing south along the mountains gave us a brief upslope event. A secondary surge was forecast for today, bringing with it a deeper upslope and a better chance for snow. I wasn't paying too much attention to anything until I heard on the radio this morning that the Weather Service had suddenly upped snow predictions.
When I got to work and had a look at things, I saw this:
(click for larger image)
Hello Winter-time Denver Cyclone! (I guess it is still Fall, but still...) The Cyclone tends to form a day or two after passage of a Canadian cold front when the surface flow generally has a south and east component. We were a little more east than south today, but the return flow along the foothills gave us enough spin to categorize the cyclone. It was gorgeous on radar, with a nice convergence boundary setting up from DIA curving south and west toward Elbert. Very cool to see today. I don't have any specific links ... but do a search for "denver cyclone" or "Edward J. Szoke" and you should turn up some good results (if you're looking for more info).
Anyway, it seems that the forecast may have been increased as a result of this formation, which can amplify precipitation (and mesoscale vertical motion) in the area. At my apartment, we saw about 3-4" and we're a little on the chilly side at 13ºF currently.
... okay, so I went out and checked ... 3.5" of very light, fluffy snow. I don't have my gauge set up at my new apartment, but I'd estimate the water content at somewhere between 1/15 and 1/20.
ALSO! I'm happy to announce that Marta Nelson, who succeeded me as president of Metro State's Student Chapter of the American Meteorological Society when I graduated, has organized a big get-together on December 19th. This will be the December "Convergence!" and I am going to cancel the January 3rd meeting. This Convergence! will be held at the school in a large-capacity room with plenty of guests and probably an opportunity to show video. More details to come.
Radar image courtesy of IPS Meteostar Inc.