odels had been uniform in bringing a deep trough into the west, which would go down the pleasant ridge we had been living under seemingly since summer.There didn't appear to be much doubt as to whether the downfall would decline as c or not.It definitely would be cold enough.So, today I watched as the cold front pushed through early this morn and set us up into deep upslope for the day.The radar began to filling up returns on the Movement Range while it was still sunny across the Urban Corridor.I started looking a little more closely at the RUC and saw a bit of instability as well, which made sense since lapse rates were decent.Sure enough, lightning began to read up in the mountains.Over the following pair of hours, the open skies over the metro gave way to a rapidly moistening atmosphere.The radar returns began to hand over the Footies and so into the Urban Corridor.I decided to direct outside with my camera to make a look.A bit of a shelf cloud forming on the escape from snow showers moving out of the mountains.
As the precipitation grew eastward, cold air began to come out of the mountains, undercutting the upslope.While I was standing there taking photos, I endured a few spits of light rain but this was soon replaced with sleet.The sleet surprised me.I had predicted graupel with the available instability, but not the sleet.I had to consider for a bit to flesh out how it happened and as far as I could tell, it was simply the undercutting of the upslope flow by the cold pool.That allowed the rain to pass through the subfreezing air close to the earth and get an ice pellet.Soon, the pellets falling changed from clear, frozen rain drops to white, accreted snow pellets or graupel.I sort of love graupel.In fact, way back when in high school, I wrote an article for the local paper in Butte, Montana about the difference between graupel and hail since I was tired of people telling me that they had been hailed on during a convective snow shower.If you're curious about the processes, I'll explain it briefly here.Graupel is formed in the like way as a hailstone with the chief difference being that for graupel, the total depth of the convective cloud is below freezing.The snow pellet is formed by accumulation of ice crystals as it travels up and low in the storm's updraft.For hail, the freezing layer is usually higher up in the obscure and therefore the "rock" when traveling up and down in the updraft spends some time accumulating water and so having it freeze when it is higher.Anyway, I figured we would see some graupel and we almost surely did!I was hoping for some larger pellets, but most were fairly small.
Back at my apartment, the graupel actually changed back into rain for a spell before snow slowly started mixing in.Over the following minute or so, it really started snowing large dendrites for perhaps a half hour.Most of these melted, but finally the snow began to collect on grassy surfaces.I figured it was high time to raise up the hearth and do some hot cocoa!All weather should be enjoyed...
I was subject to pass the repose of the evening indoors, but I caught a glance of color outside of my window and noticed that the sunset might be peeking through.I put on my warm clothes and got my camera again, making my way back out to the empty lot east of my apartment complex.Unfortunately, the little hollow in the stratus that let the sunset through had shut up, but I figured since I was out, I might as easily take the best of it.So, for the following hour, I walked round the Greenwood Plaza area and took pictures, occasionally being startled by a blink of short or two in the sky.Interestingly, the precipitation was almost over, but I kept seeing flashes.
Russian Olive after the snow.
Snow on the top of Plaza Tower One.City lights of Denver reflecting off of the stratus deck with the Landmark towers almost hitting their heads on the ceiling.
Evening traffic at South Syracuse Way and East Caley.
"The Cascades"
Another trip through the Museum of Outdoor Art.
The WeidenblumeVillage CenterIt was really a beautiful even to go out for a bit of a walk.It wasn't too dusty and just nice to be "experiencing" the first snowfall of the year.Even at home late in the evening, I would occasionally see a twinkle in the sky outside.I yet feel this strange as most of the hurry had moved well off to the east, but I am unable to explicate it otherwise.Dann.
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