CODOS UPDATE April 3: Dust Event #4, More Coming
Greetings from Silverton,
Since our last update a week ago we received 0.7” precipitation on March 30-31 and on the associated storm front the southern mountains received a bit of dust (dust event #4 for the season). Like D3, this was a very light event at Swamp Angel Study site. It is so mild you feel it’s presence more than really see the dust layer itself. Other areas, like near Silverton, the dust is much more obvious being concentrated at the surface in select areas of the landscape. Fair to say this event was unevenly distributed across the mountains (it closed roads in Southeastern Colorado). So far this season we received a dust-on-snow event on March 5 (D3), Feb. 22 (D2), and D1 occurred sometime in November. All these events were considered mild events. A very good season so far in terms of dust severity being at a minimum (of course a good year for a big snowpack too).
I would really like to see dust to stay at a minimum this spring, it would make for another unique season for the record books; a huge snowpack free to melt at it’s own pace, mostly unencumbered by dust radiative forcing. However, the spring season typically ushers in more frequent dust events, which puts the dust at the top of the peak of the season’s accumulated snow. And, currently, a storm is approaching bringing high winds to Southwest Colorado. There are red flag wind and dust warnings. We will see how the soil moisture in the Four Corners region does at minimizing dust mobilization.
I imagine we will issue another update within a few days to summarize the dust event that is likely about to happen and to shift focus towards spring melt. The forecast is calling for the current storm to hit with snowfall tonight thru Tuesday in the Northern San Juans and thru Wednesday for Northern Colorado. Following this, a major warm-up will ensue. The last few years spring weather was dry/warm with average to severe dust making for rapid ablation of the snowpack. How this spring will unfold remains to be seen, but my guess is we will shift gears rather quickly, from a cooler and wetter than normal winter to a warm and dry spring. There is a lot of activity going on at Senator Beck Study Basin. We completed the first CODOS circuit of the season a couple weeks ago, we are currently digging out the stream gauge to get that operational, conducting snow profiles, and ensuring the station sensors are operating as expected, all in preparation for a big snowmelt season.
More Soon,
Jeff Derry
