Greetings from Silverton,
We conducted the CODOS tour the middle of April and finished a few sites on April 22. Starting on April 25 (along with a D5 event on April 23 and D6 event on April 25) most of the Colorado mountains experienced a week of stormy weather that mostly arrested or slowed down snow melt as seen in many stream gauges. After these last few days of warm, sunny weather, we have seen an uptick of stream flow. Now, the forecast for the next 4-5 days is for increased cloud cover, a cooling trend, and chance of precipitation in the form of rain or snow at higher elevations. Depending on how much precipitation in the form of rain we receive, along with general weather conditions, will of course determine how much this uptick in stream discharge continues. Rain, especially if accompanied with a moist, warm air mass that sits on the snow, can increase the energy inputs and ramp up melt on an already ripe snowpack. When warm and sunny conditions return, southern Colorado where dust is at or near the surface of the snow, will see dust enhanced snow melt. Northern areas of Colorado, that have remained dust free since our last field observations in middle/latter April, will see a more "natural" snow melt scenario in terms of not being influenced by the increased solar absorption of dust on the snowpack surface.
At Senator Beck Basin, as of Wednesday, May 4, D2-D6 are all in the top 50 cm (20") of the snowpack. D6, being a light event, is on the surface. D5, a moderate/heavy event, is 14 cm (5.5") below the surface at our study plot. However, D5/D6 were merged and exposed on southern (SE-SW) aspects and lower elevations.
As mentioned in the CODOS Trip Summary for April, many locations (McClure Pass, Park Cone, Spring Creek Pass, Wolf Creek Pass, Grande Mesa) had dust at or very near the surface prior to the April 25-30 storm events.
We plan to begin the May CODOS Tour starting sometime the latter part of next week, depending on on-site and weather conditions. Fortunately, we are seeing continued chances of precipitation. Please see precipitation and temperature forecasts below.
More soon,
Jeff Derry