Peak snowpack in Colorado is way behind us but during this time of the year, we watch the snow dwindle slower than it is now thanks to late-season storms and relatively cool spring temperatures. This year, however, has not provided any late-season action but instead, warmth and dryness has overcome the state.
Snowpack is pretty variable from one side of the state to the other. The Laramie and North Platte basin is sitting at 88% of average. The Upper Rio Grande, however, is sitting at just 3% of average and melting fast.
The San Miguel, Delores, etc is sitting at 10% of average for the date and also melting fast. There are several stations that are already at zero snowpack. For some lower elevation stations, this is normal. For others, not so much. Regardless, the story here is that the SW mountains are melting very fast and are on track to challenge the earliest melt out on record.
Right now in the San Miguel, Delores, Animas and San Juan watershed, there is 0.4″ of SWE or Snow Water Equivalent. There should be 6.3″ of SWE for this date. The melt rate in this basin so far this month is just under a half inch of SWE per day. (0.4″ per day). With only 0.4″ of snowpack left, this basin should melt out in the next few days which would make this seasons melt out the earliest on record or damn close.
The Upper Rio Grande basin is sitting with only 0.1″ of SWE. Ideally there should be 5.0″ of SWE at this date. This basin is melting at an average of 0.24″ per day – or about a quarter inch per day. At this rate, the basin should completely melt out today or tomorrow. This will be close, but it’s on track to tie the melt out for the earliest date on record.
Of course, an early melt off has many repercussions on the upcoming summer and fire seasons. We would like a normal snowmelt or even slow melt because that allows for more moisture to be held in the soils during the approaching hotter months. Also, with lower soil moisture now, any late-Spring or summer rains will be soaked up rather than running off into reservoirs and storage areas.
Many areas of the west are – and have been – battling low storage levels and a quick melt off this season means that we will continue to have below average water storage levels through the summer.
The rest of the Colorado basins are faring okay – and that’s relative to what’s happening in the San Juans. All basins are below where they should be for this date alluding to the likely possibility that all of Colorado will melt out earlier than normal this year. There is some weather incoming that could boost numbers slightly at the end of the week but it looks like only the northern basins will benefit.