OK, it’s April 1, and this is no joke. The official runoff forecast, done by genuine professionals, will be out next week, but we can get a pretty complete picture from the Snotel data. These numbers are river basin snow water equivalent content, in percent of April 1 average:
- Upper Colorado River: 111
- Upper Rio Grande (the part in Colorado): 65
- Upper Rio Grande (the part in New Mexico): 63
- Rio Chama (a Rio Grande tributary in NM): 60
- Pecos: 11
- Gila (the NM part): 30
Elephant Butte Reservoir, New Mexico’s largest, was at 38 percent of average March 1. This is a reminder of the significance of both decadal-scale climate variability (a huge wet year last year didn’t alleviate the problem) and growing human withdrawls from the system (there are more people here now than there used to be).
You can see from the map a pretty clear La Nina pattern, dry in the south and wet in the north, though that may just be dumb luck rather than a genuine teleconnection.