The following conditions influenced this month's forecasts:

Precipitation:
Seasonal October through December precipitation is above average due to a wet October. November was dry with precipitation amounts generally less than 70 percent of average.

December precipitation was generally below average across much of the Basin, with the exception of a few high elevation sites that received amounts near or slightly above average.

Snow:
Current snow water equivalent for the entire basin is 85% of average for early January. The Animas basin was near 90% of average on January 1st and the San Juan above Navajo was near 80 percent of average.

Animas River Basin Snow Plot.

San Juan Basin (above Navajo Reservoir) Snow Plot.

Streamflow:
Streamflow volumes for December ranged from 65% of average at the Basin outlet to near 90% of average at higher elevations.

Soil Moisture:
Modeled soil moisture indicated near to slightly above average soil moisture conditions over the San Juan Basin last fall, prior to the onset of snow accumulation.

Climate Forecasts:
La Nina climate conditions exist and a weak to moderate La Nina episode is anticipated to continue through the winter season. The La Nina climate condition suggests drier than average conditions possible over the San Juan Basin. The La Nina climate condtion was considered when developing the forecasts.

Forecast Summary:
Seasonal precipitation is above average due to a wet October. Snowpack conditions are below average due to drier weather in November and December. Soil Moisture was near to slightly above average entering the winter season. La Nina climate conditions suggest below average precipitation is possible over the San Juan Basin through spring. April-July runoff volumes are expected to range from 75 to 95 percent of the 1981-2010 average.

Differences between the full period forecasts and the residual forecasts may not exactly equal the actual observed volumes due to rounding conventions (see Definitions section).