NRCS February 1, 2014 Colorado Basin Outlook Report — snowy and wet finale to January #COdrought

February 1, 2014 snowpack by sub-basin via the NRCS
February 1, 2014 snowpack by sub-basin via the NRCS

Click here to read the report. Here’s an excerpt:

Summary

Colorado typically receives 20 percent of its snowpack in January, but this year, after a great start to the snow season it seemed as though January might disappoint. From January 15th to 27th snow accumulation statewide was almost nil, but thankfully winter storms during the last week of the month brought a snowy and wet finale. The entire state reaped the benefits of the late January storms. The northern and central mountains received enough snow to push snowpack reports back to above normal totals. In the southern part of the state the moisture was especially welcome since the region had received very little snow since early December. The storms improved snowpack percentages in this region but it was not enough for them to reach normal conditions. Water storage in the state has improved over the past month but statewide totals are still tracking slightly below average for this time of year. Storage in the southwest, Upper Rio Grande and Arkansas basins remains well below average. With only 40 percent of the winter snow accumulation season remaining, water managers in these regions should pay close attention to the weather patterns over the next couple months in order to make informed decisions concerning their water supplies.

Snowpack

Data collected from manual snow courses and automated SNOTEL sites across Colorado showed an overall increase in the snowpack during January. Statewide snowpack totals were 107 percent of median as of February 1. Looking beyond statewide totals, the data vividly shows the variability between the northern and southern part of the state. The combined San Juan (Animas, Dolores, San Miguel and San Juan) basins has declined from 100 percent of median on January 1 to 82 percent as of February 1. The Upper Rio Grande basin’s snowpack has also decreased since last month’s report; dropping from 99 percent of median on January 1 to 82 percent of median on February 1. The Arkansas basin saw a slight improvement in it’s snowpack from 105 percent to 108 percent of median, but this was mostly a result of the Upper Arkansas jumping from 92 percent to 119 percent of median. The snowpack in the lower reaches of the basin had significant decreases this month. The South Platte basin had the most notable gain in snowpack totals during January, with an increase from 99 percent of median to 126 percent of median as of February 1.

Precipitation

Statewide monthly SNOTEL precipitation totals were 117 percent of median for January, but three basins fell short of the “normal” mark for the month. The Gunnison basin recorded 92 percent of average for monthly precipitation and was at 97 percent for year-to-date precipitation as of February 1. The combined San Juan basins only recorded 59 percent of normal precipitation for the month, and year-to-date precipitation dropped to 87 percent of average. The Upper Rio Grande basin recorded monthly totals at 57 percent of average which dropped year-to-date precipitation to 82 percent of average. The remaining basins all recorded above average precipitation for the month of January. The Colorado and the South Platte basins both received well above average precipitation at 152 percent and 183 percent respectively.

Reservoir Storage

Colorado’s reservoir storage volumes are slightly below average for this time of year. Statewide storage was 90 percent of average at the end of January, which is a major improvement over the 69 percent of average reported last year at the same time. Both the South Platte and Yampa/White basins are reporting above average storage levels, at 111 percent and 112 percent respectively. The Colorado basin is currently storing water at near normal levels; 98 percent of average as of January 31. While the remaining basin’s storage volumes are all below average currently, current volumes are improvements compared to last year’s for this same date. The Arkansas basin has the lowest storage volumes as a percent of average, at 64 percent of average and 25 percent of capacity. The Upper Rio Grande is also storing well below normal amounts of water; storage was 65 percent of average at the end of January.

Streamflow

This month’s streamflow forecasts for the spring and summer season follow the trends observed in the snowpack reports. Near to above normal runoff is predicted for the Yampa/White, Colorado, Gunnison, South Platte and Upper Arkansas basins. Overall the February 1 forecasts in these regions have improved compared to those issued last month. Most forecasts in these areas are slightly above normal. Spring runoff in the combined San Juan basins is now expected to be around 80 percent of normal, all current forecasts in these basins have declined from last month’s. In the Upper Rio Grande basin the forecasts have also decreased from those issued last month, with larger decreases as you move from the headwaters of the basin to the southern tributaries. The forecasts for the downstream tributaries of the Arkansas basin have also dropped compared to last month’s in contrast to the improvements in the headwaters region mentioned above.

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