Following a warm a dry autumn, winter has brought significant precipitation to the entire state, along with occasional cold snaps. As a result, all basins have experienced dramatic snow accumulation and are now well above normal for snowpack. Increased precipitation has also helped to alleviate drought conditions in many regions of the state, although moderate and severe drought remains on the eastern plains. Reservoir storage is above average and at this time water providers and agricultural producers have no significant concerns entering into the spring snow accumulation months.
- Statewide water year- to- date snowpack as of January 18 is at 156 percent of average, representing a dramatic change from two months ago when snowpack accumulation was off to a much later than normal start. . The Yampa & White currently has the lowest snowpack in the state at 141 percent of normal while the basins of the Southwest have the highest snowpack at 170 percent of normal.
- All basins received well above average precipitation in December ranging from a low of 144 percent in the Yampa & White to a high of 187 percent in South Platte. January to-date has seen even more accumulation ranging from a low of 236 percent of average in the Rio Grande to a high of 345 percent of average in the South Platte. Statewide December precipitation was 168 percent of average and January to–date is at 280 percent of average.
- Reservoir storage statewide remains high at 105% of normal. The Yampa & White River basins along with the Southwestern basins have the highest storage levels in the state at 118 and 114% of average, respectively. The Upper Rio Grande has the lowest storage levels at 86% percent.
- Temperatures in northern areas of the state reached record lows of -48 degrees Fahrenheit (Walden) during recent cold snaps; while some SNOTEL sites are reporting 400+ percent of normal accumulation. On the plains the presence of snow on the ground provides insulation and protection to crops, like winter wheat, during these arctic blasts.
- The Surface Water Supply Index (SWSI), calculated based on January 1 streamflow forecast and reservoir storage, is near normal statewide.
- Despite heavy precipitation statewide, much of the eastern plains remain in some level of drought classification following a warm and dry fall. 20 percent of the state is currently experiencing abnormally dry conditions (D0) while 35 percents is classified as moderate drought (D1), less than 1 percent of the state, mostly in Lincoln County, is experiencing severe drought. This is an improvement from recent conditions.
- A weak La Niña was diagnosed for late 2016, but forecasts indicate that it is unlikely to last and instead El Nino conditions are projected to develop during the spring. The development of a strong El Nino would favor increased precipitation for Colorado; however it is unclear if this will be a strong event.
- Short term forecast show less active systems through the end of the month that are likely to result in dryer conditions than we have seen during the first half of January.
- Globally 2016 was the warmest year on record, in Colorado 2016 was the 5th warmest year on record.
The US Drought Monitor shows persistent dry conditions along the eastern plains of Colorado, despite significant precipitation over the last two months. The majority of this (35%) is moderate drought. Following very dry conditions in October and November, snowpack accumulation has rebounded to 156% of normal, with only 40% of normal snowfall needed to reach the normal peak. Snowpack at mountain SNOTEL sites is well above average in all basins of the state.
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