We’re in the time of year where one good storm, like the one last Thursday, can really move the snowpack as a percent of average. Here’s the graph for the South Platte River Basin. Here’s the 24 hour precipitation map for Jefferson County for December 22, 2011 from CoCoRaHS.
Click on the thumbnail graphic to the right for the snowpack map from last Friday.
The Colorado River Basin is at 67% of average. Statewide is 78%. Dry in the Fraser River headwaters.
Here’s a look at the Madden-Julian Oscillation which is overpowering La Niña right now — according to the staff at the National Weather Service in Boulder — from Bob Berwyn writing for the Summity County Citizens Voice. From the article:
The resulting weather pattern has looked much more like an El Niño phase of the Pacific cycle, but the good news (for Colorado) is that the Madden-Julian phase has weakened. That means that a more typical La Niña pattern — with a storm track out of the northwest — may once again begin to dominate Colorado weather.
In fact, a series of small and fast-moving storms is starting to line up in the Pacific Northwest, with a chance of snow in the northern mountains Wednesday night and the potential for a few more disturbances to cross the area on and off through the end of the week.
The Madden-Julian oscillation is a 30- to 60-day cycle featuring an eastward progression of large regions of both enhanced and suppressed tropical rainfall, observed mainly over the Indian Ocean and Pacific Ocean.