The regional precipitation for the western states of the U.S. during the recent 5 years has been falling below normal. The blue line is the historical average. Winter months are normally the wettest. Instead, the red bars indicate below normal amounts each year. One year ago, I wrote about this situation. The much needed precipitation is not coming.
Despite a brief period of rain and snow in Nov/Dec, the region has returned to below normal precipitation in what should be a rainy season. Data from the Western Regional Climate Center for January 2015 shows much of the region receiving much less than the average (red and orange).
What About El Niño?
Earlier in 2014, hopes were building for the formation of an El Niño. In May, I posted some information about El Niño formation and why it might help the western states. The odds of El Niño have slowly decreased during the year. They are now at 50-60% which is not strong. There were promising signs early in the winter. The chart above shows that has changed. The region has also been about 5˚F warmer than average for the month of January.
By November 2014, climate scientists were hoping to see signs of the El Niño having an effect on the Jet Stream and weather patterns that would be helpful.
Dr. Jeff Masters, co-founder of Weather Underground, wrote in his excellent blog last week that California is slipping back into exceptional drought since the brief rains. (Another post by Jeff January 30 reiterates) The chart shows that 58% of the state was in exceptional drought during the summer dry period. That fell to 32% in December. It has climbed back up to 39% as of mid-January. The western states will be moving into the dry months soon. Unless precipitation comes, the western states’ reservoirs and snow packs will remain depleted.