The Weather in the West is Changing

The latest U.S. winter outlook spells trouble for dry California and Colorado. If the dry parts of the West receive far more moisture through the winter than has occurred for more than a century, they will be in for a drought worse than any in the past century. The outlook from the latest government weather forecaster, the National Weather Service in Boulder, Colorado, calls for an average of about 20 inches of snow from Colorado to Washington and as much as 60 inches for Washington to California.

It is difficult to believe that even the current model suggests such a severe winter in Washington, D.C. and other parts of the West. In fact, a few days ago we warned that even more water was likely in the Pacific Northwest, due to a shift in the jet stream and associated westerlies that will bring moist air from the north that is not present in the Southwest.

If that is the case, we can expect heavy snows here, in Colorado and California, much colder and potentially longer than this winter, all caused by a shift in the jet stream. This is the same pattern we saw during the last major drought in the West and a recent warm episode in the Southwest.

California and Colorado face a similar situation. Drought conditions continue to worsen in both states, and the West clearly had more prolonged wet years than any in the recent past. The last few years have been the warmest of the century. Even though temperatures have been very mild in both Arizona and California, they are still warmer than any period that had occurred in the last 150 years. It is hard to think of another example of such a prolonged high temperature period in this part of the world.

Even though temperatures are warming, there is a problem with that warm-up. With less water in the West, the weather patterns are changing as well. More moisture now goes east than west, and thus we see westerly winds blowing into the West instead of north.

The most recent report from the NOAA also notes that global warming will impact the weather in the West. It predicts that a strong jet stream and unusually warm phase of the Madden-Julian Oscillation will shift moisture eastward in the Pacific, pushing a lot of it into the Southwest. That is a very bad thing for California and Colorado.

The same thing is happening in the Southwest which, along

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