Wednesday, December 18, 2013

Washington Cascades Weather - Extended

Updated 12-17-2013

Forecast models continue the trend of below normal mountain snow through 12-31-2013. We will get some snow at times but weather systems that move into our region will move into a ridge of high pressure and this will tend to reduce the amount of snowfall we get. As of 12-15-2013 most of the West Cascades snow on the ground as percent of normal is below normal: Snoq Pass is 25% of normal, Stevens Pass 60% of normal, and Paradise at Mt. Rainier 62% of normal.

The main reason for this dry pattern is there has  been a trough of low pressure and pool of cold air in the Midwest east towards East Coast. This has seemed to lock the ridge of high pressure over the West Coast (see map below) for much of the time during the late fall. Will this continue to be the pattern during the winter? Time will tell.

Average position at 500 mb (18,000') for 14 day period ending 12-31-2013. Ridge on West Coast and trough Midwest towards East Coast

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