Thursday, December 19, 2019

Winter Rain

Here is an update of a figure that I have posted and discussed several times over the past nine years or so. The running total for this 2019-2020 winter, which when it ends will be in a new decade, is off to a good start. As of mid-December this winter has already surpassed the entire, disappointing, strong El Niño winter of 2015-2016.
This winter's ONI is expected to remain on the warm side of neutral territory, just less than the +0.5 threshold that is used to categorize El Niño. This winter's data point may end up shifted a little to the right or left, but probably not by much--the consensus of dynamical model forecasts of (sea surface temperatures that go into calculating) ONI has verified well over the last few years. The only question is how far the point will move up on the vertical scale of precipitation. It would be a shame if this winter ended clustered with the red data points from the 1950's and 2000's. Instead, given the head start, I'll be optimistic that by the end of March this winter will be comparable to 2018-2019.