The El Nino Southern Oscillation (ENSO) pattern continues to be neutral, which means neither El Nino nor La Nina is dominating right now. What does this ENSO Neutral pattern, which I like to call "La Nada", mean for us in the DC Metro?
First of all, what is ENSO anyway? The ENSO is monitored in the waters off the coast of Ecuador in the Eastern Pacific. If the water temperature is above normal for a few months in a row, this is considered an El Nino. La Nina conditions are characterized by below-normal water temperatures for at least a few months at a time.
In this article I wrote earlier in the winter, I talked about the effects of the oscillation. El Nino winters are known to bring more coastal winter storms to our area, but they also tend to give us milder than average temperatures. This can either result in chilly, rainy weather; or, if an arctic outbreak arrives at the right time, we end up with a huge snowstorm. This was the case with the President's Day Blizzard of 1979, and with the Snowmageddon Storm of 2010. La Nina winters are colder than average in the DC Metro, but they're also typically drier. A strong La Nina (when ocean temperatures are far below average) results in very low snow totals for us, despite the plentiful cold air. In fact, we average less than 10" of snow during a strong La Nina, whereas in a typical season we can expect about 15" of snow. (Of course, "typical" is a bit misleading; more on that here).
So here we are, at the tail end of winter, with "La Nada" conditions persisting. Without a strong signal from the Eastern Pacific, it's hard to say if our temperature ups and downs will lead us to a final winter storm before spring arrives. But we can take a cue from what we've seen so far this year!
Since 2013 started, the year has been characterized by rollercoaster temperatures. After a beautiful Inauguration Day with a high of 47 degrees, we suffered an arctic blast that kept temperatures below freezing for more than 4 days in a row. On February 15th, we had a high temperature of 60 degrees; just 2 days later, the high was only 34. These are just a couple examples of the temperature ups and downs we've had this year. Also, after a bone-dry 2012, we've finally begun to see a return of regular precipitation to our area. Up until now, the moisture hasn't coincided with enough cold air to bring us a heavy snowfall. As the winter winds down and the sun angle gets higher, the likelihood diminishes that it'll happen this winter, but there's still an outside chance that we'll get a snowstorm before the springtime flowers start blooming.