La Nina and What That Means for Summer In Pac NW

I have received a few questions regarding our La Nina situation and what that entails for summer. Well to be completely honest with you, in the Northwest, it means nothing. In general, a La Nina winter (that continues into the summer OR that transitions to a "neutral" summer, more on that in a minute) has practically no effect for our summer weather.

You can see here in this schematic that during the Northern Hemisphere winter, a "cold episode" (aka La Nina) brings a cooler and wetter pattern here to the Northwest. And if you have lived through this Spring, you can surely attest to this being true. But in the summer, there is nothing out of the ordinary. So if I was to make a prediction for this summer I would say it would be climatoligically normal. 70s and somewhat dry. Now that isn't to say we won't see a heat wave (for our standards that's reaching the 90s) or get a little wet for a couple days, but according to the research we have on La Nina summers, there would be nothing out of the ordinary.

So what about an El Nino summer you ask? Practically the same.

The real impact is in the winter, not summer.

As you can see, the variations on climate are only clearly visible during the winter.

So what is the forecast for this summer?? Well the models run by the Climate Prediction Center have not narrowed down on one particular idea. Here is a plot of all the different models and how they are projecting our transition from La Nina.

The models (on average) are trending for us to reach a neutral winter for 2011-2012. Now I don't want to really "scare" anyone but our neutral winters here in the NW typically bring our strongest storms (I have not done a lot of research on this but maybe I shall). The December 08 snow storm was a neutral winter. Plenty of wind storms come through in neutral winters also.

We shall see how this plays out but for now, enjoy our NEAR 70 DEGREE FRIDAY!!

-Aaron