La Nina is Not Going Away. What does the imply for this summer time’s climate?

 It’s now clear that La Nina shouldn’t be going away, and will hold round into subsequent winter.   

Chilly water is entrenched over the central and jap tropical Pacific (the definition of La Nina) and the newest forecast mannequin runs recommend a continuation into fall.

A number of of you will have requested:   what does this indicate for our summer time climate?

Let me let you know.   

However first, the underside line:   the summer time results of La Nina are modest, however will push the western aspect of our area in direction of cooler than regular situations.

The Impacts

Throughout La Nina years, sea floor temperatures off the West coast are often cooler than regular, and people cooling results unfold inland. 

 For instance, right here is the ocean floor temperate distinction from regular for the summer time months (Might by means of September) for La Nina years.    Blue colours are cooler than regular.

And if we common floor air temperatures for La Nina summers and subtract these temperatures from regular, we discover that cooler than regular summer time temperatures (e.g., inexperienced colours within the determine beneath) happen from California to Washington throughout La Nina summers (temperatures anomalies in diploma C are proven beneath).

In distinction, West Coast precipitation is hardly modified…maybe barely drier on the western sides of the Cascades.  I think it’s because the colder water works in opposition to thunderstorms.  Curiously, La Nina appears to have extra summer time influence over the Midwest U.S.

Summer season versus Winter

La Nina (and El Nino) have way more influence on West Coast climate throughout winter and early spring than summer time.    The ambiance is much extra energetic in the course of the cool season, with stronger, extra energetic movement within the midlatitudes and extra interplay between the tropics and midlatitudes.

A Report-Breaking Spring

As I’ll element in a future weblog, we’re on observe to “take pleasure in” the good spring in a half-century.  Proper now, the common April/Might excessive temperature at SeaTac is the second-lowest prior to now 50 years (see beneath).  And there are quite a lot of chilly temperatures forward.

And at Yakima, this spring IS the coldest by far.

La Nina will get a part of the blame…however not all.

And I hate to let you know this…. record-breaking chilly will likely be returning later this week.  So do not put your sweaters away but.