A Weak El Nino Transitioning to La Nada

During the past few months we have moved from near neutral conditions (La Nada) to a weak El Nino (warmer than normal temperatures in the central and eastern tropic Pacific)--providing some insights into the weather later this year.

Looking at the temperatures in the central tropical Pacific (the Nino 3.4 area), the water temperatures have moved from a bit cooler than normal in September to around .5C above normal.  This is a minimal El Nino.



Next, viewing water temperatures in an east-west slice of the Pacific Ocean--from the surface to about 300 meters below the surface-- show warmer than normal conditions (red/orange colors). 

The trade winds have weakened as well--another marker of El Nino.  This is a very weak, minimal El Nino.  And the strength of the signal is important.

Last month, the NOAA Climate Prediction Center was projecting that this spring we could move into neutral territory (tropical sea surface temps within .5C of normal)-- see below

And the January extended forecast from many modeling systems (see below) generally indicates neutral conditions, slightly weighted towards the warm side.  The latest European Center model is similar.


The key point in all this, is that with a weak El Nino grading to neutral (normal, La Nada) conditions in the tropical Pacific, there is no reason to expect conditions in our area to be different from normal.  They could be, of course, but the tropical Pacific will not be weighting the atmospheric dice in any direction (something that a strong El Nino or La Nina would do).

What about the BLOB?  How is it going?  The latest sea surface temperature anomaly map (difference from normal) shows cool water immediately off the West Coast, but evidence of a weak blob (1-2C above normal) off the coast.   Let's call it a junior blob...much, much weaker than the one we experienced a few years ago.


Comments

Post a Comment

Popular posts from this blog

Why so little lightning in the Pacific Northwest? And a very nice weekend ahead.

Image
During the past 24-hours, there have been a few lightning strokes over the region (see below) but nothing to write home about (see below). It turns out that the Pacific Northwest and the remainder of the West Coast have some of the lowest frequencies of thunderstorms in the entire country (see below). But why?    My podcast provides the answer. And I also give the weekend forecast....and I think most will like what I have to say. To listen to my podcast, use the link below or access it through your favorite podcast service. Some major podcast servers:     Like the podcast? Support on Patreon 
Read more

The Time of Year You Can See the Air Move

Image
  Most of the time, you can not see the air move.   You can feel it, but the complex, turbulent motions are invisible to you, except when it interacts with leaves and branches on trees and plants. But for a few weeks of the year, the sky is full of small, cotton-like tuffs that like a natural MRI machine reveals the complex three-dimensional motions of the atmosphere.   Cottonwood season.  And we right in the middle of it.   Being cottonwood aware is of particular value this year.  It reveals the active dispersion and movement of air that makes the outdoors essentially COVID safe, and thus should be of some comfort for those nervous about transmission outside. Cottonwood seeds are embedded in small cotton-like fibers.   A million seeds weigh about 3 pounds.  Yes, each seed and tuff weights about .000003 pounds.   And that fact, plus the cottonwood tuff, means that these seeds fall VERY, VERY, VERY slowly.   So slowly that they are excellent markers for the three-dimensional flow of the
Read more

A Much Colder Than Normal April: But How Unusual?

Image
  April was a chilly month over the Northwest, but how chilly?     It turns out the answer depends on where you are located. The difference between this April's temperatures from normal across Washington State (below) shows that the entire state was well below normal.  The eastern side of the state was particularly frigid:  some areas were more than 6 degrees below normal.   Considering the west side of the state, the April mean temperatures at SeaTac Airport are plotted below.   This April was the coolest since 2011. April 2020 was in 15th place for the coolest April since the mid-1940s and was a bit more than 4F below normal.  So if you felt that you were cheated out of normal spring warmth...you are right. But if you really wanted to experience extraordinary April cold you had to be east of the Cascade crest. Consider Yakima.  Wow.  It had the third coldest April temperature since the mid-1940s.   And the all-time record in 1955 was only slightly colder. If you want a longer-te
Read more