Brian Bledsoe

A couple months ago, we were telling you that there was potential for a La Niña
episode, before the year was done
[https://www.weather5280.com/blog/2020/03/03/la-nina-potential-later-this-year/]
. 

While we were pretty sure about some of the signals, ENSO forecasting this time
of year is always tough. Models struggle in the spring, and this is
affectionately called the "spring predictability barrier". We've seen ENSO
events show up in the modeling only to disappear as we enter into summer.
However, the signals we talked about back in early March are still there. 

The chart below shows how the equatorial upper oceanic heat content has fallen
off a cliff during the past month.

Looking deeper into the ocean, we are seeing the same thing:

The animation above shows the erosion of the warm anomalies that were present in
the Central Pacific, that were responsible for Modoki El Niño
[https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/prelude_to_ensofaq.shtml] 
conditions last fall and winter. 

The replacing of those warm anomalies with colder anomalies, is a continuation
of our thinking from early March, and that is that La Niña is going to make an
attempt this year.  Much of the latest modeling suggests this too:

While not all of the above models are on the same page, many of them drop the
Nino 3.4 SST Anomaly below -0.5 toward late summer. Looking at the current sea
surface temperature anomaly map, there's still a considerable amount of work to
do, but it appears as though that work is being done. While plenty of warm
anomalies in place across the ENSO region, as we saw above cooling is underway
at the surface and sub-surface, so we'll watch to see how that evolves in the
coming months. Here are the latest anomalies: 

Will all of this impact the next few months? Insider Pros can find our latest
three month outlook here
[https://www.weather5280.com/blog/2020/04/29/long-range-update-may-june-july-2020/]
.

La Niña development update