Ski-Doo Snowmobiles Forum banner
1 - 20 of 25 Posts

·
Fuzzy but not Blue........
Joined
·
10,651 Posts
Discussion Starter · #1 ·
uly 2021 ENSO update: La Niña Watch
Author:
Tom Di Liberto
July 8, 2021

As things stand with the El Niño-Southern Oscillation (ENSO), neutral conditions are currently present in the tropical Pacific and favored to last through the North American summer and into the fall. But forecasters at NOAA’s Climate Prediction Center have issued a La Niña Watch, which means they see La Niña likely emerging (~55%) during the September-November period and lasting through winter.
Pacific Ocean, June sea surface temperature anomaly

June 2021 sea surface temperature departure from the 1991-2020 average. Image from Data Snapshots on Climate.gov.
Where we are:
I know you’re all excited for me to talk about La Niña, but I’m a killjoy, so bear with me for a second while I talk about the current state of the Pacific. In June, ocean surface temperatures were near the 1991-2020 average across the equatorial Pacific, including the all-important Nino3.4 region (check out this post for more on ENSO indices), which we use to monitor the state of ENSO. Specifically, the June sea surface temperature in the Nino3.4 region was 0.25 degrees Celsius below average, well within the ENSO-neutral range. Ocean temperatures in this region have been quickly returning to near-average conditions over the last several months, increasing by nearly half a degree Celsius since April and over a degree Celsius since last winter’s La Niña peak.
But as we have said, so many, many times: there is more to ENSO than just the surface of the ocean. Putting on our snorkels, let’s dive beneath the surface of the Pacific, where things aren’t as near average but still firmly indicative of an ENSO stuck in neutral. Waters were slightly warmer than average, except for the eastern Pacific where cooler-than-average waters developed near the thermocline—the layer of water that marks the transition between the warmer upper ocean and colder deeper ocean. But overall, nothing to write home about.
To finish off this trilogy of signs about our current ENSO-neutral Pacific, we look to the skies! After all, ENSO is a coupled atmosphere/ocean climate phenomenon. And for the past month, that atmosphere has been pretty darn neutral. Winds at both low and high levels of the atmosphere were pretty normal, and while thunderstorm activity was reduced near the dateline, things were mostly average elsewhere.
There hasn’t been a more boring trilogy since Star Wars episodes 1-3 (yeah…I said it). But then again, that’s expected during neutral ENSO conditions across the Pacific.
CPC IRI ENSO outlook July 2021

The official CPC/IRI ENSO probability forecast, based on a consensus of CPC and IRI forecasters. It is updated during the first half of the month, in association with the official CPC/IRI ENSO Diagnostic Discussion. It is based on observational and predictive information from early in the month and from the previous month. Image from IRI
Where we’re going:
It might seem odd, then, with things seeming so… blah… that a La Niña Watch has been issued. To clarify, a La Niña Watch means conditions are favorable for the development of La Niña within the next six months. So, what’s in the climate model “tea leaves” that has helped scientists feel comfortable enough to start throwing the La Niña label around?
The answer, in part, lies in a strong computer model consensus. While most of the models we look at predict ENSO-neutral to continue to last through fall, many models from the North American Multi-Model Ensemble (NMME) favor a transition to La Niña during the fall and into winter. The NMME is incredibly helpful to forecasters in predicting the future state of ENSO, especially when we are past the notorious spring barrier, a time when model accuracy wanes.
ENSO Nino3.4 values, La Nina

Monthly sea surface temperature anomalies (difference from average) in the Niño 3.4 region of the tropical Pacific for 2020-21 (purple line) and all other years starting from first-year La Niña winters since 1950. Climate.gov graph based on ERSSTv5 temperature data.
Where’s the beef?
Is it all that unusual to have two La Niña winters back-to-back? Nope! In fact, of the twelve first-year La Niña events, eight (!) were followed by La Niña the next winter, two by neutral, and two by El Niño. Honestly, with those numbers, it would have been more surprising if we thought neutral conditions would continue all year.
Putting all of those 12 first-year La Niñas together with 2020-2021, it’s evident how much this last year doesn’t stand out. Though, twelve past cases are not a ton to rely on by itself. This La Niña Watch is buoyed by much more than that.
One specific reason why and when any change to ENSO is important is the potential influence on the Atlantic and eastern Pacific hurricane season. As noted on the ENSO Blog in the past, La Niña can help make atmospheric conditions more conducive for tropical cyclones to form the Atlantic, and less conducive in the Eastern Pacific. If 2021 so far is any indicator, it could be an active year: through the beginning of July, five named storms in the Atlantic have already formed, a new record—breaking the previous record set just last year. In August, the Climate Prediction Center will issue an updated hurricane outlook, so stay tuned for more info on that. In the meantime, you can read the outlook from May to see what scientists were thinking two months ago.
ENSO Blog
A blog about monitoring and forecasting El Niño, La Niña, and their impacts.
Disclaimer:
The ENSO blog is written, edited, and moderated by Michelle L’Heureux (NOAA Climate Prediction Center), Emily Becker (University of Miami/CIMAS), Nat Johnson (NOAA Geophysical Fluid Dynamics Laboratory), and Tom DiLiberto and Rebecca Lindsey (contractors to NOAA Climate Program Office), with periodic guest contributors.
Ideas and explanations found in these posts should be attributed to the ENSO blog team, and not to NOAA (the agency) itself. These are blog posts, not official agency communications; if you quote from these posts or from the comments section, you should attribute the quoted material to the blogger or commenter, not to NOAA, CPC, or Climate.gov.
Blog index

Share This:
2
 

·
That's probably sarcasm.
2016 1200 Renegade X
Joined
·
21,022 Posts
Give me the Cole’s Notes version.


Sent from the Island of Misfit Toys.
 
  • Like
Reactions: JLR82

·
Registered
Joined
·
9,899 Posts
Yep, Bastardi was hinting at a La Nina for this upcoming winter. He was also talking about a cool versus a warm May and it's effect on the hurricane season and the subsequent effects for the upcoming winter. He said a cool May means a more active hurricane season and a colder winter. May was indeed chilly compared to averages but this summer since then has definitely been hotter & drier than average. Hopefully that means a colder & snowier than average upcoming winter...knock on wood...do your snow dances...LOL
 

·
Super Moderator
Joined
·
29,355 Posts
It hasn't been hotter or drier here! But it is getting better. Today was really hot and dry.
 

·
Ford hater
Joined
·
19,960 Posts
It hasn't been hotter or drier here! But it is getting better. Today was really hot and dry.
Yeah… this part of wny isn’t dry… we’ve been getting blasted with tons of rain. This was 24hrs ago
1972990

Deep enough we had to chain the dumpster to the building to stop it from floating away
 
  • Like
Reactions: MX-Z Man

·
Ford hater
Joined
·
19,960 Posts
1972991
 

·
Keeping Skioutty on his toes...
2017 Ski doo Renegade 900...2022 Polaris Indy 137 XC 650
Joined
·
31,247 Posts
The last couple of days of rain showers have helped a lot in Maine other than that it has been drier than a popcorn fart...
 

·
Registered
Joined
·
1,128 Posts
I hear you loud and clear on the rain! A buddy and I were supposed to go to the vintage show today in Marienville, but with all the rain, we bowed-out. Disappointed to say the least!
Here's hoping for a La Nina season and an ample amount of white gold this season! 🍻
 

·
Super Moderator
Joined
·
29,355 Posts
Flipping rain, rain, and more rain here!

Enough already.
 

·
Ford hater
Joined
·
19,960 Posts
Severe drought here in Minnesota, El Nino, La Nina, don't believe a word the forecasters say about this upcoming winter, they said the same thing last winter and we had one of our worst on record
Come to western ny, we are flooding, we have flooded areas I’ve never seen flooded before. Local greenhouse has about 3’ of water in it from yesterday say, and the local water treatment plant got flooded with about 1.5 million gallons of water yesterday, among the whole central area of the county being under water still


Sent from my iPhone using Tapatalk
 
  • Like
Reactions: jak and MX-Z Man

·
Ford hater
Joined
·
19,960 Posts
Someone people take some of this rain, this is still flooded 48hrs later
1973182
 

·
Ford hater
Joined
·
19,960 Posts
1973183
 

·
Ford hater
Joined
·
19,960 Posts
1973184
 

·
Ford hater
Joined
·
19,960 Posts
1973185
 
1 - 20 of 25 Posts
Top