Like and not like.
When we look at the 2015-2016 El Nino and compare it with the 1997-1998 monster we find both similarities and differences.
First the differences. The 2015-2016 El Nino is firing off in a global atmosphere that is on the order of 0.25 C hotter than 1997-1998. It’s an event that’s spring-boarding off an unprecedented hot blob of water in the Northeastern Pacific. One that some studies have linked to human-forced climate change and that has been associated with a plethora of ills ranging from failing ocean health, to the California drought, to strange and troubling warm air and water invasions entering the Arctic. It’s an event that’s occurring in the context of yet another extreme warm air invasion of the Arctic now ongoing in the North Atlantic. And, likely, it’s an event that has, overall, been torqued and twisted by the ongoing pressure of atmospheric and ocean influences associated with human-forced climate change.
Now the similarity. Though a bit more widespread, the heat content of the current El Nino is about equal to that of the monster 1997-1998 El Nino. In other words, there’s an enormous punch of heat hitting the atmosphere from this thing. As a result, you’re bound to get some extraordinarily profound weather impacts. You can see this heat evidenced in the sea surface heights map provided by NASA yesterday below:
(Sea Surface Heights graphic by NASA shows a very intense El Nino currently ongoing in the Equatorial Pacific. Image source: NASA.)
These extreme and very widespread sea surface heights represent a massive load of heat energy steaming off of Equatorial Pacific waters. And what this means is that more severe weather due to the El Nino influence alone is likely in store.
NASA notes that A Still-Growing El Nino is Set to Bear Down on The US:
The current strong El Niño brewing in the Pacific Ocean shows no signs of waning, as seen in the latest satellite image from the U.S./European Ocean Surface Topography Mission (OSTM)/Jason-2 mission. El Niño 2015 has already created weather chaos around the world. Over the next few months, forecasters expect the United States to feel its impacts as well. The latest Jason-2 image bears a striking resemblance to one from December 1997, by Jason-2’s predecessor, the NASA/Centre National d’Etudes Spatiales (CNES) Topex/Poseidon mission, during the last large El Niño event.
El Nino May Hit New Peak Amidst Another Strong Westerly Wind Burst
NASA also hints that the current very strong El Nino may not have even reached peak yet. In evidence to NASA’s statement, this week another strong westerly wind burst (WWB) roared out across the Equatorial Pacific. The winds howled with near gale force intensity against the prevailing trades along a broad stretch of water between New Guinea and the Date Line. Such westerlies tend to increase the intensity of El Nino by generating strong down-welling Kelvin Waves that deliver yet more heat to the sea surface in the Eastern Equatorial Pacific. Heat that then pools out, radiating its energy load into the atmosphere to far-ranging weather impact.
(Another strong westerly wind burst runs against the trades on Tuesday, December 29th in the above Earth Nullschool/GFS graphic. Image source: Earth Nullschool.)
Long range models, though pointing toward a peak in December (which may be subject to revision given the intensity of the current WWB), also indicate a rather long lasting event. NOAA’s CFSv2 ensemble, for example, doesn’t show a transition to Nino neutral status until summer — possibly even late summer. As a result, El Nino effects will likely linger for quite a few more months at least while a second peak in intensity over the coming month would further extend and intensify El Nino-related impacts.
Severe Impacts On the Horizon
Regardless of peak intensity timing or overall duration, there’s rough weather expected in the pipe. Even though we’ve already seen instances of severe weather likely associated with El Nino such as the severe four season storm in the Central US, the Eastern US heatwave, droughts across Central America, India, the Carribean and Brazil, Australian heatwaves and a shift of the storm track toward Iceland in the North Atlantic among other impacts, many forecasters believe the worst is still to come.
As an example, Oxfam International recently warned:
“The El Niño weather system could leave tens of millions of people facing hunger, water shortages and disease next year if early action isn’t taken to prepare vulnerable people from its effects.”
But perhaps some of the most devastating impacts could come as storms finally roar into the US West Coast or even as heavy weather continues over the Central US and Northern England. The recent severe weather is expected this week to bring some of the highest Mississippi River levels on record. But if a new set of severe storms emerge, the floods could repeat or worsen — much as we’ve seen during the historic floods gripping North England this year. Floods that could continue hitting the UK through to April. For the West Coast, the heavy storms could come suddenly, unexpectedly and all at once.
NASA notes that recent strong El Ninos have delivered as much as twice the typical amount of rainfall to Southern California:
In 1982-83 and 1997-98, large El Niños delivered about twice the average amount of rainfall to Southern California, along with mudslides, floods, high winds, lightning strikes and high surf.
Although, historically, very extreme events have been capable of delivering quite a bit more. Something to consider when human-forced warming of the globe by about 1 C since the 1880s has amped up the rate of evaporation and precipitation by about 7-8 percent globally. And to this point, though NASA isn’t saying it directly at this time, it is all-too-possible that human forced climate change is adding more intensity to the El Nino related severe weather events we’ve already seen and are likely to see over the coming months. So when you hear it’s the worst flood ever or the worst drought ever or, especially, the hottest day ever, don’t just think El Nino. Think El Nino on climate change steroids.
Hat Tip to Colorado Bob
Hat Tip to Alex Vasquez
Hat Tip to DT Lange