By P Gosselin on 20. November 2021
The accumulated cyclone energy (ACE) is the best measure of overall tropical activity and it is below-normal for the 2021 season across the Northern Hemisphere.
Data: Colorado State University, NOAA
Overview
Tropical cyclone activity across the Northern Hemisphere has been below-normal in 2021 in much the same way as it was last year. Specifically, while the Atlantic Basin featured above-normal tropical activity in this year and last, the Pacific Ocean experienced below-normal conditions in both years leading the way to below-normal levels across the hemisphere as a whole.
In terms of tornadoes, it has been another below-normal season in the US with no EF-5’s recorded. There was, however, tornadic activity in some unusual places in 2021 including the Mid-Atlantic and New England.
Colder-than-normal sea surface temperatures continue to dominate the scene in the equatorial part of the Pacific Ocean. These “La Nina” conditions likely played an important role in the above-normal tropical activity across the Atlantic Basin in 2021 and the below-normal activity in the Pacific Ocean. Map NOAA, tropicaltidbits.com
Northern Hemisphere Tropical Activity…below-normal
There is no tropical activity right now in either the Atlantic or Pacific Ocean and none is expected in the near term. In fact, the tropical activity in both of these large bodies of water may very well be done for the 2021 season and there has been a rather dramatic drop off of activity in recent weeks. In fact, the quiet period in terms of tropical activity began in October and it turned out to be rather unusual in that there were no “major” hurricanes (Category 3 or above) anywhere across the globe.
October surprise
According to Dr. Philip Klotzbach of Colorado State University, this is the first time since 1977 that there were no “major” hurricanes during the month of October anywhere across the globe. Furthermore, in the period from mid-October to mid-November, the accumulated cyclone energy (defined below) across the globe was the lowest in the satellite era (since 1966).
The 2021 Atlantic Basin was above-normal in terms of the number of named storms (21) making it the third most active on record when using that particular metric.
There is another metric known as the accumulated cyclone energy (ACE) that meteorologists tend to favor in order to assess overall tropical activity in a given season. The ACE metric – which was originally created by Dr. William Gray and associates at Colorado State University and later tweaked by NOAA – not only factors in the intensity of a tropical cyclone, it also takes into account its longevity.
Average energy per storm much lower
While the “number of storms” in the Atlantic Basin this season was ranked quite high on the historical scale, the average ACE per storm was much lower down on the rankings with past seasons. This result is indicative of the fact that many of this year’s named tropical systems were short-lived and/or relatively weak.
Last 50-years+ of Global and Northern Hemisphere Accumulated Cyclone Energy: 24 month running sums. Note the year indicated represents the value of ACE through the previous 24-months for the Northern Hemisphere (bottom line/gray boxes) and the entire global (top line/blue boxes). The area in between represents the Southern Hemisphere total ACE. Courtesy Dr. Ryan Maue
Elevated Atlantic activity linked to cool equatorial Pacific
The above-normal activity in the Atlantic Basin this year (and also in 2020) was fueled in part by La Nina conditions in the equatorial part of the Pacific Ocean. Typically, colder-than-normal sea surface temperatures in the tropical Pacific Ocean (i.e. La Nina conditions) lead to reduced overall wind shear in the tropical Atlantic Ocean and this, in turn, is a favorable factor for the formation and intensification of tropical cyclones in that part of the hemisphere.
Suppressed Pacific activity
While La Nina conditions were a favorable factor for tropical activity in the Atlantic Basin, it tended to suppress activity in the equatorial part of the Pacific Ocean. In both regions of the Pacific Ocean (i.e. to the east and west of the “international date line”), overall tropical activity was below-normal this season in terms of accumulated cyclone energy. The drop off in activity in the Pacific Ocean began as early as the month of September in that there was only one named storm (Olaf) making it the least active month since 2010.
Of all the countries around the world, the US has the highest number of tornadoes and this year has been below-normal across the nation. The annual tornado trends chart is a result of the following methodology applied to the SPC observed tornado dataset by Harold Brooks, NSSL and Greg Carbin, NOAA/SPC.
Details: A simple linear regression equation is fit to the 1954-2007 annual tornado totals. This equation is then used to compute the delta, or difference, between the original/observed annual tornado total and the smoothed, or “adjusted” annual total represented by the point on the linear trend line for that year.
US tornadic activity…below-normal
2021 has been a below-normal year in terms of number of tornadoes across the nation falling below the “25th percentile. The United States has the most tornadoes of any country, as well as the strongest and most violent tornadoes. Despite several outbreaks in March and another large outbreak at the beginning of May, the year as a whole remains below-average due largely due to inactivity during the months of April and June.
Unusual tornado activity
While the nation as a whole has experienced less tornadic activity than normal, there have been some areas that have experienced unusual action. For example, the Mid-Atlantic region experienced an unusual tornado outbreak this mid-summer that had its origins in the Upper Midwest.
On July 29th , numeric tornadic supercells developed across the eastern Ohio Valley and Mid-Atlantic resulting in many tornadoes. In fact, a few of the tornadoes were strong and damaging including an EF-3 tornado that caused severe damage in the Philly suburbs of Trevose and Bethlehem. It was the first EF-3 tornado in lower Bucks County ever, but an F3 tornado came through Central Bucks some 125 years ago in 1896, according to the National Weather Service.
Another unusual tornado caused damage in southeastern Pennsylvania during the late summer (9/1/21) as an EF-2 touched down in the Philly suburb of Fort Washington.
In addition, in just the past week, there was an unusual tornado outbreak in portions of New York and New England. On Saturday, November 13th, strong storms generated at least 11 confirmed tornadoes that touched down in New York State and New England with all being classified as EF-0 or EF-1.
According to the Eastern Region NWS, there were 6 tornadoes on Long Island (plus one Friday in the mid Hudson Valley of New York State), 4 in Connecticut and 3 in Rhode Island (2 of the tornadoes crossed from CT into RI). According to the NWS, there had not been a tornado recorded in Connecticut or Rhode Island in the month of November since 1950.
According to NOAA’s Storm Prediction Center (SPC), the last recorded EF-5 tornado – the most violent classification level – was in the year 2013
No EF-5 tornado in 8 years
One of the notable findings of the 2021 US tornado season is that it featured no EF-5 tornadoes which are the most powerful of all. In fact, it has now been more than 8 years since the last EF-5 tornado struck in the US which was in Moore County, Oklahoma during May of 2013. According to NOAA, there have been a total of 36 EF-5 tornadoes in the US since 1970 with 14 of those occurring in the 1970s.
NOAA now puts a name on any swirl on the satellite which is why we have so many “named” storms and when you divide this number into the ACE, you get a very low ACE/storm. Everyone following this pretty much knows this. It’s all part of the hottest month ever game being played on the American people. More storms = more and bigger headlines.
It is much the same with Doppler weather radar, which warns of tornadoes that may only exist for a few minutes, and do not touch down
Yes the modern weather radar can pick tornadoes up before they become tornadoes. Some of these weather forecasters are very good at their job. And they are appreciated. The storm chasers, too. Both of them make tornado season much easier to live with because we are well informed about the weather situations in real time.
Our Met Office do the same. The even broadcast cyclonic systems that hit as storms named by Ireland or Spain or France even though they are barely breezes and drizzle when they hit here.
I can’t get used to naming thunderstorms. Happily, they don’t do that around here, at least not locally. I think the national Weather Channel may give a name to a thunderstorm on occasion. It’s silly, imo. I would protest if my local meterologist started naming thunderstorms.
OMG! Our children won’t know what hurricanes are. We’re doomed!
OK, I laughed out loud on that one.
It’s all part of a plot by deniers, to lull the people into complacency, only to come back with a vengeance in … Oh, I dunno – 100 years from now. All the bad stuff is 100 years in the future .. until the future arrives, and then it’s still 100 years in the future.
From the article: “In addition, in just the past week, there was an unusual tornado outbreak in portions of New York and New England. On Saturday, November 13th, strong storms generated at least 11 confirmed tornadoes that touched down in New York State and New England with all being classified as EF-0 or EF-1.”
Look where the focus of the jet stream is located:
https://earth.nullschool.net/#current/wind/isobaric/500hPa/orthographic=-93.16,36.54,304/loc=-78.468,44.448
It is right where these tornadoes are breaking out.
The location of the jet streams is the key factor in where tornado outbreaks occur.
To elaborate a little: Strong winds out of the southwest are what generate tornadoes, so when the jet stream dips down and then curves back north, where it curves back north is where the focus of the energy will be, so whereever you see this pattern in warm weather you are probably going to see a tornado outbreak of one kind or another, depending on temperature differentials and the amount of humidity involved.
Tornado outbreaks occur in the south-central States as spring and summer come and go, and then this focus of energy moves to the northeast like it is doing now. Since the northeast usually has cooler temperatures, the tornadoes generated are usually smaller than those in the midwest or southeast U.S.
A look back in the records reveals that these days many times more EF 1 and 2 storms are being reported than even in the first decade of this century. I believe this inflation is due to an increasingly dispersed population, ever increasing Doppler Radar coverage, and ever increasing numbers of trained spotters.
Bingo
As an aside, isn’t it interesting how the jet stream seems to want to avoid Hudson’s and James Bays, and Greenland?
For the time being anyway.
If you look at the link, you can see that the focus of the jet stream’s energy has moved a little farther to the east. The marker was on the eastern edge of the upward curving jet stream when I first posted the link, and now the eastern edge has moved eastward.
The whole jet stream progresses eastward this way almost like a solid mass, with fluctuations up and down.
Someday children won’t know what a tornado is because the humans!!!
“Klotzbach of Colorado State University, this is the first time since 1977 that there were no “major” hurricanes during the month of October anywhere across the globe.”
1977…hmm, the depths of the “Ice Age Cometh” 35yr cooling spell that we all caused! The biggest rejiggering of the temperature record was inspired by the realization that the Dirty Thirties hot period, followed by deep cooling before CO2 was a factor showed that natural variability was huge and didn’t correlate with the CO2 graph.
Moreover, the global warming that minions hyped on about was simply the climb out of the cold spell depths of the 70s. Hansen even agreed at the time that super el niño of 1998 didnt set a new record. As it turned out, 1998 was also the turning point for the 18yr Dreaded Pause that was interrupted by the brief 2015 el Niño. We’ve been cooling since then.
Klotzbach is right, it’s just like the 70s right now. We should run a pool to bet on which climateers will abandon ship over the the coming years.
Jim Kossin, senior scientist with the Climate Service, an organization that provides climate risk modeling and analytics to governments and businesses, interviewed by CNN on August 21, 2021.
So there you have it. The results are in. It’s obvious there isn’t any greenhouse warming occurring because the good confidence Jim Kossin’s models produce ensures there would have been stronger hurricanes this year if there was.
You can’t have good confidence in your model one way but not the other.
2021, last 6 months…
1 in 1,000 year rain events: three
Record setting heatwaves: at least 3
Record new high temperatures: multiple.
Severe rain events in half a dozen countries on top.
As usual you count weather events.
You don ‘t know what climate is.
Situation normal. Global and NH ACE below average.
And don’t even think about harping about the number of named storms in the Atlantic. A decade ago the Average ACE intensity of named TS was over 8. This year it was 3! IOW Griff they are naming storms they never named before to fool the easily fooled like you.
Rah you are on top of your game lately.
Checking out Dr Ryan Maue’s ACE index and listening to Joe Bastardi. I’m merely regurgitating what I have learned from those two excellent sources.
Grif, stop pointing to local weather records as being “proof” that climate is changing. Weather records are broken all the time, due to the chaotic nature of weather.
Earth warmed 1F in 50 years hohum. That’s like moving to a new house that is 200 miles further south or 200 feet lower elevation. People can deal with that, indeed they hardly notice the difference. If that were not true there wouldn’t be so many people living in the tropics. Most people prefer warmer weather, just look where fastest US population growth has occurred the past 60 years.
The most extreme warming is at night in places that are below freezing. Meanwhile due to more CO2 the Sahel is greening and crop yields are skyrocketing. The human condition across the spectrum has been improving due in part to expanding access to energy. What’s not to like.
Long term data shows: Droughts are not increasing, floods are not increasing. hurricanes are not getting worse, tornadoes are not getting worse, etc. Islands continue to grow despite gradual sea level rise.
It’s a big world, just from random chance, there should be thousands of 1 in 1000 year events every year.
Records only go back a few decades, it’s trivially easy to set new ecords.
Severe rain events that just happened to be less severe than rain events over the last several hundred years.
“Below Normal Extremes…2021 Northern Hemisphere Cyclone Activity Below Normal…US Tornadoes Below Normal”
A climatista disaster!
And yet CO2 continues to climb.
Simon, Griff, Lloydo and the rest of you cucks ….shouldn’t we have more tornadoes and hurricanes now? Shouldn’t these storms be bigger now too?
Somebody needs to send this article to all the major media outlets, and dare them to report it … and then release the names of all media outlets that refused to release the info.
Dare the major media to print the truth. They won’t of course.
Hell, the Weather Channel won’t even report it!
Most certainly not the Weather Porn Channel.
They’d selectively report the “unusual” tornado activity and the above average activity. A Disasterist can always find something positive to cling onto.
Reduce the meridional temperature gradient(by warming the higher latitudes)………reduce the intensity of the jet stream in between them……….reduce the number of violent tornadoes.
https://www.drroyspencer.com/2019/05/recent-tornadoes-are-due-to-unusually-cold-weather/
Also reduce the intensity of extratropical cyclones.
Increased convection though.
Changing available energy for extratropical cyclones and associated convection in Northern Hemisphere summer
https://www.pnas.org/content/116/10/4105
Those silly bomb cyclones. Shouldn’t “increased convection” mean more tornadoes not less?
“Shouldn’t “increased convection” mean more tornadoes not less?”
Menace, if all the other factors that caused tornadoes remained unchanged, then that would be the case……but they aren’t the same.
We obviously need convection present to develop a tornado but you need convection +the right conditions with the convection to cause tornadoes, especially the stronger tornadoes.
One of those key ingredients is a steep temperature gradient from north to south in the Northern Hemisphere.
Global warming/climate change has featured a DECREASE in that key ingredient because of the amount of warming being greater as you move pole-ward………and so we’ve seen a notable drop off of violent tornadoes.
The places with the MOST thunderstorms don’t have to most tornadoes, which is also evidence of the other factors being needed.
Places with the most thunderstorms:
https://www.wunderground.com/blog/weatherhistorian/thunderstorms-the-stormiest-places-in-the-usa-and-the-world.html
Region with the most tornadoes…………displaced north and west(into the colder/drier air and where the jet streams are stronger) of the areas that have the most convection/thunderstorms:
https://en.wikipedia.org/wiki/Tornado_Alley
Of course, ACE would be even more accurate if it was an area-weighted sum so the size of the windfield was included, and not just the highest speed. With modern satellite information and computers, you would think that this would be the standard.
“According to NOAA, there have been a total of 36 EF-5 tornadoes in the US since 1970 with 14 of those occurring in the 1970s.”
So, 14 in the 70’s – a 10 year span, and the balance, 22 events, spread over the next 40 years. I guess, more tornados, and further north, when the weather is cooler. Who would have thunk it?
14 F-5s in the 70s, at the time of the peak of the fictional hype about an ice age coming. At a time when the Arctic had so much ice the scammers choose a year in that decade to be where they start their misleading sea ice extent graphs to portray a decline.
A time when this Hoosier experienced the worst blizzard on record to hit the state of Indiana resulting in the lowest winter air pressure reading ever recorded in the state. The Ohio river froze so solid one could walk over between Indiana and Kentucky. Snow on many of the north-south roads out in the country that was so deep that plows were useless and front loaders had to be used to dig through it.
And now the morons are complaining about the weather?
G’Day Rah,
“… the worst blizzard on record to hit the state of Indiana …”
Have never had to suffer through a blizzard. For the past 51 years have lived in either southern California or southern Arizona.
But you jogged my memory. SoCal, Friday, January 4, 1974. At Beaumont – about 25 miles east of San Bernardino – at 2,600 ft – 16 inches of the white stuff. Not “normal” at all.
Trying to get home from work. A VW ‘Bug’. The last mile my wife drove while I stood on the rear bumper hanging onto a roof rack. I don’t think about it often, but when I do I still shiver.
Excellent photo of a tornado! Is this a still photo or a frame from video? I would love to see the video if it exists and is available to watch.