The 2021 Hurricane Season Has Begun

The extremely active 2020 Atlantic hurricane season burned through the alphabet with 30 named storms including 14 Hurricanes and 7 Majors.

The two seasonal hurricane forecasts that I trust the most are from Colorado State led by Dr. Phil Klotzbach and NOAA’s Climate Prediction Center. Both of these outfits have a long track record of accuracy, experience, and transparency.

Colorado State

17 Named Storms, 8 Hurricanes, 4 Major Hurricanes, ACE = 150

NOAA Outlook

13-20 Named Storms [Ana through Victor]

6-10 Hurricanes, 3-5 Major Hurricanes, ACE = 110% – 190% of median (130)

Historical Context of 2020 Season

In 2020, the Accumulated Cyclone Energy (ACE) amounted to about 185 units — a metric of storm and seasonal activity that combines intensity and duration. It’s pretty simple to calculate ACE: take the advisory wind speed squared and add it up 4-times per day. The easiest example is a Category 3 Major Hurricane at 100-knots for 1-day = 4 units of ACE. A tropical storm at 35-knots for 1-day has only 0.49 units of ACE. More intense storms will run up the ACE especially the monster open-ocean major hurricanes on a 10-day course from the coast of Africa and around the Bermuda high.

The 2021 seasonal forecast from CSU = 150 and NOAA = 140-250.

Over the past 50-years, the Atlantic basin has transitioned from an inactive-era to an active-era exactly in 1995. Indeed, the mean ACE between the two periods has doubled from 68 to 135. There are various theories for the change in Atlantic hurricane activity including the Atlantic Multidecadal Oscillation (AMO) and the reduction of aerosols against the backdrop of anthropogenic global warming. When will the AMO cycle soon shift back to a colder-state with inactive hurricane activity? I’d lean toward 2030.

Next 7-days

No tropical storm activity is expected in the Atlantic. That’s no surprise considering it’s early June and climatologically we do not see much activity — even in extremely busy season.

Week 2

Looking at the ECMWF Ensembles toward mid-June, there is a hint of activity in the Gulf of Mexico. Here, the ocean temperatures are plenty warm but the wind shear is typically high so any storms are lopsided and difficult to develop.

Development chances of something — a named storm — probably in the 10-20% range at this point. We’ll have plenty of time to watch the storm-happy GFS model and its ensembles. The 2021 season will have two fully comparable ensemble systems from ECMWF and NOAA for medium-range hurricane forecasting. Finally.

Weather models posted here are from a subscription service mainly for professionals aptly named Weather Models that costs about $10/month on an annual basis. Of course there are many free sources on the web today, but I would be flying blind without access to the best of everything.

Updates Ahead I’ll be updating this Newsletter every day until the end of the hurricane season. I have yet to figure out the schedule. But, I have plenty of other weather and climate related topics to get into while we wait for hurricane season to heat up — and it certainly will.

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Admin
June 2, 2021 10:43 am

Thanks Ryan

stewartpid
Reply to  Charles Rotter
June 2, 2021 10:56 am

Indeed Ryan – thanks.
Can u comment on Joe Bastardi’s forecasts …. good, bad or indifferent …. not one of your top two obviously.

Ossqss
Reply to  Charles Rotter
June 2, 2021 7:38 pm

I second that Dr. Maue.

Your take has been invaluable over the years to many of us in the vulnerable zones for the Canes. Considering the season officially started yesterday, I would suggest some of his links for those interested. Ryan Maue () / Twitter

Weather and Climate (substack.com)

dk_
June 2, 2021 11:02 am

Excellent. Please don’t neglect the Pacific. Tropical Storm Blanca, well off Baja, at this moment is affecting weather in Texas. Those of the same sort can somethimes bring moisture to the entire desert Southwest U.S.

Editor
June 2, 2021 11:34 am

Thanks, Ryan. I’m looking forward to your updates throughout the season.

Regards,
Bob

The Fringe
June 2, 2021 12:23 pm

These forecasts mimic ours first put out in March. The April Update includes the impact forecast. Please take note we have been doing that since 2014. Last year showed great skill as you can see if you read this link ( The last year’s forecast and result of where they were going is on there) You will notice the numbers referenced here are what we put out, but on March 10th. You will also see reference to the work I have been doing vs past seasons on why storms go to where they are going and of late, the link to hyper active spring MJO’s Judge the tree by the fruit on it. Peace. https://www.weatherbell.com/april-2021-hurricane-forecast-update

DMacKenzie,
June 2, 2021 12:45 pm

The hurricane count went up in the 90’s along with several orders of magnitude of growth of the internet. Funny how opinion reinforcement works….

https://upload.wikimedia.org/wikipedia/commons/0/0c/Internet_Hosts_Count_log.svg

Duane
June 2, 2021 12:46 pm

Thanks for the quantitative data on cumulative storm intensity-duration data. This is certainly a big step up from the “hurricanes for dummies” approach taken by most media outlets, both national and local here in Florida.

I think there is another dimension to quantifying tropical storm system performance that needs to be identified and tracked as well. Which is, how many of these “named storms” never make a landfall or even a near landfall? Because those aren’t storms that we really care about. And in fact, in past centuries or even just a few decades ago, these storms were never sensed, monitored, or tracked, so for all intents and purposes, they did not exist as far as humans were concerned.

So why not count such storms? Well because they were never part of the historical record until a few decades ago, so counting all these “no account” storms appears to inflate the frequency and intensity in current times that are being used to infer and claim an effect due to claimed “global warming”.

No modern scientific records of tropical weather were collected until after the European contact in the late 15th century. The only indigenous peoples who had a written language were the residents of Meso-America which had relatively few landfalling hurricanes, because most go through the Antilles and then impact the mainland of North America in the northern Gulf and Atlantic coast areas. And those languages in any event disappeared from use and only became readable as a function of scientific study undertaken in the 19th and 20th centuries.

We had quite a few “no account” storms last year, and the first named storm this season was also a no-account storm.

Garboard
Reply to  Duane
June 2, 2021 2:38 pm

Aka fish storms

Felix
Reply to  Duane
June 2, 2021 2:57 pm

And how many of these storms were only categorized because political leaders wanted it, when they would not have been categorized before satellites because they never came close to land? I know there has been some change due to that, but not how much, nor whether it applies here?

Russell Johnson
Reply to  Duane
June 2, 2021 5:17 pm

They use “no-account” “storms to pad the numbers, shouldn’t happen. First name “Ana” was wasted on a nothing subtropical collection of thunderstorms!

John Hultquist
Reply to  Duane
June 2, 2021 5:30 pm

A resident of possible impact regions can say “Because those aren’t storms that we really care about.”
Note that I can say the same about any hurricane because I don’t live even close to a place that will see one.
On the other hand, I do care about them all. Call me curious.

Greg
Reply to  Duane
June 3, 2021 4:58 am

Yes, there was a recent change as to what got a name which meant a high wind got a name. This means they can happily feed increased counts of “named stormed” to the press to keep the fearmongering alive on a slow news days.

Hoi poloi are conned into thinking this means increased activity ( which is of course “our fault” ) even when ACE of actual hurricane storms way be lower.

It’s all lies, smoke and mirrors and red-scaft tricks when it comes to “climatology”.

It’s more based on controlling the language than it is on science.

Last edited 4 months ago by Greg
Paul Johnson
June 2, 2021 12:50 pm

What does Joe Bastardi say?

rah
Reply to  Paul Johnson
June 2, 2021 1:41 pm

A very active season. Can’t access the actual report right now. Saturday he also said that conditions on about June 10th will be very condusive for TS formation off the East coast of the US. Named off several analogs.

Windsong
Reply to  Paul Johnson
June 2, 2021 2:56 pm

The comment at 12:23 by The Fringe reads like Joe could have wrote it, and links to his work.

ATheoK
Reply to  Windsong
June 2, 2021 7:29 pm

Joe Bastardi has never shown reluctance to using his own name, and is rasther ‘in your face’ about it..
There are many others at Weatherbell.com, where Ryan Maue also worked for several years, who might write under pseudonyms.

Peter W
June 2, 2021 12:53 pm

With respect to the 2020 season, I have an observation or two.

Two of the named storms formed off the coast of the Carolinas and had zero chance of developing into anything serious. Why bother to name them? The only thing they were going to affect was ocean traffic.

Several other storms with were named also had little or no chance of developing. Of course, the high number of named storms is why we have been told about how active a season it was.

And how far back in time was it valid to compare with other seasons? Years ago there were no satellites and no way to detect many of the storms we tracked and named this past year.

I am sure many other questions could be raised by those more knowledgeable than I am.

Rud Istvan
Reply to  Peter W
June 2, 2021 1:08 pm

All excellent points. My father flew instrumented B-29s for 3 years off Guam into typhoons, as part of the earliest military research on tropical cyclones. as XO of the 409th typhoon chasers. Cyclones have been dinner table conversation for many decades.
There really are ‘before weather satellite’ and ‘after weather satellite eras that are not strictly comparable. What is comparable are records of landfalling tropical storms and hurricanes. A historic ACE just on those is probably a legitimate comparison.
Just like for tornados, there are ‘before’ Doppler radar and ‘after’ Doppler radar eras. The difference especially affects quantity of EF1s.

Duane
Reply to  Peter W
June 2, 2021 1:42 pm

Names storms quite often degrade back into unnamable systems or even just disturbances.

The naming convention this past three quarters of a century, since the practice evolved of naming storms, is to name any system that achieves at least tropical storm strength, 39 mph or higher. We’re not going to see that change anytime soon.

But naming storms has no scientific value, or relation to their relevance to human activity, hence my comment above about “no account” storms that never make landfall.

That’s not how science works. Naming storms is a socio-political convenience, not a scientific distinction. And we’re talking science here.

Michael S. Kelly
Reply to  Duane
June 3, 2021 2:59 am

I name all of our weather. At the moment, we’re experiencing “Lamar” calm air, clear skies, and very pleasant temperature.

Doing this makes life much more confusing than it needs to be. But I’m retired, and can afford it…

Last edited 4 months ago by Michael S. Kelly
TonyL
Reply to  Peter W
June 2, 2021 1:56 pm

???????
Two of the named storms formed off the coast of the Carolinas and had zero chance of developing into anything serious. Why bother to name them?

My understanding is that a storm gets named when the wind speed exceeds 39 mph. It then becomes officially a “Tropical Storm”. So records should be directly comparable year on year.

BUT: And this is a Big But.
We have seen the National Hurricane Center, in the past several years, inflating wind speeds, and so naming all kinds of minor storms. A usual ploy is to abandon wind speed measured at 10 meters as per the formal definition, and use estimated, and even estimated at altitude.

Especially with hurricanes, we have seen that NHC really has it’s thumb on the scale.

Something to watch for this year:
Wait for a hurricane rated as Cat. 3, check it out, fine print says “estimated at altitude”.
Watch for landfall, or passing over a weather buoy, see the measured speed rates it as a Cat 1.
Note well that the Saffir–Simpson scale is specifically measured at 10 meters. Estimated at altitude may well have some use but it is *not* Saffir–Simpson. When NHC assigns a Cat. number based on estimated speed, they are inflating the season strength and count numbers.

Rud Istvan
Reply to  TonyL
June 2, 2021 2:22 pm

TonyL, there is some truth in what you say. But there is also an inherent problem you did not note. The windspeed definition is at 10 meters, true. But it is also just outside the eyewall, where the wind is strongest thanks to conservation of momentum. That can be a surprisingly small area just a couple of miles or so wide on each side of the eyewall. The further away, the lower the windspeed will be for reasons of basic physics. So a lot of the ‘estimated/observed’ lower speed stuff is just locational mismatch to the full definition.

When Wilma gave us a near direct hit in 2004, our complex suffered enormous damage. We missed the eyewall, the northern edge of which went about 10 miles south —Hollywood, south of the Fort Lauderdale airport which defines the southern city limit. We are at the extreme north of Fort Lauderdale. No roofs ripped off here. We drove weeks later that 10 miles into Hollywood, and saw the significantly greater damage with roofs roofs ripped off there. No blue tarps here. Almost nothing but blue tarps there.

TonyL
Reply to  Rud Istvan
June 2, 2021 2:56 pm

Rud is 100% correct as usual.
I would also point out that I have seen a couple of instances in the last few years where the eye scored a bullseye on a weather station or buoy and the readings gave the lie to what the NHC was saying. Obviously, I was not the only one to notice.

Ossqss
Reply to  Rud Istvan
June 2, 2021 5:52 pm

Rud, I would note that the delta in housing build dates showed very clearly the performance of the new building codes after that storm. Virtually no homes built to the newer codes showed much damage. Older homes and neighborhoods showed the significant deficit in their construction methodologies since the code changes came into play after Andrew.

Latitude
Reply to  TonyL
June 2, 2021 2:27 pm

exactly……

John Hultquist
Reply to  TonyL
June 2, 2021 5:39 pm

A usual ploy is to abandon wind speed measured at 10 meters as per the formal definition, and use estimated, and even estimated at altitude.”

You call it a ploy, but the transition to “remote sensing” began long ago and will continue. Many earth-science students learn about “ground-truthing” … wait for it … on the ground.

ATheoK
Reply to  TonyL
June 2, 2021 7:48 pm

Hurricane naming standards were changed to allow NHC and NOAA to inflate the numbers of hurricanes.

From WUWT “NOAA claims: “Extremely active” hurricane season possible for Atlantic Basin

Joel O’Bryan: “What cannot be denied is that in recent decades the NOAA/NHC straff{sic} has taken to naming every tropical low out in the Atlantic or Carribean or GoM that they can ID. So using [# named TC’s] is a completely erroneous metric now to compare to historical standards, as the politicized staff at the NHC have changed the naming standards.”

NHC is using their satellite algorithm using barometric pressure estimates to calculate estimated wind speeds so they can not instantly apply “tropical depression” and “hurricane” labels based upon calculations without a storm actually existing for many hours or days.

John Hultquist
Reply to  Peter W
June 2, 2021 5:34 pm

“… had zero chance of developing into anything serious.”

This phrase fits the two babies my grandmother had in the very early 1900s.
She named them anyway.

Dave P
June 2, 2021 1:07 pm

“… calculate ACE: take the advisory wind speed squared and add it up 4-times per day.”

I think you forgot “divide by 10,000” after squaring the wind speed.

Rud Istvan
Reply to  Dave P
June 2, 2021 3:31 pm

Correct to make manageable published ACE scales, but incorrect for the actual original technical definition. Just looked it up. A ‘Yein’ (German language joke).
I proudly join Ryan Maue as someone who (usually) gets the big picture right, but sometimes gets the little details wrong—and almost always quickly caught at public ‘peer’ reviewed WUWT.

ATheoK
Reply to  Rud Istvan
June 2, 2021 8:10 pm

but sometimes gets the little details wrong”

Minor quibbles:

  • I’ve rarely seen/read Ryan getting serious technical detail wrong.
  • Ryan is allowed to sometimes make typing errors, just as most of us do. (I’m an exception as I make many typing errors)
  • Everyone is entitled to their own opinions.
  • What better place to receive polite correction, such as Dave P provided, than at WUWT?
Patrick B
June 2, 2021 1:21 pm

I’m surprised no one has assembled a history of Colorado’s and NOAA’s predictions versus actual results versus the mean with some error bars.

Certainly the first question in anyone’s mind should be how good are these entities at predicting a season especially compared to what is the expected mean. In other words prove some competence before we bother to grant these predictions any validity. And no, I’m not interested in their “updated” predictions made later in the season.

Climate believer
Reply to  Patrick B
June 2, 2021 2:08 pm

Not quite sure where Mr Maue’s “a long track record of accuracy” comes from concerning NOAA’s predictions, I don’t find them at all impressive.

Examples of how they predict:

2012 they said there would be between 12 and 17 named storms, there was 19.
They also said there would be between 5 and 8 hurricanes, there was 10.
They also said there would be 2 or 3 major hurricanes, hurray! there was 2.

August hurricane prediction from NOAA over twenty years,

13/20 right for major hurricane predictions
10/20 right for hurricane predictions
10/20 right for named storms

Last year they didn’t get any right.

Prediction, 19-25 named storms, actually 30.
Prediction, 7-11 hurricanes, actually 14.
Prediction, 3-6 major hurricanes, actually 7.

Latitude
Reply to  Climate believer
June 2, 2021 2:29 pm

accuracy is a sliding scale

Devils_Tower
June 2, 2021 2:20 pm

As for the AMO status, it may already be shifting.

Interesting reference in either case…

https://www.nature.com/articles/s41598-017-11046-x

UNGN
June 2, 2021 5:15 pm

Hurricane wind speeds seem to be no longer measured by boats, buoys, and ground instruments, but by radars & satellites sending data to computers 5,000 miles away from the storm. Wind speeds 500 – 1,000 feet up are way higher than those on the ground.

This seems to me a recipe for data manipulation. 25 years ago, we weren’t measuring Hurricanes by their wind speeds at 1000 ft AGL

Mumbles McGuirck
Reply to  UNGN
June 2, 2021 6:27 pm

“25 years ago, we weren’t measuring Hurricanes by their wind speeds at 1000 ft AGL”

Actually, maximum windspeed estimates have long been based on aircraft observations at approximately 10,000 feet and reduced to 10 meter standard by a percentage. Nowadays, these obs are supplemented by satellite measurements of ocean surface roughness. Only when a hurricane makes landfall do they get direct measurements of 10 meter winds. And it’s almost certain the anemometer wasn’t where the highest winds were.

Ossqss
Reply to  Mumbles McGuirck
June 2, 2021 9:03 pm

I would add that they altered the metric for aggregation of such a few years back. I don’t have the link, but they now can capture a reading from a peripheral T-storm in the air, and it can become the whole storm. Hence, why the land and buoy readings don’t match up to such upon reanalysis, if anybody even looks at that stuff.

Greg
June 3, 2021 4:44 am

I don’t like graphs with arbitrarily chosen boxes to force the reader to a given conclusion.

If I try to ignore the boxes, I see and “active period”. from 1995 to 2005. Then a newer more active period from 2016 to present.

Blocking this all into two arbitrary periods now and high, ignores the “landfall drought” of 2005 to 2015 which seems relfected in lower activity generally in the Atlantic basin.

It also plays into the cult mindset of those who want to see everything as “it’s worse than ever” and therefore must be due to CO2.

Here is a more nuanced look at ACE ( done in 2017,need updating ). We see the lower average from the late 20th C. was probably due to two major stratospheric eruptions, the like of which we have not seen since.

comment image

https://climategrog.wordpress.com/ace_n_atl_2017/

Last edited 4 months ago by Greg
Greg
Reply to  Greg
June 3, 2021 5:12 am

Here’s an other ACE graph with a longer history ( bear in mind the pre-1950 data is a lot less reliable.

comment image

The similarity to AMO is quite strong.

Last edited 4 months ago by Greg
D Boss
June 3, 2021 4:44 am

The problem is, ACE is a made up number not reflecting any actual “energy” calculation.

OK fine, as a make believe “index” for comparing Hurricane seasons it can serve a purpose.

HOWEVER, NOAA and the NHC have been moving the goalposts for at least 4-5 years to skew the ACE higher!

I watch closely and follow the official declarations along with the raw data to make my own judgements as I live in S Florida. You can catch them in lies about sustained winds again and again and again – starting about 4-5 years ago and getting worse every season since.

Examples are the raw data from Hurricane hunter aircraft – you can view this data and routinely they are using wind speeds from flight levels (10,000 feet ASL) as sustained winds on the surface. When it is an absolute fact that wind speed decreases near the surface.

Often a dropsonde will show surface wind much lower, but the official wind speed stays as it was at 10,000 ft….

Cross checking this data fudging you can find ocean buoys that the eyewall passes over being 1-2 Categories less sustained wind than the “official” proclamation is.

Another cross check is radar data of the eyewall rotation speed vs radius – again 1-2 categories less than official sustained wind speeds.

By raising the wind speed, you artificially bump up the ACE value thus supporting the false Climate Cult of Thermageddon narrative! And this fudging then classifies mere fish storms as hurricanes and minor ones as major, etc.

(they are even smarter than those who are constantly fudging land temperature data – they bump up hurricane wind speeds out over the ocean, but as it approaches land they bring the official sustained numbers back to reality so ground based wind measuring can’t reveal their blatant lying easily)

Greg
June 3, 2021 5:04 am

It’s pretty simple to calculate ACE: take the advisory wind speed squared and add it up 4-times per day.

Really, it’s that simplistic ?

Energy is an extensive property ie it depends on the amount of air moving at a certain speed not just the speed. Surely there is more energy in something like Sandy precisely because of it’s massive extent?

If ACE only depends on spot wind speed it is implicitly assuming all cyclones are the same size !!

Whats up with that?

Rob
June 3, 2021 8:51 am

I have the same issue with ACE as I do with sunspots: Measurement quality bias. The massive change in our technology in the past 30-40 years (call it the Satellite era for short) has made for an increase in recorded tropical storms/wind speeds and this is confounding any calculation of a trend in ACE.

2hotel9
June 3, 2021 3:43 pm

I wonder if all the TV “meteorologists” will wear 2 masks as they stand on a windy beach proclaiming we are all gonna die in a fiery flood? And will they use some new, eerily dramatic muzak or just recycle the old crap? Inquiring minds and what not.

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