Wrapping up September with 20 named storms

Hurricane Sam continues is trek over the open ocean north of the Lesser Antilles, still as a formidable Category 4 hurricane.  It has persisted as a Category 3-4 hurricane Saturday morning, and will probably remain at that intensity for another couple of days until it starts to find cooler water and strong vertical wind shear. 

Sam is forecast to pass just east of Bermuda, and the island is under a tropical storm watch.  Then it will gradually transition to an extratropical cyclone by the middle of next week and will be a potent player in the north central Atlantic, including the UK perhaps, eventually.

On Wednesday afternoon, the tropical wave near the coast of Africa, Invest 90L, was upgraded to Tropical Depression 20, then to Tropical Storm Victor six hours later.  The only other year to have 20 named storms form before October was 2020.

Victor is an impressively large circulation -- much larger than Sam was when it exited the continent.  And it also became a tropical storm REALLY far south at 8.3N... the only other storm to form farther south than Victor was Kirk in 2018 (8.1N).  Bret in 2017 is a close contender, as it became a wave with tropical storm force winds at 7.8N but wasn't officially a tropical storm until 9.2N.

If this had formed a couple weeks sooner, its odds of being a long-track deep-tropics hurricane would be really good, but that gets harder to do this late in the season.  The NHC forecast is in good agreement with the the models, which takes Victor toward the northwest and over cooler waters within a week.

Victor has a shot at becoming a hurricane on Friday, but after that the window of opportunity begins to close on it.  If it does, it would be the season's 8th hurricane, and recent seasons with an 8th hurricane on or before October 1 are 2020, 2017, 2012, 2005, 1995...

As of now, there are not any other areas of interest, but October can be a busy month, and we tend to see development much closer to land: the western Caribbean, Gulf of Mexico, and off the southeast US coast. Only one more name is left on the regular list: Wanda... then we move to the new auxiliary list that I mentioned in Tuesday's post.

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Sam still a major hurricane, Victor and Wanda on the horizon?

As of Tuesday morning, the 2021 hurricane season has accrued as much ACE (Accumulated Cyclone Energy) as an entire average season would, and it is not even October yet.  Moreover, only two names remain in the regular name list -- Victor and Wanda -- and they are likely to get used within the next few days.  The extraordinary combination of exhausting the regular name list and having a full season's worth of ACE prior to October 17th has happened just once before, and that was just last year!  It took the mega 2005 season until October 17th to achieve that.

Sam has been a Category 3-4 hurricane since Saturday morning, and probably will be for another five days or so.  Its intensity peaked on Sunday night, when according NHC's "best-track" data, it was just a sneeze away from Category 5 status (and the post-season reanalysis could find that it did indeed make it).  The maximum sustained winds were 155mph, and 160mph is the Category 5 threshold.

The track and intensity forecasts for Sam have become remarkably uniform across models, so it should continue to be a well-behaved hurricane.  The NHC forecast shown below is very similar to all of the model guidance: a turn to the north later in the week as it gets picked up by a mid-latitude trough, perhaps passing east of Bermuda (could be close), all the while maintaining Category 3-4 intensity. So in the coming week, the only areas that need to be concerned are Bermuda (Saturday) and Newfoundland (Monday).

The next two areas of interest are both easterly waves and are both in the far eastern Atlantic, so I'll address them together.  The western one is tagged as Invest 91L and the eastern one is 90L; both left the continent at a very low latitude. It's actually hard to distinguish them in this satellite image, but there are two waves in there, more or less on the ends of the strip of clouds.

The latest European model ensemble suggests that both are likely to develop, so it could be a race to the final two names on the list (Victor and Wanda), but also that neither of them are threats to land any time soon, if ever.  It's too soon to be confident in any final outcome, but there's plenty of time to watch.

And finally, the remnants of Peter are actually still lurking.  Peter dissipated as a tropical cyclone six days ago, but the remnant vortex did not, and it could make a comeback this week.  It's about 350 miles east of Bermuda, and *if* it reforms, it would zip off to the northeast and probably only last a day or two, so it's really not of much concern.  Peter came from an easterly wave that left Africa on September 13th!

So, if Victor and Wanda are used in the near future, the end of the regular list is upon us yet again.  When that happened in 2005 and 2020, the Greek alphabet served as the auxiliary/overflow list (Alpha, Beta, Gamma, Delta, etc) but the use of the Greek alphabet was discontinued permanently after the 2020 season, so the World Meteorological Organization created a list of 21 auxiliary names that will be used, starting over with A: 

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Sam rapidly intensifies to Category 4 hurricane

Not surprisingly, Sam did indeed strengthen significantly over the past couple of days.  As of Sunday morning, it's a Category 4 hurricane... three days ago it was a tropical depression!  It is also the season's 4th major hurricane (Category 3+) now; Grace, Ida, and Larry were the other three.

There is a whole spectrum of intensification rates of course, from very slow to very fast.  Conventionally, the top 5% of rates is given the designation "rapid intensification" which corresponds to an intensity increase of at least 35mph in a 24-hour period.  The National Hurricane Center provides advisories with intensity estimates every six hours, so a new 24-hour period begins every six hours.  Sam experienced a total of seven RI periods, five of which were consecutive!  (in this table, the intensity is given in knots (nautical miles per hour)... 1kt=1.15mph... and RI periods are highlighted in red)

While that peak rate of 45 kt in 24 hr is impressive, it is very far from a record.  The record-holder in the Atlantic is Hurricane Wilma in 2005: 95 kt in 24 hr.  The record anywhere in the world belongs to Hurricane Patricia (East Pacific, 2015): 105 kt in 24 hr.

Of course, the ACE (Accumulated Cyclone Energy) is exploding due to Sam, and it will surpass the value that a full average season accrues on Tuesday... before October even starts!  By the end of the day, it will be at about 124% of average for the date.

Now on to the forecast.  Model guidance continues to show Sam turning north before reaching the Caribbean islands, then continuing northward.  It's not in any rush, so we'll still be dealing with  Hurricane Sam for at least another week.  In this new product from OU grad student Tomer Burg, a super-ensemble plot shows the track spread valid next Sunday morning.  By "super-ensemble", I mean this includes members from three different global model ensembles as well as their deterministic runs: GFS, ECMWF, and UKMET... a total of 118 members. (aside: this is a very nice product... I remember it being talked about 15 years ago as a way to replace the static "cone of uncertainty" with a dynamic one, the issues are timeliness and reliability)

Sam is about to leave an area of low ocean heat content and pass over much higher ocean heat content in the coming five days.  All of the rapid intensification that just occurred was over low OHC!  A slow-moving very strong hurricane requires high OHC to sustain itself.  OHC is integrated energy, so it's far more useful than just the sea surface temperature.  Big hurricanes really churn up the ocean, upwelling water from below.  If that water is cool, the hurricane will weaken, but if the warm water is deep, very little weakening will occur.  I overlaid the current NHC forecast "cone" on the OHC map below.

In short, Sam is not a threat to land any time soon, but is forecast to remain a major hurricane for probably another week or so.  It's definitely one to watch in Bermuda.

Elsewhere across the basin, there are some areas of interest. One is former-Peter near Bermuda which has a small chance of re-development, another is a wave in the deep tropics that doesn't look so healthy, and the most likely area to watch is an easterly wave that's still over western Africa.

That wave over Africa is strongly favored to develop by long-range model guidance. It's a really long way from anything, but it's worth introducing. The next name on the list is Victor.

By the way, if you missed yesterday's post, please check it out: I highlight this blog's 25th anniversary and the 20th anniversary of my "Tropical Cyclone Radar Loops" webpage!

http://bmcnoldy.blogspot.com/2021/09/tropical-cyclone-radar-loops-turns-20.html

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"Tropical Cyclone Radar Loops" Turns 20

Twenty years ago today, the "Tropical Cyclone Radar Loops" webpage was born.  It is strange for me to think about, but on September 25th, 2001, some current college students were not born yet!

Radar image of intensifying Hurricane Dolly on the morning of July 23, 2008.  The dramatic eyewall configuration and evolution was documented in a 2012 paper: "Observed Inner-Core Structural Variability in Hurricane Dolly (2008)".

I was just a few months out of graduate school, and had been hunting for archives of radar coverage of hurricanes making landfall for many months as I was really interested in polygonal eyewalls and mesovortices (poster from December 2000, paper from December 2002). I was at Colorado State University at the time, and asked around the large pool of tropical cyclone experts there, emailed colleagues, etc. -- no luck. Radar images were available in real-time on some websites of course, but even then they only displayed the most recent couple of hours at best.

36-hour radar loop of Category 5 Hurricane Maria crossing the Leeward Islands on September 18-19, 2017.

I begrudgingly concluded that no such resource existed, so I created one.  Of course, I had to write all of the scripts that would handle this task, so that was Step 1. Step 2 was getting people to know that it finally existed!  The webpage would be a home for current radar loops/animations of active storms that were many hours or even days long, but then serve as an archive of those loops. Little did I know that I would still be adding to it twenty years later.

The first entry to the site was Typhoon Lekima as it was nearing Taiwan (see below). As of September 25, 2021, the archive contains 492 radar loops spanning 198 tropical cyclones using radars in 30 different countries.  It's certainly not a complete record of tropical cyclone landfalls, and it was never intended to be; but I try to capture them when possible.  I have been able to backfill some cases in rare instances, but for the most part, every loop in that archive was created and available online in real-time.

The first entry to the Tropical Cyclone Radar Loops webpage was this one of Typhoon Lekima making landfall in southern Taiwan in September 2001.

All of the loops are available as animated GIFs, and some are available in other formats too.  Through trial and error, this was the format that was the most universally compatible.  It works on desktop computers, laptops, smartphones, PowerPoint slides, and different operating systems.  The downside is that the file size can get quite large for long loops.

But over the past two decades, I have helped dozens of people who requested assistance with using a specific loop: making a subset of a large one, resizing a loop to make it more social media-friendly, creating one in a different format such as MP4, and so on.  So if you want something that's not exactly available on the website, let me know and I'd be happy to help if I can.

I hope people continue to find this resource as useful as I have!

http://bmcnoldy.rsmas.miami.edu/tropics/radar/

One other milestone anniversary to share: the "Tropical Atlantic Update" blog (the one you're reading) turned 25 this month!  I started it partway through the 1996 hurricane season when I was a junior at Lycoming College, and had no intention of doing it again in 1997.  But I did, and again in 1998, and then there was no turning back.  From the beginning, the intent was to write brief public-friendly updates on activity in the tropical Atlantic.  For the casual coastal resident or even weather enthusiast, it would provide the information needed to keep tuned in to what's going on... what, when, and where the threats were, if any.

It actually began as an email distribution list, and people could request to be added to the list.  It quickly grew to several hundred people, so managing it got simpler when I transitioned it to a more proper "blog" (the term "weblog", or "blog" for short, didn't exist then). Sadly, I don't have any of the posts archived from 1996-2001, so the first post available on here is from July 2002.  All of this was also well before social media existed, and before the wealth of model guidance websites that we enjoy today existed.

Over these past 25 years, I have written about 1350 updates spanning 430 tropical cyclones. During that time period, 50 storm names have been retired, so there was certainly no shortage of impactful activity to write about.

In summary, I just want to thank everyone who reads this for their interest over the years.  I know some of you have been with me from the humble beginnings, so a special thank you for not tuning me out yet!

http://bmcnoldy.blogspot.com/

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Hurricane Sam expected to keep strengthening as it heads west

Rapid intensification is a specific term that we use to describe the upper end of tropical cyclone intensification rates -- roughly the top 5% or so.  That translates to an increase in intensity of at least 35 mph in a 24 hour period.  Sam just did that and became the season's 7th hurricane.  It was a tropical depression with 35mph peak winds yesterday morning and is a Category 1 hurricane with 75mph peak winds a day later.

The National Hurricane Center is forecasting Sam to become a Category 4 hurricane on Sunday, but there are error bars around that just like there are for track.  As it intensifies over very warm water and negligible vertical wind shear, it will be moving slowly around the southern end of the subtropical ridge, not even reaching the longitude of the Lesser Antilles until late next week!

Looking ahead a little bit, let's suppose Sam becomes a major hurricane on Saturday (Category 3+)... the list of years with four major hurricanes by September 25th during the satellite era is relatively short but impressive: 2017, 2010, 2005, 2004, 1999, 1996, 1969.  

There are still important differences among long-range models, and the NHC track tends to be a blend of them.  The Leeward Islands and eastern Greater Antilles should still be paying very close attention to Sam, as it could potentially impact those islands as early as next Thursday.  The latest ensemble forecasts from ECMWF and GFS are shown below for reference.

Six aircraft from NOAA and the Air Force will be flying through and around this hurricane nonstop starting on Saturday, and the data they collect get ingested into models, which should help to increase forecaster confidence in the guidance.

In one week, the two models have noticeably different depictions of the mid-level steering patterns, though both now suggest that Sam does not make a direct hit on the Caribbean islands (the ECMWF was showing that for many consecutive runs).

Aside from Sam, there are three other areas of interest with the potential to become tropical cyclones in the next five days: ex-Odette in the north-central Atlantic, an easterly wave that's still over Africa, and a non-tropical low near Bermuda.   When the time comes, the next name on the list is Teresa (and if you enjoy hurricane history, here's a tidbit on Twitter regarding the original set of six lists that we still use).

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Tropical Depression Eighteen (future-Sam) forms in deep tropics

Since my previous post on Monday, Peter and Rose have both fizzled out with little fanfare, they were both mid-range tropical storms that were around for 2.5 days.  The easterly wave that had just left the African coast is farther west now of course, and was upgraded to Tropical Depression 18 on Wednesday afternoon.

This latest tropical cyclone is all-but-certain to become the 18th named storm, Sam, and then the season's 7th hurricane after that. As we see in the satellite image above, the storm appears to be well-organized, though there is a lot of dry dusty Saharan air immediately to its north and east -- that has probably been limiting a more rapid intensification.  The depression is centered about 1800 miles east of the Lesser Antilles.

Over the next week, TD18/Sam is going to move relatively slowly around the subtropical High... but the exact strength and placement of that High (ridge) will determine how close it gets to the northern Lesser Antilles and eastern Greater Antilles.  The NHC forecast splits the difference between some models that keep it more to the south and some that are quicker to recurve it.  So the Leewards, Virgin Islands, and Puerto Rico should absolutely be paying very close attention to this, as it could be about a week away, but could also be a major hurricane at that point.

The latest example of that spread is illustrated by the European global model ensemble (ECMWF, left) and American global model ensemble (GFS, right) below.  While some forecasts among these two are fairly similar (the eastern part of the ECMWF spread and the western part of the GFS spread), the western part of the ECMWF spread has some serious implications for land impacts.

It's worth noting that over the past few days, the ECMWF deterministic runs have been far more consistent with the more western/southern track, while the GFS deterministic runs have drifted around more and have had a northern bias.

Anything beyond this 10-day timeframe shown above is not worth thinking about yet, as even this is clearly stretching the limits of predictability.

We're also still watching ex-Odette... yes, the Odette that became a post-tropical cyclone five days ago.  It's still out there in the north-central Atlantic between Newfoundland and the Azores, and has a shot at transitioning back to a subtropical or tropical low in the coming days as it moves south over warmer water.  It is not expected to drift back closer to land.

Future-Sam and even reborn-Odette should start contributing to the season's ACE (Accumulated Cyclone Energy) shortly, but in the meantime, the ACE as of today is down to 111% of average for the date.  If Sam were not in the cards, the 2021 season would cross the "average" line for the first time on October 1st.  To put the current ACE value in recent historical perspective, the 2017 season was 2.1x higher by now, and even 2020 was 1.3x higher by now.  The season with the most ACE by this date, 1933, was 2.6x higher by now and we likely missed some of the activity!

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Watching far eastern Atlantic for next storm... Sam?

Since my previous post on Friday, we have had Odette, Peter, and Rose form in the Atlantic!  And, we're likely going to see the season's 18th named storm form this week: Sam.

Odette (15L) was a named storm for only a day, and came from the area of interest that was off the North Carolina coast on Friday.  The other two areas that were highlighted in that post became Peter (16L) and Rose (17L), and they are both still active. 

Neither Peter nor Rose will be able to strengthen much, and both will remain far out in the ocean.  Both are facing wind shear and dry air to different degrees.

Peter is located just north of the Leeward Islands and is close to a strong upper-level low pressure system which is forcing the thunderstorm activity east of the circulation center.  Rose is west of Cabo Verde and is close to ingesting lots of dry Saharan air.  Both are forecast to track toward the northwest then north in the coming days.  The only potential concern would be Bermuda this weekend, but impacts from Peter would not be significant.

It's worth pointing out that Rose became the season's 17th named storm on September 19th.  Since 1851, only two other seasons had the 17th named storm so early in the year: 2005 and 2020.  Rose is also still a name from the original 1979 list and has never been used before now! 

Now on to what will almost certainly become Sam: Invest 98L.  This easterly wave left the west coast of Africa on Sunday morning and has been strongly favored by the model guidance to develop and to maintain a track in the deep tropics for a while.

The model guidance is generally bullish on this system, eventually.  It's in a tight spot right now, with Rose immediately to its northwest and Saharan air streaming off the continent to the north. 

The latest deterministic (single higher-resolution run compared to the ensembles) European model run brings this storm very close to or over the northern Leeward Islands next Wednesday as a hurricane.  The latest American model run is two days slower and 275 miles farther north.  Clearly, there is some disagreement to sort out in the coming days, but they both have a hurricane tracking through the deep tropics next week.

European (top) and American (bottom) deterministic runs, both valid when the storm is at the longitude of the Leeward Islands.  For the European run, that's next Wednesday, but next Friday for the American model.

Looking at the updated ACE (Accumulated Cyclone Energy) chart, 2021 is now at about 117% of average for the date.  This time of year, it takes a decent amount of activity just to keep up with climatology, and a couple of low-end tropical storms don't quite cut it, so we're creeping closer to average every day... for now.

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A lull after nonstop action with Ida through Nicholas

Since my previous post on Tuesday morning, nothing has happened!  That in itself is odd to say when there are multiple features of interest and it's mid-September.  Neither the disturbance that was near the Bahamas nor the wave in the far eastern Atlantic have developed yet, though both are still expected to.

The western system, Invest 96L, is now centered just 150 miles off the North Carolina coast and appears quite close to becoming the season's next tropical or subtropical cyclone.  In the satellite animation below, it's easy to see the clouds rotating around a low-level center, but all of the thunderstorm activity is displaced to the north and east. It is expected to head off toward the northeast, intensifying as it does so... transitioning to a strong extratropical cyclone by the end of Saturday.

If it develops into a tropical or subtropical storm in the short window remaining, the next name on the list is Odette. Reaching 15 named storms is above average for an entire season, let alone by mid-September... the only seasons with 15+ named storms before September 19th are 2020, 2011, and 2005!

The wave that we've been watching since it left the African coast four days ago, Invest 95L, is now centered about 1200 miles east of the Lesser Antilles and is zipping westward at 20 mph.  It has struggled to develop, but NHC still gives it a 70% probability of formation within the next five days, somewhere in the shaded area in the map at the top. 

If it does form, the model guidance generally keeps it pretty weak and just north of the Caribbean on Monday-Tuesday, then some start showing intensification as it turns north.  There's not a lot of confidence in anything longer-range than Monday-Tuesday because it's so weak and disorganized now.  Certainly the northeast Caribbean should be watching it closely, but there's a lot of time to wait and watch for any potential US east coast or Bermuda encounters.

Finally, a new easterly wave has existed the African coast, but it's likely to turn to the northwest and find itself over cool water in less than a week.

The ACE (Accumulated Cyclone Energy) is now at about 124% of average for the date... it would actually slip below average for the first time this year on September 28th if nothing else is named by then, which is unlikely.

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Hurricane Nicholas hits Texas, and keeping a close eye on Africa

Since my previous update two days ago, Tropical Storm Nicholas formed on September 12th in the Bay of Campeche, then rapidly intensified to a hurricane just as it made landfall near Galveston in the early morning hours of the 14th. Nicholas is the season's 14th named storm and 6th hurricane... the average dates for those to occur: November 18th and October 15th.  This is quite an exceptional level of activity so early in the season.

[By the way, Category 2 Hurricane Ike made landfall in Galveston too, on September 13th, 2008... Nicholas missed that anniversary by a few hours.]

Throughout the day on Monday, Nicholas had some really favorable conditions to work with, and some not-so-favorable. The center reformed in different locations, shear made the storm lopsided, dry air eroded large portions of it away, but at the end of the day (literally), the super-warm Gulf of Mexico provided it with enough fuel to just barely cross the Category 1 hurricane threshold.

http://bmcnoldy.rsmas.miami.edu/tropics/radar/

By far, the greatest threat from Nicholas has been and continues to be the heavy rain.  As you can see in that radar loop above, most sectors of the storm are devoid of rainfall, but where it does exist, it's persistent and slow-moving.  The areas at highest risk for flash flooding are highlighted below:

We've been watching pre-Nicholas for the past 5-6 days, since it was near Nicaragua. Although some of these storms aren't named systems for very long, or it seems like they pop up out of nowhere, they most definitely do not. Some just take a long time to fester and once they finally get their act together they're already near landfall.

As my friend and colleague Bob Henson pointed out in a blog post, Nicholas is now the 19th named storm to make landfall in the U.S. since May 2020... the average is about three per year.

Now shifting our attention to Africa, recall that easterly wave I mention in Sunday's update.  It has wasted no time getting better organized once it left the coast.  Currently tagged as Invest 95L, it is quite close to becoming Tropical Depression 15, and then Tropical Storm Odette would be the next name.

The GFS and ECMWF global model ensembles both favor this for development, but neither are alarmingly bullish on intensifying it too soon.  It's in no rush to head westward, so even if it were to develop and reach the Lesser Antilles, it wouldn't reach the islands until the Sunday-Tuesday timeframe.  There's plenty of time to wait and let this do its thing.

One thing the ensembles have indicated in the past several runs is that a stronger version of the storm is more likely to turn northward well before the Lesser Antilles, while a weaker version could cruise much closer to the Caribbean.  We would be wise to watch the progress of a strong wave in the deep tropics in mid-September very closely.

And finally, that area north of the Bahamas that I mentioned on Sunday now has a more focused low pressure center, and we could see some development of that in the coming days as it drifts north.  As of now, it's nothing to be concerned about, just worth keeping an eye on it.  The National Hurricane Center is giving it a 60% probability of becoming a tropical cyclone in the next five days somewhere in the shaded area on the map.

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No active storms on peak of the season, but lots to watch

From last Thursday's post on the peak of the hurricane season, I mentioned that the peak of the season is generally the second week of September, but if a specific date has to be chosen, I recommended September 12th (today). As of this writing, we happen to have zero active tropical cyclones on September 12th... but a whole lot to talk about.

The National Hurricane Center is highlighting five areas of potential formation within the next five days, two of which I'll focus on because of their eventual potential impacts.  But the five areas are shown above, with yellow indicating an area with a low probability of formation, orange is medium, and red is high.

The one of immediate concern is a disturbance in the Bay of Campeche, which has been a feature of interest for the past few days since it was north of Honduras then drifted across the Yucatan peninsula.  This is identified as Invest 94L, and is quite likely to become at least a tropical depression by later today.

Models are in good agreement on a track toward the north, scraping the Mexico/Texas coastline over the next few days, dropping heavy rain along the way.  They're also in good agreement on it remaining relatively weak -- none have it reaching hurricane intensity (but let's not rule that out completely... after all, it's mid-September!).  As of now, the greatest threat posed by this system is the rain, and significant totals are expected over southeast Texas and southern Louisiana in the next five days, which will inevitably result in flash flooding.

The next feature I'll highlight is an easterly wave that's still over Africa... but models have been consistently bullish on its development and eventual track through the deep tropics.  There's another easterly wave centered over Cabo Verde too (Invest 93L), but that one is less likely to develop and more likely to take a track toward the northwest.  Since there's so much going on, I'll just focus on the one still over land.

The American (GFS, top) and European (ECMWF, bottom) global model ensembles are shown below... these are the trackable low pressure centers out through the next ten days from the most recent run.  When you look at long-range forecasts of activity, it's important to not focus on details.  Blur your eyes, look for trends in the percent of members that develop it and the general placement of the tracks.  From this, we can be quite confident that the easterly wave will develop, that it's likely to become a hurricane, and that it could be a threat to the eastern Caribbean next Sunday-Tuesday.

The area north of the Bahamas that's shaded in orange on the map at the top of the post is not a current disturbance at all, but rather an area where one could form later in the week. *IF* something is able to develop there, it could have impacts from North Carolina up into the northeast U.S. in the Friday-Saturday timeframe, but it does not appear to be a big concern at this point.  Something to keep an eye on if you're in that area though.

The next names on the list are Nicholas, Odette, and Peter.  All three of those names are originals from the 1979 list, but they have only been used once before (2003)!

And finally, an update on the progression of Accumulated Cyclone Energy (ACE) for the season: it's at about 143% of average for the date, using a 1971-2020 climatology.  This season's ACE is 1.4 times higher than 2020's was on this date, but way lower than mega-seasons like 2017, 2008, 2005, 2004, etc. In other words, it's noteably high, but very far from touching any records.

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