2021 Indicators: SST's / SAL / MSLP / Shear / Steering / Instability / Sat Images

[AlphaToOmega]

There is one rule of hurricane seasons: never doubt September. Should these runs verify, 2021 would have Rose by September 21. The only seasons with the 17th storm in September are 2020, 2005, and 2011. If another storm forms between September 21 and September 30, it would put 2021 ahead of 2005. At this point, October is likely going to be the decisive month; it will determine whether or not the hurricane season flops (like 2011) or gets put in the history books (like 2005 and 2020).



We saw this months ago. Run after run, the CanSIPS shows -VP over Africa and the Indian Ocean, leading to an active hurricane season.

[SconnieCane]

There is one rule of hurricane seasons: never doubt September. Should these runs verify, 2021 would have Rose by September 21. The only seasons with the 17th storm in September are 2020, 2005, and 2011. If another storm forms between September 21 and September 30, it would put 2021 ahead of 2005. At this point, October is likely going to be the decisive month; it will determine whether or not the hurricane season flops (like 2011) or gets put in the history books (like 2005 and 2020).
https://i.postimg.cc/KvMYzfgb/ecens-2021-09-14-12-Z-168-50-258-0-350-MSLP-Surface-tracks-lows.png
https://i.postimg.cc/fRQR0dx9/gefs-2021-09-14-12-Z-168-50-258-0-350-MSLP-Surface-tracks-lows.png

We saw this months ago. Run after run, the CanSIPS shows -VP over Africa and the Indian Ocean, leading to an active hurricane season.
https://i.postimg.cc/W1KLkcRf/cansips-chi200-global-1.png
https://i.postimg.cc/bvtX0VpY/cansips-chi200-global-2.png
https://i.postimg.cc/wvXSZt1S/cansips-chi200-global-3.png
https://i.postimg.cc/3N3PTKpW/cansips-chi200-global-4.png

As I posted on another forum...

"Well, this season may not be playing out exactly like us weenies had anticipated, but just like last season, just about everything is making landfall, most of it in the CONUS."

What I mean by this is that while far from a flop of a season already, 2021 (also much like 2020) has lacked the one thing I was most interested to see (and I doubt I was alone in this), which was for at least one of those landfall threats to emanate from a quick-developing AEW which goes the distance, with days and days (not just the 6-12 hours before landfall) of stadium-eye satellite stuff, >40 ACE, and nail-biting watching the model tracks windshield wiper back and forth. With Larry, it was pretty clear from the get-go that it was going to be a non-factor at least in terms of the CONUS and points south/southeast, and we thought 95L had the potential to be this but that has appeared to fall apart in recent days with both track and intensity, although it's too completely rule it out as a potential threat down the line.

[aspen]

If the tropics continue to underwhelm worldwide after Chanthu/Larry/Nicholas, could this be foreshadowing a circulation collapse next year like in 2013? I recall people saying that 2012’s struggle storms (lots of formation but lots not reaching their full potential) was a sign of what was to come next season.

[AlphaToOmega]

If the tropics continue to underwhelm worldwide after Chanthu/Larry/Nicholas, could this be foreshadowing a circulation collapse next year like in 2013? I recall people saying that 2012’s struggle storms (lots of formation but lots not reaching their full potential) was a sign of what was to come next season.

2020 certainly had a lot of underperforming storms in September. Look at what happened in October
It is too early to draw any conclusions

[Category5Kaiju]

There is one rule of hurricane seasons: never doubt September. Should these runs verify, 2021 would have Rose by September 21. The only seasons with the 17th storm in September are 2020, 2005, and 2011. If another storm forms between September 21 and September 30, it would put 2021 ahead of 2005. At this point, October is likely going to be the decisive month; it will determine whether or not the hurricane season flops (like 2011) or gets put in the history books (like 2005 and 2020).
https://i.postimg.cc/KvMYzfgb/ecens-2021-09-14-12-Z-168-50-258-0-350-MSLP-Surface-tracks-lows.png
https://i.postimg.cc/fRQR0dx9/gefs-2021-09-14-12-Z-168-50-258-0-350-MSLP-Surface-tracks-lows.png

We saw this months ago. Run after run, the CanSIPS shows -VP over Africa and the Indian Ocean, leading to an active hurricane season.
https://i.postimg.cc/W1KLkcRf/cansips-chi200-global-1.png
https://i.postimg.cc/bvtX0VpY/cansips-chi200-global-2.png
https://i.postimg.cc/wvXSZt1S/cansips-chi200-global-3.png
https://i.postimg.cc/3N3PTKpW/cansips-chi200-global-4.png

As I posted on another forum...

"Well, this season may not be playing out exactly like us weenies had anticipated, but just like last season, just about everything is making landfall, most of it in the CONUS."

What I mean by this is that while far from a flop of a season already, 2021 (also much like 2020) has lacked the one thing I was most interested to see (and I doubt I was alone in this), which was for at least one of those landfall threats to emanate from a quick-developing AEW which goes the distance, with days and days (not just the 6-12 hours before landfall) of stadium-eye satellite stuff, >40 ACE, and nail-biting watching the model tracks windshield wiper back and forth. With Larry, it was pretty clear from the get-go that it was going to be a non-factor at least in terms of the CONUS and points south/southeast, and we thought 95L had the potential to be this but that has appeared to fall apart in recent days with both track and intensity, although it's too completely rule it out as a potential threat down the line.

I think somebody pointed this out in an earlier post (which I very well agree with), but much like 2005, 2004 and 2017 were also extreme seasons that should not be expected to occur very often. 2004 and 2017 were extreme in the sense that they had multiple CV major hurricane hits on the CONUS and racked up more than 220 ACE. Ivan, Irma, you name it. Something I have learned from what I have seen so far this year is just that. Getting a 2004 or 2017-like season is simply very hard to do. If anything, our WAM should be weaker than what it is now to get such a kind of season (only 15 and 17 NSs formed each of those years, showing how they were pure quality seasons that did not emphasize quantity as much). In fact, it seems like there's some sort of trade-off with quality/multiple US major CONUS landfalling hurricanes and quantity/more homegrown activity. Of course, 1995 and 2010 are examples of seasons that were quantity and quality, but their CV storms did not affect the US as badly. It is also interesting to note how many of the multiple CONUS-major CV hurricane hit seasons were burst seasons rather than slow burn.

[Category5Kaiju]

If the tropics continue to underwhelm worldwide after Chanthu/Larry/Nicholas, could this be foreshadowing a circulation collapse next year like in 2013? I recall people saying that 2012’s struggle storms (lots of formation but lots not reaching their full potential) was a sign of what was to come next season.

Personally, I do not think so. In fact, the answer to this question remains to be seen for a while as we do not have an idea on what ENSO phase next year will be. Also, unlike 2012, we still had major Cat 4+ cyclones in all three basins (Atlantic especially included) which 2012 lacked, so I am honestly unsure if the conditions in 2012-2013 will necessarily be the same as 2021-2022.

[ElectricStorm]

If the tropics continue to underwhelm worldwide after Chanthu/Larry/Nicholas, could this be foreshadowing a circulation collapse next year like in 2013? I recall people saying that 2012’s struggle storms (lots of formation but lots not reaching their full potential) was a sign of what was to come next season.

It's barely past peak season and we've already had more majors than 2012

But I don't really think the previous year has much to do with the next year

[Category5Kaiju]

Also I think it is pretty imperative that we should still keep an eye on what October brings. I sincerely feel that October is a very underrated month (with August and September taking the fame from many individuals). Since 1995, here's what October (and beyond) memorably delivered:

1995: Opal and Roxanne
1998: Mitch
1999: Lenny
2000: Keith
2001: Michelle
2005: Wilma
2008: Paloma
2012: Sandy
2014: Gonzalo (not retired but impactful and strong to Bermuda)
2015: Joaquin
2016: Matthew and Otto
2018: Michael
2020: Delta, Zeta, Eta, and Iota

That's 13 years with a major late season, impactful and destructive Cat 3+ hurricane. This also does not count years that had a major late season hurricane that was not impactful (Omar in 2008 or Lili in 1996 as examples). October can still in many cases deliver nasty storms, and just because it's fall, trick-o-treat season, or much after the September 10 peak does not mean anything when it comes down to the potential for hazardous major hurricane impacts.

[tolakram]

2013 is an outlier similar, but opposite, of 2005. I doubt it happens again unless it's a new climate pattern we're not familiar with. We'll have to wait until later in October to make a determination if this season turned unfavorable or not. When in the middle of a season it's hard to make a judgement, especially when models aren't doing a very good job predicting development. IMO

[AlphaToOmega]

Right now, there is sinking air in the Atlantic; there has been sinking air in the Atlantic for a week or so at this point. The reasons there has been activity are the African Standing Wave and climatology.

The ECMWF shows an African Standing Wave all the way through October. A weak CCKW should create a burst of activity at the end of September. A strong CCKW should create another burst of activity in the middle of October. Climatologically, October is not as favorable as September, but it still counts as part of the peak of hurricane season; and the month could still produce give or take 5-6 storms given these factors.

Should this verify, it would virtually guarantee that 2021 will rival 2020 and 2005 in terms of activity. The thing that will likely determine if 2021 breaks the records of 2020 and 2005 is how active November and December are.

[ElectricStorm]

Right now, there is sinking air in the Atlantic; there has been sinking air in the Atlantic for a week or so at this point. The reasons there has been activity are the African Standing Wave and climatology.

The ECMWF shows an African Standing Wave all the way through October. A weak CCKW should create a burst of activity at the end of September. A strong CCKW should create another burst of activity in the middle of October. Climatologically, October is not as favorable as September, but it still counts as part of the peak of hurricane season; and the month could still produce give or take 5-6 storms given these factors.

Should this verify, it would virtually guarantee that 2021 will rival 2020 and 2005 in terms of activity. The thing that will likely determine if 2021 breaks the records of 2020 and 2005 is how active November and December are.

https://i.postimg.cc/JnNpbq5S/241222563-1496350387385525-5844399051510248176-n.png

2021 almost certainly will not get anywhere close to 2005 or 2020 levels of activity. Just because a favorable phase is coming up does not guarantee record levels of activity.

[Hammy]

If the tropics continue to underwhelm worldwide after Chanthu/Larry/Nicholas, could this be foreshadowing a circulation collapse next year like in 2013? I recall people saying that 2012’s struggle storms (lots of formation but lots not reaching their full potential) was a sign of what was to come next season.

I wouldn't say Nicholas underwhelmed, most models showed a fairly weak system. So far, Claudette aside, everything in the Gulf and Caribbean has overperformed.

As far as the Atlantic goes at least, 2012 had basin-wide problems and most storms had difficulty establishing an inner core, and it seemed the subtropics was a hot spot--in fact if you compare 2012/13 there's similar clustering as well.

This year seems like it's behaving more like 1985 or 2007, where the overwhelming majority of the open Atlantic either struggles or is void of storms (this year having Larry as an obvious exception), while everything near land peaks around landfall--look at Dean and Felix for example in 07 compared to the rest of the basin.

[ElectricStorm]

I don't really get where the notion that this season is underperforming is coming from. I mean, Larry was 10kts less than forecasted, which isn't much at all. Nothing else has really underperformed this year. We're already at 3 majors, which is around the average for an entire season. So... I'm not seeing an underperforming season.

[Category5Kaiju]

I don't really get where the notion that this season is underperforming is coming from. I mean, Larry was 10kts less than forecasted, which isn't much at all. Nothing else has really underperformed this year. We're already at 3 majors, which is around the average for an entire season. So... I'm not seeing an underperforming season.

We are also neck-to-neck with the WPAC and EPAC in terms of named storms, and in terms of ACE we're doing fairly above average for this time of year so far. If anything, relative to the Atlantic, it's the WPAC and EPAC that have been underperforming significantly in comparison to other years.

[Hammy]

I don't really get where the notion that this season is underperforming is coming from. I mean, Larry was 10kts less than forecasted, which isn't much at all. Nothing else has really underperformed this year. We're already at 3 majors, which is around the average for an entire season. So... I'm not seeing an underperforming season.

The open Atlantic has underperformed in general (models constantly blew Henri up into a major due to poor dry air input and Larry did come in weaker than the models indicated) and I think people are applying this far too broadly to the entire basin.

[Teban54]

I don't really get where the notion that this season is underperforming is coming from. I mean, Larry was 10kts less than forecasted, which isn't much at all. Nothing else has really underperformed this year. We're already at 3 majors, which is around the average for an entire season. So... I'm not seeing an underperforming season.

Guess people expect the MDR to pump out Cat 4s after Cat 4s like 2010 and 2017 every time a season is predicted to be close to hyperactive.

Also, I would argue it takes more energy to produce a large high-end Cat 3 like Larry than a small Cat 4, but that might be just me.

[Steve]

Pages behind and I’m not catching up. This is the [tm] Phase 3 of the MJO. This time we have a stalled out tropical system likely to just rain itself out over the southeast plus a surge coming up off the east coast.

[dexterlabio]

If the tropics continue to underwhelm worldwide after Chanthu/Larry/Nicholas, could this be foreshadowing a circulation collapse next year like in 2013? I recall people saying that 2012’s struggle storms (lots of formation but lots not reaching their full potential) was a sign of what was to come next season.

I remember all those talks about how the TC activity worldwide was seemingly low back then, and some people pointed out that it's because of the "lack of warmth" as we were going 3 consecutive seasons with cold neutral-strong La Nina. I think Kingarabian will remember this. I don't remember much about the rationale behind that theory.

[AlphaToOmega]

I expect some activity between now and the end of September, followed by a burst of activity at the end of September. There is likely to be even more activity during this September because of the African Standing Wave. I expect another sustained burst of activity between October 6 and October 25.

This coincides with another peak of hurricane season. There are two climatological peaks of hurricane season: one in mid-September and one in mid-October.

[WiscoWx02]

Right now, there is sinking air in the Atlantic; there has been sinking air in the Atlantic for a week or so at this point. The reasons there has been activity are the African Standing Wave and climatology.

The ECMWF shows an African Standing Wave all the way through October. A weak CCKW should create a burst of activity at the end of September. A strong CCKW should create another burst of activity in the middle of October. Climatologically, October is not as favorable as September, but it still counts as part of the peak of hurricane season; and the month could still produce give or take 5-6 storms given these factors.

Should this verify, it would virtually guarantee that 2021 will rival 2020 and 2005 in terms of activity. The thing that will likely determine if 2021 breaks the records of 2020 and 2005 is how active November and December are.

https://i.postimg.cc/JnNpbq5S/241222563-1496350387385525-5844399051510248176-n.png

2021 almost certainly will not get anywhere close to 2005 or 2020 levels of activity. Just because a favorable phase is coming up does not guarantee record levels of activity.

I agree, we will never see what we saw last year or in 2005 again simply because no two hurricane seasons are the same. We might see one major hurricane in October but probably nothing more than that. We will probably have some weaker storms as well but they won't come close to what we saw last year. I definitely think the coasts should watch out come October given the expected pattern though. Not as bullish on October as I was before, but still think it will be an active month.