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

[AlphaToOmega]

If Pamela does become a strong major (Cat 4 or higher) and the Atlantic fails to produce anything in the next 3-4 weeks — despite the VP setup and ENSO setup favoring activity in the Caribbean over the EPac — then clearly something anomalous is going on. Could it just be the atmosphere taking a long time to adjust to the La Niña, or something else at play?

This year worldwide has been very strange in terms of TC activity, with many droughts and peaks across all three big NHem basins. The Atlantic has had plenty of peaks (late June, Aug20th-Sep5th, late September) and droughts (July10th-Aug10th, mid September), but so have both Pacific basins. The EPac was pumping out storms at a surprisingly good rate before shutting down after Olaf, and the WPac went without a single major for over 4 months before producing back-to-back Cat 5s (Chanthu and Mindulle).

There is this property of the MJO called amplitude. For 2021, it has been very high, which has caused huge bursts of activity this year. No need to overthink it

[WiscoWx02]

 https://twitter.com/RyanMaue/status/1446552770845282328

[aspen]

If Pamela does become a strong major (Cat 4 or higher) and the Atlantic fails to produce anything in the next 3-4 weeks — despite the VP setup and ENSO setup favoring activity in the Caribbean over the EPac — then clearly something anomalous is going on. Could it just be the atmosphere taking a long time to adjust to the La Niña, or something else at play?

This year worldwide has been very strange in terms of TC activity, with many droughts and peaks across all three big NHem basins. The Atlantic has had plenty of peaks (late June, Aug20th-Sep5th, late September) and droughts (July10th-Aug10th, mid September), but so have both Pacific basins. The EPac was pumping out storms at a surprisingly good rate before shutting down after Olaf, and the WPac went without a single major for over 4 months before producing back-to-back Cat 5s (Chanthu and Mindulle).

There is this property of the MJO called amplitude. For 2021, it has been very high, which has caused huge bursts of activity this year. No need to overthink it

I know, but intraseaonal variation seems especially pronounced this year. The 4-month MH gap in the WPac and the lackluster climo peak in the Western Hemisphere are things I would not have expected going in to this season.

[Hammy]

If Pamela does become a strong major (Cat 4 or higher) and the Atlantic fails to produce anything in the next 3-4 weeks — despite the VP setup and ENSO setup favoring activity in the Caribbean over the EPac — then clearly something anomalous is going on. Could it just be the atmosphere taking a long time to adjust to the La Niña, or something else at play?

This year worldwide has been very strange in terms of TC activity, with many droughts and peaks across all three big NHem basins. The Atlantic has had plenty of peaks (late June, Aug20th-Sep5th, late September) and droughts (July10th-Aug10th, mid September), but so have both Pacific basins. The EPac was pumping out storms at a surprisingly good rate before shutting down after Olaf, and the WPac went without a single major for over 4 months before producing back-to-back Cat 5s (Chanthu and Mindulle).

There is this property of the MJO called amplitude. For 2021, it has been very high, which has caused huge bursts of activity this year. No need to overthink it

It's still strange that the Atlantic has seemed almost completely incapable of producing anything between the MJO or Kelvin waves. It seems once that leaves the basin it shuts off entirely--given the intensity of storms we see when it arrives (even if it's just one strong storm), this year really is behaving like a more intense version of 2014 in the Atlantic.

[Category5Kaiju]

If Pamela does become a strong major (Cat 4 or higher) and the Atlantic fails to produce anything in the next 3-4 weeks — despite the VP setup and ENSO setup favoring activity in the Caribbean over the EPac — then clearly something anomalous is going on. Could it just be the atmosphere taking a long time to adjust to the La Niña, or something else at play?

This year worldwide has been very strange in terms of TC activity, with many droughts and peaks across all three big NHem basins. The Atlantic has had plenty of peaks (late June, Aug20th-Sep5th, late September) and droughts (July10th-Aug10th, mid September), but so have both Pacific basins. The EPac was pumping out storms at a surprisingly good rate before shutting down after Olaf, and the WPac went without a single major for over 4 months before producing back-to-back Cat 5s (Chanthu and Mindulle).

There is this property of the MJO called amplitude. For 2021, it has been very high, which has caused huge bursts of activity this year. No need to overthink it

It's still strange that the Atlantic has seemed almost completely incapable of producing anything between the MJO or Kelvin waves. It seems once that leaves the basin it shuts off entirely--given the intensity of storms we see when it arrives (even if it's just one strong storm), this year really is behaving like a more intense version of 2014 in the Atlantic.

If I may ask out of curiosity, why do you pick 2014 as a comparison year with this year again? Iirc wasn't 2014 a hyperactive EPAC as it was entering El Nino territory, which obviously shut down the Atlantic and only allowed it to produce 8 storms total?

[Category5Kaiju]

 https://twitter.com/BenNollWeather/status/1446462129310101511




I mean, this is a textbook moderate La Nina. While I personally do not think it will happen and that the CCKW will allow the Atlantic to wake up later this month, if for whatever reason the Atlantic fails to become active in the next couple of weeks, then honestly my mind would be blown.

[Hammy]

There is this property of the MJO called amplitude. For 2021, it has been very high, which has caused huge bursts of activity this year. No need to overthink it

It's still strange that the Atlantic has seemed almost completely incapable of producing anything between the MJO or Kelvin waves. It seems once that leaves the basin it shuts off entirely--given the intensity of storms we see when it arrives (even if it's just one strong storm), this year really is behaving like a more intense version of 2014 in the Atlantic.

If I may ask out of curiosity, why do you pick 2014 as a comparison year with this year again? Iirc wasn't 2014 a hyperactive EPAC as it was entering El Nino territory, which obviously shut down the Atlantic and only allowed it to produce 8 storms total?

2014 was very quiet on the Atlantic side, and development was nonexistent in the suppressive MJO phase, but like clockwork, every time a favorable MJO entered the Atlantic, in spite of everything else, we'd still get a hurricane, even if it was the only system that formed. The SST pattern is different and 2014 was a budding Nino, but still something the season has in common, albeit more active--each time we get more favorable phases in the Atlantic we'll get a fairly strong system surrounded by a bunch of weaker ones despite the seemingly unfavorable upper air pattern.

It differs from years like 2012 or 16 where the MDR was unfavorable the entire season, literally everything struggled from the start, inner core issues etc, and development (or at least peak) generally limited to the subtropics prior to October.

[AlphaToOmega]

Should this verify, this could mean we could be tracking major hurricanes into November. It is, however, too early to make such a judgement.

[WiscoWx02]

Should this verify, this could mean we could be tracking major hurricanes into November. It is, however, too early to make such a judgement.

https://i.postimg.cc/pTfvt8yJ/cansips-chi200-global-2.png
https://i.postimg.cc/j50T9vqj/rpnj-KN1sty.png

I agree. Just cause something looks to happen doesn’t mean it has too. Laws of probability which go way over my head

[Teban54]

If Pamela does become a strong major (Cat 4 or higher) and the Atlantic fails to produce anything in the next 3-4 weeks — despite the VP setup and ENSO setup favoring activity in the Caribbean over the EPac — then clearly something anomalous is going on. Could it just be the atmosphere taking a long time to adjust to the La Niña, or something else at play?

This year worldwide has been very strange in terms of TC activity, with many droughts and peaks across all three big NHem basins. The Atlantic has had plenty of peaks (late June, Aug20th-Sep5th, late September) and droughts (July10th-Aug10th, mid September), but so have both Pacific basins. The EPac was pumping out storms at a surprisingly good rate before shutting down after Olaf, and the WPac went without a single major for over 4 months before producing back-to-back Cat 5s (Chanthu and Mindulle).

If anything, Pamela might be a sign of what could come in the Atlantic once MJO arrives.

[Teban54]

If Pamela does become a strong major (Cat 4 or higher) and the Atlantic fails to produce anything in the next 3-4 weeks — despite the VP setup and ENSO setup favoring activity in the Caribbean over the EPac — then clearly something anomalous is going on. Could it just be the atmosphere taking a long time to adjust to the La Niña, or something else at play?

This year worldwide has been very strange in terms of TC activity, with many droughts and peaks across all three big NHem basins. The Atlantic has had plenty of peaks (late June, Aug20th-Sep5th, late September) and droughts (July10th-Aug10th, mid September), but so have both Pacific basins. The EPac was pumping out storms at a surprisingly good rate before shutting down after Olaf, and the WPac went without a single major for over 4 months before producing back-to-back Cat 5s (Chanthu and Mindulle).

There is this property of the MJO called amplitude. For 2021, it has been very high, which has caused huge bursts of activity this year. No need to overthink it

I know, but intraseaonal variation seems especially pronounced this year. The 4-month MH gap in the WPac and the lackluster climo peak in the Western Hemisphere are things I would not have expected going in to this season.

Probably just because the amplitude of the MJO is extremely high this year.

October 2020, from indicators thread:


October 2021:

[Teban54]

A bit off-topic, but yet another reminder of how unrealistic the GFS' modelling of cold fronts can be:
 https://twitter.com/burgwx/status/1446659795298263044

[Hammy]

A bit off-topic, but yet another reminder of how unrealistic the GFS' modelling of cold fronts can be:
https://twitter.com/burgwx/status/1446659795298263044?s=20

This is a long term problem with the GFS and has become a horrendous false advertiser during winter with cold weather or snow. With this large of an error, it would have significant implications regarding the shear levels in the Caribbean and East Coast, likely not being as favorable as it shows.

[aspen]

A bit off-topic, but yet another reminder of how unrealistic the GFS' modelling of cold fronts can be:
https://twitter.com/burgwx/status/1446659795298263044?s=20

This is a long term problem with the GFS and has become a horrendous false advertiser during winter with cold weather or snow. With this large of an error, it would have significant implications regarding the shear levels in the Caribbean and East Coast, likely not being as favorable as it shows.

Wouldn’t a huge, deep cold front like the ones the GFS constantly shows increase the shear over the Caribbean instead of lowering it?

[Category5Kaiju]

One thing I have also noticed is that the GFS does not develop anything big in the Atlantic in the next weeks because it has yet another EPAC system spin up very fast after Pamela, but literally off the C American coast. I find that a bit hard to believe if you had to ask me.

[aspen]

One thing I have also noticed is that the GFS does not develop anything big in the Atlantic in the next weeks because it has yet another EPAC system spin up very fast after Pamela, but literally off the C American coast. I find that a bit hard to believe if you had to ask me.

Ignore any long-range GFS EPac hurricane right off of Central America. They almost never verify and are just bias.

[SFLcane]

I for one in my personal opinion think the season is over for conus and Florida. Maybe something weak subtropical in nature which is always possible this time of the yr in the Caribbean.

Other then that smooth sailing till 2022

[toad strangler]

I for one in my personal opinion think the season is over for conus and Florida. Maybe something weak subtropical in nature which is always possible this time of the yr in the Caribbean.

Other then that smooth sailing till 2022

You have valid reasons to think so. Less than three weeks to go before the latest CONUS Oct ‘cane landfall date passes. 1985 being the only exception since at least 1850 that saw the only two Nov HURRICANE landfalls. What an anomalous pattern that was. . Could see a weak system though.

[AlphaToOmega]

I for one in my personal opinion think the season is over for conus and Florida. Maybe something weak subtropical in nature which is always possible this time of the yr in the Caribbean.

Other then that smooth sailing till 2022

You have valid reasons to think so. Less than three weeks to go before the latest CONUS Oct ‘cane landfall date passes. 1985 being the only exception since at least 1850 that saw the only two Nov HURRICANE landfalls. What an anomalous pattern that was. . Could see a weak system though.

Not so fast just yet

[Category5Kaiju]

I recently made a bet with one of my close wx friends; while I think we (CONUS and the other major landmasses) still need to watch for a possible potent hurricane later this month when the favorable CCKW passes (which, as we have seen throughout this season, have consistently sparked a burst in activity in the Atlantic), he thinks we're completely done now. The loser has to do 50 burpees straight. Boy is this going to be a fun game