2022 Indicators (SSTs/SAL/MSLP/Shear/Steering/Instability) and >Day 16 Models

[Shell Mound]

We are very much in a +AMO. Bs to think we aren’t. A -AMO wouldn’t produce the type of landfalls we been seeing every year since 2016.

There have been plenty of strong landfalls during -AMOs (i.e., 1970’s Celia, 1975’s Eloise, and so on). Arguably -AMOs tend to produce more high-end impacts, at least under some circumstances, because they favour homegrown genesis and/or nearshore RI (i.e., 1992’s Andrew and 2018’s Michael).

I still think that the warmer subtropics vs. the relatively cooler MDR indicate that we have been in at least a weak -AMM since 2013. I think that the warm subtropical northwestern Atlantic outweighs the lingering warmth near the Canaries insofar as it best signifies a net trend toward a -AMM on balance.

Until we start seeing more years with a warmer MDR relative to the subtropics, I’m saying that we are currently in a long-term -AMM cycle. A classic +AMM features a cooler subtropical northwestern Atlantic vs. the deep tropics (MDR and/or Caribbean). The pattern since 2013 has generally been the opposite.

With well-above-average SST firmly established in the subtropics, 2022 will likely feature suppressed activity in the MDR and/or Caribbean, owing to stability and issues with TUTTs (anticyclonic wave-breaking via “streamers”). Getting long-trackers like Irma or Sam will be more difficult than in a +AMM cycle.

2018 was a spring -AMM turned +AMM. Wouldn’t get such a wet Africa without a +AMM.

-AMO historic US landfalls are basically 1906 Mississippi, 1915 Galveston, 1915 New Orleans, 1918 Key West, Carmen, Allen, Hugo and Andrew. That’s a relatively short list compared to +AMO in part due to rising motion over the Central America shearing the Caribbean to the point where the Caribbean once went 7 years without a hurricane during a -AMO.

As this chart illustrates, the pattern over the subtropical and northern North Atlantic since 2013 has clearly been that of a -AMM. Furthermore, note the Atlantic Niño and cooler MDR. Only the Canary Current is somewhat warmer than one might have expected in a -AMM, but otherwise the SST-derived data strongly suggest a trend toward a -AMM. Since 2016 the average annual number of major hurricanes in the Atlantic basin has been roughly four. Of these, roughly two per year attained MH status in the deep tropics (MDR and/or Caribbean). A total of four MH per year lies below the mean of 4.5 MH per season recorded from 1991–2020, so recent seasons’ MH totals, in particular since 2016, have been averaging below the previous +AMM mean. (Personally, I don’t think Zeta and Grace were majors, so I excluded them.) Also, in a true +AMM most of the MH would be attaining their peaks in the deep tropics rather than be evenly split between the deep tropics and subtropics. Overall, we have been seeing fewer MH per season, especially in the deep tropics, and have been seeing fewer long-trackers in the deep tropics as well vs. 1995–2012.

[NotSparta]

There have been plenty of strong landfalls during -AMOs (i.e., 1970’s Celia, 1975’s Eloise, and so on). Arguably -AMOs tend to produce more high-end impacts, at least under some circumstances, because they favour homegrown genesis and/or nearshore RI (i.e., 1992’s Andrew and 2018’s Michael).

I still think that the warmer subtropics vs. the relatively cooler MDR indicate that we have been in at least a weak -AMM since 2013. I think that the warm subtropical northwestern Atlantic outweighs the lingering warmth near the Canaries insofar as it best signifies a net trend toward a -AMM on balance.

Until we start seeing more years with a warmer MDR relative to the subtropics, I’m saying that we are currently in a long-term -AMM cycle. A classic +AMM features a cooler subtropical northwestern Atlantic vs. the deep tropics (MDR and/or Caribbean). The pattern since 2013 has generally been the opposite.

With well-above-average SST firmly established in the subtropics, 2022 will likely feature suppressed activity in the MDR and/or Caribbean, owing to stability and issues with TUTTs (anticyclonic wave-breaking via “streamers”). Getting long-trackers like Irma or Sam will be more difficult than in a +AMM cycle.

2018 was a spring -AMM turned +AMM. Wouldn’t get such a wet Africa without a +AMM.

-AMO historic US landfalls are basically 1906 Mississippi, 1915 Galveston, 1915 New Orleans, 1918 Key West, Carmen, Allen, Hugo and Andrew. That’s a relatively short list compared to +AMO in part due to rising motion over the Central America shearing the Caribbean to the point where the Caribbean once went 7 years without a hurricane during a -AMO.

https://i.ibb.co/TL5HKkt/AMMchange-2.png

As this chart illustrates, the pattern over the subtropical and northern North Atlantic since 2013 has clearly been that of a -AMM. Furthermore, note the Atlantic Niño and cooler MDR. Only the Canary Current is somewhat warmer than one might have expected in a -AMM, but otherwise the SST-derived data strongly suggest a trend toward a -AMM. Since 2016 the average annual number of major hurricanes in the Atlantic basin has been roughly four. Of these, roughly two per year attained MH status in the deep tropics (MDR and/or Caribbean). A total of four MH per year lies below the mean of 4.5 MH per season recorded from 1991–2020, so recent seasons’ MH totals, in particular since 2016, have been averaging below the previous +AMM mean. (Personally, I don’t think Zeta and Grace were majors, so I excluded them.) Also, in a true +AMM most of the MH would be attaining their peaks in the deep tropics rather than be evenly split between the deep tropics and subtropics. Overall, we have been seeing fewer MH per season, especially in the deep tropics, and have been seeing fewer long-trackers in the deep tropics as well vs. 1995–2012.

1995-2012 had not a single major hurricane in the deep tropics though, while we have seen some since 2013 (I do know the NHC says there were but I do not consider them to be major hurricanes). That means we're currently in more of a true +AMM than 1995-2012

[Yellow Evan]

There have been plenty of strong landfalls during -AMOs (i.e., 1970’s Celia, 1975’s Eloise, and so on). Arguably -AMOs tend to produce more high-end impacts, at least under some circumstances, because they favour homegrown genesis and/or nearshore RI (i.e., 1992’s Andrew and 2018’s Michael).

I still think that the warmer subtropics vs. the relatively cooler MDR indicate that we have been in at least a weak -AMM since 2013. I think that the warm subtropical northwestern Atlantic outweighs the lingering warmth near the Canaries insofar as it best signifies a net trend toward a -AMM on balance.

Until we start seeing more years with a warmer MDR relative to the subtropics, I’m saying that we are currently in a long-term -AMM cycle. A classic +AMM features a cooler subtropical northwestern Atlantic vs. the deep tropics (MDR and/or Caribbean). The pattern since 2013 has generally been the opposite.

With well-above-average SST firmly established in the subtropics, 2022 will likely feature suppressed activity in the MDR and/or Caribbean, owing to stability and issues with TUTTs (anticyclonic wave-breaking via “streamers”). Getting long-trackers like Irma or Sam will be more difficult than in a +AMM cycle.

2018 was a spring -AMM turned +AMM. Wouldn’t get such a wet Africa without a +AMM.

-AMO historic US landfalls are basically 1906 Mississippi, 1915 Galveston, 1915 New Orleans, 1918 Key West, Carmen, Allen, Hugo and Andrew. That’s a relatively short list compared to +AMO in part due to rising motion over the Central America shearing the Caribbean to the point where the Caribbean once went 7 years without a hurricane during a -AMO.

https://i.ibb.co/TL5HKkt/AMMchange-2.png

As this chart illustrates, the pattern over the subtropical and northern North Atlantic since 2013 has clearly been that of a -AMM. Furthermore, note the Atlantic Niño and cooler MDR. Only the Canary Current is somewhat warmer than one might have expected in a -AMM, but otherwise the SST-derived data strongly suggest a trend toward a -AMM. Since 2016 the average annual number of major hurricanes in the Atlantic basin has been roughly four. Of these, roughly two per year attained MH status in the deep tropics (MDR and/or Caribbean). A total of four MH per year lies below the mean of 4.5 MH per season recorded from 1991–2020, so recent seasons’ MH totals, in particular since 2016, have been averaging below the previous +AMM mean. (Personally, I don’t think Zeta and Grace were majors, so I excluded them.) Also, in a true +AMM most of the MH would be attaining their peaks in the deep tropics rather than be evenly split between the deep tropics and subtropics. Overall, we have been seeing fewer MH per season, especially in the deep tropics, and have been seeing fewer long-trackers in the deep tropics as well vs. 1995–2012.

First off, why are you comparing 2013-2021 to 1995-2012 and not 1970-94? 1995-2012 had remarkable persistence of +AMO and even then, the differences between the two look more driven by AMOC changes than an explicit -AMO reversal. Im also not sure you know what the +AMM even is; the map you posted did not indicate any significant changes to the AMM. According to the link you posted, 4.5 per season is not the 1991-2000 average. 3.2 is. We’ve also averaged more MH’s per season from 2016-2021 than 1995-2012, and all majors from 2019-21 except Epsilon have been in the deep tropics.

[CyclonicFury]

The MDR has not been quiet in the last several years. 4 of the last 5 seasons have had at least one Category 4+ hurricane in the deep tropics east of 60°W. If you look back at history, seasons with extreme MDR activity like 2004 or 2017 are not a very common occurrence, even in a +AMO. We had several seasons from 1995 to 2012 that had weaker MDR activity than the past several years (such as 2001, 2002, 2005, 2007 and 2012).

Not one Atlantic hurricane season from 1970-94 had more than 3 major hurricanes. We've had four seasons in the last seven that had 4 or more major hurricanes.

[Kingarabian]

I want to say a active year like 2021, but 3rd year Nina's have led to pretty average Atlantic hurricane seasons. Maybe if we get an unprecedented La Nina the outcome would be different than Climo.

[AlphaToOmega]

We know that the AMO will be positive and that the PDO will be negative by ASO. This means that in terms of activity, we really only have a few things to consider. Still, there are eight possibilities for how this season might pan out:

1. AMM by ASO? (Leaning positive)
2. ENSO by ASO? (Leaning negative)
3. Atlantic Nino* by ASO? (Tossup)

*Atlantic Nino is determined by Atl Nino 3 minus MDR SSTA

There are eight possibilities for ASO (all analogs are between 1995 and 2021 and have +AMO and -PDO for ASO):

1. +AMM/+ENSO/+AtlNino: 2012
2. +AMM/+ENSO/-AtlNino: 2006
3. +AMM/-ENSO/+AtlNino: 1999, 2007, 2008, 2021
4. +AMM/-ENSO/-AtlNino: 1998, 2001, 2005, 2010, 2011, 2013, 2017, 2020
5. -AMM/+ENSO/+AtlNino: N/A
6. -AMM/+ENSO/-AtlNino: 2000
7. -AMM/-ENSO/+AtlNino: N/A
8. -AMM/-ENSO/-AtlNino: N/A

During this +AMO phase, there has been only season that featured a -AMM during ASO but a -PDO and +AMO during that same time period: 2000. Based on these analogs, the chance of a -AMM during ASO is 6.67%, which means there is a 93.34% chance of a +AMM during ASO. Combined with climate models (which typically skew towards -AMM during ASO) showing a +AMM during ASO and the fact that the WAM has been warming the AMM during summer ever since 2016, I think there is enough information to call a +AMM during ASO:



However, the call of a +AMM during ASO changes very little; only one potential analog gets removed (2000). We still have the ENSO and Atlantic Nino, which can still decide everything about this season.

[Yellow Evan]

Although I don’t really anticipate it, we can’t rule out somewhat of a -AMO if the WAM suddenly shuts off, which will probably happen at some point in the next several years. I’d wager it happening after a Nino though.

[AlphaToOmega]

Here are the potential patterns for 2022, determined by the analogs:







These will be updated when further information is obtained, reducing the number of possible analogs.

[InfernoFlameCat]

I want to say a active year like 2021, but 3rd year Nina's have led to pretty average Atlantic hurricane seasons. Maybe if we get an unprecedented La Nina the outcome would be different than Climo.

Well climo isn't very accurate here because there isn't much climo to analyze this kind of scenario because of its rarity.

[InfernoFlameCat]

Although I don’t really anticipate it, we can’t rule out somewhat of a -AMO if the WAM suddenly shuts off, which will probably happen at some point in the next several years. I’d wager it happening after a Nino though.

I wonder if a third Nina can throw off the AMO. I don't have much knowledge in what makes AMOs + or - but a third Nina might prolong the AMO+? what do y'all think?

[Kingarabian]

I want to say a active year like 2021, but 3rd year Nina's have led to pretty average Atlantic hurricane seasons. Maybe if we get an unprecedented La Nina the outcome would be different than Climo.

Well climo isn't very accurate here because there isn't much climo to analyze this kind of scenario because of its rarity.

It has happened 3x in the past 70ish years and it will need to be factored in pre season predictions.

[InfernoFlameCat]

A third Nina could really help promote warmer waters on the surface of the tropical Atlantic because the sun has been heating up roughly the same surface water for 3 years without significant mixture with cooler water. This might possibly lead to very warm waters that are rather shallow. Therefore, upwelling might be more of an issue with tropical cyclones because the cooler water underneath the surface layer may in fact be abnormally cold. It hasn't had ample mixture with the surface waters to help moderate the temperature differences. Besides, warmer water doesn't mix downward because its lighter. This is a very big leap I am making and take what I said with a grain of salt. Its a big leap that I am fostering, but I think that might happen.

The reasons this might not be the case would be due to ocean currents that would disrupt this process, the sea already mixes up the the water for this to build up over time, and the Nina effect might not be strong enough to create something like that.

What do y'all think? I believe this could possibly happen, but I lack any evidence that would point toward such an event.

[Kingarabian]

A third Nina could really help promote warmer waters on the surface of the tropical Atlantic because the sun has been heating up roughly the same surface water for 3 years without significant mixture with cooler water. This might possibly lead to very warm waters that are rather shallow. Therefore, upwelling might be more of an issue with tropical cyclones because the cooler water underneath the surface layer may in fact be abnormally cold. It hasn't had ample mixture with the surface waters to help moderate the temperature differences. Besides, warmer water doesn't mix downward because its lighter. This is a very big leap I am making and take what I said with a grain of salt. Its a big leap that I am fostering, but I think that might happen.

The reasons this might not be the case would be due to ocean currents that would disrupt this process, the sea already mixes up the the water for this to build up over time, and the Nina effect might not be strong enough to create something like that.

What do y'all think? I believe this could possibly happen, but I lack any evidence that would point toward such an event.

La Nina doesn't affect Atlantic ocean SST's directly. It mainly limits EPAC TC production which allows rising motion and favorable shear over the Atlantic ocean.

[Yellow Evan]

Although I don’t really anticipate it, we can’t rule out somewhat of a -AMO if the WAM suddenly shuts off, which will probably happen at some point in the next several years. I’d wager it happening after a Nino though.

I wonder if a third Nina can throw off the AMO. I don't have much knowledge in what makes AMOs + or - but a third Nina might prolong the AMO+? what do y'all think?

The most obvious teleconnection to hurt the AMO is La Niña —> +NAO —> -AMO. In addition, it’s been speculated that the expansion of the Hadley Cell induced by persistent Ninas increase stability in the tropics which may be why years immediately after El Niño tend to be hyperactive. However, I wouldn’t expect a full 1970 style AMO flip or anything because historically they’ve occurred as a result of moderate to strong El Niño’s.

[Shell Mound]

2018 was a spring -AMM turned +AMM. Wouldn’t get such a wet Africa without a +AMM.

-AMO historic US landfalls are basically 1906 Mississippi, 1915 Galveston, 1915 New Orleans, 1918 Key West, Carmen, Allen, Hugo and Andrew. That’s a relatively short list compared to +AMO in part due to rising motion over the Central America shearing the Caribbean to the point where the Caribbean once went 7 years without a hurricane during a -AMO.

https://i.ibb.co/TL5HKkt/AMMchange-2.png

As this chart illustrates, the pattern over the subtropical and northern North Atlantic since 2013 has clearly been that of a -AMM. Furthermore, note the Atlantic Niño and cooler MDR. Only the Canary Current is somewhat warmer than one might have expected in a -AMM, but otherwise the SST-derived data strongly suggest a trend toward a -AMM. Since 2016 the average annual number of major hurricanes in the Atlantic basin has been roughly four. Of these, roughly two per year attained MH status in the deep tropics (MDR and/or Caribbean). A total of four MH per year lies below the mean of 4.5 MH per season recorded from 1991–2020, so recent seasons’ MH totals, in particular since 2016, have been averaging below the previous +AMM mean. (Personally, I don’t think Zeta and Grace were majors, so I excluded them.) Also, in a true +AMM most of the MH would be attaining their peaks in the deep tropics rather than be evenly split between the deep tropics and subtropics. Overall, we have been seeing fewer MH per season, especially in the deep tropics, and have been seeing fewer long-trackers in the deep tropics as well vs. 1995–2012.

First off, why are you comparing 2013-2021 to 1995-2012 and not 1970-94? 1995-2012 had remarkable persistence of +AMO and even then, the differences between the two look more driven by AMOC changes than an explicit -AMO reversal. I’m also not sure you know what the +AMM even is; the map you posted did not indicate any significant changes to the AMM. According to the link you posted, 4.5 per season is not the 1991-2000 average. 3.2 is. We’ve also averaged more MH’s per season from 2016-2021 than 1995-2012, and all majors from 2019-21 except Epsilon have been in the deep tropics.

The altered AMOC is likely driven by climate change, as melting polar ice and increased freshwater influx leads to more North Atlantic deep water, hence cooling of the far northern North Atlantic south of Greenland, so to me large-scale forces are driving the same factors that lead to a more -AMO over time. AMM stands for Atlantic meridional mode and is indirectly related to the AMO, given that a -AMM (+AMM) correlates with a cool (warm) MDR and a warm (cool) Gulf of Guinea. As far as MH per season are concerned, I calculated the mean of 1995–2012, excluding 1991–4 due to the previous -AMO, and came up with 3.7. Additionally, like Epsilon, Dorian, Humberto, Laura, Zeta, Ida, and Grace did not become majors in the deep tropics (MDR and/or Caribbean), even if several of them did originate there. Anyway, given climate change (weaker AMOC) and the likelihood of a third-year Niña, stability and possibly the TUTT are likely to impede activity in the MDR in 2022 once more.

[Shell Mound]

The MDR has not been quiet in the last several years. 4 of the last 5 seasons have had at least one Category 4+ hurricane in the deep tropics east of 60°W. If you look back at history, seasons with extreme MDR activity like 2004 or 2017 are not a very common occurrence, even in a +AMO. We had several seasons from 1995 to 2012 that had weaker MDR activity than the past several years (such as 2001, 2002, 2005, 2007 and 2012).

Not one Atlantic hurricane season from 1970-94 had more than 3 major hurricanes. We've had four seasons in the last seven that had 4 or more major hurricanes.

Your point about Category-4+ systems is well taken. However, regarding 1970–94, I would opine that 1975 (Doris), 1976 (Candice and Gloria), 1978 (Cora and Flossie), and 1980 (Bonnie and Ivan) likely featured at least four majors, based on satellite imagery and reconnaissance, pending reanalysis. Also, if, given its relatively high MSLP vs. FL winds and large size as well as its poor satellite-derived presentation, one does not regard last year’s Grace as a major, then only three of the last seven seasons have featured four or more majors.

[InfernoFlameCat]

The MDR has not been quiet in the last several years. 4 of the last 5 seasons have had at least one Category 4+ hurricane in the deep tropics east of 60°W. If you look back at history, seasons with extreme MDR activity like 2004 or 2017 are not a very common occurrence, even in a +AMO. We had several seasons from 1995 to 2012 that had weaker MDR activity than the past several years (such as 2001, 2002, 2005, 2007 and 2012).

Not one Atlantic hurricane season from 1970-94 had more than 3 major hurricanes. We've had four seasons in the last seven that had 4 or more major hurricanes.

Your point about Category-4+ systems is well taken. However, regarding 1970–94, I would opine that 1975 (Doris), 1976 (Candice and Gloria), 1978 (Cora and Flossie), and 1980 (Bonnie and Ivan) likely featured at least four majors, based on satellite imagery and reconnaissance, pending reanalysis. Also, if, given its relatively high MSLP vs. FL winds and large size as well as its poor satellite-derived presentation, one does not regard last year’s Grace as a major, then only three of the last seven seasons have featured four or more majors.

Grace was a Major per the NHC. It doesn't matter what the pressure is. The pressure doesn't define the category of a storm; it is only loosely correlated with wind speed. Grace could have a pressure of 1010mb and still be a major if it had 100+ knot 1 minute sustained wind speeds and a closed low pressure system.

[SFLcane]

Might want to go check out wxman57's season forecast in the hurricane seasonal thread.

[SFLcane]

Phil Klotzbach updated the AMO index with February results, I see. February value was -0.81. Definitely cool. Here are plots 1950-2022 and 2000-2022.

What kinda season are you expecting? Numbers?

I'm thinking that the MDR may be more favorable east of the Caribbean than it has been since 2017. Increased risk of a significant hurricane impact for the islands (sorry, Luis). Analogs suggest a significant east coast threat (includes Florida). Numbers-wise, thinking 19/8/4. With so many weak, short-lived storms now being named, the 19 number may be low. Nearly half of the 2021 storms were "shorties". Ratio of named storms to hurricanes used to be 2:1. Now, with better detection of weak systems out to sea and changing naming criteria, that ratio is more like 3:1. 30-yr average is 14/7/3, so a bit above average activity. No El Nino likely. Probably cool-neutral. Not an inhibiting factor.

Two weeks from today I'll be seeing Klotzbach at the NTWC in S. Padre. We've been discussing the season over the past few months. He'll officially release his projections then.

Just saw your threat map and wow. Can you share your analog years you are using?

[Yellow Evan]