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

[Ubuntwo]

Sea surface temperatures remain at or above average, with some warming in the MDR and slight cooling in the Caribbean.

OISST analysis:


CRW analysis:


Reynolds analysis:


Where is the 'below average' narrative coming from? Are people still using CDAS?

[Cat5James]

Where is the 'below average' narrative coming from? Are people still using CDAS?[/quote]

Its nonsense... this flurry of waves in June is a precursor for what lies ahead this season.

[aspen]

Sea surface temperatures remain at or above average, with some warming in the MDR and slight cooling in the Caribbean.

OISST analysis:
https://cdn.discordapp.com/attachments/289981599448039425/858436587528519680/oisst_anom_1d_tropatl_2021062400.png

CRW analysis:
https://cdn.discordapp.com/attachments/289981599448039425/858436922417479720/ct5km_ssta_v3.png

Reynolds analysis:
https://media.discordapp.net/attachments/289981599448039425/858437025287372840/atl_anom.png?width=725&height=668

Where is the 'below average' narrative coming from? Are people still using CDAS?

Probably. However, other maps show that SSTs in the eastern half of the MDR aren’t quite warm enough yet — this is June, after all.

[AlphaToOmega]

In my opinion, people are too fixated on SSTs. They are important, but they are only one piece of the story. What matters is velocity potential; higher SSTs create areas of -VP, and -VP creates wetter air and lowers wind shear. VP is a general indicator of favorability. From what I have gathered (correct me if I am wrong), rising air over Africa means a more active Atlantic, and rising air over the Americas means a more active Pacific.

2021 May VP anomalies:
https://psl.noaa.gov/cgi-bin/data/composites/comp.pl?var=Velocity+Potential&level=.2101+sigma&mon1=4&mon2=4&iy=2021&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&ipos%5B1%5D=&ipos%5B2%5D=&ineg%5B1%5D=&ineg%5B2%5D=&timefile0=&tstype=0&timefile1=&value=&typeval=1&compval=1&lag=0&labelcolor=Color&labelshaded=Shaded&type=2&scale=100&contourlabel=1&switch=0&cint=&lowr=&highr=&proj=ALL&xlat1=0&xlat2=90&xlon1=0&xlon2=360&custproj=Northern+Hemisphere+Polar+Stereographic&level1=1000mb&level2=10mb&Submit=Create+Plot

2020 May VP anomalies:
https://psl.noaa.gov/cgi-bin/data/composites/comp.pl?var=Velocity+Potential&level=.2101+sigma&mon1=4&mon2=4&iy=2020&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&ipos%5B1%5D=&ipos%5B2%5D=&ineg%5B1%5D=&ineg%5B2%5D=&timefile0=&tstype=0&timefile1=&value=&typeval=1&compval=1&lag=0&labelcolor=Color&labelshaded=Shaded&type=2&scale=100&contourlabel=1&switch=0&cint=&lowr=&highr=&proj=ALL&xlat1=0&xlat2=90&xlon1=0&xlon2=360&custproj=Northern+Hemisphere+Polar+Stereographic&level1=1000mb&level2=10mb&Submit=Create+Plot

2019 May VP anomalies:
https://psl.noaa.gov/cgi-bin/data/composites/comp.pl?var=Velocity+Potential&level=.2101+sigma&mon1=4&mon2=4&iy=2019&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&ipos%5B1%5D=&ipos%5B2%5D=&ineg%5B1%5D=&ineg%5B2%5D=&timefile0=&tstype=0&timefile1=&value=&typeval=1&compval=1&lag=0&labelcolor=Color&labelshaded=Shaded&type=2&scale=100&contourlabel=1&switch=0&cint=&lowr=&highr=&proj=ALL&xlat1=0&xlat2=90&xlon1=0&xlon2=360&custproj=Northern+Hemisphere+Polar+Stereographic&level1=1000mb&level2=10mb&Submit=Create+Plot

2018 May VP anomalies:
https://psl.noaa.gov/cgi-bin/data/composites/comp.pl?var=Velocity+Potential&level=.2101+sigma&mon1=4&mon2=4&iy=2018&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&ipos%5B1%5D=&ipos%5B2%5D=&ineg%5B1%5D=&ineg%5B2%5D=&timefile0=&tstype=0&timefile1=&value=&typeval=1&compval=1&lag=0&labelcolor=Color&labelshaded=Shaded&type=2&scale=100&contourlabel=1&switch=0&cint=&lowr=&highr=&proj=ALL&xlat1=0&xlat2=90&xlon1=0&xlon2=360&custproj=Northern+Hemisphere+Polar+Stereographic&level1=1000mb&level2=10mb&Submit=Create+Plot

2017 May VP anomalies:
https://psl.noaa.gov/cgi-bin/data/composites/comp.pl?var=Velocity+Potential&level=.2101+sigma&mon1=4&mon2=4&iy=2017&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&ipos%5B1%5D=&ipos%5B2%5D=&ineg%5B1%5D=&ineg%5B2%5D=&timefile0=&tstype=0&timefile1=&value=&typeval=1&compval=1&lag=0&labelcolor=Color&labelshaded=Shaded&type=2&scale=100&contourlabel=1&switch=0&cint=&lowr=&highr=&proj=ALL&xlat1=0&xlat2=90&xlon1=0&xlon2=360&custproj=Northern+Hemisphere+Polar+Stereographic&level1=1000mb&level2=10mb&Submit=Create+Plot

2016 May VP anomalies:
https://psl.noaa.gov/cgi-bin/data/composites/comp.pl?var=Velocity+Potential&level=.2101+sigma&mon1=4&mon2=4&iy=2016&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&ipos%5B1%5D=&ipos%5B2%5D=&ineg%5B1%5D=&ineg%5B2%5D=&timefile0=&tstype=0&timefile1=&value=&typeval=1&compval=1&lag=0&labelcolor=Color&labelshaded=Shaded&type=2&scale=100&contourlabel=1&switch=0&cint=&lowr=&highr=&proj=ALL&xlat1=0&xlat2=90&xlon1=0&xlon2=360&custproj=Northern+Hemisphere+Polar+Stereographic&level1=1000mb&level2=10mb&Submit=Create+Plot

From the looks of it, 2021 has the most favorable May VP pattern. Only 2020 and 2018 could really compare to 2021. These are only for May, and things could easily change; however, it seems interesting that 2021 seems to have a more favorable pattern than 2020.

[Category5Kaiju]

In my opinion, people are too fixated on SSTs. They are important, but they are only one piece of the story. What matters is velocity potential; higher SSTs create areas of -VP, and -VP creates wetter air and lowers wind shear. VP is a general indicator of favorability. From what I have gathered (correct me if I am wrong), rising air over Africa means a more active Atlantic, and rising air over the Americas means a more active Pacific.

2021 May VP anomalies:
https://psl.noaa.gov/cgi-bin/data/composites/comp.pl?var=Velocity+Potential&level=.2101+sigma&mon1=4&mon2=4&iy=2021&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&ipos%5B1%5D=&ipos%5B2%5D=&ineg%5B1%5D=&ineg%5B2%5D=&timefile0=&tstype=0&timefile1=&value=&typeval=1&compval=1&lag=0&labelcolor=Color&labelshaded=Shaded&type=2&scale=100&contourlabel=1&switch=0&cint=&lowr=&highr=&proj=ALL&xlat1=0&xlat2=90&xlon1=0&xlon2=360&custproj=Northern+Hemisphere+Polar+Stereographic&level1=1000mb&level2=10mb&Submit=Create+Plot

2020 May VP anomalies:
https://psl.noaa.gov/cgi-bin/data/composites/comp.pl?var=Velocity+Potential&level=.2101+sigma&mon1=4&mon2=4&iy=2020&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&ipos%5B1%5D=&ipos%5B2%5D=&ineg%5B1%5D=&ineg%5B2%5D=&timefile0=&tstype=0&timefile1=&value=&typeval=1&compval=1&lag=0&labelcolor=Color&labelshaded=Shaded&type=2&scale=100&contourlabel=1&switch=0&cint=&lowr=&highr=&proj=ALL&xlat1=0&xlat2=90&xlon1=0&xlon2=360&custproj=Northern+Hemisphere+Polar+Stereographic&level1=1000mb&level2=10mb&Submit=Create+Plot

2019 May VP anomalies:
https://psl.noaa.gov/cgi-bin/data/composites/comp.pl?var=Velocity+Potential&level=.2101+sigma&mon1=4&mon2=4&iy=2019&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&ipos%5B1%5D=&ipos%5B2%5D=&ineg%5B1%5D=&ineg%5B2%5D=&timefile0=&tstype=0&timefile1=&value=&typeval=1&compval=1&lag=0&labelcolor=Color&labelshaded=Shaded&type=2&scale=100&contourlabel=1&switch=0&cint=&lowr=&highr=&proj=ALL&xlat1=0&xlat2=90&xlon1=0&xlon2=360&custproj=Northern+Hemisphere+Polar+Stereographic&level1=1000mb&level2=10mb&Submit=Create+Plot

2018 May VP anomalies:
https://psl.noaa.gov/cgi-bin/data/composites/comp.pl?var=Velocity+Potential&level=.2101+sigma&mon1=4&mon2=4&iy=2018&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&ipos%5B1%5D=&ipos%5B2%5D=&ineg%5B1%5D=&ineg%5B2%5D=&timefile0=&tstype=0&timefile1=&value=&typeval=1&compval=1&lag=0&labelcolor=Color&labelshaded=Shaded&type=2&scale=100&contourlabel=1&switch=0&cint=&lowr=&highr=&proj=ALL&xlat1=0&xlat2=90&xlon1=0&xlon2=360&custproj=Northern+Hemisphere+Polar+Stereographic&level1=1000mb&level2=10mb&Submit=Create+Plot

2017 May VP anomalies:
https://psl.noaa.gov/cgi-bin/data/composites/comp.pl?var=Velocity+Potential&level=.2101+sigma&mon1=4&mon2=4&iy=2017&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&ipos%5B1%5D=&ipos%5B2%5D=&ineg%5B1%5D=&ineg%5B2%5D=&timefile0=&tstype=0&timefile1=&value=&typeval=1&compval=1&lag=0&labelcolor=Color&labelshaded=Shaded&type=2&scale=100&contourlabel=1&switch=0&cint=&lowr=&highr=&proj=ALL&xlat1=0&xlat2=90&xlon1=0&xlon2=360&custproj=Northern+Hemisphere+Polar+Stereographic&level1=1000mb&level2=10mb&Submit=Create+Plot

2016 May VP anomalies:
https://psl.noaa.gov/cgi-bin/data/composites/comp.pl?var=Velocity+Potential&level=.2101+sigma&mon1=4&mon2=4&iy=2016&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&iy=&ipos%5B1%5D=&ipos%5B2%5D=&ineg%5B1%5D=&ineg%5B2%5D=&timefile0=&tstype=0&timefile1=&value=&typeval=1&compval=1&lag=0&labelcolor=Color&labelshaded=Shaded&type=2&scale=100&contourlabel=1&switch=0&cint=&lowr=&highr=&proj=ALL&xlat1=0&xlat2=90&xlon1=0&xlon2=360&custproj=Northern+Hemisphere+Polar+Stereographic&level1=1000mb&level2=10mb&Submit=Create+Plot

From the looks of it, 2021 has the most favorable May VP pattern. Only 2020 and 2018 could really compare to 2021. These are only for May, and things could easily change; however, it seems interesting that 2021 seems to have a more favorable pattern than 2020.

Oh yeah, I mean what you just showed may also be partially responsible for why 2020 had little to no MDR activity (especially during this time of the year) with a lot of SAL while this year we are on the verge of seeing possibly 2 storms form near or in the MDR...in June! This is especially concerning as we head into ASO, when we could really see long-trackers. Btw welcome to Storm2k!

[Shell Mound]

Sea surface temperatures remain at or above average, with some warming in the MDR and slight cooling in the Caribbean.

OISST analysis:
https://cdn.discordapp.com/attachments/289981599448039425/858436587528519680/oisst_anom_1d_tropatl_2021062400.png

CRW analysis:
https://cdn.discordapp.com/attachments/289981599448039425/858436922417479720/ct5km_ssta_v3.png

Reynolds analysis:
https://media.discordapp.net/attachments/289981599448039425/858437025287372840/atl_anom.png?width=725&height=668

Where is the 'below average' narrative coming from? Are people still using CDAS?

The general SST configuration is starting to resemble 2017’s, although the deep tropics are still cooler than that year. But the MDR is finally above average.

We could see three tropical storms within the upcoming week, including two within the next three days: 95L, 96L, and the AEW that has just left W Africa.

[AlphaToOmega]

The Atlantic is expected to be ripe for tropical development until July 25. After July 25, sinking air as a result of a suppressed MJO phase is expected to be present throughout Africa, which should be a handicap for the strong WAM. It is also important to note that sinking air does not exclude the possibility of subtropical development.



A surge of activity in early and mid July is possible given this. If this verified, this might be the first season in a while without people saying "season cancelled".

[ElectricStorm]

The Atlantic is expected to be ripe for tropical development until July 25. After July 25, sinking air as a result of a suppressed MJO phase is expected to be present throughout Africa, which should be a handicap for the strong WAM. It is also important to note that sinking air does not exclude the possibility of subtropical development.

[url]https://i.postimg.cc/qBZWFQTb/cfs-avg-chi200-Mean-global-fh168-1008.gif [/url]

A surge of activity in early and mid July is possible given this. If this verified, this might be the first season in a while without people saying "season cancelled".

They would just season cancel in August instead

[aspen]

The Atlantic is expected to be ripe for tropical development until July 25. After July 25, sinking air as a result of a suppressed MJO phase is expected to be present throughout Africa, which should be a handicap for the strong WAM. It is also important to note that sinking air does not exclude the possibility of subtropical development.

[url]https://i.postimg.cc/qBZWFQTb/cfs-avg-chi200-Mean-global-fh168-1008.gif [/url]

A surge of activity in early and mid July is possible given this. If this verified, this might be the first season in a while without people saying "season cancelled".

That’s the complete opposite of the Euro velocity potential, which shows increased rising motion over Africa starting in late July after the suppressive MJO phase in the Atlantic dissipates.

[tolakram]

The Atlantic is expected to be ripe for tropical development until July 25. After July 25, sinking air as a result of a suppressed MJO phase is expected to be present throughout Africa, which should be a handicap for the strong WAM. It is also important to note that sinking air does not exclude the possibility of subtropical development.

[url]https://i.postimg.cc/qBZWFQTb/cfs-avg-chi200-Mean-global-fh168-1008.gif [/url]

A surge of activity in early and mid July is possible given this. If this verified, this might be the first season in a while without people saying "season cancelled".

That’s the complete opposite of the Euro velocity potential, which shows increased rising motion over Africa starting in late July after the suppressive MJO phase in the Atlantic dissipates.

Listening to Bastardi's Saturday Summary on Weatherbell. It's free, though you have to put up with his ramblings which can be quite expensive. Euro has been doing quite badly with MJO forecasts.

[Steve]

The Atlantic is expected to be ripe for tropical development until July 25. After July 25, sinking air as a result of a suppressed MJO phase is expected to be present throughout Africa, which should be a handicap for the strong WAM. It is also important to note that sinking air does not exclude the possibility of subtropical development.

[url]https://i.postimg.cc/qBZWFQTb/cfs-avg-chi200-Mean-global-fh168-1008.gif [/url]

A surge of activity in early and mid July is possible given this. If this verified, this might be the first season in a while without people saying "season cancelled".

That’s the complete opposite of the Euro velocity potential, which shows increased rising motion over Africa starting in late July after the suppressive MJO phase in the Atlantic dissipates.

Listening to Bastardi's Saturday Summary on Weatherbell. It's free, though you have to put up with his ramblings which can be quite expensive. Euro has been doing quite badly with MJO forecasts.

I managed to find about 2 listenable minutes this week.

[Category5Kaiju]

The Atlantic is expected to be ripe for tropical development until July 25. After July 25, sinking air as a result of a suppressed MJO phase is expected to be present throughout Africa, which should be a handicap for the strong WAM. It is also important to note that sinking air does not exclude the possibility of subtropical development.

[url]https://i.postimg.cc/qBZWFQTb/cfs-avg-chi200-Mean-global-fh168-1008.gif [/url]

A surge of activity in early and mid July is possible given this. If this verified, this might be the first season in a while without people saying "season cancelled".

They would just season cancel in August instead

No no, you need a 185 mph Category 5 hurricane to slam Miami in July. Then there will be zero season cancelled remarks

[AlphaToOmega]

CanSIPS:


CFSv2:


The CanSIPS is more bullish than the CFSv2, but both generally indicate -VP anomalies over Africa and +VP anomalies over the Pacific and the Americas. Should either of these verify, the 2021 Atlantic Hurricane Season will be above-average (CFSv2) or possibly hyperactive (CanSIPS).

[Category5Kaiju]

CanSIPS:
[url]https://i.postimg.cc/d0dj2bPC/cansips-chi200-global-4.png [/url]

CFSv2:
[url]https://i.postimg.cc/h40M3RJb/cfs-mon-01-chi200-global-3.png [/url]

The CanSIPS is more bullish than the CFSv2, but both generally indicate -VP anomalies over Africa and +VP anomalies over the Pacific and the Americas. Should either of these verify, the 2021 Atlantic Hurricane Season will be above-average (CFSv2) or possibly hyperactive (CanSIPS).

While we still have several months before the heart of hurricane season, at this point I am on the verge of predicting that later on in the season, should this kind of pattern persist with relatively favorable conditions otherwise, we may end up in a situation later this season where the newly formed auxiliary list may come in handy

[AlphaToOmega]

CanSIPS forecast:


Sept 2020 VP anomalies:


CFSv2 forecast:


Sept 2020 and 2018 VP anomalies composite:


The CanSIPS is suggesting a potential 2020 repeat, and the CFSv2 is suggesting a season in between 2020 and 2018. Should the CanSIPS scenario play out, we may have a season with ~180 ACE à la 2020. Should the CFSv2 scenario play out, we may have a season with ~155 ACE. However, neither of those would put us over the hyperactive threshold of ~210 unless we have many long-trackers.

[SconnieCane]

I think someone posted in one of the storm threads that if two of the current three active cyclones/AOIs in the North Atlantic get named, we'll beat last year for the earliest 5th named storm. Granted we can argue about whether naming criteria have changed and things are getting named now that wouldn't have 20-30 years ago (a similar debate is to be had about tornado ratings on the F/EF-scales), making comparing recent seasonal activity with historical ones not as clear-cut as we might like. That said, the fact that there is even the possibility of challenging 2020's formation records the very next season is not good.

[aspen]

I think someone posted in one of the storm threads that if two of the current three active cyclones/AOIs in the North Atlantic get named, we'll beat last year for the earliest 5th named storm. Granted we can argue about whether naming criteria have changed and things are getting named now that wouldn't have 20-30 years ago (a similar debate is to be had about tornado ratings on the F/EF-scales), making comparing recent seasonal activity with historical ones not as clear-cut as we might like. That said, the fact that there is even the possibility of challenging 2020's formation records the very next season is not good.

Now that 96L became Danny, there’s a chance of both the earliest 5th AND 6th named storm records from last year falling, if 95L and the wave behind it develop like the HWRF really wants them to.

Elsa and Fred, back to back MDR tropical storms (or maybe weak hurricanes) in the first week of July….talk about an ominous sign for peak season.

[Category5Kaiju]

I think someone posted in one of the storm threads that if two of the current three active cyclones/AOIs in the North Atlantic get named, we'll beat last year for the earliest 5th named storm. Granted we can argue about whether naming criteria have changed and things are getting named now that wouldn't have 20-30 years ago (a similar debate is to be had about tornado ratings on the F/EF-scales), making comparing recent seasonal activity with historical ones not as clear-cut as we might like. That said, the fact that there is even the possibility of challenging 2020's formation records the very next season is not good.

Now that 96L became Danny, there’s a chance of both the earliest 5th AND 6th named storm records from last year falling, if 95L and the wave behind it develop like the HWRF really wants them to.

Elsa and Fred, back to back MDR tropical storms (or maybe weak hurricanes) in the first week of July….talk about an ominous sign for peak season.

Some models (I believe most recently sometime this morning) were even trying to develop a system in the Gulf separate from 95L and the wave behind it. Not convinced it will happen of course, but if it does we could be dealing with Grace, and this would certainly pull 2021 ahead of 2020 in terms of earliest 5th, 6th, and 7th storm formations, and highly likely be very sinister for what's to come later. Either way, the fact that we already have 2 strong MDR candidates is quite worrisome.

[Beef Stew]

While the formation of frequent early season TC’s (especially in the subtropics) isn’t on its own indicative of a strong ASO, it seems to be that the background state of 2021- similar to 2020- is proving to be more conductive for genesis than most. We have Danny on June 28th- nearly two months ahead of Dorian’s formation in 2019, a season which still managed to produce 18 named storms. With an active wave train already presenting itself, and a strong WAM being forecast, the potential for going deep into the name list is certainly presenting itself.

[Category5Kaiju]

While the formation of frequent early season TC’s (especially in the subtropics) isn’t on its own indicative of a strong ASO, it seems to be that the background state of 2021- similar to 2020- is proving to be more conductive for genesis than most. We have Danny on June 28th- nearly two months ahead of Dorian’s formation in 2019, a season which still managed to produce 18 named storms. With an active wave train already presenting itself, and a strong WAM being forecast, the potential for going deep into the name list is certainly presenting itself.

Earlier this year there were quite a few predictions that 2021 would not be a busy season because 2020 went Greek, much like 2005. However, I think what we are seeing now disproves the notion that just because the preceeding year is very busy that the next year would be inactive. So far it definitely does not seem like 2021 is going to follow the 2005-2006 pattern that some people initially thought would be the case especially after seeing a record shattering season. The atmospheric/oceanic conditions are what matter in a given season, not how the preceeding season did.