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

[AlphaToOmega]

I think looking at raw MDR SSTs is very misleading. The ITCZ is much farther south this year than last year, meaning tropical waves are going to develop in warmer waters. Therefore, while the MDR might be slightly cooler than last year, waves are developing in warmer waters.

Well if they are going anywhere other than South America they have to actually cross the MDR. There's a reason why the correlation between SSTs and ACE is strongest in the MDR. Tc’s Don't stay at 10N all the way across If they do they hit land real quick.

The season is expected to be mainly low-riders, and the southern part of the MDR is the one with positive SST anomalies. It is the northern part of the MDR with negative SST anomalies.

[Category5Kaiju]

We still have several months to go, but let's just pretend that this UOHC held in peak season. Sure, the chances of seeing a redux of Luis, Irma, or Igor may not be high, but then again, looking west of 50 W, the UOHC is very supportive for intense hurricanes, and the UOHC south of 10 N is extremely high. In terms of land impacts, west of 50 W is what matters, and given the insane level of UOHC in the WCAR, Gulf Loop Current, and south of the typical MDR, one would have to wonder if this kind of setup would favor low riders this season.

[toad strangler]

Andy doesn't know what to make of it.

 http://twitter.com/AndyHazelton/status/1414709335301709833

[aspen]

Andy doesn't know what to make of it.

http://twitter.com/AndyHazelton/status/1414709335301709833?s=20

If the early August Kelvin Wave verifies (I find it more likely than the late August one due to being only 2 weeks away and therefore subjected to less time-based forecast uncertainty), it will constructively interfere with the ASW/WAM around August 4th or so, potentially leading to a spike in activity. The wave gets into the Atlantic in late July based on the first Euro forecast map. Any AEWs that are within the basin at that time could find an improving environment and could get a shot at development.

Elsa showed that CCKW-triggered development can happen and can result in an impactful storm. I believe someone mentioned Ivan or a similar low-rider was also triggered by a passing enhanced Kelvin Wave.

[cycloneye]

Mix signals is the theme.

 https://twitter.com/AndyHazelton/status/1414716363717885953

[captainbarbossa19]

Ah yes. It's that wonderful time of the year when we are in a suppressed state with little to no activity. As usual many "experts" are having doubts about peak season activity. I can tell you that I have seen this year after year. Do NOT trust any model projection a month away. For whatever reason, it seems like when the Atlantic is in a suppressed state, models often like to overextend the length and intensity of the pattern. I cannot tell you how many times I have seen the models show nothing a week before the tropics become active. In this case, I think that there will be an increase in activity towards August. Whether or not we see any hurricanes then remains to be seen, but I do not trust models and have seen them fail countless times when predicting changes with the MJO etc.

[Category5Kaiju]

Ah yes. It's that wonderful time of the year when we are in a suppressed state with little to no activity. As usual many "experts" are having doubts about peak season activity. I can tell you that I have seen this year after year. Do NOT trust any model projection a month away. For whatever reason, it seems like when the Atlantic is in a suppressed state, models often like to overextend the length and intensity of the pattern. I cannot tell you how many times I have seen the models show nothing a week before the tropics become active. In this case, I think that there will be an increase in activity towards August. Whether or not we see any hurricanes then remains to be seen, but I do not trust models and have seen them fail countless times when predicting changes with the MJO etc.

I specifically remember something like this happening with Dorian and Erin in 2019; I remember how the models did not really develop any of them until they were, well, about to develop into bona fide TCs. I am sure this happened many times last year, but I specifically remember that in 2019 due to how inactive the earlier part of the season was and me thinking that if the models were right then we would see little activity to close out the month of August. That obviously did not occur.

[abajan]

Interesting discussion on a somewhat difficult to grasp subject.

[youtube]https://youtu.be/DJeiKq-3XGY[/youtube]

[AlphaToOmega]

The CFSv2 still wants to kill the West African Monsoon.

[cycloneye]

The CFSv2 still wants to kill the West African Monsoon.

Do you have a graphic or link?

[aspen]

The CFSv2 still wants to kill the West African Monsoon.

Seeing how this year’s precipitation over Africa has even put 2020 to shame, that’s not happening lol.

[AlphaToOmega]

The CFSv2 still wants to kill the West African Monsoon.

Do you have a graphic or link?

[Kingarabian]

https://www.tropicaltidbits.com/analysi ... el=cfs-mon

[Category5Kaiju]

The CFSv2 still wants to kill the West African Monsoon.

Yeah I don't know how much stock I would put into that, the fact that we already had an MDR hurricane and have the ITCZ look pretty active even during a suppressed phase makes me want to believe otherwise.

[DorkyMcDorkface]

The CFSv2 still wants to kill the West African Monsoon.

IIRC the CFS has a prevalent progressive bias when it comes to killing off standing waves (ASW/WAM in particular) so I would take it with a grain of salt.

[Yellow Evan]

CFS is always trying to kill the ASW in the long range during the summer.

[DorkyMcDorkface]

I must say, the ITCZ remains very active convectively despite a strong suppressive kelvin wave lingering overhead:

[Stormybajan]

I must say, the ITCZ remains very active convectively despite a strong suppressive kelvin wave lingering overhead:
https://cdn.discordapp.com/attachments/733552978572869632/864338661239685140/GANIMNLpe4a25.png
https://cdn.discordapp.com/attachments/733552978572869632/864336153632178207/image0.jpg

Just a quick question here..Where would the ITCZ usually linger at this time of year (mid-July)? I've never paid much attention to it and I know the Atlantic Nino will drag it more the south

[Category5Kaiju]

I must say, the ITCZ remains very active convectively despite a strong suppressive kelvin wave lingering overhead:
https://cdn.discordapp.com/attachments/733552978572869632/864338661239685140/GANIMNLpe4a25.png
https://cdn.discordapp.com/attachments/733552978572869632/864336153632178207/image0.jpg

Just a quick question here..Where would the ITCZ usually linger at this time of year (mid-July)? I've never paid much attention to it and I know the Atlantic Nino will drag it more the south

I would think more along roughly 10-15 N (at least from what I can remember in previous seasons I have tracked). Most of the action you see is at 10 N or slightly south of that, so I think it's pretty evident that the ITCZ has been shifted a bit southward.

[SconnieCane]

Ah yes. It's that wonderful time of the year when we are in a suppressed state with little to no activity. As usual many "experts" are having doubts about peak season activity. I can tell you that I have seen this year after year. Do NOT trust any model projection a month away. For whatever reason, it seems like when the Atlantic is in a suppressed state, models often like to overextend the length and intensity of the pattern. I cannot tell you how many times I have seen the models show nothing a week before the tropics become active. In this case, I think that there will be an increase in activity towards August. Whether or not we see any hurricanes then remains to be seen, but I do not trust models and have seen them fail countless times when predicting changes with the MJO etc.

I specifically remember something like this happening with Dorian and Erin in 2019; I remember how the models did not really develop any of them until they were, well, about to develop into bona fide TCs. I am sure this happened many times last year, but I specifically remember that in 2019 due to how inactive the earlier part of the season was and me thinking that if the models were right then we would see little activity to close out the month of August. That obviously did not occur.

I seem to remember a similar thing occurring in 2017 not long before the Atlantic exploded with Irma, Jose and Maria; and again in 2018 shortly before the early September burst of activity that gave us Florence among others. The only year in the last five it didn't really happen was last, only because tropical cyclogenesis just kept on occurring; although it wasn't always as strong as anticipated going into the year due to the unusually high-latitude ITCZ, "wave clumping," and SAL.