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

[SFLcane]

For us tc trackers all we can do is continue to wait.

[AlphaToOmega]

This is not a lot of SAL. The impacts of SAL on TC activity are being greatly exaggerated. Remember 2017 had a dust outbreak right before Harvey

[aspen]

For us tc trackers all we can do is continue to wait.

Or track Grace and Henri, both of which will be around for quite some time and have at least some chance to become hurricanes.

[AlphaToOmega]

Unlike in July, the MJO seems to be favorable for the rest of August. August is NOT going to shut down. July was a product of an unfavorable MJO AND a lot of SAL. Activity will ramp up significantly after August 20. It is becoming EXTREMELY dangerous to assume the best-case scenario.

[tolakram]

Unlike in July, the MJO seems to be favorable for the rest of August. August is NOT going to shut down. July was a product of an unfavorable MJO AND a lot of SAL. Activity will ramp up significantly after August 20. It is becoming EXTREMELY dangerous to assume the best-case scenario.

That's your opinion, we'll see in a couple of weeks. There's nothing wrong with people giving their analysis here and it's not extremely dangerous to assume a best case scenario here. Let's just stop that nonsense right now. This is an indicators discussion thread.

[Category5Kaiju]

I personally do not find anything anomalous or strange with that dust plume, prior active seasons iirc have had that happen, and if last year had major dust problems but still produced a very active season in the end (albeit backloaded), then I don’t see why this dust plume would be anything significant for this season.

[Iceresistance]

Mid-August North Atlantic Global SST anomalies.

The square area between 80°W to 45°W & from 25°N to 50°N is WAY above normal, & the GoM is STILL boiling . . .

[SFLcane]

This is not a lot of SAL. The impacts of SAL on TC activity are being greatly exaggerated. Remember 2017 had a dust outbreak right before Harvey
https://i.postimg.cc/TwP32VJ3/geos5-atl-dustext-2021081612-f122.png

Have a link for the Sal graphic in 2017 before Harvey, Irma?

[SFLcane]

Things are either gonna explode eventually or this will be a memorable September upcoming. One thing I can see now is the rest of August could be shut down with a big trade surge inbound.

https://i.postimg.cc/PxFGhtNM/5-EE8-CC92-1-D37-453-F-BE69-22-B22-FDE99-AB.jpg

If you look at the EPS, after the suppressed Kelvin Wave, there's another CCKW right at the end of the month. So September 1-10 would be the window I would look for at this point. If that doesn't produce a long tracker or two, we're looking at an underachieving season.

https://i.postimg.cc/zfQZYzyF/F516-B099-FC32-467-D-B9-E8-776-E12-FF0692.jpg

What do you mean a “big trade surge”? All of those are negative anomalies.

Positive u wind is westerly and Negative is easterly. Negative anomalies = stronger winds from the east. Given the mean winds are already out of the east there, it means a strong surge of easterly low level winds.

[Category5Kaiju]

Also I am not sure if it's just me, but doesn't it seem like many recent years have been backloaded, with the strongest hurricanes occurring in late September to even November? 2011, 2012 2014, 2015. 2016, 2017, 2018, and 2020 come into mind, so maybe the SAL and what not (along with the developing La Nina) we are seeing now would simply push the season's activity slightly down the calendar with perhaps the strongest storm of the season occurring late rather than shutting down or limiting this season's potential in a significant manner?

[cycloneye]

We wait and watch.

 https://twitter.com/AndyHazelton/status/1427625423018545159

[tolakram]

The more convection over Africa the more SAL (not a perfect match) and the more outflow, meaning more trade winds. This seems to trend well with more western development. In slower years perhaps there's a better chance of long trackers? I'm not sure if this correlates or not, but it seems if the wave train is super active then most activity will be in the western half of the basin.

[Category5Kaiju]

The more convection over Africa the more SAL (not a perfect match) and the more outflow, meaning more trade winds. This seems to trend well with more western development. In slower years perhaps there's a better chance of long trackers? I'm not sure if this correlates or not, but it seems if the wave train is super active then most activity will be in the western half of the basin.

Interestingly, it seems like the years with a phenomenal NS count (2005 and 2020) were west-focused with little intense MDR activity. Years like 2004 and 2017 were long-tracker heavy, but in total their NS counts were not very striking (15 and 17 respectively).

[SFLcane]

Anyone have an SAL outbreak archive form 2017 before we had that outbreak Harvey, Irma etc.

[Category5Kaiju]

Anyone have an SAL outbreak archive form 2017 before we had that outbreak Harvey, Irma etc.

Weeniepatrol's recent post (#2572) has a snapshot of the massive dust plume roughly 12 days before Irma formed; not exactly sure where or how weeniepatrol saved the SAL graphic though?

[kevin]

Also I am not sure if it's just me, but doesn't it seem like many recent years have been backloaded, with the strongest hurricanes occurring in late September to even November? 2011, 2012 2014, 2015. 2016, 2017, 2018, and 2020 come into mind, so maybe the SAL and what not (along with the developing La Nina) we are seeing now would simply push the season's activity slightly down the calendar with perhaps the strongest storm of the season occurring late rather than shutting down or limiting this season's potential in a significant manner?

I did some calculations of the number of Oct - Dec named storms since 2000, including the % of the total number of storms of that year. Same goes for major hurricanes. For simplicity I only included them if their formation date was in October or beyond. I simply combined it using "# named Oct-Dec storms * % of named storms + 5 * #MH oct-Dec * % of total MH" to get an indication for how backloaded a season was, expressed with a "Backload score". I added a factor 5 to the MH value to roughly reflect the average ratio of MHs to other tropical storms.

Year / Backload score / # named Oct-Dec storms / % of total named storms / # major Oct-Dec storms / % of total MH
2000 / 1.1 / 4 / 27% / 0 / 0%
2001 / 8.3 / 7 / 47% / 2 / 50%
2002 / 0.0 / 0 / 0% / 0 / 0%
2003 / 1.6 / 5 / 31% / 0 / 0%
2004 / 0.6 / 3 / 20% / 0 / 0%
2005 / 7.2 / 11 / 39% / 2 / 29%
2006 / 0.0 / 0 / 0% / 0 / 0%
2007 / 0.3 / 2 / 13% / 0 / 0%
2008 / 5.6 / 5 / 31% / 2 / 40%
2009 / 1.0 / 3 / 33% / 0 / 0%
2010 / 1.3 / 5 / 26% / 0 / 0%
2011 / 0.2 / 2 / 11% / 0 / 0%
2012 / 3.8 / 5 / 26% / 1 / 50%
2013 / 1.2 / 4 / 29% / 0 / 0%
2014 / 3.6 / 3 / 38% / 1 / 50%
2015 / 0.1 / 1 / 9% / 0 / 0%
2016 / 5.3 / 2 / 13% / 2 / 50%
2017 / 1.8 / 4 / 24% / 1 / 17%
2018 / 3.1 / 3 / 20% / 1 / 50%
2019 / 2.7 / 7 / 39% / 0 / 0%
2020 / 19.4 / 7 / 23% / 5 / 71%

If you plot it you do get an upwards trend, but this is mainly caused by 2020, which was so backloaded it's ridiculous. No other season came even close to what the last months of 2020 did. If you remove 2020 you get a near constant trend, even downwards by -0.008 "Backload score" per year, but that's so small that it's negigible. So it seems that, if this methodology is used, at least in the 2000 - 2020 timeline there is no clear increase in backloaded seasons (if we define backloaded as starting on the 1st of October). Perhaps it would be slightly different if you also include the last week of September in the calculation, since then you also get storms like Joaquin and Matthew from recent years. And it might also shift a bit if you only consider the peak date of a storm instead of its formation date, but that was a bit too much work for me to do now .

[SoupBone]

Unlike in July, the MJO seems to be favorable for the rest of August. August is NOT going to shut down. July was a product of an unfavorable MJO AND a lot of SAL. Activity will ramp up significantly after August 20. It is becoming EXTREMELY dangerous to assume the best-case scenario.

Why are you being argumentative over people posting opposing opinions? You're posting definitive statements, which is worse. It does appear that several pieces of the puzzle are not coming together for the next week and a half for sure, beyond that is anyone's best guess.

 https://twitter.com/JasonDunning/status/1427609769699856387

[SFLcane]

:uarrow:
https://i.imgur.com/8eRGifv.jpg

This current SAL outbreak is even bigger than that. But certainly it could flip after.

[AutoPenalti]

Man, it has become tradition for me to view the Irma thread every season when posts become bearish.

[toad strangler]

Man, it has become tradition for me to view the Irma thread every season when posts become bearish.

Yesh, I'm starting to get bearish reading all of this. I might have to brush up on it too