2020 Indicators: SST's / SAL / MSLP / Steering / Shear / Instability / Sat Images

[cycloneye]

Another nugget by Ventrice.

 https://twitter.com/MJVentrice/status/1278802867885875207

[SFLcane]

Another nugget by Ventrice.

https://twitter.com/MJVentrice/status/1278802867885875207

Thought Tutt was in full control?

We should be rolling in a few weeks.

[CyclonicFury]

Although I am bullish on ASO, I am somewhat bearish about July.

[Shell Mound]

2020:


2017:


2010 (image from 1 July was not available, for some reason):


2005:


Even the corrected TCHP/OHC data suggest that 2020 is actually ahead of 2005, 2010, and 2017, even if SSTs are “officially” a bit lower than these years’.

[cycloneye]

 https://twitter.com/webberweather/status/1279005748975095809

[cycloneye]

Yikes.

 https://twitter.com/webberweather/status/1279006634682056704

[Shell Mound]

Is anyone able to make a similar graph and linear regression for total major hurricanes vs. date of fourth named storm? TheAustinMan, perhaps?

 https://twitter.com/splillo/status/1275929630621364224

[toad strangler]

 http://twitter.com/AndyHazelton/status/1279008147609354241

[CyclonicFury]

The deep tropics appear shut down for the first half of July. No signs of any activity in the MDR or Caribbean any time soon. For the second half of July, it's too early to tell.

However, I think we will have to keep looking for non-tropical mischief near the US over the next 10 days or so. At the moment, it appears unlikely we are going to have a very active July like 1996, 2005 or 2008, but it's likely we'll get at least one named storm this month.

I still expect a very active ASO though. We are in that typical July lull. Even some big deep tropics years, like 1998 and 1999, did not have any MDR activity before late July.

[weathaguyry]

What scares me is the abnormal placement of the Bermuda High to the NE. If this is a feature that is present during peak season it could lead to some devastating tracks with storms moving due North along the east coast. Think tracks like Irene 11’, Gloria 85’, or Donna 60’, which all raked multiple different areas on the East Coast due to the Bermuda high blocking the storms from moving straight OTS.

[toad strangler]

 http://twitter.com/DrShepherd2013/status/1279144776869306375

[ScottNAtlanta]

Yikes.

https://twitter.com/webberweather/status/1279006634682056704

It's a indicative of the +AMM
Westerly winds in the Tropical Atlantic
Warming of the waters off southern Brazil
Very wet in Africa
Paired with a +AMO has always fostered busy seasons

[TheAustinMan]

Is anyone able to make a similar graph and linear regression for total major hurricanes vs. date of fourth named storm? TheAustinMan, perhaps?

I graphed as follows, keeping the years from 1979-2019 to allow for comparison.

The eye might be drawn to some pattern in the chart, but I think there isn't a whole lot to glean from this particular pairing of variables (in addition, the number of major hurricanes is a rather coarse value, and you don't get the granularity you might get from something like ACE or named storms). If a season is getting its fourth storm well into September, then as one might expect there is a greater "time crunch" to generate major hurricanes, so those years are on the bottom right. Other than that, the timing of the fourth storm doesn't really say a whole lot about how many major hurricanes are going to form. So long as enough of a peak season window remains, major hurricanes may or may not form, depending on the conditions in peak season.

18 KB. Source: Made using Excel.


And since I mentioned it earlier, here's the same comparison with ACE. A little stronger of a correlation, but still not well correlated in general, with the range of possible outcomes being quite wide.

19 KB. Source: Made using Excel.


I think the only confident takeaway from this comparison is that if you have more storms early in the season, that gives the season more time to increase storm counts during the peak period. Doesn't really say a whole lot about how strong those storms will be.

[Shell Mound]

Is anyone able to make a similar graph and linear regression for total major hurricanes vs. date of fourth named storm? TheAustinMan, perhaps?

I graphed as follows, keeping the years from 1979-2019 to allow for comparison.

The eye might be drawn to some pattern in the chart, but I think there isn't a whole lot to glean from this particular pairing of variables (in addition, the number of major hurricanes is a rather coarse value, and you don't get the granularity you might get from something like ACE or named storms). If a season is getting its fourth storm well into September, then as one might expect there is a greater "time crunch" to generate major hurricanes, so those years are on the bottom right. Other than that, the timing of the fourth storm doesn't really say a whole lot about how many major hurricanes are going to form. So long as enough of a peak season window remains, major hurricanes may or may not form, depending on the conditions in peak season.

18 KB. Source: Made using Excel.
https://i.imgur.com/ZDP70DP.png

And since I mentioned it earlier, here's the same comparison with ACE. A little stronger of a correlation, but still not well correlated in general, with the range of possible outcomes being quite wide.

19 KB. Source: Made using Excel.
https://i.imgur.com/VP5aNYT.png

I think the only confident takeaway from this comparison is that if you have more storms early in the season, that gives the season more time to increase storm counts during the peak period. Doesn't really say a whole lot about how strong those storms will be.

Do you have similar charts for date of earliest (S)TS formation in the MDR vs. seasonal ACE and/or total MH?

[TheAustinMan]

Do you have similar charts for date of earliest (S)TS formation in the MDR vs. seasonal ACE and/or total MH?

There's not a whole lot to see there, in my opinion. There's technically a downsloping correlation there, but given the range of outcomes, it appears to be a rather unproductive predictor:

10 KB. Source: Made using Excel


10 KB. Source: Made using Excel

[Shell Mound]

 https://twitter.com/AndyHazelton/status/1279419455429320704



 https://twitter.com/philklotzbach/status/1279426052423446529



 https://twitter.com/philklotzbach/status/1279426717346443265



 https://twitter.com/AndyHazelton/status/1279421766079844353



 https://twitter.com/DrKimWood/status/1279432978620391430

[Shell Mound]

Do you have similar charts for date of earliest (S)TS formation in the MDR vs. seasonal ACE and/or total MH?

There's not a whole lot to see there, in my opinion. There's technically a downsloping correlation there, but given the range of outcomes, it appears to be a rather unproductive predictor:

10 KB. Source: Made using Excel
https://i.imgur.com/fawCgAD.png

10 KB. Source: Made using Excel
https://i.imgur.com/pnmjOpW.png

If we get Edouard and then Fay—if not additional storms—in the subtropics before the end of the month but see nothing in the MDR, will people reconsider the prospects of a hyperactive 2020 Atlantic hurricane season? Based on the data you posted, there does not seem to be much of a correlation between pre-August activity in the MDR and the seasonal ACE (which is heavily weighted toward hurricanes, especially majors) and/or the total number of MH. Nevertheless, the correlation between formation date and ACE seems to be somewhat stronger than that between formation date and MH. Note that there were four seasons since 1979 with ACE ≥ 200: 1995, 2004, 2005, and 2017. Half of those years—1995 and 2004, specifically—did not feature a TS in the MDR before August, yet ended up with ACE essentially on par/comparable with that of 2017, and the sample size is rather limited. (Even if one includes the entire HURDAT2 record back to 1851, just eight seasons mustered seasonal ACE ≥ 200, including 1893, 1926, 1933, and 1950; among the latter four seasons, two did not feature a TS in the MDR before August.)

[toad strangler]

Do you have similar charts for date of earliest (S)TS formation in the MDR vs. seasonal ACE and/or total MH?

There's not a whole lot to see there, in my opinion. There's technically a downsloping correlation there, but given the range of outcomes, it appears to be a rather unproductive predictor:

10 KB. Source: Made using Excel
https://i.imgur.com/fawCgAD.png

10 KB. Source: Made using Excel
https://i.imgur.com/pnmjOpW.png

If we get Edouard and then Fay—if not additional storms—in the subtropics before the end of the month but see nothing in the MDR, will people reconsider the prospects of a hyperactive 2020 Atlantic hurricane season?

No

[AnnularCane]

There's not a whole lot to see there, in my opinion. There's technically a downsloping correlation there, but given the range of outcomes, it appears to be a rather unproductive predictor:

10 KB. Source: Made using Excel
https://i.imgur.com/fawCgAD.png

10 KB. Source: Made using Excel
https://i.imgur.com/pnmjOpW.png

If we get Edouard and then Fay—if not additional storms—in the subtropics before the end of the month but see nothing in the MDR, will people reconsider the prospects of a hyperactive 2020 Atlantic hurricane season?

No

Pretty much my immediate thought too.

[Shell Mound]

If we get Edouard and then Fay—if not additional storms—in the subtropics before the end of the month but see nothing in the MDR, will people reconsider the prospects of a hyperactive 2020 Atlantic hurricane season?

No

Pretty much my immediate thought too.

Personally, I suspect that we’ll rival or match 2005 in terms of overall NS and end up with a seasonal ACE index of at least ~225-230. The MDR will largely wait till August, in line with climatology. ASO will likely be extremely busy in the deep tropics, but we will likely see Edouard and Fay in the subtropics before then. The current pace of activity is solidly ahead of 2005’s and looks to continue over the next few weeks, at least outside the deep tropics. After that, particularly in August, the pace of activity in the MDR/Caribbean will likely accelerate, and without El Niño the prospects of a prolonged season rise, making 2005’s record even more doable. This is going to be a historic season in some fashion.