2019 Indicators: SST'S / Sal / MSLP / Steering / Shear / Instability (See updated graphics at first post)

[DioBrando]

So a few weak model runs and the season cancellers come back?

I know that! That's why I'm ignoring any season cancel posts.
A few weak model runs, a sprinkle of dry air and a wisp of wind shear doesn't mean it's gonna stay that way!
In fact they're gonna peter out once the suppressive phase moves out in early September

[DioBrando]

CFS does not appear to have any larger systems or major hurricanes in seven of the last ten runs, and the most recent two look very dead through most of the season, with maybe 5-6 weaker systems. It's looking fairly likely that whatever happens with TD5 and 98L, whether they manage to strengthen or (in TD5's case) find more favorable conditions down the road, or if they simply don't organize much more beyond where they are, is going to preview how the rest of the season's going to go, because it appears the current conditions are going to last the remainder of the season, as we're approaching the time of the year where the real meat is thrown at us.

This happened last year until Florence decided to show up.
Also look at Matty and Nicky.

[Hammy]

CFS does not appear to have any larger systems or major hurricanes in seven of the last ten runs, and the most recent two look very dead through most of the season, with maybe 5-6 weaker systems. It's looking fairly likely that whatever happens with TD5 and 98L, whether they manage to strengthen or (in TD5's case) find more favorable conditions down the road, or if they simply don't organize much more beyond where they are, is going to preview how the rest of the season's going to go, because it appears the current conditions are going to last the remainder of the season, as we're approaching the time of the year where the real meat is thrown at us.

I wouldn't put a lot of trust into the CFS - wasn't it consistently showing an absolutely dead August? Long-range models have been pretty bad this season.

Most of August was dead and so far south of 35N (north of which is hard to tell if tropical or not, so I only focus on south of there) we've still only had a depression that will probably only strengthen to a moderate tropical storm (something weak did show up in that area off and on but I wrote it off assuming 96L situation) and a potentially non-developing invest off Florida. It's also showing very little over the next two weeks (a few small systems in the MDR, could be weak storms or could be minimal hurricanes) but the long trackers it was showing for September have been gone from the majority of the most recent runs.

Whether this means the season is trending quieter, or that the CFS just tends to to better at it's relative medium range (it was showing an active September 15-October 20 a few weeks back) is yet to be seen but my confidence is not high in this season (either in an active one, or a quiet one) regardless.

[DioBrando]

CFS does not appear to have any larger systems or major hurricanes in seven of the last ten runs, and the most recent two look very dead through most of the season, with maybe 5-6 weaker systems. It's looking fairly likely that whatever happens with TD5 and 98L, whether they manage to strengthen or (in TD5's case) find more favorable conditions down the road, or if they simply don't organize much more beyond where they are, is going to preview how the rest of the season's going to go, because it appears the current conditions are going to last the remainder of the season, as we're approaching the time of the year where the real meat is thrown at us.

I wouldn't put a lot of trust into the CFS - wasn't it consistently showing an absolutely dead August? Long-range models have been pretty bad this season.

Most of August was dead and so far south of 35N (north of which is hard to tell if tropical or not, so I only focus on south of there) we've still only had a depression that will probably only strengthen to a moderate tropical storm (which the CFS did off and on hint at, but I assumed it would be another 96L situation) and a potentially non-developing invest off Florida. It's also showing very little over the next two weeks (a few small systems in the MDR, could be weak storms or could be minimal hurricanes) but the long trackers it was showing for September have been gone from the majority of the most recent runs.

Whether this means the season is trending quieter, or that the CFS just tends to to better at it's relative medium range (it was showing an active September 15-October 20 a few weeks back) is yet to be seen but my confidence is not high in this season (either in an active one, or a quiet one) regardless.

All because of a (very quick) suppressive KW coming into the Atlantic very shortly. Obviously the models will respond to short-term blips like these.
Who knew we were getting Chantal?

At the moment, I'm putting my money on the first major hurricane either being the G or the H named storm. Banking more on H at this point.

Conditions are at the moment, getting SLIGHTLY more unfavorable in the short term given:
1) Suppressive CCKW phase (which will BE GONE by mid-September)
2) Dried up waves thanks to SAL promoted by sinking motion
3) A pocket of high shear in the Caribbean

...all three of these factors will be GONE by the middle of September thanks to models (which I can't be bothered to put here)...

...CFS consistently showing low shear and warm temps...

...Convective motion coming back into the Atlantic....

Yes, the first major probably might be here by the middle of September. I'm guessing out-to-sea though.

[Hammy]

All because of a (very quick) suppressive KW coming into the Atlantic very shortly. Obviously the models will respond to short-term blips like these.
Who knew we were getting Chantal?

At the moment, I'm putting my money on the first major hurricane either being the G or the H named storm. Banking more on H at this point.

Conditions are at the moment, getting SLIGHTLY more unfavorable in the short term given:
1) Suppressive CCKW phase (which will BE GONE by mid-September)
2) Dried up waves thanks to SAL promoted by sinking motion
3) A pocket of high shear in the Caribbean

...all three of these factors will be GONE by the middle of September thanks to models (which I can't be bothered to put here)...

...CFS consistently showing low shear and warm temps...

...Convective motion coming back into the Atlantic....

Yes, the first major probably might be here by the middle of September. I'm guessing out-to-sea though.

Shear is above normal through the first two weeks of September across most of the tropical Atlantic.




GFS similarly shows a parade of upper lows moving west through the Bahamas and Gulf over the next two weeks.

[DioBrando]

All because of a (very quick) suppressive KW coming into the Atlantic very shortly. Obviously the models will respond to short-term blips like these.
Who knew we were getting Chantal?

At the moment, I'm putting my money on the first major hurricane either being the G or the H named storm. Banking more on H at this point.

Conditions are at the moment, getting SLIGHTLY more unfavorable in the short term given:
1) Suppressive CCKW phase (which will BE GONE by mid-September)
2) Dried up waves thanks to SAL promoted by sinking motion
3) A pocket of high shear in the Caribbean

...all three of these factors will be GONE by the middle of September thanks to models (which I can't be bothered to put here)...

...CFS consistently showing low shear and warm temps...

...Convective motion coming back into the Atlantic....

Yes, the first major probably might be here by the middle of September. I'm guessing out-to-sea though.

Shear is above normal through the first two weeks of September across most of the tropical Atlantic.

https://i.imgur.com/dayK3yB.png
https://i.imgur.com/PMm1S7q.png

GFS similarly shows a parade of upper lows moving west through the Bahamas and Gulf over the next two weeks.

at least the map isn't colored red unlike 2 weeks ago which clearly shows signs of improvement.

This run wasn't cherry picked from the models either. after this date, the reds are diminishing.

[captainbarbossa19]

After years of watching S2K forums throughout the season, I think that many on this board go through a sequence of changing opinions. While this is not true every season, many seasons often follow this timeline.

1. June 1st: Everyone is excited about the upcoming season. Many are anticipating upcoming action later in the month, but most know that the real action will most likely start in August.
2. July 1st: One or two TCs manage to form in June. Many complain about how weak and disorganized the cyclones are.
3. July 15th: Lots of SAL is present in the Atlantic basin. However, most people are not surprised by this, as they were expecting it.
4. August 1st: Atlantic is still slow. Dry, stable air is present in the tropics. However, models are beginning to suggest things will be changing within a few weeks.
5. August 15th: Models show nothing in the near-future. Many are becoming skeptical about the season amounting to anything significant.
6. August 23rd: There are multiple invests in the Atlantic and conditions are rapidly beginning to change. The models begin to show cyclogenesis. Many quickly change their minds about a quieter season.
7. August 31st: There is now at least one active TC. There is a potential that at least one TC could become a hurricane. Many people appear shocked by the increased activity.
8. September 30th: Several TCs have already formed and dissipated. A few who suggested that the season would be quiet now state that they always knew the Atlantic would spring to life.
9. November 30th: The last storm probably has dissipated by this point. Many look back at the season and state that they are surprised with the outcome.

https://media.giphy.com/media/3orieRw298XmtPdcf6/giphy.gif
Not again!

I believe I should add in my list a tenth point, "August 24th: Some experts continue to doubt signs of the Atlantic awakening. These experts issue outlooks that support original ideas of a quieter season."

[Hammy]

As I reference it frequently I did want to post a few notes on the CFS: It's not entirely out of the question that I'm under-estimating the intensity of the systems as the resolution on the site I use is very low for all models but it's the only one I can find the 12H plots for to get a general picture of what it's forecasting for the season.


Something like this from Aug 18 run is pretty clearly a major hurricane--the site doesn't ever put the isobars too close together so after a certain point there just aren't anymore below that.


The two MDR-forming systems from the latest run, both are small so I don't venture to assume either are majors, but given the duration it can be assumed the one in the center is a hurricane, while the one at bottom doesn't last too long so probably is a storm.


Caribbean zoom--another example system that can safely be assumed to be a sub-major hurricane.


Probable major that's been showing up intermittently near the end of several runs.

https://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=noat&MODELL=cfs&MODELLTYP=1&BASE=-&VAR=pslv&HH=12&ZOOM=0&WMO=&ARCHIV=0&LOOP=1&RES=0 The run itself, usually starts updating around 430am eastern time, it's usually finished by noon the next day. Clicking North America gets you the Gulf and East Coast subregions, and Caribbean is under Central America, for anyone else who wants to check.

[DioBrando]

As I reference it frequently I did want to post a few notes on the CFS: It's not entirely out of the question that I'm under-estimating the intensity of the systems as the resolution on the site I use is very low for all models but it's the only one I can find the 12H plots for to get a general picture of what it's forecasting for the season.

https://i.imgur.com/Tm6k4Io.png
Something like this from Aug 18 run is pretty clearly a major hurricane--the site doesn't ever put the isobars too close together so after a certain point there just aren't anymore below that.

https://i.imgur.com/PM1JZ42.png
The two MDR-forming systems from the latest run, both are small so I don't venture to assume either are majors, but given the duration it can be assumed the one in the center is a hurricane, while the one at bottom doesn't last too long so probably is a storm.

https://i.imgur.com/J8rXlmG.png
Caribbean zoom--another example system that can safely be assumed to be a sub-major hurricane.

https://i.imgur.com/4C0OeQT.png
Probable major that's been showing up intermittently near the end of several runs.

https://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=noat&MODELL=cfs&MODELLTYP=1&BASE=-&VAR=pslv&HH=12&ZOOM=0&WMO=&ARCHIV=0&LOOP=1&RES=0 The run itself, usually starts updating around 430am eastern time, it's usually finished by noon the next day. Clicking North America gets you the Gulf and East Coast subregions, and Caribbean is under Central America, for anyone else who wants to check.

What is the name of that major according to the suggestions in the model? To get an idea of how much we'll end at?

[Hammy]

As I reference it frequently I did want to post a few notes on the CFS: It's not entirely out of the question that I'm under-estimating the intensity of the systems as the resolution on the site I use is very low for all models but it's the only one I can find the 12H plots for to get a general picture of what it's forecasting for the season.

https://i.imgur.com/Tm6k4Io.png
Something like this from Aug 18 run is pretty clearly a major hurricane--the site doesn't ever put the isobars too close together so after a certain point there just aren't anymore below that.

https://i.imgur.com/PM1JZ42.png
The two MDR-forming systems from the latest run, both are small so I don't venture to assume either are majors, but given the duration it can be assumed the one in the center is a hurricane, while the one at bottom doesn't last too long so probably is a storm.

https://i.imgur.com/J8rXlmG.png
Caribbean zoom--another example system that can safely be assumed to be a sub-major hurricane.

https://i.imgur.com/4C0OeQT.png
Probable major that's been showing up intermittently near the end of several runs.

https://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=noat&MODELL=cfs&MODELLTYP=1&BASE=-&VAR=pslv&HH=12&ZOOM=0&WMO=&ARCHIV=0&LOOP=1&RES=0 The run itself, usually starts updating around 430am eastern time, it's usually finished by noon the next day. Clicking North America gets you the Gulf and East Coast subregions, and Caribbean is under Central America, for anyone else who wants to check.

What is the name of that major according to the suggestions in the model? To get an idea of how much we'll end at?

Supposing both 98L and TD5 get named, and that systems I'm assuming to be non-developing waves on the run aren't, that would likely be Nestor. Though the mid-latitudes are probably busier than I'm extrapolating, as the model resolution makes it near impossible to tell whether systems north of 30-35 or so are tropical.

[DioBrando]

As I reference it frequently I did want to post a few notes on the CFS: It's not entirely out of the question that I'm under-estimating the intensity of the systems as the resolution on the site I use is very low for all models but it's the only one I can find the 12H plots for to get a general picture of what it's forecasting for the season.

https://i.imgur.com/Tm6k4Io.png
Something like this from Aug 18 run is pretty clearly a major hurricane--the site doesn't ever put the isobars too close together so after a certain point there just aren't anymore below that.

https://i.imgur.com/PM1JZ42.png
The two MDR-forming systems from the latest run, both are small so I don't venture to assume either are majors, but given the duration it can be assumed the one in the center is a hurricane, while the one at bottom doesn't last too long so probably is a storm.

https://i.imgur.com/J8rXlmG.png
Caribbean zoom--another example system that can safely be assumed to be a sub-major hurricane.

https://i.imgur.com/4C0OeQT.png
Probable major that's been showing up intermittently near the end of several runs.

https://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=noat&MODELL=cfs&MODELLTYP=1&BASE=-&VAR=pslv&HH=12&ZOOM=0&WMO=&ARCHIV=0&LOOP=1&RES=0 The run itself, usually starts updating around 430am eastern time, it's usually finished by noon the next day. Clicking North America gets you the Gulf and East Coast subregions, and Caribbean is under Central America, for anyone else who wants to check.

What is the name of that major according to the suggestions in the model? To get an idea of how much we'll end at?

Supposing both 98L and TD5 get named, and that systems I'm assuming to be non-developing waves on the run aren't, that would likely be Nestor. Though the mid-latitudes are probably busier than I'm extrapolating, as the model resolution makes it near impossible to tell whether systems north of 30-35 or so are tropical.

How is (assuming) Lorenzo looking like on the model? I'd like to see what I'd be like.

[NotSparta]

All because of a (very quick) suppressive KW coming into the Atlantic very shortly. Obviously the models will respond to short-term blips like these.
Who knew we were getting Chantal?

At the moment, I'm putting my money on the first major hurricane either being the G or the H named storm. Banking more on H at this point.

Conditions are at the moment, getting SLIGHTLY more unfavorable in the short term given:
1) Suppressive CCKW phase (which will BE GONE by mid-September)
2) Dried up waves thanks to SAL promoted by sinking motion
3) A pocket of high shear in the Caribbean

...all three of these factors will be GONE by the middle of September thanks to models (which I can't be bothered to put here)...

...CFS consistently showing low shear and warm temps...

...Convective motion coming back into the Atlantic....

Yes, the first major probably might be here by the middle of September. I'm guessing out-to-sea though.

Shear is above normal through the first two weeks of September across most of the tropical Atlantic.

https://i.imgur.com/dayK3yB.png
https://i.imgur.com/PMm1S7q.png

GFS similarly shows a parade of upper lows moving west through the Bahamas and Gulf over the next two weeks.

That's not really an unfavorable look, a lot of it is easterly shear anomalies, and where it's more NW, is a region where easterly shear rules anyway

[Hammy]

What is the name of that major according to the suggestions in the model? To get an idea of how much we'll end at?

Supposing both 98L and TD5 get named, and that systems I'm assuming to be non-developing waves on the run aren't, that would likely be Nestor. Though the mid-latitudes are probably busier than I'm extrapolating, as the model resolution makes it near impossible to tell whether systems north of 30-35 or so are tropical.

How is (assuming) Lorenzo looking like on the model? I'd like to see what I'd be like.

Fish hurricane, starting around 1032H on that run (Oct 6).

[tarheelprogrammer]

So a few weak model runs and the season cancellers come back?

It is almost September and conditions are struggling to improve. Most systems are underperforming. It is getting to a point where it is time to admit that a below average season is a strong possibility. Am I completely ruling out the possibility of an uptick in activity? No, but this is a place to talk about current and future conditions. Currently, the Atlantic is struggling and so are all the other basins. It happens. 2013 has shown us it is possible.

[zhukm29]

So a few weak model runs and the season cancellers come back?

It is almost September and conditions are struggling to improve. Most systems are underperforming. It is getting to a point where it is time to admit that a below average season is a strong possibility. Am I completely ruling out the possibility of an uptick in activity? No, but this is a place to talk about current and future conditions. Currently, the Atlantic is struggling and so are all the other basins. It happens. 2013 has shown us it is possible.

Can we stop bringing up the 2013 comparisons everytime we get a lull in activity? 2013, like 2005, is a very rare event, and the conditions that made 2013 happen are not the conditions we have now. Yes, we can have a below average season, but there are several seasons that started off slow and ramped up quickly in September and October. 2001 is a very good example of a season like this, and conditions are more similar to 2001 than they are to 2013 - because 2001 is a "normal" season while 2013 is an extreme anomaly. Even in 2016, the season started off very weak but ended with a bang in October. There are way more years where conditions caused a season to be backloaded than years where an unexpected weakening of the thermohaline circulation cause major atmospheric disruptions and a suppression of cyclogenesis (aka 2013, the season that every season is compared to).

Comparing every single season to 2013 whenever there is a weak model run is like comparing the season to 2005 whenever there is an uptick in activity. But every single year since 2013 (including 2017, which is on a level with 2005) has been compared to 2013 in some form during the season. If there is evidence that suggests that the Atlantic will remain dead in September, it would be greatly appreciated. But simply using a few model runs to claim that the Atlantic will stay dead in September is not helpful (it certainly didn't help in August).

[DioBrando]

Supposing both 98L and TD5 get named, and that systems I'm assuming to be non-developing waves on the run aren't, that would likely be Nestor. Though the mid-latitudes are probably busier than I'm extrapolating, as the model resolution makes it near impossible to tell whether systems north of 30-35 or so are tropical.

How is (assuming) Lorenzo looking like on the model? I'd like to see what I'd be like.

Fish hurricane, starting around 1032H on that run (Oct 6).

Humberto? Karen?

(It'll be awesome if the fellow Italian was also a harmless fish hurricane.)

[DioBrando]

So a few weak model runs and the season cancellers come back?

It is almost September and conditions are struggling to improve. Most systems are underperforming. It is getting to a point where it is time to admit that a below average season is a strong possibility. Am I completely ruling out the possibility of an uptick in activity? No, but this is a place to talk about current and future conditions. Currently, the Atlantic is struggling and so are all the other basins. It happens. 2013 has shown us it is possible.

Can we stop bringing up the 2013 comparisons everytime we get a lull in activity? 2013, like 2005, is a very rare event, and the conditions that made 2013 happen are not the conditions we have now. Yes, we can have a below average season, but there are several seasons that started off slow and ramped up quickly in September and October. 2001 is a very good example of a season like this, and conditions are more similar to 2001 than they are to 2013 - because 2001 is a "normal" season while 2013 is an extreme anomaly. Even in 2016, the season started off very weak but ended with a bang in October. There are way more years where conditions caused a season to be backloaded than years where the weakening of the thermohaline circulation cause major atmospheric disruptions and a suppression of cyclogenesis (aka 2013, the season that every season is compared to).

Comparing every single season to 2013 whenever there is a weak model run is like comparing the season to 2005 whenever there is an uptick in activity. But every single year since 2013 (including 2017, which is on a level with 2005) has been compared to 2013 in some form during the season. If there is evidence that suggests that the Atlantic will remain dead in September, it would be greatly appreciated. But simply using a few model runs to claim that the Atlantic will stay dead in September is not helpful (it certainly didn't help in August).

ABSOLUTELY. I MUST AGREE WITH YOU. Hit the nail on the head.

Anyway, long-range is mostly inaccurate imo so I usually take them with a grain of salt. like the long range cfs last year, in late july in the epac where conditions were hostile, didn't see hector or lane coming.

[Hammy]

I'll add to the 2013-talk being iffy--all you have to do is look at the 500MB charts to see this year is completely different. That year remained in a springtime pattern and we were getting winter-like 500MB lows forming very close to the MDR with routine frequency. One of which literally caused the season to have no major hurricanes as Humberto would've likely become one had one of these lows not steered it straight north into cold water. The WAM was also largely nonexistent that year, and there were tropical waves stalling and dissipating without even making it over open waters (because of this same 500MB anomaly leading to almost no steering currents at times), something I've literally never seen before or since in my more than quarter century of hurricane tracking.

[1900hurricane]

Honestly, things to me look pretty average overall. +VPA is beginning to move away from Africa, so I might expect slightly below average activity over the next week or so, but that still leaves most of September. After that, guidance differs on what to do with the +VPA, with some camping it out near the IDL while others have dual maxes over the CPac and IO. The second would be a more favorable look for the NAtl, but it's worth noting that the +PDO may favor the CPac location. +VPA might not be make or break in September anyway, and other signals don't appear particularly strong to me either way. 1970-2018 average September ACE is about 48 for the NAtl by the way, which is about half the season's ACE on average. Currently, I'm thinking we might see a 40-50 ACE September, which is near to slightly below the mean, but also right near the median.

[Ntxw]

Honestly, things to me look pretty average overall. +VPA is beginning to move away from Africa, so I might expect slightly below average activity over the next week or so, but that still leaves most of September. After that, guidance differs on what to do with the +VPA, with some camping it out near the IDL while others have dual maxes over the CPac and IO. The second would be a more favorable look for the NAtl, but it's worth noting that the +PDO may favor the CPac location. +VPA might not be make or break in September anyway, and other signals don't appear particularly strong to me either way. 1970-2018 average September ACE is about 48 for the NAtl by the way, which is about half the season's ACE on average. Currently, I'm thinking we might see a 40-50 ACE September, which is near to slightly below the mean, but also right near the median.

https://i.imgur.com/9oXxN3y.gif

https://i.imgur.com/GfZA307.png

The key (in my opinion) for a big deep tropics "lid come off" type event is for the convection over the Maritime Continent to really start firing off. That's more indicative of Nina like forcing (2016 and 2017) that went bonkers in September and beyond. The biggest factor against such an ordeal of convection over Indonesia at the moment is the anomalous cold waters there. There is a fairly robust relationship between Atlantic MDR activity to Africa->MC phases in September.

I think something like 2004 is more likely (but not as extreme ACE) where vigorous waves will come off Africa and will search for better conditions north of 20N to the west. So conditions are getting better, waves are decent and matter if/when they find better conditions in the sweet spots.