2022 Indicators (SSTs/SAL/MSLP/Shear/Steering/Instability) and >Day 16 Models

[skyline385]

If this is the case why couldn't any of the hurricane forecasters see this? Why didn't any of them react to it?

Webb mentioned a few weeks ago that instability is not a factor in seasonal forecasts and this season serves as a lesson to why it should be.

Seems like a pretty big statement to make about ALL hurricane forecasts. Was he talking hurricane forecasts or model predictions? I never consider what a model says to be a forecast, forecasters make forecasts, models are tools used in forecasting. CSU uses hindcasting, so they would not use a model prediction.

He was talking about seasonal forecasters not model forecasts. Check out the August CSU forecast, the word “instability” appears only once in the entire 43 page forecast and that is when Phil talks about how sub topic SSTs can potentially affect instability in the MDR. There is no analysis of current instability in the Atlantic in the forecast.


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[tolakram]

Webb mentioned a few weeks ago that instability is not a factor in seasonal forecasts and this season serves as a lesson to why it should be.

Seems like a pretty big statement to make about ALL hurricane forecasts. Was he talking hurricane forecasts or model predictions? I never consider what a model says to be a forecast, forecasters make forecasts, models are tools used in forecasting. CSU uses hindcasting, so they would not use a model prediction.

He was talking about seasonal forecasters not model forecasts. Check out the August CSU forecast, the word “instability” appears only once in the entire 43 page forecast and that is when Phil talks about how sub topic SSTs can potentially affect instability in the MDR. There is no analysis of current instability in the Atlantic in the forecast.


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My assumption would be quite different, but I would ask CSU rather than assuming. Since CSU hindcasts I would have expected them to run their hindcasts using all kinds of parameters and dropping the ones that don't change the hindcast outcome. I would doubt a group with as much experience as CSU would leave it out by accident. It could be lack of reliable data for the reason it's left out, I don't think we know without Phil directly addressing it.

[skyline385]

Seems like a pretty big statement to make about ALL hurricane forecasts. Was he talking hurricane forecasts or model predictions? I never consider what a model says to be a forecast, forecasters make forecasts, models are tools used in forecasting. CSU uses hindcasting, so they would not use a model prediction.

He was talking about seasonal forecasters not model forecasts. Check out the August CSU forecast, the word “instability” appears only once in the entire 43 page forecast and that is when Phil talks about how sub topic SSTs can potentially affect instability in the MDR. There is no analysis of current instability in the Atlantic in the forecast.


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My assumption would be quite different, but I would ask CSU rather than assuming. Since CSU hindcasts I would have expected them to run their hindcasts using all kinds of parameters and dropping the ones that don't change the hindcast outcome. I would doubt a group with as much experience as CSU would leave it out by accident. It could be lack of reliable data for the reason it's left out, I don't think we know without Phil directly addressing it.

I am not questioning Phil’s forecasts and i don’t think even Webb was. Phil is one of the top experts in this field and is far more knowledgeable on the subject than any of us here. But according to Webb (for whatever reason, be it lack of data or lack of research on it), instability analysis is not included in seasonal forecasting which partially answers your initial question as to why forecasters did not see this.


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[Deshaunrob17]

When Euro and Icon strikes again!!!! Probably still has time for things to change , but this 96l is looking like another underachiever in the Deep Tropics

I’ve said this 2 weeks ago and it I’ll say it again, Nothing seems to be materializing with the Deep Tropics this year … However, we still have 2 weeks of September and October is known for Caribbean and Gulf activity. Let’s continue to watch and see!!

Both Euro and Icon models have been too bullish with MDR systems this year!!! Ask me why ? I don’t know!!!

[Kingarabian]

This is sometimes forgotten but on average the Atlantic won't be active (ACE+NS) if the EPAC is active. One basin usually sets up sinking motion over the other.

[aspen]

This is sometimes forgotten but on average the Atlantic won't be active (ACE+NS) if the EPAC is active. One basin usually sets up sinking motion over the other.

It’s unusual this year, though, because even though the EPac is more active than it should be with such a strong -ENSO, it’s only around average. 2018 was far more active and didn’t totally shut off the Atlantic. Maybe a combination of the -ENSO shifting activity east and the warmer spots in the PDO/PMM regions are to blame? I have a feeling SSTAs in the EPac may need to be factored in more in future seasonal forecasts, if the not-actually-cool PDO/PMM are at least part of the reason why this season busted so badly; I’m leaning more towards the volcano theories.

[Kingarabian]

This is sometimes forgotten but on average the Atlantic won't be active (ACE+NS) if the EPAC is active. One basin usually sets up sinking motion over the other.

It’s unusual this year, though, because even though the EPac is more active than it should be with such a strong -ENSO, it’s only around average. 2018 was far more active and didn’t totally shut off the Atlantic. Maybe a combination of the -ENSO shifting activity east and the warmer spots in the PDO/PMM regions are to blame? I have a feeling SSTAs in the EPac may need to be factored in more in future seasonal forecasts, if the not-actually-cool PDO/PMM are at least part of the reason why this season busted so badly; I’m leaning more towards the volcano theories.

2018 was near average NS. There's some exceptions as theres nothing concrete in weather, but it's usually only one of the basins dominating.

[skyline385]

 https://twitter.com/webberweather/status/1570042125877907456

[tolakram]

https://twitter.com/webberweather/status/1570042125877907456?s=46&t=Zy3cyByvhnFgHIYZgrOVMg

I was going to say that seems like a better indicator than stability, which can very greatly month to month, but it looks just a bit lower than last year.

Copying the images

[Teban54]

https://twitter.com/webberweather/status/1570042125877907456?s=46&t=Zy3cyByvhnFgHIYZgrOVMg

Sounds like a good explanation until you realize 2018 also had a weak gradient, and global activity went haywire that year.

[WiscoWx02]

https://twitter.com/webberweather/status/1570042125877907456?s=46&t=Zy3cyByvhnFgHIYZgrOVMg

Sounds like a good explanation until you realize 2018 also had a weak gradient, and global activity went haywire that year.

This makes perfect sense to me. Third year La Nina's tend to harm more than help tropical activity....now we know why. Seems like El Nino is what we need to hard reset things after all. The warmer than normal subtropics also plays a part in it I'm sure, also important to note that in 2018 the subtropics weren't roaring hot compared to normal like they have been this year. Yes they were above average but not to this extent. Also we were going into an El Nino so the heat budget was in the process of being restored to the tropics so there are differences. Of course, with the subtropics cooling thanks to cooler mid latitude temps as fall steps in, this will likely sharpen the gradient and we will need to watch the tropics more actively, I think 96L may be the start of things getting going due to the falling sea surface temps in the subtropical Atlantic thanks in part to Earl.

[FireRat]

https://twitter.com/webberweather/status/1570042125877907456?s=46&t=Zy3cyByvhnFgHIYZgrOVMg

Sounds like a good explanation until you realize 2018 also had a weak gradient, and global activity went haywire that year.

This makes perfect sense to me. Third year La Nina's tend to harm more than help tropical activity....now we know why. Seems like El Nino is what we need to hard reset things after all. The warmer than normal subtropics also plays a part in it I'm sure, also important to note that in 2018 the subtropics weren't roaring hot compared to normal like they have been this year. Yes they were above average but not to this extent. Also we were going into an El Nino so the heat budget was in the process of being restored to the tropics so there are differences. Of course, with the subtropics cooling thanks to cooler mid latitude temps as fall steps in, this will likely sharpen the gradient and we will need to watch the tropics more actively, I think 96L may be the start of things getting going due to the falling sea surface temps in the subtropical Atlantic thanks in part to Earl.

This may be what happened in other seasons like 2001 for example, which was at its most active during FALL

[Hammy]

Sounds like a good explanation until you realize 2018 also had a weak gradient, and global activity went haywire that year.

This makes perfect sense to me. Third year La Nina's tend to harm more than help tropical activity....now we know why. Seems like El Nino is what we need to hard reset things after all. The warmer than normal subtropics also plays a part in it I'm sure, also important to note that in 2018 the subtropics weren't roaring hot compared to normal like they have been this year. Yes they were above average but not to this extent. Also we were going into an El Nino so the heat budget was in the process of being restored to the tropics so there are differences. Of course, with the subtropics cooling thanks to cooler mid latitude temps as fall steps in, this will likely sharpen the gradient and we will need to watch the tropics more actively, I think 96L may be the start of things getting going due to the falling sea surface temps in the subtropical Atlantic thanks in part to Earl.

This may be what happened in other seasons like 2001 for example, which was at its most active during FALL

Also worth noting the CFS, since July, has been showing a very backloaded season. Aug 25-Sep 5 is where it showed the end of the quiet period, and mid to late September is when it showed the peak of the season.

[Ntxw]

Fiona has produced 2.4 units of ACE. The current forecast out to 120H could net another ~6. Beyond that the ET transition will quick with fast movement. 12-14 units might be the final range. ACE should be in the mid 40s after this system for the season.

[KWT]

Fiona has produced 2.4 units of ACE. The current forecast out to 120H could net another ~6. Beyond that the ET transition will quick with fast movement. 12-14 units might be the final range. ACE should be in the mid 40s after this system for the season.

The only thing I would say is the NHC forecast is very conservative for Fiona, plenty of models are much stronger throughout next week than the NHC. It will be very much a wait and see job, because obviously a 80-100mph cane is going to be giving out much less ACE than a 120-140mph type hurricane.

Regardless Fiona isn't getting the type of numbers to even get close to average on its own, its probably going to require at least a major in October to get towards those sorts of numbers, even if Fiona does indeed come in stronger than currently expected.

[Ntxw]

Fiona has produced 2.4 units of ACE. The current forecast out to 120H could net another ~6. Beyond that the ET transition will quick with fast movement. 12-14 units might be the final range. ACE should be in the mid 40s after this system for the season.

The only thing I would say is the NHC forecast is very conservative for Fiona, plenty of models are much stronger throughout next week than the NHC. It will be very much a wait and see job, because obviously a 80-100mph cane is going to be giving out much less ACE than a 120-140mph type hurricane.

Regardless Fiona isn't getting the type of numbers to even get close to average on its own, its probably going to require at least a major in October to get towards those sorts of numbers, even if Fiona does indeed come in stronger than currently expected.

It has until next Saturday per the models before ET or Land in Canada. Duration determines too the ACE. A major+ could yield 16-18 units and if it were to sustain cat 4 the ~20 units is possible, using the ACE equation and current forecast.

[KWT]

Fiona has produced 2.4 units of ACE. The current forecast out to 120H could net another ~6. Beyond that the ET transition will quick with fast movement. 12-14 units might be the final range. ACE should be in the mid 40s after this system for the season.

The only thing I would say is the NHC forecast is very conservative for Fiona, plenty of models are much stronger throughout next week than the NHC. It will be very much a wait and see job, because obviously a 80-100mph cane is going to be giving out much less ACE than a 120-140mph type hurricane.

Regardless Fiona isn't getting the type of numbers to even get close to average on its own, its probably going to require at least a major in October to get towards those sorts of numbers, even if Fiona does indeed come in stronger than currently expected.

It has until next Saturday per the models before ET or Land in Canada. Duration determines too the ACE. A major+ could yield 16-18 units and if it were to sustain cat 4 the ~20 units is possible, using the ACE equation and current forecast.

Indeed, it probably has something between 20-24 advisories worth to accumulate ACE.

At 3.8 ACE at the moment, even if it simply held 65kts from now on we are going to end within your initial range, and unless something really unexpected happens further north it does seem to suggest the NHC was indeed being conservative. I suspect it will produce enough ACE to get the season as a whole beyond 50. Still low though and a long way short of even a bang average season.

[Category5Kaiju]

[MarioProtVI]

Seeing the models rn with Fiona and the future Caribbean system is making me believe more and more that Hammy was right when the CFS was showing a delayed peak. Late season will be interesting given models do show shear decreasing in the Caribbean for at least the first half of October.

[AxaltaRacing24]

Seeing the models rn with Fiona and the future Caribbean system is making me believe more and more that Hammy was right when the CFS was showing a delayed peak. Late season will be interesting given models do show shear decreasing in the Caribbean for at least the first half of October.

Yeah this season is in full swing now.