Seasonal Indicators (Beyond Day 16): Instability / SST's / MSLP / Steering / Sal

[Hammy]

Hammy,
You might have missed the post right above yours that shows that phase 6, where the MJO is projected to stay in/near for the rest of August per the Euro ensemble and some other models, has actually been one of the most active since 1995 for Atlantic genesis rates in August.

I did indeed see the post, and we may very well have 3-5 storms form before then. But with a few exceptions the storms listed in that post struggled and more than likely the storms this year that form during that phase will as well, as Fiona is currently doing.

Note that 5 of those 7 years that I listed (excluding 2016 since it isn't finished) with formations during August in phase 6 had at least one H come out of those.

Two of those were long-lived and may not have become hurricanes during that phase, the other two were essentially home-grown systems that formed in the western Atlantic. Leaving 2004 as the exception, which was absurdly active to begin with. I think we "missed our chance" so to speak to have another hurricane before then after the Gulf system failed to make it over water--unless we have another similar situation occur (which models don't indicate) I find it highly likely that we'll get several weaker storms but no hurricanes for the next 2-3 weeks as the MJO phase in this case doesn't seem to be in any hurry to move.

[NDG]

I did indeed see the post, and we may very well have 3-5 storms form before then. But with a few exceptions the storms listed in that post struggled and more than likely the storms this year that form during that phase will as well, as Fiona is currently doing.

Note that 5 of those 7 years that I listed (excluding 2016 since it isn't finished) with formations during August in phase 6 had at least one H come out of those.

Two of those were long-lived and may not have become hurricanes during that phase, the other two were essentially home-grown systems that formed in the western Atlantic. Leaving 2004 as the exception, which was absurdly active to begin with. I think we "missed our chance" so to speak to have another hurricane before then after the Gulf system failed to make it over water--unless we have another similar situation occur (which models don't indicate) I find it highly likely that we'll get several weaker storms but no hurricanes for the next 2-3 weeks as the MJO phase in this case doesn't seem to be in any hurry to move.

Chances of a hurricane forming during Phase 6 might be low over the Atlantic but is sure not 0%

[beoumont]

Tropical full moon genesis parameter in full effect tonight. Moon also approaching perigee - in three days.

[Kazmit]

We could definitely see Gaston and Hermine before August is over.

[tolakram]

 https://twitter.com/philklotzbach/status/766385841174409216

[gatorcane]

Just a week ago, looked like August might be pretty quiet. Now not so much. Things change quickly in the Tropics

[NDG]

I need to search the internet to find out what is really the hurricane count in the Atlantic when the MJO is on Phase 6 during late August early September time frime, I bet is much higher than when compared to June-July or late Oct-Nov time frame because I bet Dr Phil's research is taking the whole hurricane season into the equation.

[LarryWx]

I need to search the internet to find out what is really the hurricane count in the Atlantic when the MJO is on Phase 6 during late August early September time frime, I bet is much higher than when compared to June-July or late Oct-Nov time frame because I bet Dr Phil's research is taking the whole hurricane season into the equation.

I just analyzed some stats. For August through the period 1975-2015 excluding 1978, 71 H's existed. Only 4 of these 71 (6%) existed at least partially during phase 6: Belle of 1976; Alex, Charley, and Danielle of 2004. When keeping in mind that 96 of the 1,240 August days (8%) for those 40 years were during phase 6. I'd call the 6% of H's existing during phase 6 rather light and give Hammy and you credit. There are so many ways to look at these kinds of things. What I had looked at, frequency of genesis of TS's 1995-2015, does make phase 6 look active. But this way (which included more years, too) makes phase 6 look a bit quiet. Then again, as you said, the chance of a H during phase 6 isn't near 0 either.

[NDG]

Thanks.

BTW, here's is their research, definitely no where close to 0% so perhaps it should be worded that Phase 1 & 2 enhances hurricane formation over the Atlantic lol.

Also, can you break them down by El Nino years, La Nina years & Neutral ENSO years? I am sure it also makes a huge difference.

[centuryv58]

Not to dwell on the point, but has anyone (everyone) noticed the MDR is active this season. Just want to have this in the comment stream for later reference, as necessary.

[LarryWx]

:uarrow: Thanks.

BTW, here's is their research, definitely no where close to 0% so perhaps it should be worded that Phase 1 & 2 enhances hurricane formation over the Atlantic lol.

Also, can you break them down by El Nino years, La Nina years & Neutral ENSO years? I am sure it also makes a huge difference.

Thanks for posting that. I don't like to break down things into too many categories due to possibly getting too small samples. But I can tell you off of the bat that those 4 H's that existed in August during phase 6 were all during oncoming weak El Nino's (1976 and 2004). Does that mean that the chances for a H during phase 6 in August is near 0? I still say no.

[tolakram]

 https://twitter.com/philklotzbach/status/766766872255565824




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[Hammy]

 https://twitter.com/philklotzbach/status/766766872255565824




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This basically supports the Euro being correct with 99L not developing.

[tolakram]

Unless the GFS is correct about the MJO.

[Bocadude85]

 https://twitter.com/philklotzbach/status/766766872255565824




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This basically supports the Euro being correct with 99L not developing.

The mjo does not need to be in a favorable phase for us to see development in the Atlantic as we just saw with Fiona.

[Ntxw]

The mjo does not need to be in a favorable phase for us to see development in the Atlantic as we just saw with Fiona.

With the MJO though she might have become a pretty decent hurricane. The MJO is not the be all end all, however having it on your side can be a big help.

Overall though the season is showing to be active, with possibilities. These next couple of weeks will be crucial because this is the meat of the season and where ACE climatologically is expanding rapidly.

[CYCLONE MIKE]

 https://twitter.com/philklotzbach/status/766766872255565824




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This basically supports the Euro being correct with 99L not developing.

The mjo does not need to be in a favorable phase for us to see development in the Atlantic as we just saw with Fiona.

Development like a short term minimal tropical storm that will spend most of its life as a depression and remnant low

[Bocadude85]

This basically supports the Euro being correct with 99L not developing.

The mjo does not need to be in a favorable phase for us to see development in the Atlantic as we just saw with Fiona.

Development like a short term minimal tropical storm that will spend most of its life as a depression and remnant low

Thanks to SAL and shear.

[LarryWx]

Unless the GFS is correct about the MJO.

Good point. However, I almost never bet on the GFS over the Euro (especially EPS) because the EPS usually has done better with the MJO. Let's see what happens.

[LarryWx]

The mjo does not need to be in a favorable phase for us to see development in the Atlantic as we just saw with Fiona.

With the MJO though she might have become a pretty decent hurricane. The MJO is not the be all end all, however having it on your side can be a big help.

Overall though the season is showing to be active, with possibilities. These next couple of weeks will be crucial because this is the meat of the season and where ACE climatologically is expanding rapidly.

That's quite possible. I now agree that hurricanes, themselves, have been a bit underdone on average since 1975 during phase 6 in August vs the average for all August days. However, even with that, there were 2 storms that became not only H's but also major H's during phase 6 in August out of 28 overall Aug MH since 1975: Belle of 1976 and Charley of 2004. So, you never know.