2017 indicators: SST's / MSLP / SAL / Steering / Instability

[Yellow Evan]

@kingarabian,

I think some are not convinced the oncoming El Nino will affect the heart of the hurricane season and that it wont fully mature until Fall/Winter. In your opinion will the El Nino come during the Summer or later?


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I also think people are overestimating the time it takes for the atmosphere to enter an El Nino base state.

[Hurricaneman]

Y'all are putting too much emphasis on SST. The tropical waters of the Atlantic basin are always warm enough to support major hurricanes in the heart of the season. Dry air and shear are the cane killers. I'm hedging my bets that a weak El Nino develops this season.....MGC

Precisely this. Waters in the Atlantic and the GOM will ALWAYS be favorable for TC development.

As Ntxw has pointed out in the ENSO thread, the background state of the planet is nowhere near Nina (to promote an above average/average hurricane season) and it's still in a Nino state. A warm PDO, plenty of warm waters in the Pacific, a tanking SOI, and now successive WWB's ... unless these change it'll be hard in my opinion to forecast an above average season in the Atlantic. But we know numbers don't matter for the Atlantic. A disturbance in the right area at the right time can be devastating and can generate a lot of ACE.

Joaquin in 2015 was a great example of this and so was Andrew in 1992 and Betsy in 1965

[TheStormExpert]

As Ntxw has pointed out in the ENSO thread, the background state of the planet is nowhere near Nina (to promote an above average/average hurricane season) and it's still in a Nino state. A warm PDO, plenty of warm waters in the Pacific, a tanking SOI, and now successive WWB's ... unless these change it'll be hard in my opinion to forecast an above average season in the Atlantic. But we know numbers don't matter for the Atlantic. A disturbance in the right area at the right time can be devastating and can generate a lot of ACE.

So you're saying just because we're nowhere near an La Niña we cannot have just an average season?

Even during the Super El Niño of 2015 conditions were favorable enough to allow only an a somewhat below average season which produced two majors including a near Cat.5 in October.

Overall I'd say 2015 over-performed somewhat meaning that this season could do just the same. Obviously there are still some hints that the Atlantic MAY still be in it's active era.

It's also funny how just several months ago those who are screaming El Niño now were saying this season could be just as active or slightly more active than last season. Just goes to show how quickly things can change and that nothing is set in stone.

[Alyono]

As Ntxw has pointed out in the ENSO thread, the background state of the planet is nowhere near Nina (to promote an above average/average hurricane season) and it's still in a Nino state. A warm PDO, plenty of warm waters in the Pacific, a tanking SOI, and now successive WWB's ... unless these change it'll be hard in my opinion to forecast an above average season in the Atlantic. But we know numbers don't matter for the Atlantic. A disturbance in the right area at the right time can be devastating and can generate a lot of ACE.

So you're saying just because we're nowhere near an La Niña we cannot have just an average season?

Even during the Super El Niño of 2015 conditions were favorable enough to allow only an a somewhat below average season which produced two majors including a near Cat.5 in October.

Overall I'd say 2015 over-performed somewhat meaning that this season could do just the same. Obviously there are still some hints that the Atlantic MAY still be in it's active era.

It's also funny how just several months ago those who are screaming El Niño now were saying this season could be just as active or slightly more active than last season. Just goes to show how quickly things can change and that nothing is set in stone.

That was due to the niño being west based. The shear only extended to about 60W except when Danny formed. Thankfully, it extended to 55W then or else the islands would have had a cat 4

Had that niño not been as strong as it was, 2015 would have been a 1979-like season

If we get a niño this year, I expect it to be centered even farther west than 2015s, basically centered south of HI. May not do much for the Atlantic, while creating conditions beyond favorable for cat 3+ hurricanes to strike HI

[TheStormExpert]

As Ntxw has pointed out in the ENSO thread, the background state of the planet is nowhere near Nina (to promote an above average/average hurricane season) and it's still in a Nino state. A warm PDO, plenty of warm waters in the Pacific, a tanking SOI, and now successive WWB's ... unless these change it'll be hard in my opinion to forecast an above average season in the Atlantic. But we know numbers don't matter for the Atlantic. A disturbance in the right area at the right time can be devastating and can generate a lot of ACE.

So you're saying just because we're nowhere near an La Niña we cannot have just an average season?

Even during the Super El Niño of 2015 conditions were favorable enough to allow only an a somewhat below average season which produced two majors including a near Cat.5 in October.

Overall I'd say 2015 over-performed somewhat meaning that this season could do just the same. Obviously there are still some hints that the Atlantic MAY still be in it's active era.

It's also funny how just several months ago those who are screaming El Niño now were saying this season could be just as active or slightly more active than last season. Just goes to show how quickly things can change and that nothing is set in stone.

That was due to the niño being west based. The shear only extended to about 60W except when Danny formed. Thankfully, it extended to 55W then or else the islands would have had a cat 4

Had that niño not been as strong as it was, 2015 would have been a 1979-like season

If we get a niño this year, I expect it to be centered even farther west than 2015s, basically centered south of HI. May not do much for the Atlantic, while creating conditions beyond favorable for cat 3+ hurricanes to strike HI

So you expect a Modoki El Niño? Also, what are you thoughts and opinions on how this season might turnout?

[Alyono]

not sure how this may affect things, but I was reading twitter today and seeing some rumblings of an ATLANTIC niño

[TheStormExpert]

not sure how this may affect things, but I was reading twitter today and seeing some rumblings of an ATLANTIC niño

Yeah still not sure what an "Atlantic Niño" means.

 https://twitter.com/MJVentrice/status/859724055531986944




 https://twitter.com/MJVentrice/status/859725084247949312




 https://twitter.com/EricBlake12/status/859733976465932288

[tarheelprogrammer]

not sure how this may affect things, but I was reading twitter today and seeing some rumblings of an ATLANTIC niño

A few sources:

http://www.jamstec.go.jp/aplinfo/climate/?p=628

http://www.aoml.noaa.gov/general/enso_faq/

[tolakram]

It's may so perhaps time to start watching some of the graphs.

Tropical Atlantic

Instability a lot higher than previous years, but still mostly below average.


Shear running near or a little above average, hard to see any real trend here so far.



Caribbean

Instability near to above normal.


Shear seems to be above normal.


Unfortunately the archives have not been updated for years so I can't find charts from last year for comparison.

source: http://www.ssd.noaa.gov/PS/TROP/TCFP/atlantic.html

[weathaguyry]

The sub-tropics don't look as good as prior years, possibly signaling more activity towards the tropics and less "slop storms" in the sub-tropics

[tarheelprogrammer]

When do tropical waves start coming off the coast of Africa, and head toward the Caribbean?

[Kazmit]

When do tropical waves start coming off the coast of Africa, and head toward the Caribbean?

Anytime from now really, however tropical waves off of Africa really start ramping up in June, and July is the peak. Here's a useful source: http://severe.worldweather.wmo.int/TCFW/RAIV_Workshop2016/04_TropicalWaves_JohnCangialosi.pdf

[Hammy]

Not that I'm expecting 2013 repeat suddenly, but the pattern seems to have been fairly consistent since February, with strong cold outbreaks still coming down with the weather systems tracking farther south. I know 2013 was a result of the thermohaline circulation weakening, and causing the spring pattern to continue the rest of the year--is there some way to check the circulation and salinity compared to normal, or is that not usually known in real time?

[weathaguyry]

Not that I'm expecting 2013 repeat suddenly, but the pattern seems to have been fairly consistent since February, with strong cold outbreaks still coming down with the weather systems tracking farther south. I know 2013 was a result of the thermohaline circulation weakening, and causing the spring pattern to continue the rest of the year--is there some way to check the circulation and salinity compared to normal, or is that not usually known in real time?

As of now, the reason the cold outbreaks are coming down is because of a big ridge over Norhern Canada that may stay for a while, the GFS shows some hints of the ridge weakening and shifting east towards the middle of the month, allowing more warmer air to flood the atmosphere, but we shall see

[TheStormExpert]

Not that I'm expecting 2013 repeat suddenly, but the pattern seems to have been fairly consistent since February, with strong cold outbreaks still coming down with the weather systems tracking farther south. I know 2013 was a result of the thermohaline circulation weakening, and causing the spring pattern to continue the rest of the year--is there some way to check the circulation and salinity compared to normal, or is that not usually known in real time?

As of now, the reason the cold outbreaks are coming down is because of a big ridge over Norhern Canada that may stay for a while, the GFS shows some hints of the ridge weakening and shifting east towards the middle of the month, allowing more warmer air to flood the atmosphere, but we shall see

There's also this, something we haven't seen in quite awhile.

[WeatherEmperor]

If the NAO has been mostly positive this winter/spring how come the east coast trough has been so strong? This contrasts to last year which had stronger ridging by the east coast


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[TheStormExpert]

If the NAO has been mostly positive this winter/spring how come the east coast trough has been so strong? This contrasts to last year which had stronger ridging by the east coast


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The East Coast trough hasn't been that strong up till the past week or so. Only the Northeast U.S. experienced a colder than normal winter.

[tarheelprogrammer]

When do tropical waves start coming off the coast of Africa, and head toward the Caribbean?

Anytime from now really, however tropical waves off of Africa really start ramping up in June, and July is the peak. Here's a useful source: http://severe.worldweather.wmo.int/TCFW/RAIV_Workshop2016/04_TropicalWaves_JohnCangialosi.pdf

Thank you for the information. Have a great day

[weathaguyry]

If the NAO has been mostly positive this winter/spring how come the east coast trough has been so strong? This contrasts to last year which had stronger ridging by the east coast


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The East Coast trough hasn't been that strong up till the past week or so. Only the Northeast U.S. experienced a colder than normal winter.

It was much more evident especially in March, when everyone else was basking in early spring warmth, and I was shivering in 16 degree nighttime lows on Long Island.

[NDG]

If the NAO has been mostly positive this winter/spring how come the east coast trough has been so strong? This contrasts to last year which had stronger ridging by the east coast


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Mostly positive PNA during the past 8 weeks will cause deep troughs across the NE US from time to time.

Edit: To many's surpre, the overall pattern since the start of Spring is of higher heights across the NE US.