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

[Kazmit]

I think that 2013 could be a year to compare to, but it was more of an anomaly, because there were issues with getting out of a spring pattern, which had nothing to do with ENSO or SSTA's. I don't know of anytime other than 2013 and 2005 where there was a huge forecasting failure for the Hurricane Season. By what I'm seeing now, I think that pattern is progressing nicely towards summer, and I don't see anything that would stop the progress. Someone correct me if I am wrong please.

I agree. Although right now I can see the similarities between 2013 and this year, I think that this year seems to be moving out of a spring pattern, at least during the next couple of weeks before the season really gets started.

[Ntxw]

Do any of you guys have the ECMWF sea level pressure forecast maps for 2013? I would like to see if it showed higher pressures for ASO and maybe we just didnt pay attention to it. Is that the case?


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Here is the graphic of May 2013 for ASO.

http://i.imgur.com/95CbR6M.png

So it looks like near normal pressures in the Atlantic below subtropics and above normal pressures in the EPAC, a signal for a big season..yet did not happen.

Of course we're all speculating on a pattern months away which no one can predict.

[TheStormExpert]

 https://twitter.com/michaelrlowry/status/864881218692816896




 https://twitter.com/michaelrlowry/status/864881647417782272

[AutoPenalti]

https://twitter.com/michaelrlowry/status/864881218692816896

https://twitter.com/michaelrlowry/statu ... 7417782272

Can someone give a brief summary about those tweets? They don't load for me on my phone for whatever reason.

[ScottNAtlanta]

My point earlier wasnt about a forecast for 2013, but the conditions that we ended up with. That pressure forecast was issued is Jan 2013, and I think we can agree that pressures ended up being much higher than forecast due to the erosion of the cool anomalies that while present in May were not during the heart of the season. If you look at the video of the recent trend in the Atlantic cool anomalies they have been getting colder and have yet to peak while in 2013 it was the exact opposite. They were trending warmer in the subtropics. All I am trying to convey is that if the current situation maintains itself...lots of forecasts this season are looking very under done to me.

[WeatherEmperor]

My point earlier wasnt about a forecast for 2013, but the conditions that we ended up with. That pressure forecast was issued is Jan 2013, and I think we can agree that pressures ended up being much higher than forecast due to the erosion of the cool anomalies that while present in May were not during the heart of the season. If you look at the video of the recent trend in the Atlantic cool anomalies they have been getting colder and have yet to peak while in 2013 it was the exact opposite. They were trending warmer in the subtropics. All I am trying to convey is that if the current situation maintains itself...lots of forecasts this season are looking very under done to me.

The pressure map was issued May 1, 2013. Europeans notate dates in reverse...1 May, 2013


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[ScottNAtlanta]

ooops...just saw that, However, it was still wrong for the heart of the season

[Ntxw]

Well to be fair we aren't in the heart of the season yet, we have no idea if the conditions will or will not turn out a certain way. No one in 2013 May were able to point out the conditions to come so all we can do is point out a similar date and project

[Hammy]

Well to be fair we aren't in the heart of the season yet, we have no idea if the conditions will or will not turn out a certain way. No one in 2013 May were able to point out the conditions to come so all we can do is point out a similar date and project

There were atmospheric signs that we didn't realize until after the fact, once forecasters figured out why the season was dead. And knowing now what we didn't know in 2013, it's easier to know specifically what signs to look for.

[Ntxw]

Well to be fair we aren't in the heart of the season yet, we have no idea if the conditions will or will not turn out a certain way. No one in 2013 May were able to point out the conditions to come so all we can do is point out a similar date and project

There were atmospheric signs that we didn't realize until after the fact, once forecasters figured out why the season was dead. And knowing now what we didn't know in 2013, it's easier to know specifically what signs to look for.

Well how do we know something else won't be a deterrent? Its always easier after the fact to point at something to comfirm than to predict it. The 500mb pattern this year doesn't resemble 2013 I agree

[USTropics]

2013 was as much an anomaly as 2005 in my opinion, just on the opposite spectrum. The MDR had large areas of sinking air for most of the year, coupled with above average subsidence (SAL and a severe drought in Brazil suppressed convection). A vigorous TUTT also dominated most of the western basin during the peak of the season, contributing to above average shear and increased sinking air. Unfortunately, preseason forecasts can't accurately predict these type of factors.

[Hammy]

Well to be fair we aren't in the heart of the season yet, we have no idea if the conditions will or will not turn out a certain way. No one in 2013 May were able to point out the conditions to come so all we can do is point out a similar date and project

There were atmospheric signs that we didn't realize until after the fact, once forecasters figured out why the season was dead. And knowing now what we didn't know in 2013, it's easier to know specifically what signs to look for.

Well how do we know something else won't be a deterrent? Its always easier after the fact to point at something to comfirm than to predict it. The 500mb pattern this year doesn't resemble 2013 I agree

Not necessarily saying there will or won't be inhibiting factors, but merely that 2013 was not only an anomaly, but the cause was as well--and if a similar thing happens with the ocean circulation, there would be signs that may not have been taken into account last time that likely would this time.

I do think it's possible that the current pattern of off and on cool spells might be an indicator, but it's too early to be sure and there are other things to look at (as I don't know what the full effects of this were, just that the cooler weather was one of them.) If there are issues going on with the ocean circulation, I think we'll have a much clearer idea of what effects we'll see well before mid-August, unlike 2013.

[Ntxw]

Not necessarily saying there will or won't be inhibiting factors, but merely that 2013 was not only an anomaly, but the cause was as well--and if a similar thing happens with the ocean circulation, there would be signs that may not have been taken into account last time that likely would this time.

I do think it's possible that the current pattern of off and on cool spells might be an indicator, but it's too early to be sure and there are other things to look at (as I don't know what the full effects of this were, just that the cooler weather was one of them.) If there are issues going on with the ocean circulation, I think we'll have a much clearer idea of what effects we'll see well before mid-August, unlike 2013.

2013 was an anomaly for sure, so was 2005. Might point was really too much emphasis on SST anomalies and too little on atmospheric conditions for analogs.

[NDG]

Going back to 2013's ECMWF MSLP forecast for ASO period it did a fairly good job on catching on the dry stable conditions starting on its shorter term forecast for that period, starting in its June 1st forecast its trend was for higher pressures & more stable conditions over the Atlantic. Could this year be the opposite of it trending towards lower pressures and more unstable conditions for the Atlantic? We shall see.

[gatorcane]

Mid-level dry air was the killer for the 2013 Atlantic season despite most other indicators including above normal SSTs suggesting an active season. I recall NWS Miami mentioning mid-level dry air suppressing rain chances numerous times in their discussions in the summer of 2013. We will see how much of that is around this season.

[Kazmit]

Mid-level dry air was the killer for the 2013 Atlantic season despite most other indicators including above normal SSTs suggesting an active season. I recall NWS Miami mentioning mid-level dry air suppressing rain chances numerous times in their discussions in the summer of 2013. We will see how much of that is around this season.

If I can recall, dry air was very much of an inhibitor last year, mostly during July as tropical waves from West Africa continually failed to develop. I am wondering how much of an issue SAL will be this season, as it is difficult to predict.

[cycloneye]

Mid-level dry air was the killer for the 2013 Atlantic season despite most other indicators including above normal SSTs suggesting an active season. I recall NWS Miami mentioning mid-level dry air suppressing rain chances numerous times in their discussions in the summer of 2013. We will see how much of that is around this season.

If I can recall, dry air was very much of an inhibitor last year, mostly during July as tropical waves from West Africa continually failed to develop. I am wondering how much of an issue SAL will be this season, as it is difficult to predict.

Plenty of sal out there.

[Hammy]

ITCZ looks fairly moist for this time of year (though at it's typically low latitude.) One thing different from 2013 I'm noticing is the lack of strong waves over Africa for most of the year, whereas already we're seeing visible distinct waves.

[tarheelprogrammer]

Mid-level dry air was the killer for the 2013 Atlantic season despite most other indicators including above normal SSTs suggesting an active season. I recall NWS Miami mentioning mid-level dry air suppressing rain chances numerous times in their discussions in the summer of 2013. We will see how much of that is around this season.

If I can recall, dry air was very much of an inhibitor last year, mostly during July as tropical waves from West Africa continually failed to develop. I am wondering how much of an issue SAL will be this season, as it is difficult to predict.

Plenty of sal out there.

Is that above normal for this time of the year?

[tarheelprogrammer]

A few good articles that explain why 2013 was a failure prediction wise.

http://www.npr.org/2013/11/29/247825778/forecast-bust-why-2013-hurricane-predictions-were-so-wrong

https://www.usatoday.com/story/weather/2013/10/26/quiet-hurricane-season/3187621/

http://www.climatecentral.org/news/what-happened-to-the-2013-atlantic-hurricane-season-16616