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

[Ntxw]

Great discussion guys on CCKWs, agree with the above! As with anything else it is good, imo, to use it with everything else as another piece of the puzzle rather than as emphasizing it as a sole forecasting tool.

[NDG]

I remember back in 2013 many professionals forecasting the Atlantic to finally get going when the MJO was forecasted to pass through the Atlantic, it was a big bust because it never helped the Atlantic. There are other factors behind the overall picture of what it takes for tropical cyclones to develop. IMO.

Below are 2004 & 2005 MJO phases during July-September period. Back in 2004 the active phase over the western hemisphere during July didn't helped the Atlantic at all.

[CyclonicFury]

Not trying to rag on Mike Ventrice, but I feel he puts too much weight on CCKW signals. It's to the point where he makes it seem as if CCKW phases are the sole indicators/precursors of TC activity which we all know is not true. That's why I felt uneasy when he had a tweet storm that the Atlantic will see a significant TC outbreak simply because a CCKW crossed the Atlantic.

I agree with you. Mr. Ventrice is a very smart guy and his research for CCKWs has been very valuable, but he does seem to put too much stock into CCKW forecasts. He acts like it is impossible for a TC to form without a supportive CCKW. The Atlantic does not simply shut down in late August-early September (unless it is a season like 2013, which is highly unlikely). Last season we had sinking motion for most of the season and still had lots of storms, although most of the storms during September were very weak.

[cycloneye]

 https://twitter.com/MJVentrice/status/894864204133531648




 https://twitter.com/EricBlake12/status/894865630163238912

[SFLcane]

Yea well with all do respect to ventrice i'll believe it when i see it. Not much of anything on the models right now.

[RL3AO]

Yea well with all do respect to ventrice i'll believe it when i see it. Not much of anything on the models right now.

Soon enough the models will show something. Then people can go back to complaining about the models showing something.

[gatorcane]

To reiterate on the upgraded models: genesis may not show up until we are within a week or even less (maybe 3-5 days). Take 99L for example, ECMWF had nothing in the medium-range run after run, then suddenly something shows up. Going into the long-range (as much as we want that clarity) doesn't always tell us much and certainly not a two week GFS run.

[WeatherEmperor]

https://twitter.com/MJVentrice/status/8 ... 4343519233


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[RL3AO]

https://twitter.com/MJVentrice/status/894907744343519233


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I'm guessing the primary impact of the MJO on the EPac and Atlantic is the negative VP anomalies at 200 mb, since the OLR signature of the MJO doesn't make it past the WPac (or CPac during +ENSO years). The RMM diagram is a useful tool, but it doesn't tell the whole story. It's driven by OLR, U200, and U850 anomalies. That's what makes the MJO so complicated. No one can even agree on how to define it.

[tarheelprogrammer]

https://twitter.com/MJVentrice/status/894907744343519233


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What does this show exactly?

[Hurricaneman]

https://twitter.com/MJVentrice/status/894907744343519233


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What does this show exactly?

The models completely were wrong about the MJO and is nowhere near verifying from even their 5 day forecasts

[RL3AO]

https://twitter.com/MJVentrice/status/894907744343519233


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What does this show exactly?

The models completely were wrong about the MJO and is nowhere near verifying from even their 5 day forecasts

Not really. Those are two ways of displaying the MJO. He was only pointing out that the RMM index shouldn't be the only thing you look at as it is showing the MJO as weak although there is a fairly strong mjo signal using filtered velocity potential (which isn't used in the RMM index)

[WeatherEmperor]

https://twitter.com/MJVentrice/status/8 ... 4178383872

A little more explanation on the MJO effect on the Atlantic.


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[Kingarabian]

What does this show exactly?

The models completely were wrong about the MJO and is nowhere near verifying from even their 5 day forecasts

Not really. Those are two ways of displaying the MJO. He was only pointing out that the RMM index shouldn't be the only thing you look at as it is showing the MJO as weak although there is a fairly strong mjo signal using filtered velocity potential (which isn't used in the RMM index)

Well since CCKW are measured through VP 200 anomalies, how do we know we're not mixing up the MJO and a CCKW?

[RL3AO]

The models completely were wrong about the MJO and is nowhere near verifying from even their 5 day forecasts

Not really. Those are two ways of displaying the MJO. He was only pointing out that the RMM index shouldn't be the only thing you look at as it is showing the MJO as weak although there is a fairly strong mjo signal using filtered velocity potential (which isn't used in the RMM index)

Well since CCKW are measured through VP 200 anomalies, how do we know we're not mixing up the MJO and a CCKW?

That's where the filtered part comes in. Each equatorial wave has an approximate propagation speed (frequency) so the data is filtered for each specific wave. Although, once the MJO loses its convection signal, it begins to move faster and approaches the CCKW speed.

[NDG]

Yea well with all do respect to ventrice i'll believe it when i see it. Not much of anything on the models right now.

Emily & Franklin was sort of a surprise to the models, the possible development of 99L north of the Lesser/Greater Antilles is another one. Seems like it has been like that this season so far.
I got to the point to where if development is on their long range I toss it out the window

[SFLcane]

More strong wording from Ventrice... Iam ready to track some long track cv storms

 https://twitter.com/MJVentrice/status/895040941962256386

[Steve]

Yea well with all do respect to ventrice i'll believe it when i see it. Not much of anything on the models right now.

Emily & Franklin was sort of a surprise to the models, the possible development of 99L north of the Lesser/Greater Antilles is another one. Seems like it has been like that this season so far.
I got to the point to where if development is on their long range I toss it out the window

I think both were sort of obvious even if Emily would have remained a frontal low. I'm not as smart as a computer model and I thought the patterns and respective environments were there (different as they were) for both. The Mesoscale models figured out Emily. For us observing, it was more just recognizing what was going on than relying on the global models to show genesis. Same thing with 99L. It's been pretty apparent that areas toward the Bahamas were going to be ripe at times. That's been the case for a while. I think most people would give genesis off the SE Coast (if not closer to the big islands) probably a 60% chance. GFS didn't have it and it's our main national model.

[chaser1]

[/quote]Well since CCKW are measured through VP 200 anomalies, how do we know we're not mixing up the MJO and a CCKW?[/quote]

IDK how might this interact with the added influence of the AMO and POD as a result of a primarily neutral ENSO, on the USA

[Kingarabian]

Pretty strong signal from the global models that the EPac will come alive soon, with hints of another July-esque TC break. Based on the Epac and Atlantic relationship where if one basin is active the other tends to be inactive, aside from potential Gert, I would say Atlantic activity will cease until late August/early September if the EPac outbreak verifies.