2017 Global Model Runs Discussion (Out to day 16)

[jason1912]

A bit out in fantasy range but..

When?

Will likely be gone next run but it may signal an active period soon.

[abajan]

A bit out in fantasy range but..
http://i.imgur.com/quJhySx.png

When?

Will likely be gone next run but it may signal an active period soon.

It's still there in the 6Z run, but weaker.

[RL3AO]

While the last Kelvin wave somewhat ignited things (it tried with 99L and maybe helped flare up Franklin - although I suspect it was going to develop anyway), that wave does seem to be amplifying the existing easterly waves over Africa. I'm curious to see if the models start trending towards an MDR storm or two over the next couple weeks.

[StormTracker]

I think the wave behind 99L will probably have a better chance of maturing earlier & faster because of 99L clearing out a lot of SAL.

[Siker]

12z EPS perking up for MDR action from the wave coming off in a week and another in 10 days.

[tarheelprogrammer]

Quick question. Is the CMC out performing the new GFS?

[Hammy]

Quick question. Is the CMC out performing the new GFS?

At this point it really wouldn't surprise me if they were neck and neck with skill level

Evidenced by the latest GFS showing three storms suddenly form at the same time in the EPAC in close proximity, which is quite a bit worse than anything the CMC ever shows in the tropics.

[Kingarabian]

The GFS is not doing anything crazy. Its recent depictions have been observed before.

GFS simply has a very potent CCKW in the EPac thus leading to a very active monsoon trough - similar to what we see in the WPac.

[tolakram]

Quick question. Is the CMC out performing the new GFS?

I deleted a bunch of useless responses to this question. Opinions with the added flavor of GFS sucks need to stop. We have google, we have data, if you're not willing to do the research and don't have a factual answer then don't answer the question.

We want to foster good conversations here and certainly not stifle discussions but a page of 'GFS sucks' just doesn't cut it. Hopefully you all understand.

[tolakram]

Some of the model verification graphs are free, like this one from Weatherbell. Unfortunately this is 500mb skill, not skill at predicting tropical cyclones.

http://models.weatherbell.com/verf/ecmwf_gfs_nh_f120.png

A google search of CMC Model Verification will quickly take you to the Canadian weather site with model verification graphics.

The following graphs, based on the root mean square error (RMSE) of the 500 hPa geopotential height forecasts against the North American radiosonde observation network, give an idea of how well a numerical model forecasts the overall synoptic pattern of the atmosphere over North America.


https://weather.gc.ca/verification/monthly_ts_e.html



Lower numbers are better, so you can see the euro and the UKMET both doing quite well while the GFS and CMC are more tangled but generally the GFS does better. This is 5 day performance which is what is typically scored. Going to the one day performance ...



CMC is doing quite well at 24 hours, tangled in with bot the Euro and UKMET. The GFS not doing quite so well but the range here is quite small.

Another way to look at this is via an error growth chart, which gives a slightly better visual of accuracy, unfortunately the latest month available is June.



The last study I know of comparing models and tropical cyclone prediction performance had the GFS ahead of the Euro due to the fact that the Euro regularly misses tropical cyclogenesis while the GFS tends to produce more false storms. If both models show something then usually it's a clear sign something will develop, unfortunately the Euro has been doing it's fair share of false spinups this year.

[caneman]

Some of the model verification graphs are free, like this one from Weatherbell. Unfortunately this is 500mb skill, not skill at predicting tropical cyclones.

http://models.weatherbell.com/verf/ecmwf_gfs_nh_f120.png

A google search of CMC Model Verification will quickly take you to the Canadian weather site with model verification graphics.

The following graphs, based on the root mean square error (RMSE) of the 500 hPa geopotential height forecasts against the North American radiosonde observation network, give an idea of how well a numerical model forecasts the overall synoptic pattern of the atmosphere over North America.


https://weather.gc.ca/verification/monthly_ts_e.html



Lower numbers are better, so you can see the euro and the UKMET both doing quite well while the GFS and CMC are more tangled but generally the GFS does better. This is 5 day performance which is what is typically scored. Going to the one day performance ...



CMC is doing quite well at 24 hours, tangled in with bot the Euro and UKMET. The GFS not doing quite so well but the range here is quite small.

Another way to look at this is via an error growth chart, which gives a slightly better visual of accuracy, unfortunately the latest month available is June.



The last study I know of comparing models and tropical cyclone prediction performance had the GFS ahead of the Euro due to the fact that the Euro regularly misses tropical cyclogenesis while the GFS tends to produce more false storms. If both models show something then usually it's a clear sign something will develop, unfortunately the Euro has been doing it's fair share of false spinups this year.

Finally, someone has done the research. I wouldnt have known where to look. Thank you. I suspected this to be true as I see hits and misses and flip flops from all models. All models have their strengths and weaknesses. The King Euro crap is tiresome, boorish and flat out childish and in many cases unfounded. It keeps me from visiting here regularly. Maybe a mod can post this as a sticky? That way if someone decided to make statements without fact, they can be deleted and directed to an area for accuracy. Thanks again.

[gatorcane]

Looks like the GFS shows a trough that sits along the Eastern seaboard for the next 10 days at least.

[PTrackerLA]

And a totally dead Atlantic, ensembles show this as well .

[WeatherEmperor]

Looks like the GFS shows a trough that sits along the Eastern seaboard for the next 10 days at least.

[i]

It has been talked about that long periods of an east coast trof are associated with a -NAO. If that is the case it should remain - for nearly 10 days or so. There are hints the NAO will turn + aroung the 19th or 20th so could we see ridging replace the east coast trof at that time? Let's see.


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[Siker]

12z Euro spins up a TD East of the Caribbean at 240 hours. This wave has had some EPS support for the past several days but will not emerge from Africa for at least 6 more days.

[gatorcane]

12z Euro spins up a TD East of the Caribbean at 240 hours. This wave has had some EPS support for the past several days but will not emerge from Africa for at least 6 more days.

Here is the image showing the low east of the Southern Lesser Antilles. Note the huge trough still over the Eastern Seaboard of the US at 240 hours similar to the GFS which has a deep-layer trough around this same time (though not as deep). But that low is far enough south that it could impact the islands. Obviously 10 days out so who knows.

[Siker]

CPC highlights this area:

http://stormboard.proboards.com/attachm ... nload/1155

[Hurricaneman]

CPC highlights this area:

http://stormboard.proboards.com/attachm ... nload/1155

Only members there can see it

[gatorcane]

00Z Euro again has development in the MDR with a TS approaching the Lesser Antilles when the run ends:

[tarheelprogrammer]

ECMWF is hinting at waves starting to role off in a week or so. No development, but these look like they are stronger than recent waves. They are also at a higher latitude.