2016 Global Model Runs Discussion (Out to Day 16)

[Siker]

An issue popping up on the GFS is the broad nature of the wave; you can see up to three vorticity maxima as the wave comes off the African coast. Recent runs have the compact southern maximum that was previously being developed getting stretched out and absorbed into the northern maximum, which happens to be carrying a decent amount of SAL with it.

[RL3AO]

What exactly does caving to a model mean? How is it defined? I've seen both global models show a wave with one occasionally getting TC genesis. This whole caving to a model comes across as typical "King Euro" trollishness. Models are tools. They aren't conscious beings. If you only use one global model, you will miss a whole lot about whats happening in the atmosphere.

[tarheelprogrammer]

What exactly does caving to a model mean? How is it defined? I've seen both global models show a wave with one occasionally getting TC genesis. This whole caving to a model comes across as typical "King Euro" trollishness. Models are tools. They aren't conscious beings. If you only use one global model, you will miss a whole lot about whats happening in the atmosphere.

Not trolling just saying the GFS model went toward the ECMWF and CMC. That is obvious when you see the GFS spit out TS/Hurricane for multiple runs in a row only to eventually come around to what the ECMWF/CMC showed from the very beginning. Just an observation and obviously it is never a good idea to follow only one model but it was the only one showing a TC multiple runs in a row. Therefore I only posted about it changing its solution because the others stayed the same.

[JaxGator]

What exactly does caving to a model mean? How is it defined? I've seen both global models show a wave with one occasionally getting TC genesis. This whole caving to a model comes across as typical "King Euro" trollishness. Models are tools. They aren't conscious beings. If you only use one global model, you will miss a whole lot about whats happening in the atmosphere.

Not trolling just saying the GFS model went toward the ECMWF and CMC. That is obvious when you see the GFS spit out TS/Hurricane for multiple runs in a row only to eventually come around to what the ECMWF/CMC showed from the very beginning. Just an observation and obviously it is never a good idea to follow only one model but it was the only one showing a TC multiple runs in a row. Therefore I only posted about it changing its solution because the others stayed the same.

I think the Euro also showed a low on one of its run as well. Yesterday I think.

[Hammy]

What exactly does caving to a model mean? How is it defined? I've seen both global models show a wave with one occasionally getting TC genesis. This whole caving to a model comes across as typical "King Euro" trollishness. Models are tools. They aren't conscious beings. If you only use one global model, you will miss a whole lot about whats happening in the atmosphere.

Not trolling just saying the GFS model went toward the ECMWF and CMC. That is obvious when you see the GFS spit out TS/Hurricane for multiple runs in a row only to eventually come around to what the ECMWF/CMC showed from the very beginning. Just an observation and obviously it is never a good idea to follow only one model but it was the only one showing a TC multiple runs in a row. Therefore I only posted about it changing its solution because the others stayed the same.

I think the Euro also showed a low on one of its run as well. Yesterday I think.

Between the Euro/GFS, one usually "caves" to the other each time a storm/phantom storm is involved. The Euro has a terrible track record of finding storms prior to them developing, while the GFS has an equally bad record of showing storms that don't form. Especially if a wave has not yet emerged, you will rarely find both models showing development, and one of them will obviously be wrong in the end. In this case, unless it turns out to be a convective feedback issue, the Euro turned out correct.

[Ntxw]

Michael Ventrice said it best when looking out more than 5+ days. Where a puff of cloud can be blown up into a sprawling hurricane or remain just a puff of cloud. Which is why incorporating all guidance is best advice when leaning long range.

 https://twitter.com/MJVentrice/status/755822055417847808

[USTropics]

One of the best ways that tropical models were explained to me in my MET class was they're like bingo cards. The more bingo cards you play, the higher chance you have of winning

Forecasters should be able to take the forecasts of several computer models and compare them. Even though these forecasts may not be the same, an experienced meteorologist can blend the predictions of the models (a consensus forecast), with the hopes of improving the forecast.

No model can be 100% accurate. Though technology continues to advance, there is a practical limit to what computers can do, so there will never be a perfect computer forecast (which is saying something when an IBM supercomputer can do 450 billion equations a second).

The models should really be used for identifying consistency and trends (among previous runs of the same model and compared to other model outputs), not what one, singular output is detailing.

[USTropics]

From Jeff Master's Blog post this evening:

As is usually the case when the Eastern Pacific is active, the Atlantic is quiet. This inverse correlation in activity occurs because the conditions over the Eastern Pacific driving this July's bounteous activity--surface low pressure and rising air--creates a compensating area of sinking air over the tropical Atlantic, creating surface high pressure and dry weather--the antithesis of conditions needed for tropical cyclone formation. There are no tropical cyclone threat areas in the Atlantic to discuss today, and none of the reliable models for tropical cyclone formation is predicting development during the coming five days. However, for the first time all month, NHC is not highlighting any new areas for tropical cyclone development in the Eastern Pacific over the next five days, and the GFS model is not predicting anything new will form. That may mean it will be the Atlantic's turn to get active during the last few days of July, and a number of recent runs of the GFS model have been highlighting the possible development late this month of a tropical wave predicted to come off the coast of Africa around July 27. There will be plenty of dry air and dust from the Saharan Air Layer (SAL) around through the end of the month, though, which will likely make it challenging for any tropical waves to develop (check out this animation of the 10-day African dust forecast from NASA.

Animation referenced: http://portal.nccs.nasa.gov/cgi-fp/fp_2 ... 00&&loop=0

[Siker]

Tonight's run has a much better organized storm than the past few as the energy manages to consolidate itself well:

[Hammy]

Tonight's run has a much better organized storm than the past few as the energy manages to consolidate itself well:

Seems to support the possibility that the earlier bad runs (which went from a TS to a gyre in short time) were feedback issues. The GEM/Euro runs will be interesting if they show anything or not, especially the former as it's better at picking up genesis.

[USTropics]

Through 144 hours, the ECMWF at least acknowledges it this run:

[USTropics]

06z GFS mirroring the 00z run. Essentially the same location and pressure at 150 hours:

[cycloneye]

Umm,bad year so far for ECMWF.

 https://twitter.com/EricBlake12/status/756831199700586497

[NDG]

Yeah, definitely the Euro has not done so well on the EPAC, it has at least being too aggressive with storms. IMO.

[JaxGator]

The GFS 12z run still shows Earl and the wave behind it has a low with it too.

[gatorcane]

A little surprised the GFS is back to showing a tropical storm again for the Cape Verde wave while bringing in the timeframe each run and with no other global model showing development. Might it be right?

[JaxGator]

A little surprised the GFS is back to showing a tropical storm again for the Cape Verde wave while bringing in the timeframe each run and with no other global model showing development. Might it be right?

Guess we'll see. I'm not in any model camp but it's interesting of the current model divide.

[TheStormExpert]

Maybe since it's a small compact tropical cyclone that's why the Euro does not show it?

[JaxGator]

Maybe since it's a small compact tropical cyclone that's why the Euro does not show it?

That's possible too.

[Yellow Evan]

Maybe since it's a small compact tropical cyclone that's why the Euro does not show it?

That's possible too.

Given the resolution of the ECMWF compared to the GFS, that's unlikely.