2020 Global Model Runs Discussion (Out thru day 16)

[Steve]

Here is one more chart you can use to "verify" MJO model vs. actual weather. This chart is described as:

Approximate locations of the MJO centre of convection RMM Index phases 1-8. Phase1 includes signals both from the initiation of an MJO event in the western Indian Ocean basin and the breakdown of MJO events in the mid- Pacific Ocean. During phases 2 through 8 the MJO travels east at 4-10 days/phase.

So you would look to those areas of the Pacific and Indian Oceans to see where the convection is firing off and locate "about the center" of it. Lots of refiring from Indonesia and a bit east toward New Guinea (Phases 4/5 which we have been and are in)



Satellite of the area
https://www.accuweather.com/en/id/jakar ... ite/208971

[Hurricaneman]

The GFS is probably showing it’s mjo bias and I’m thinking it circles around to phase 2 like the CFS and that would move the activity to the Atlantic, and that would be around the 20th so that’s when I believe the Atlantic will start to come to life but 1 or 2 weaker systems between now and then could be possible

[Steve]

The GFS is probably showing it’s mjo bias and I’m thinking it circles around to phase 2 like the CFS and that would move the activity to the Atlantic, and that would be around the 20th so that’s when I believe the Atlantic will start to come to life but 1 or 2 weaker systems between now and then could be possible

You're probably right about the bias. I'm curious if it's still going to be leaning that heavily on Phase 1 by the end of the week. It wants to move the enhanced areas toward the EPAC and keep them there though it clearly shows a more favorable Atlantic than what it is now.

https://www.cpc.ncep.noaa.gov/products/ ... hi/gfs.gif

[CrazyC83]

Something tells me the lack of aviation flights is absolutely killing us with tropical forecasting this season. The global models have bombed just about every storm this year, while the HMON and HWRF have generally done the best. With 95L, no model even tries to develop it even though conditions look fairly decent.

[Chris90]

In regards to the MJO and Kelvin Waves, I also like to view it at Tropical Tidbits using the GFS model. If you select the GFS, then select regions, scroll down to the bottom, select world, then select “upper dynamics” then select 200mb CHI anomaly from there. It gives you the world view of favorable VP anomalies and suppressive anomalies. Favorable anomalies are green, there’s 10 shades to show just how amplified they are, and suppressive anomalies are orange/red, with 10 shades also to show level of amplification. I don’t put a whole lot of stock into future forecasts from it, but I like to check the analysis at initialization point usually daily. It’s a good graphic to watch and see what the trends are.

Also, Mark Sudduth has those episodes of “Hurricane U” which are really good, and I think it was the episode from April 8th, but he had Ben Noll on as a guest, and Ben said something like 85% of ATL storms that form during phases 1 or 2 of the MJO become hurricanes. That’s not an exact quote, and the details might be a little off because I’m going from memory, but it was in that ballpark. I can’t remember if that applied to all storms or just the MDR, but it’s something to keep in mind while watching the MJO.

[gatorcane]

Something tells me the lack of aviation flights is absolutely killing us with tropical forecasting this season. The global models have bombed just about every storm this year, while the HMON and HWRF have generally done the best. With 95L, no model even tries to develop it even though conditions look fairly decent.

Aren’t these these same models used in how we come up with seasonal forecast numbers and long-range predictions on how active a season will be months in advance?

[NDG]

Something tells me the lack of aviation flights is absolutely killing us with tropical forecasting this season. The global models have bombed just about every storm this year, while the HMON and HWRF have generally done the best. With 95L, no model even tries to develop it even though conditions look fairly decent.

The HWRF didn't do very well with Gonzalo, it erroneously forecasted it to become a MH on many runs as it was to track across the Windward Islands, while the Euro was correct in it falling apart.
But Global models indeed have a hard time with AEWs in a low latitude with development.

[NDG]

Something tells me the lack of aviation flights is absolutely killing us with tropical forecasting this season. The global models have bombed just about every storm this year, while the HMON and HWRF have generally done the best. With 95L, no model even tries to develop it even though conditions look fairly decent.

Aren’t these these same models used in how we come up with seasonal forecast numbers and long-range predictions on how active a season will be months in advance?

As the season goes by I don't think the CSU team looks at the long range models too much, they put more stock at current conditions across the Atlantic Basin & ENSO then compare it to active seasons that have had the same conditions.

[NDG]

August 10, 2017

Euro went back to showing absolutely nothing for the full run.

Might be on to something. I think it looks like August will be well below normal.

Development is currently favored in the EPac by the models. So I would assume that will intermittently cease Atlantic activity until favorable conditions shift back towards the Atlantic.

viewtopic.php?f=31&t=118543&start=1160

[toad strangler]

August 10, 2017

Euro went back to showing absolutely nothing for the full run.

Might be on to something. I think it looks like August will be well below normal.

Development is currently favored in the EPac by the models. So I would assume that will intermittently cease Atlantic activity until favorable conditions shift back towards the Atlantic.

viewtopic.php?f=31&t=118543&start=1160

LOL, Wash, Rinse, Repeat

[TheStormExpert]

August 10, 2017

Euro went back to showing absolutely nothing for the full run.

Might be on to something. I think it looks like August will be well below normal.

Development is currently favored in the EPac by the models. So I would assume that will intermittently cease Atlantic activity until favorable conditions shift back towards the Atlantic.

viewtopic.php?f=31&t=118543&start=1160

Sounds like the same thing is happening this year!

Of course that was pre-Harvey most folks were talking about, correct? Not saying 95L will be a Harvey repeat but never put an invest to rest too soon!

[BYG Jacob]

August 10, 2017

Might be on to something. I think it looks like August will be well below normal.

Development is currently favored in the EPac by the models. So I would assume that will intermittently cease Atlantic activity until favorable conditions shift back towards the Atlantic.

viewtopic.php?f=31&t=118543&start=1160

LOL, Wash, Rinse, Repeat

Just put your little hand in mine

[EquusStorm]

In other news, the global model that has consistently blown up every dog fart and faltering tropical depression into a major hurricane in the East Pacific while completely ignoring Atlantic systems until they're already strong tropical storms continues to suggest major hurricanes in the East Pacific and nothing in the Atlantic. Big shocker.

Probably going to be at least a little closer to that than it was in July this time though (it's supported by virtually all the globals now) but still. Keep forecasting the exact same thing for long enough and it's bound to coincidentally happen at least once

[Steve]

It shows no signs of backing down yet even though none of the other models are that close to it. Here's today's MJO updates:

GFS


CFS


ECMWF


CMC

[TheStormExpert]

In other news, the global model that has consistently blown up every dog fart and faltering tropical depression into a major hurricane in the East Pacific while completely ignoring Atlantic systems until they're already strong tropical storms continues to suggest major hurricanes in the East Pacific and nothing in the Atlantic. Big shocker.

Probably going to be at least a little closer to that than it was in July this time though (it's supported by virtually all the globals now) but still. Keep forecasting the exact same thing for long enough and it's bound to coincidentally happen at least once

Which model are we talking about here?

[EquusStorm]

In other news, the global model that has consistently blown up every dog fart and faltering tropical depression into a major hurricane in the East Pacific while completely ignoring Atlantic systems until they're already strong tropical storms continues to suggest major hurricanes in the East Pacific and nothing in the Atlantic. Big shocker.

Probably going to be at least a little closer to that than it was in July this time though (it's supported by virtually all the globals now) but still. Keep forecasting the exact same thing for long enough and it's bound to coincidentally happen at least once

Which model are we talking about here?

I'll give the GFS the benefit of the doubt since at least some increase in EPac and a relative minimum in ATL is supported by many other globals right now but its track record in the tropics got a lotta catching up to do so I'm not taking it at face value

[TheStormExpert]

In other news, the global model that has consistently blown up every dog fart and faltering tropical depression into a major hurricane in the East Pacific while completely ignoring Atlantic systems until they're already strong tropical storms continues to suggest major hurricanes in the East Pacific and nothing in the Atlantic. Big shocker.

Probably going to be at least a little closer to that than it was in July this time though (it's supported by virtually all the globals now) but still. Keep forecasting the exact same thing for long enough and it's bound to coincidentally happen at least once

Which model are we talking about here?

I'll give the GFS the benefit of the doubt since at least some increase in EPac and a relative minimum in ATL is supported by many other globals right now but its track record in the tropics got a lotta catching up to do so I'm not taking it at face value

I’ll just go ahead and not point any fingers and say that all the global models have done poorly so far this year! Not even the Canadian which used to blowup every thunderstorm in the Atlantic his gun-ho-crazy about anything.

[gatorcane]

The GFS continues to show hostile conditions across the Atlantic over the full 384 hours (Aug 26th), a lot of dry air and shear. Meanwhile over in the EPAC it shows 4 named storms and 1 major hurricane.

[tarheelprogrammer]

The GFS continues to show hostile conditions across the Atlantic over the full 384 hours (Aug 26th), a lot of dry air and shear. Meanwhile over in the EPAC it shows 4 named storms and 1 major hurricane.

If by the end of the week there is nothing being shown on the models, it may be time to start questioning hyper activity in the Atlantic.

[Ivanhater]

The GFS continues to show hostile conditions across the Atlantic over the full 384 hours (Aug 26th), a lot of dry air and shear. Meanwhile over in the EPAC it shows 4 named storms and 1 major hurricane.

Eh, I'm seeing signs of the waves slowing down in the western Caribbean and a CAG like setup near the end. That is where I'd be looking in future runs