ATL: HERMINE - Models

[tarheelprogrammer]

One of these two models (GFS and ECMWF) will be dead wrong. If I was a betting man I would throw down money on the ECMWF. Just not a lot of money. What are the upper level conditions like on the ECMWF?

[stormlover2013]

basically same as GFS with GFS showing storm in gulf and EURO just showing the vorticity

[SouthFLTropics]

This reminds me very much of Frances in the early stages. Models originally wanted to turn it out to see only to see them shift west over and over with time. I'd expect maybe one more shift west on the GFS before it starts shifting back to the right again. Then the question will be how much it shifts right before it comes back west again. Somewhere in the middle of those shifts lies the ultimate solution, assuming it even develops. I can't recall a time when the GFS showed such development and the Euro showed nothing. They couldn't be any more different. With that said, the synoptic pattern looks very similar.

SFT

[gatorcane]

Anybody notice the ECMWF has a much stronger Bermuda High and ridge over the SE US than the 00Z? That would make sense, given how strong the Bermuda High has been this summer. Even Fiona, though weak, gets pushed way west this run...

[NDG]

I am starting to lean that 99L will be a Caribbean cruiser, I don't see it going north of the Lesser Antilles. East Coast ridging over all could stay strong.
Here is a good example of how much the ECMWF has being trying to forecast for the east coast ridging pattern to collapse but over all is staying put. So in another words, I don't see the ridging pattern over the east coast going away any time soon.

[p1nheadlarry]

Anybody notice the ECMWF has a much stronger Bermuda High and ridge over the SE US than the 00Z? That would make sense, given how strong the Bermuda High has been this summer. Even Fiona, though weak, gets pushed way west this run...

Very true, other models haven't picked up on that as well, not just with 99L but all year

[gatorcane]

I am starting to lean that 99L will be a Caribbean cruiser, I don't see it going north of the Lesser Antilles. East Coast ridging over all could stay strong.
Here is a good example of how much the ECMWF has being trying to forecast for the east coast ridging pattern to collapse but over all is staying put. So in another words, I don't see the ridging pattern over the east coast going away any time soon.

http://www.tropicaltidbits.com/analysis ... atl_11.png
http://www.tropicaltidbits.com/analysis ... _atl_6.png

Could be a Caribbean cruiser but had the ECMWF developed this like the GFS, it looks to me it would take a similar track as the GFS. Seems both of these models are converging on a similar 500MB pattern in the medium to long-range guidance.

[SFLcane]

 https://twitter.com/adriansweather/status/766716417341288448

[stormlover2013]

yep exactly but its still 250 hours out..

[cycloneye]

 https://twitter.com/TropicalTidbits/status/766626161694744576

[gatorcane]

12Z JMA loop:

[Frank2]

Still, per the current track it's near 10N, and more likely to be in the Caribbean, and with a strong high to the north, would be similar to the trend of zonal systems. It's not surprising that some models are already picking up on this...

[OuterBanker]

12Z JMA loop:

Gator, Interesting JMA. I see Gaston in the islands, but what's that off the NC coast. Is that Fiona after a stall heading west?

[USTropics]

 https://twitter.com/TropicalTidbits/status/766698045136330752

[gatorcane]

One thing is for sure, if the ECMWF gets this correct with no development and the GFS is wrong, that may make some of us question the GFS medium to long-range rest of season although some of us already are from the phantom storms of previous seasons in the medium range.

One comment somebody did make is that the ECMWF does have a tendency sometimes to show something in the long-range only to lose it for a few runs and then have it come back in the medium range. Could this be what is happening here?

[USTropics]

Even within 24 hours, there is a noticeable difference in vorticity strength between the two models:

GFS 12z 24 hours:


ECMWF 12z 24 hours:

[USTropics]

Perhaps the strength of Fiona is causing a slight issue with the ECMWF? It appears to have a stronger Fiona in 24 hours compared to the GFS.

[NDG]

I am starting to lean that 99L will be a Caribbean cruiser, I don't see it going north of the Lesser Antilles. East Coast ridging over all could stay strong.
Here is a good example of how much the ECMWF has being trying to forecast for the east coast ridging pattern to collapse but over all is staying put. So in another words, I don't see the ridging pattern over the east coast going away any time soon.

http://www.tropicaltidbits.com/analysis ... atl_11.png
http://www.tropicaltidbits.com/analysis ... _atl_6.png

Could be a Caribbean cruiser but had the ECMWF developed this like the GFS, it looks to me it would take a similar track as the GFS. Seems both of these models are converging on a similar 500MB pattern in the medium to long-range guidance.

Yeah, through day 5 they are fairly similar but through day 7 the ECMWF, which is usually king at this period, has a stronger ridge to the north of the Greater Antilles.

[LarryWx]

12Z JMA loop:

Gator, Interesting JMA. I see Gaston in the islands, but what's that off the NC coast. Is that Fiona after a stall heading west?

That looks like a different system (mainly upper air??) as Fiona is well NE of Bermuda then moving away.

This run of the 12Z JMA appears to me like it would likely recurve 99L well off of the SE coast but maybe later impacting E NC to the NE US.

[Bocadude85]

Perhaps the strength of Fiona is causing a slight issue with the ECMWF? It appears to have a stronger Fiona in 24 hours compared to the GFS.

Judging by the current presentation of this disturbance on satellite I would think the GFS has a better handle on this, at least in the short term. It seems to me the Euro shears this out after 24 hours.