Tropical Wave in East Atlantic (Is Invest 97L)

[LarryWx]

Why so many pages on a pouch? Is this one more likely to develop than others before it?

It looks like it could be a significant threat to land, and as a potential major hurricane as well. Just like 99L/Hermine's thread.

But it is even more intriguing than Hermine since we have the GFS showing a CAT 5 in the Gulf. Plus overall models are even more bullish than Hermine.

By the way will the normally overbullish HWRF and GFDL show CAT 6s if the GFS is showing a CAT 5?

I was just now looking back at Hermine threads. The GFS high res had Hermine at 904 in one run and another run had it at 907 mb, these in the vicinity of the Bahamas. I'd take these high res GFS cat 5's with a cat 5 sized grain of salt. The high res runs of the GFS & Euro often overdo intensity, especially within the 25-35N area. I don't know why but they keep doing so. I'm not saying they can't on occasion be right but taking the "under" (as in not as strong) in the vast majority of these extreme runs has easily ended up being right.

[Alyono]

EC seems to be trending stronger

[TheAustinMan]

EC seems to be trending stronger

MSLP Anomalies:


500mb (Steering Layer, generally) Anomalies:

[LarryWx]

You have that backwards. Several runs of the GFS had 99L becoming a sub-940MB low near or over the Bahamas well out past day 7, while the Euro showed squadoosh. Eventually they flip-flopped as the tracks shifted south toward and through the Florida straits - the ECM showed a much stronger system in the eastern GOMEX while the GFS trended much weaker.

I was just looking back at the pre-99L pouch thread and the 99L/pre-Hermine model thread. Although the Euro had 2 runs (8/14-15 runs) with a TC in/near the L.A.'s (one a H) even before the GFS had a TC on any run in that area, the Euro then went on to drop TC development for good in that area and didn't develop it at all for a number of days of runs afterward. Otoh, the GFS started developing it near or east of the L.A.'s right after the Euro dropped it though this was only for a couple of runs. Then neither developed it for several days. Then the GFS starting around 8/18 to have a number of runs developing it with several doing so near 50-55W and giving the L.A.'s a TS. Some of these GFS runs at high res had sub 940's off the SE coast per what AJC said with one at 907 and another at 904 while the Euro had nothing! The Euro easily outperformed the GFS overall during these early stages. Also, these GFS runs turned out to be way too east likely due to showing a TC way too early.

Related to this, look at this 8/19 post from Tolakram:

viewtopic.php?p=2520178#p2520178

well that is interesting and thanks for the correction AJC3 and LarryWx. Maybe the GFS CAT 5 model storm is just that - a model storm.

Gator, you're welcome. I made a second post about the 904 and 907 my runs before I saw you posted this reply. Anyway, it isn't easy to remember. So, I had to go back into the threads to remind myself. Even though the Euro did far better overall in the early stages, I was surprised to find that the Euro had two runs with a TC even before the GFS as I stated in the other post! So, technically, the Euro was initially worse.

[LarryWx]

Warning about the 12Z Euro: for the 2nd run in a row, it has a strong upper low in the E US 144 hours whereas the GFS/CMC have no such thing and much higher hts. This could easily be bogus and its downstream effects of what could easily be a phantom upper low could affect the pouch's track quite a bit.

[Alyono]

EC is much stronger this run

[RL3AO]

Warning about the 12Z Euro: for the 2nd run in a row, it has a strong upper low in the E US 144 hours whereas the GFS/CMC have no such thing and much higher hts. This could easily be bogus and its downstream effects of what could easily be a phantom upper low could affect the pouch's track quite a bit.

Yeah. They have some differences starting about day 5 or so with a mid-level trough near the Great Lakes. The GFS (blue circle) is progressive bringing it into the Atlantic while the Euro cuts it off and keeps it in the green box. Will have to watch future runs and see which model gets it right. That's a significant model difference considering it's only a 5 to 7 day forecast.

[Alyono]

and the NAVGEM is hopelessly lost. It is keeping this EAST of the Caribbean

[tolakram]

Euro stronger and a little further north.

[RL3AO]

GFS vs Euro. Huge difference on how to handle the trough digging into Dakotas tonight. Five days out in the mid-latitudes. This is where the Euro does best.

[wxmann_91]

The trof handling should not have too much of an effect on this storm for the next 5-6 days, as the 500mb ridge extends well into the Greater Antilles. How the trof lifts out afterward might have an effect for where this storm goes in the western Caribbean and thereafter, however.

[WeatherEmperor]

GFS vs Euro. Huge difference on how to handle the trough digging into Dakotas tonight. Five days out in the mid-latitudes. This is where the Euro does best.

Which one do u think will be correct on this?


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[fci]

60% in 5 days and not yet tagged as an Invest........That's odd..

[RL3AO]

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Based on skill scores, I'd go with the Euro when they're this far apart after six days. Doesn't seem to be making a huge difference in track in the day 7 to 10 period. The difference may be after than, but the Euro doesn't go that far.

[Alyono]

EC 951mb heading for Cayman at day 10

[RL3AO]

EC 951mb heading for Cayman at day 10

If there was any doubt the Euro wasn't on board, it is gone with this run.

[floridasun78]

60% in 5 days and not yet tagged as an Invest........That's odd..

it look their want make sure their got more models runs show we may get tropical system from this area

[Hurricaneman]

If you go out beyond 10 days it looks like it might go over the skinniest part of Cuba and near key west

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[Siker]

Full res Euro is 938mb @ 240.

[SeGaBob]

Cat 3?