2017 Global Model Runs Discussion (Out to day 16)

[gatorcane]

GFS and GEFS backing off any development next 384 hours.

The 850mb vort is there but it looks like it runs into an upper-level low shear zone just east of the Lesser Antilles and so the vort gets sheared out. It's all in the long-range though so we will keep watching:

[gatorcane]

Looks like the GFS may develop this again on this run, much stronger vort on this 12Z in a week's time than the previous run.

[GCANE]

Successive runs of GFS at July 31 is showing the Burmuda High weakening somewhat.
This should reduce the shear created by the pressure gradient of the High with the persistent Lows spinning off Mexico in the EPAC.
More importantly, the UL winds created by the Hadley cell of these two features will be less.
At this time the Burmuda High is funneling mid-layer moisture into part of the MDR in conjunction with a ULL to its east.
Looks like next week, chances should improve for TC development.

[Weather150]

I think the models could get a bit interesting by the time the weekend is here.

[Alyono]

Canadian and UKMET are showing development off of the East Coast

even the GFS has something. May get something off of the East Coast this weekend

[gatorcane]

12Z GFS has a tropical storm heading WNW east of the Lesser Antilles by day 10. That is quite a Bermuda High that model is showing. But there is an upper-level low and strong wind shear ahead on this run:

[AutoPenalti]

12Z GFS has a tropical storm heading WNW east of the Lesser Antilles by day 10. That is quite a Bermuda High that model is showing. But there is an upper-level low and strong wind shear ahead on this run:

That ULL has been semi-permanently in place these past few weeks...

[Alyono]

given the very small size of that storm, it appears to be convective feedback

[TheStormExpert]

given the very small size of that storm, it appears to be convective feedback

How do you know that this is convective feedback?

[tarheelprogrammer]

12Z GFS has a tropical storm heading WNW east of the Lesser Antilles by day 10. That is quite a Bermuda High that model is showing. But there is an upper-level low and strong wind shear ahead on this run:

That ULL has been semi-permanently in place these past few weeks...

How odd is it for a ULL to park it like that for that long.

[tarheelprogrammer]

given the very small size of that storm, it appears to be convective feedback

Agreed.

[Weather150]

12z GFS ensembles showing development again after showing not that much at 06z.

[TheStormExpert]

And just like the 00z run the 12z run of the Euro shows nothing and I would expect it's ensembles to be the same.

[TheStormExpert]

12z GFS ensembles showing development again after showing not that much at 06z.

If I was a betting man I'd bet that the new-GFS happened to pick up some of it's older brothers bad habits.

[boca]

I wonder if the lid will actually come off.

[tarheelprogrammer]

I wonder if the lid will actually come off.

Same here. Looks like EPAC is taking from the Atlantic, and that ULL in the Atlantic seems permanent. Both models, the GFS and ECMWF, seem to be showing higher than normal pressure through their entire run.

[Bocadude85]

I wonder if the lid will actually come off.

Same here. Looks like EPAC is taking from the Atlantic, and that ULL in the Atlantic seems permanent. Both models, the GFS and ECMWF, seem to be showing higher than normal pressure through their entire run.

It's July... not September. You guys have been around these boards long enough to know that you don't typically see much activity in July. A ULL is not a permanent feature, perhaps the Atlantic has seen multiple ULL this year but none of them are permanent features.

[tarheelprogrammer]

I wonder if the lid will actually come off.

Same here. Looks like EPAC is taking from the Atlantic, and that ULL in the Atlantic seems permanent. Both models, the GFS and ECMWF, seem to be showing higher than normal pressure through their entire run.

It's July... not September. You guys have been around these boards long enough to know that you don't typically see much activity in July. A ULL is not a permanent feature, perhaps the Atlantic has seen multiple ULL this year but none of them are permanent features.

True, but models are not budging on showing unfavorable conditions even as we get toward mid-August in the runs. Models are usually wrong in the long range, but every model seems to be showing this. Even 2004, which did not begin until late July had a hurricane by August 3rd. All we have had so far is very weak storms. That ULL or ULLs have been present in the general area of the central Atlantic to Bahamas since late June I believe. Put all this together with the fact that it seems like the East Pacific will not slow down any time soon, and it could have a drastic negative impact on the Atlantic this season. The SST config is great, but that alone is not going to help the Atlantic. I am most likely wrong, but just going by models (short and long range) it seems awfully quiet. Could an active season be in the works, sure it could be. However, it seems the lid is slow to come off on the Atlantic. I am not saying it will not come off, but the later it does come off the less activity we will see overall.


Anyone know any favorable things that scream active season besides the SST config? I am not being a smart butt. I just want to know I have only seen the professionals point this out, but so many negatives besides that. Also, if the mods think this belongs in the Indicators thread please move it.

[wxmann_91]

I wonder if the lid will actually come off.

Same here. Looks like EPAC is taking from the Atlantic, and that ULL in the Atlantic seems permanent. Both models, the GFS and ECMWF, seem to be showing higher than normal pressure through their entire run.

It's more like because the Atlantic is inactive, tropical waves are able to cross Central America and grow in the EPAC (instead of intensifying in the Atlantic and gaining latitude earlier). So if anything it's just the opposite; an active Atlantic "takes away" from the EPAC.

[tarheelprogrammer]

I wonder if the lid will actually come off.

Same here. Looks like EPAC is taking from the Atlantic, and that ULL in the Atlantic seems permanent. Both models, the GFS and ECMWF, seem to be showing higher than normal pressure through their entire run.

It's more like because the Atlantic is inactive, tropical waves are able to cross Central America and grow in the EPAC (instead of intensifying in the Atlantic and gaining latitude earlier). So if anything it's just the opposite; an active Atlantic "takes away" from the EPAC.

True, but rising motion is in that area, and not over the Atlantic correct? When do models move that into the Atlantic?