2020 Global Model Runs Discussion (Out thru day 16)

[cycloneye]

Finnally, GFS has something developing on MDR after the 20th.

https://i.imgur.com/Hp3hnSO.gif

Hi Luis, It's too far out to trust but that would be around the time you might expect to see the flip switch.

That is why I enfatized on the 20th.

[cycloneye]

 https://twitter.com/MJVentrice/status/1292079143459446790

[AnnularCane]

I wonder why he only takes the active period to 9/18.

[TheStormExpert]

Well this is a start!

[toad strangler]

:uarrow: I wonder why he only takes the active period to 9/18.

October will be favorable as well. I'm assuming he's talking about a single long duration outbreak there. Probably a good break afterwards but by all means DO NOT count October out this year above all given indicators.

[DorkyMcDorkface]

The two waves that showed up towards the end of the 12z Euro run from yesterday were there again at 00z. The one in the CATL looks better defined, too. Once again this is roughly the time frame in which things will start to ignite once again so definitely continue to watch closely for model trends.

[gatorcane]

The GFS is showing an abundance of shear across the Western Caribbean and extending eastward in the MDR due to EPAC activity. You can see the 991MB storm in the EPAC which later goes on to becoming potentially a major hurricane.

[SFLcane]

The GFS is showing an abundance of shear across the Western Caribbean and extending eastward in the MDR due to EPAC activity. You can see the 991MB storm in the EPAC which later goes on to becoming potentially a major hurricane.

https://i.postimg.cc/sgvfm4PK/gfs-shear-atl-33.png

The Atlantic will not take off as long as the EPAC is going strong thats pretty much guaranteed. Honestly could be almost the end of August before we're totally favorable.

[Hammy]

:uarrow: I wonder why he only takes the active period to 9/18.

A lot of seasons that have active Septembers have a lull, or at least a slowing down, somewhere near the end of the month, more than likely resulting from Kelvin waves and MJO cycle.

[toad strangler]

The GFS is showing an abundance of shear across the Western Caribbean and extending eastward in the MDR due to EPAC activity. You can see the 991MB storm in the EPAC which later goes on to becoming potentially a major hurricane.

https://i.postimg.cc/sgvfm4PK/gfs-shear-atl-33.png

The Atlantic will not take off as long as the EPAC is going strong thats pretty much guaranteed. Honestly could be almost the end of August before we're totally favorable.

Sure, if you take GFS post 7 days as gospel.

[MississippiWx]

The base state in the Eastern Pacific does not favor hyperactivity. There might be a week or two of heightened activity there, but we have seen time and again this season where EPac modeled tropical cyclones fail to develop. Even when the Atlantic wouldn’t typically favor development, we’ve had development. I would be very wary of model runs showing hyperactivity in the EPac during a strengthening La Niña.

[aspen]

The GFS is showing an abundance of shear across the Western Caribbean and extending eastward in the MDR due to EPAC activity. You can see the 991MB storm in the EPAC which later goes on to becoming potentially a major hurricane.

https://i.postimg.cc/sgvfm4PK/gfs-shear-atl-33.png

The Atlantic will not take off as long as the EPAC is going strong thats pretty much guaranteed. Honestly could be almost the end of August before we're totally favorable.

Sure, if you take GFS post 7 days as gospel.

It’s highly unlikely those post day 7 storms will verify, which means it’s also highly unlikely that EPac produced shear will be present. The GFS has been busting over and over again with the EPac, so even if we do have a little rise in activity next week, chances are slim that multiple storms and at least one hurricane will be present.

[gfsperpendicular]

The GFS is showing an abundance of shear across the Western Caribbean and extending eastward in the MDR due to EPAC activity. You can see the 991MB storm in the EPAC which later goes on to becoming potentially a major hurricane.

https://i.postimg.cc/sgvfm4PK/gfs-shear-atl-33.png

The GFS has been showing the Atlantic, especially the Caribbean and MDR, overloaded with shear for over a month now and that simply has not verified so far. In other words, I'll believe it when I see it.

[EquusStorm]

The problem here is assuming the mid range GFS has a handle on the tropics at all this year

I thought we learned that in July

[SFLcane]

The GFS is showing an abundance of shear across the Western Caribbean and extending eastward in the MDR due to EPAC activity. You can see the 991MB storm in the EPAC which later goes on to becoming potentially a major hurricane.

https://i.postimg.cc/sgvfm4PK/gfs-shear-atl-33.png

The Atlantic will not take off as long as the EPAC is going strong thats pretty much guaranteed. Honestly could be almost the end of August before we're totally favorable.

Sure, if you take GFS post 7 days as gospel.

As long as there's large scale convection in the E-pac it will sheer the Atlantic.

[CyclonicFury]

The Atlantic will not take off as long as the EPAC is going strong thats pretty much guaranteed. Honestly could be almost the end of August before we're totally favorable.

Sure, if you take GFS post 7 days as gospel.

As long as there's large scale convection in the E-pac it will sheer the Atlantic.

While this is often true, it is actually possible to have the EPAC and Atlantic active at the same time. August 2016, September 2017, September-October 2018, and September 2019 are examples of this. There were a few EPAC systems active when Maria formed.

[TheStormExpert]

The Atlantic will not take off as long as the EPAC is going strong thats pretty much guaranteed. Honestly could be almost the end of August before we're totally favorable.

Sure, if you take GFS post 7 days as gospel.

As long as there's large scale convection in the E-pac it will sheer the Atlantic.

You can still get storms in the Tropical and Subtropical Atlantic even with an active East Pacific, especially now that we’re in August. The Gulf of Mexico and Caribbean will still have some shear with an active East Pacific assuming it lives up to the expectations.

[TheStormExpert]

The base state in the Eastern Pacific does not favor hyperactivity. There might be a week or two of heightened activity there, but we have seen time and again this season where EPac modeled tropical cyclones fail to develop. Even when the Atlantic wouldn’t typically favor development, we’ve had development. I would be very wary of model runs showing hyperactivity in the EPac during a strengthening La Niña.

Story of the East Pacific season thus far! Despite Douglas the basin has significantly underperformed.

[EquusStorm]

September last year saw three systems active simultaneously in both basins, with two hurricanes in the Atlantic, so despite the rule of thumb dual basin activity is certainly possible; that said it's getting off track from models probably

[Monsoonjr99]

It seems the latest model upgrades have been calibrated based on the persistent warm neutral/El Nino state that had been entrenched since 2014 (apart from two brief La Nina events in 2016 and 2017). With 2020 swinging to La Nina, the models may be way off on the base state in the EPac and Atlantic.