2020 Global Model Runs Discussion (Out thru day 16)

[toad strangler]

Another thing I’ve noticed is the GFS has pushed back development of this a few days since the overnight 00z run for what it’s worth.

Wrong

[AutoPenalti]

This looks to book it NE, looking at the H500, that ain't happening.

[chris_fit]

This looks to book it NE, looking at the H500, that ain't happening.

[TheStormExpert]

Another thing I’ve noticed is the GFS has pushed back development of this a few days since the overnight 00z run for what it’s worth.

Wrong

How is this wrong!? I’m just stating a tiny fact!

[chris_fit]

Don't see how it can do anything other than this on the 12Z - weaker too

[TheStormExpert]

GFS is MUCH weaker this run. Doesn’t even show a hurricane crossing Cuba while ejecting NE.

[aspen]

A lot weaker on this run, due to a combination of slow genesis and getting pulled up north quicker.

[chris_fit]

GFS is MUCH weaker this run. Doesn’t even show a hurricane crossing Cuba while ejecting NE.

Indeed - let's hope future runs show something similar - Runs in the last few days have been scary - I'll take this run anyday.

[toad strangler]

Another thing I’ve noticed is the GFS has pushed back development of this a few days since the overnight 00z run for what it’s worth.

Wrong

How is this wrong!? I’m just stating a tiny fact!

It's completely wrong. GFS has not pushed this back a few days

[SFLcane]

The gfs might just get us once again with a potential phantom who knows lol. Much weaker this run we will if it still developing it next week.

[Emmett_Brown]

Just an unscientific observation, but I've noticed a tendency for the GFS to show a strong storm at long range, then weaken it as it gets closer to the event. Then, the storm that actually forms ends up being intense similar to the older runs. I guess this is why we depend more on HWRF and HMON for intensity.

Edit: I should have also mentioned that this is the main reason ensembles are more useful... which is something we all know anyway

[TheStormExpert]

Wrong

How is this wrong!? I’m just stating a tiny fact!

It's completely wrong. GFS has not pushed this back a few days

Yes it has, it went from showing development beginning on the 19th to now the 21st. And no I’m not calling this a phantom storm if that’s where you trying to go.

Though the 12z GFS is much weaker so who knows anymore.

[TheStormExpert]

Just an unscientific observation, but I've noticed a tendency for the GFS to show a strong storm at long range, then weaken it as it gets closer to the event. Then, the storm that actually forms ends up being intense similar to the older runs. I guess this is why we depend more on HWRF and HMON for intensity.

Honestly the models have been nothing but crap this season thanks to COVID I assume. Hopefully next season they perform much better. But I hope this is not the case as you’re saying.

[aspen]

The gyre is still there on the 19/20th on this run. It just takes long to coalesce into a system. At this point, we don’t know how long this system will take to develop; it could quickly coalesce like what happened with Gamma (it was quite broad but tightened up VERY quickly), or it could take several days like what the weaker GFS runs have shown.

[aspen]

The 12z CMC is still quite aggressive with the central Atlantic system. It forms in as little as 3 days, and heads towards the east coast as a strong TS.

[plasticup]

GFS is MUCH weaker this run. Doesn’t even show a hurricane crossing Cuba while ejecting NE.

"Ejecting" into a Bermuda landfall.

[gatorcane]

Saved GFS loop:

No more 929MB CAT 5. Track and intensity look more realistic

[SconnieCane]

Saved GFS loop:

No more 929MB CAT 5. Track and intensity look more realistic

https://i.postimg.cc/FRtzrDhC/gfs-mslp-pcpn-watl-fh168-252.gif

Why is a Cat 5 unrealistic given the water temperatures that are down there? Not saying one is likely at this point, obviously a lot has to fall into place for an intense major hurricane, but I wouldn't call it unrealistic.

GFS, as a global model, can't resolve core pressures of major hurricanes very well, anyway.

[TheStormExpert]

Honestly you’re nuts if you believe those absurd Cat.5 intensities the GFS shows with systems all the time. I’ll never forget the sub-900mb Irma it was forecasting to slam into SE Florida for several runs. Fortunately that wasn’t the case.

[CourierPR]

Again, folks are all agog looking at one model run and treating it as THE definitive run.