2020 Global Model Runs Discussion (Out thru day 16)

[aspen]

Vorticity starts to emerge into the SW Caribbean late this weekend, and the broad gyre has formed by October 19th. A clump of vorticity within the broader gyre concentrates into "future Epsilon/Zeta/Eta" after a few days, meaning that its motion would also be influenced by the gyre as well as any troughs or ridges present. This probably explains why the system stalled out and turned west in this run.

[Frank2]

I agree TC genesis remains around the 19th, but if the system is still near Miami by the 29th something isn't right - we've seen this trend before and it often results in a non-event...

[kevin]

Wow, 12z GFS goes all out with this run. If something like this would verify I think we'll get the same Wilma comparisons we had with Delta. The only good news is that it's still far out so enough time for the models to change for better (or worse unfortunately). So still too far out atm to really put a lot of value on a specific track, but the potential for a very nasty storm is definitely there.

[weeniepatrol]

 https://twitter.com/NWSCPC/status/1316080821745319936

[cheezyWXguy]

I agree TC genesis remains around the 19th, but if the system is still near Miami by the 29th something isn't right - we've seen this trend before and it often results in a non-event...

Are we talking specifically about an event for miami or the storm existing in general? If the former, I have nothing to offer for a spot-treating forecast. If the latter, the genesis date is the important one, and changes in pattern depiction in the long range will dictate where it goes and how long it takes to get there. At this point anything beyond genesis is speculation.

[SFLcane]

 https://twitter.com/davidbernardtv/status/1316079920624340992

[AutoPenalti]

https://twitter.com/davidbernardtv/status/1316079920624340992?

Oh no, what has he done... why.

[SFLcane]

https://twitter.com/davidbernardtv/status/1316079920624340992?

Oh no, what has he done... why.

In general the gfs and ensembles have been offering something similar to that of Wilma so sure. The rest well is history

[SouthFLTropics]

12z Euro looks to be spinning up an area of vorticity in the SW Caribbean around 168 to 192 hours.

[LarryWx]

The following map of tracks taken for 10/21-31 geneses will be quite useful as regards chances of FL being hit from the W Caribbean. There are two pretty clearcut camps as regards Cuba. Not even one storm on record back to 1851 has crossed Cuba and then landfalled on FL. I was surprised to see this. All of the hits were from storms that either went around Cuba (like Wilma and the 1921 Tampa storm) or originated in the Gulf and all were, interestingly enough, moving ENE or E:



Of course that doesn't mean that there won't be an exception this time where one crosses Cuba, especially western Cuba, and then hits FL. I don't see why that isn't a reasonable possibility.

[SFLcane]

 https://twitter.com/andyhazelton/status/1316088542569865216

[Blinhart]

Please tell me that Louisiana Gulf Coast is closed off for the season, I don't want to go through another one.

[aspen]

12z Euro still doesn’t show much more than a weak low in the Caribbean, but it does have a subtropical system forming in the central Atlantic and heading towards the US east coast.

[edu2703]

12z GFS-para shows this storm crossing Central America into the Pacific

[chris_fit]

12z GFS-para shows this storm crossing Central America into the Pacific

https://s8.gifyu.com/images/410f52ce-9395-41e4-b7a0-eed04d8d412b.gif

Oh good. That puts everything rest. Bring on the 2021 Season!

/s

[blp]

Tropical Cyclone formation now showing up on the Global Tropics Hazards site.

[aspen]

The 12z Euro and GFS-Para runs both show a very similar scenario of Epsilon, Zeta, and Eta developing within the next 7-10 days, with Epsilon and Zeta both forming in the subtropics.

The Euro has Epsilon's precursor form on Saturday, and Zeta following on Monday from a large non-tropical low. It's pretty bearish on Epsilon but sends it towards the US East Coast. The precursor for Eta is present, but the Euro doesn't do anything with it.





The GFS-Parallel has a very similar precursor for Epsilon developing at the same time and location, although the system ends up as a tiny speck of vorticity. Zeta forms out of that large non-tropical low on Monday as well, and the gyre develops in Eta in the SW Caribbean.




This level of agreement between one genesis-happy model and another that couldn't sniff out a Cat 4 just a few days away is very interesting. At the very least, the precursor for potential-Epsilon should be highlighted in the TWO by Thursday at the latest.

[AutoPenalti]

12z GFS-para shows this storm crossing Central America into the Pacific

https://s8.gifyu.com/images/410f52ce-9395-41e4-b7a0-eed04d8d412b.gif

Ahh yes, typical of a monsoon gyre.

[tomatkins]

The 12z Euro and GFS-Para runs both show a very similar scenario of Epsilon, Zeta, and Eta developing within the next 7-10 days, with Epsilon and Zeta both forming in the subtropics.

The Euro has Epsilon's precursor form on Saturday, and Zeta following on Monday from a large non-tropical low. It's pretty bearish on Epsilon but sends it towards the US East Coast. The precursor for Eta is present, but the Euro doesn't do anything with it.
https://i.imgur.com/pqyF4ci.png
https://i.imgur.com/cMhv3sN.png
https://i.imgur.com/WGlgxk0.png
https://i.imgur.com/WRL3Z5P.png

The GFS-Parallel has a very similar precursor for Epsilon developing at the same time and location, although the system ends up as a tiny speck of vorticity. Zeta forms out of that large non-tropical low on Monday as well, and the gyre develops in Eta in the SW Caribbean.
https://i.imgur.com/9FPe99o.png
https://i.imgur.com/zxsy7B8.png
https://i.imgur.com/mKA2R22.png

This level of agreement between one genesis-happy model and another that couldn't sniff out a Cat 4 just a few days away is very interesting. At the very least, the precursor for potential-Epsilon should be highlighted in the TWO by Thursday at the latest.

Needless to say, if all three of these storms formed it would be nuts - tying the record for most namable storms (2005 had an unnamed tropical storm) at 28 with still more than a month left in the season. I wonder what the record is for latest date with three active named storms in the Atlantic.

[sma10]

I agree TC genesis remains around the 19th, but if the system is still near Miami by the 29th something isn't right - we've seen this trend before and it often results in a non-event...

TC genesis for Wilma occurred on Oct 15 and struck Florida Oct 24