2020 Global Model Runs Discussion (Out thru day 16)

[SFLcane]

long range EPS appears to be onboard Clustering near FL.

[Shell Mound]

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:

https://i.imgur.com/eTEzU4P.png

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.

Based on the graph, the location of TCG is significant. The 12Z G(E)FS shows a system forming directly south of Jamaica on 21 October, whereas the 12Z ECMWF/EPS/GFS-P suggest TCG, if any, closer to Nicaragua. According to historical data, systems that formed south of Jamaica during the same timeframe stayed east of 80°W, crossed Jamaica and/or eastern Cuba, and missed the CONUS, whereas a secondary cluster, closer to Central America, tracked much farther west, toward the Yucatán Channel and southern Gulf of Mexico. Therefore, if our prospective system follows the latter solution/cluster (per EC/EPS/GFS-P) instead of the former (per G[E]FS), then it is much more likely to pose a threat to the CONUS. To summarise: TCG south of Jamaica, ~75–80°W, misses CONUS; TCG east of Nicaragua, west of 80°W, poses much greater threat to CONUS. Note, however, that while the EC/EPS/GFS-P suggest a greater threat to the CONUS, they also show a much weaker system than the G(E)FS, suggesting much stronger VWS over the system.

[LarryWx]

long range EPS appears to be onboard Clustering near FL.

https://i.postimg.cc/0rg7VTxM/DCA33025-783-B-45-E0-AD40-BBC58-FD555-F7.jpg

Yeah, the 12Z EPS is more active with ~25% (~13) of its members having W Car. genesis. I see 2 of the ~13 active members (of the total of 51 members) that hit S FL. Most miss to the east over the Bahamas while moving NE to ENE. The 2 that hit FL first cross W Cuba.

[TheStormExpert]

The GFS and Euro both show completely different 500mb patterns in eight days. You pick and chose which one
You think is right!

Until they both come together on something the future track of the Western Caribbean storm is a crapshot.

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

[mlfreeman]

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:

https://i.imgur.com/eTEzU4P.png

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.

Based on the graph, the location of TCG is significant. The 12Z G(E)FS shows a system forming directly south of Jamaica on 21 October, whereas the 12Z ECMWF/EPS/GFS-P suggest TCG, if any, closer to Nicaragua. According to historical data, systems that formed south of Jamaica during the same timeframe stayed east of 80°W, crossed Jamaica and/or eastern Cuba, and missed the CONUS, whereas a secondary cluster, closer to Central America, tracked much farther west, toward the Yucatán Channel and southern Gulf of Mexico. Therefore, if our prospective system follows the latter solution/cluster (per EC/EPS/GFS-P) instead of the former (per G[E]FS), then it is much more likely to pose a threat to the CONUS. To summarise: TCG south of Jamaica, ~75–80°W, misses CONUS; TCG east of Nicaragua, west of 80°W, poses much greater threat to CONUS. Note, however, that while the EC/EPS/GFS-P suggest a greater threat to the CONUS, they also show a much weaker system than the G(E)FS, suggesting much stronger VWS over the system.

The "east of Nicaragua, west of 80W" region you're describing sounds like the lesser known of the two Hebert Boxes.

[toad strangler]

#notaphantom

[SFLcane]

#notaphantom

https://i.ibb.co/x3Bt2rh/Prediction-Center.png

Lol... I’ve said the gfs has this one pinned in terms of development. Phantom not so much.

[SFLcane]

18z gfs has this low spinning up as early as this upcoming Sunday/Monday.

[aspen]

The system stalls just south of Jamaica again on the 18z run.

[SFLcane]

[SouthFLTropics]

Quite a big difference in the steering setup between the 12z and the 18z...

[SouthFLTropics]

I don't see how this gets ejected NE across Cuba with no significant trough or weakness there. I would guess the high is going to build in and steer it west again until the next trough comes along.

[toad strangler]

Moving NNE now ... on the 18z GFS

[toad strangler]

We are in post 10 day LA LA land now anyway so the outcome is insignificant here except another huge signal from the GFS for big time Caribbean action.

[aspen]

The 18z GFS has returned to a slow, northerly track with a Cuba landfall around the 25th. Bottoms out at 938 mbar before landfall. If it stalls down in the Caribbean for longer, that’ll probably be a lot lower.

[aspen]

We are in post 10 day LA LA land now anyway so the outcome is insignificant here except another huge signal from the GFS for big time Caribbean action.

Gyre in 5-6 days, TS in 8 days, Cat 3/4 hurricane in 10 days. Talk about a strong signal. The time frame is one again consistent with this run.

[SFLcane]

One thing continues is there could very well be a strong hurricane near the peninsula. We are still talking more then 10 days out and surely things can and will change.

[toad strangler]

One thing continues is there could very well be a strong hurricane near the peninsula. We are still talking more then 10 days out and surely things can and will change.

As always this FAR out .... ensembles will be interesting.

[TheStormExpert]

One thing continues is there could very well be a strong hurricane near the peninsula. We are still talking more then 10 days out and surely things can and will change.

The GFS for the most part has been persistent with this moving mostly due north and over Cuba and The Bahamas out of the Western Caribbean outside of a few runs like today’s 12z. Those seem like outliers at the moment.

[TheStormExpert]

I don't see how this gets ejected NE across Cuba with no significant trough or weakness there. I would guess the high is going to build in and steer it west again until the next trough comes along.

The GFS is notorious for just randomly opening up weaknesses that allow escape routes for storms. Where as the Euro is notorious for overdoing ridges. Just look at the 500mb pattern for both the 12z GFS and Euro for day eight and you’ll see what I mean.