ATL: FLORENCE - Models

[hurricaneCW]

That Euro run is scary because it has Florence playing into the weather pattern the east has seen over the past month or so.

It also makes sense that the storm would struggle over the next 5 days, which would obviously induce a further west track.

And if that pattern doesn't break then those storms behind Florence would also be threatening.

[TheProfessor]

I don't know why we are getting upset at someone extracting the current path of a 240 hour storm trying to determine where it would go if the run were extended. It wasn't stated that is where they believe the storm would make landfall and the user has a disclaimer as well. I've seen this done many times in the past and I think it's fine since it's actual model discussion. We are all very curious people and when a storm approaches land as a run ends I think it's in our nature to want to figure out where it would have gone if the run had been extended 12+ hours etc. It very likely won't matter to the storm's final destination, but it could be used as a reference point to where the models were showing a storm 10 days ago then where it ended up making landfall.

[storm4u]

Something a bit troubling is that the Euro 216H point is very close to the earlier 240H location, which is some unsettling consistency that far out.

Check out the 12z Canadian pretty close to the 12z EURO

[Kingarabian]

Trend is worrying, but it's still more than 10 days out. Best we can do right now is just monitor the development of Florence since it seems to be that its track will depend on its strength.

[cycloneye]

Does anyone has the 12z Euro Ensembles run?

[Kingarabian]

Does anyone has the 12z Euro Ensembles run?

Not done running yet, should be complete within 30 minutes.

[toad strangler]

Definite strong signal for the East Coast but the spread is huge at 10 days as expected.

 https://twitter.com/ericfisher/status/1036340901830963202

[Kingarabian]

[Hypercane_Kyle]

Ryan Maue has been talking about how Jebi in the WPAC could influence whether or not a high builds in over the Atlantic Seaboard... interesting how a storm on the WPAC may ultimately influence the track of one in the ATL.

 https://twitter.com/RyanMaue/status/1036336354995712001

[RL3AO]

Ryan Maue has been talking about how Jebi in the WPAC could influence whether or not a high builds in over the Atlantic Seaboard... interesting how a storm on the WPAC may ultimately influence the track of one in the ATL.

 https://twitter.com/RyanMaue/status/1036336354995712001

The timing could work out pretty well (or actually pretty badly) for the East Coast. Time will tell. The Pacific does get really amplified over the next few days. Some ridging over the central/eastern US would make sense.

[Kingarabian]

18z GFS initialized:

[Cunxi Huang]

Ok 12z EC suggests a track which is much closer to N and S Carolina than its previous runs. Since this is a trend we need to put more eyes on Florence. Period.

[RL3AO]

One could dig into the longer term synoptic differences between the 12z Euro and GFS, but the first 48 to 72 hours are so significantly different that trying to figure out days 7 to 10 is pretty much useless.

The big difference between the models is this - the Euro is weaker and faster and the GFS is stronger and slower. The faster/weaker Euro lets Florence miss most of the north Atlantic trough around day 4 or 5 and get caught under the eastern US ridge. The stronger/slower GFS has significantly more interaction with the north Atlantic trough resulting in a Bermuda/Canadian maritime threat, but not a US one.

One major thing the Euro did better than the GFS last year with the big Cape Verde storms was identifying the faster westward movement. It seemed every run of the GFS has to shift south and west because it moved the storms too slow and poleward too quickly. Will we see the same thing again?

[AxaltaRacing24]

Ok 12z EC suggests a track which is much closer to N and S Carolina than its previous runs. Since this is a trend we need to put more eyes on Florence. Period.

This will for sure get more attention once Gordon is inland. Same situation when Harvey hit. Eyes then went to Irma.

[Kingarabian]

18z GFS through 24 hours:

[Hurricaneman]

18z GFS through 24 hours:

I think the GFS is too strong in the short run

[Hypercane_Kyle]

Pretty remarkable difference just @ 24 hours between the ECMWF and GFS:

[Kingarabian]

18z GFS hours 24-48:

[Kingarabian]

18z GFS 4 run trend @ hour 48:



Pretty consistent

[RL3AO]

Pretty remarkable difference just @ 24 hours between the ECMWF and GFS:

We've seen the same thing with so many waves and TCs out here. The GFS is usually way too aggressive with short term intensification leading to huge track errors downstream. The strongest winds around Florence are in the 850 to 700 mb level. The upper level winds are actually weaker with height. This means if the GFS is over-doing it (likely), it'll make the storm move slower. The weaker Euro and NHC forecast will move faster and more westward.