ATL: IRMA - Models

[meriland29]

Upper low is gone on the GFS..

Could you fill me in on what that means for the track

[meriland29]

[SouthFLTropics]

Further north at 108

[artist]

In a recent tweet, Met. Joe Bastardi noted he is staying with the Euro. He also said that the GFS might score a coup but he doubts it.

Can you remember the last time the GFS scored a meaningful "coup"? I didn't think so. Neither can I.

Gfs was actually better with Matthew than euro, maybe not a coup...when gfs can get the first 24h of Irma correct I will give it more weight

Sent from my DL8006 using Tapatalk

That was before the gfs was tweaked...

[KWT]

Upper high much weaker on the 18z GFS, at 591 dam, the 12z ECM is at 594 dam, which is quite a significant difference and means the GFS has nothing to keep the system heading westwards hence why it consistently lifts it up.

Something has gotta give sooner or later!

[AxaltaRacing24]

The main issue I am seeing is with the players (Irma). The field is correct (steering) but the players in the game are reacting differently.

[RL3AO]

Euro vs GFS at 120 hours - Euro still faster. Euro also stronger with central US and Ireland trough. Probably playing into the stronger ridge too.

[gatorcane]

Further north at 108

[url=https://postimages.org/https://s26.postimg.org/60bmrkvsp/gfs_z500a_Norm_atl_19.png[/url]

Yes but the low may cut off over the Midwest this time like the Euro allowing the ridge to build west. We will see.

[meriland29]

[SFLcane]

Yep should recurve here pretty easily not much to keep it moving westward.

[Spacecoast]

ECMWF control run:



Source: weather.us

Amatuer question... What is the ECMWF control run, and why is it so different than the standard ECMWF model run?
Thx...

[TheStormExpert]

18z GFS is further north compared through 5-days compared to the last 2 runs.

[meriland29]

[Frank P]

Ridge looks to be building in at H126 and back out at H132

[sma10]

The biggest difference appears to be forward motion. The GFS is consistently slower than Euro. You can see this happening again on the 18Z starting in the 48-72 hr period. I guess thats something to watch this weekend.

Yes that is interesting to see and its borne out in the ensemble as well, suggests the ECM has a stronger ridge and thus airflow round the southern side of the ridge. I suspect given what we have observed over the last 24hrs the idea of the stronger ridge seems more realistic.

And probably related to the speed is the orientation of the GFS ridge. If you watch the track in motion you can see that the ridge "topples" from the NE/SW orientation to more of a NW/SE quite rapidly. This must be what allows Irma to bounce so quickly in change of direction, and this seems to be the big difference maker in track. What's actually causing i wouldnt know but im sure the Met's can tell.

[gatorcane]

Look at the 500mb heights over the US. Big difference this run of the GFS. We should get a cutoff low.

[meriland29]

[floridasun78]

my weatherman Craig Setzer like Euro over gfs but he going watch both to see who got it right i notice alot weather look at them both dont talk about other models only gfs and Euro

[meriland29]

144

[floridasun78]

gfs want save islands past few runs