GFS is still quite insistent on its solution ...

[x-y-no]

18Z run much like the previous few runs so far.

It has Ivan passing between Jamaica and Hispaniola then turning WNW over the north side of Jamaica. Meanwhile the low in the Atlantic keeps coming WSW and eventually breaks down the ridge over Ivan. That lets Ivan turn north across central Cuba in the general direction of SE Florida.

[miamiwxgal]

I've been watching that low in the central Atlantic in the water vapor loop. IMO, this low could be very important to the final track of Ivan. How much effect will it have on the strength of the ridge? If it's strong enough to break down the ridge, then a more eastward solution could occur. If not, then a westward solution makes more sense. That is something to watch as it comes on in. Just my take on things.

[MWatkins]

18Z run much like the previous few runs so far.

It has Ivan passing between Jamaica and Hispaniola then turning WNW over the north side of Jamaica. Meanwhile the low in the Atlantic keeps coming WSW and eventually breaks down the ridge over Ivan. That lets Ivan turn north across central Cuba in the general direction of SE Florida.

Thank God I'm not the only one seeing this large mid/upper system racing down the backside of the Atlantic ridge. I have to go back to work for a while...but I am working on a post dealing with this feature and one other.

For some reason folks seem to be caught up in how the pattern looks now...and not what it will look like in 3 days...when it matters most.

MW

[wjs3]

Are you guys talking about the ULL at about 30 N 50 W hauling butt SW?

[x-y-no]

Yeah, I've got a feeling this is what the ECMWF is seeing also. But the site I know, at least, doesn't offer enough timesteps to see if that's what's happening in its version of things.

[CourierPR]

I saw that upper low also, Mike. Our local met, Don Noe, talked about making preparations tomorrow and Saturday. Might he be seeing this low as a player in Ivan's future course?

[x-y-no]

Are you guys talking about the ULL at about 30 N 50 W hauling butt SW?

Right. If you look at the WV loop

http://www.ssd.noaa.gov/PS/TROP/DATA/RT/watl-wv-loop.html

you can see it diving down from the upper right corner.

[PurdueWx80]

The GFS is further west again my friends...although just a touch. Instead of grazing Miami it is a full fledged hit.

[CourierPR]

BTW, Don Noe is usually low key and conservative when it comes to hurricane forecasts.

[huricanwatcher]

going to ride the ridge..........


HEY IVAN SAVE A HORSE RIDE A COWBOY!!! WHAT WHAT>>>>>!!

[charleston_hugo_veteran]

going to ride the ridge..........


HEY IVAN SAVE A HORSE RIDE A COWBOY!!! WHAT WHAT>>>>>!!

LOL...

[yoda]

The GFS is further west again my friends...although just a touch. Instead of grazing Miami it is a full fledged hit.

Yes that is correct.. but it looks more like a slap then a full fleged hit.... but my eye spies that the eye APPEARS to be still over water...

Lets see if the 18z GFS follows what the 12z ECMWF did from there...

[x-y-no]

The GFS is further west again my friends...although just a touch. Instead of grazing Miami it is a full fledged hit.

Yes, it has been trending slowly west. I wasn't trying to claim that the path has been exactly the same every run, just that it's still doing the same thing with the Atlantic low breaking down the ridge in every run.

The other thinkg it has been very consistant with is keeping Ivan east of Jamaica, so I consider tomorrow afternoon an important benchmark in that respect.

[mobilebay]

Actually the GFS is slightly left again. It has been trending left since Wednesday.

[PurdueWx80]

The GFS is further west again my friends...although just a touch. Instead of grazing Miami it is a full fledged hit.

Yes, it has been trending slowly west. I wasn't trying to claim that the path has been exactly the same every run, just that it's still doing the same thing with the Atlantic low breaking down the ridge in every run.

The other thinkg it has been very consistant with is keeping Ivan east of Jamaica, so I consider tomorrow afternoon an important benchmark in that respect.

That is a very good point w.r.t. Jamaica. Because of frictional effects associated w/ islands like that (and their mountains...however small they may be) will cause Ivan to go to the right of the island if it approaches Jamaica head on. This happens in Taiwan all the time, although they have some very tall mountains on the order of Hispaniola's. Otherwise, if it is south, it should stay south of the island for the most part.

[yoda]

ATT.. It APPEARS as if the ECMWF and the GFS are in agreement about the track of Ivan.. this is weird.. since when have the GFS and ECMWF ever been in agreement?

[x-y-no]

That is a very good point w.r.t. Jamaica. Because of frictional effects associated w/ islands like that (and their mountains...however small they may be) will cause Ivan to go to the right of the island if it approaches Jamaica head on. This happens in Taiwan all the time, although they have some very tall mountains on the order of Hispaniola's. Otherwise, if it is south, it should stay south of the island for the most part.

Now that's very interesting. Thanks for that bit of info. I'll watch for that effect in the future.

[x-y-no]

ATT.. It APPEARS as if the ECMWF and the GFS are in agreement about the track of Ivan.. this is weird.. since when have the GFS and ECMWF ever been in agreement?

LOL!

It sure would be nice to be able to figure out if they're arriving at the same place for the same reasons. The site I know for the ECMWF (http://www.ecmwf.int) only seems to offer a very few timesteps. Not enough to figure out what it's thinking.