Low Confidence in Models

[sfwx]

At this point, even the NHC is not going along with the models. Most of the models were in agreement and they didn't verify. What factors are causing the models to be off? Do you think the NHC is having a hard time getting a handle on this storm? Also, in the last few sentences they mention the trough coming into the SE Coast after day 5. Wouldn't that cause the storm to move more to the North?

Eric

[ColdFront77]

Forecast model guidance doesn't have to be accurate... it tends not to be. That is why it is guidance.

The National Hurricane Center doesn't see any reason to deviate from the forecast models, as this system continues on it westward trek across the Atlantic. This general westward movement makes sense with the steering pattern the storm is in.

Yes, the trough will move Isabel more north, however, the more the ridge builds before the trough makes it to the east coast will determine Isabel's position off the coastline.

[soonertwister]

WREL's new model map is up, and I can certainly see why there's little confidence in the models - they are all over the place.

http://www.wrel.com/modelmap.htm

[JCT777]

WREL's new model map is up, and I can certainly see why there's little confidence in the models - they are all over the place.

http://www.wrel.com/modelmap.htm

Of the different paths shown, the BAMM path makes the most sense to me.

[jfaul]

WREL's new model map is up, and I can certainly see why there's little confidence in the models - they are all over the place.

http://www.wrel.com/modelmap.htm

hello...those models are showing a consensus..that is about as tight as you will ever see this far out...this forecast is very straight forward..models or no models..they sytstem is trapped under a ridge...its not going anywhere but W for at least 5 days, i repeat at least 5 days

[Derecho]

At this point, even the NHC is not going along with the models. Most of the models were in agreement and they didn't verify. What factors are causing the models to be off? Do you think the NHC is having a hard time getting a handle on this storm? Also, in the last few sentences they mention the trough coming into the SE Coast after day 5. Wouldn't that cause the storm to move more to the North?
Eric

Ummm....Uhh...

Quite frankly, I don't have the foggiest idea of what you're talking about.

By normal standards, trackwise Isabel has been very well behaved (as has been true of almost all the storms this season.)

I suspect NHC is setting their record for accurate track forecasting so far this year.

Isabel turned west a degree or two further N than some models had it doing so a couple days ago. This is not some shocking unprecedented divergence from "the models"; it's routine.

CURRENTLY, there's MORE model consensus than normal for a CV storm in this location, not less.

It's not NORMAL for all the models to be directly on top of each other. The amount of "spread" at the moment really is pretty limited.

When the models look like a "Squashed Spider" THAT's when they're not in agreement.

[sfwx]

Derecho,
My comments were made after the NHC said in a previous days discussion that they had low confidence in the models at that time. I clearly see that the models are in much better agreement now. Thank you for your input.

Eric

[soonertwister]

Derecho, after the first couple of days that Fabian was a cane, I can't remember seeing anything close to the kind of spread in the models I'm seeing with Isabel. Maybe I'm wrong, but generally you'd like to see more than two models showing basically the same path, which we don't have here.

I guess observations are subjective, and I was speaking from my subjective point of view that it appeared to me that the models were scattershot.