News From the NHC -- new Link & Model Update Info

[wxman57]

Dr. Pasch pointed out a web site where you can find experimental tropical cyclone wind probabily graphics. The model analyzes the projected path and forecast wind radii and factors in average track error to compute the chances of a point near the path of a storm receiving 34, 50, and 65kt winds.

http://aller.cira.colostate.edu/tcwinds/

In other news, there were only very small modifications made to the 2004 GFS - basically to make it perform better with upper level wind flow over mountain areas. This may affect long-wave trof/ridge locations a bit, and could lead to increased accuracy with steering-level projections for tropical cyclones.

The "dissipation bias" of the GFDL has possibly been fixed. If you remember last year, many times the GFDL just dissipated a TD when the system was actually developing. Also of note is the tremendous difference between the 00Z and 12Z GFDL intensity forecasts for 2003. Side by side, the 12Z GFDL run was basically out to lunch completely for intensity forecasts. Though the 00Z run wasn't anything to write home about, it did a lot better than the 12Z run.

There have also been some changes in the small-scale physics of the GFDL that could have an impact on both intensity and track.

Also new for 2004 is the GFDN model. This model incorporates data from the Navy NOGAPS as its base rather than the GFDL's use of the GFS as the base model.

One final note, there was talk of the GFDL being replaced in 2006 by a new model which is undergoing testing in 2004/2005. I believe this was the CONU (consensus) model, but I could be wrong. This model will ONLY replace the GFDL if it proves to be superior.

That's about it for today.

[cycloneye]

Very good link that I saved thanks Chris for bringing it to the board.

[Guest]

Thanks wxman57

The GFS & GFDL sure did need some fine tuning,hope they will perform better in the upcoming season(s).

[MWatkins]

Hey WX...if you get the chance ask somebody if there was a conspiricy to drop Isabel from the GFS runs last year...or....how can one of the fastest most technologically advanced computers in the world miss a 910MB surface cyclone?

Hope you're enjoying our nice weather down here...I think I'll cut out from work early tomorrow.

MW

[hurricanemike]

Hate to bust your bubble...but the GFDN aint new...its been ran for years...just nobody outside the Navy or DoD has had access to the output.

[wxman57]

Hate to bust your bubble...but the GFDN aint new...its been ran for years...just nobody outside the Navy or DoD has had access to the output.

I figured it wasn't "NEW" new, but perhaps now it will be available for the public to look at.