Grib files to input into VPP

[jocki]

Hi there,
i am still looking for information of how to get the right weather data to input it to WinVPP. grib files are available somewhere, but where? and is there a need to process them through a navigation program like Deckman?
any help would be great!
Jocki

[nico]

http://www.globalmarinenet.net/grib.htm

Depends what you want to get, if you want to compare several boats by computing their racing time over a complex route (transatlantic,..), then yes you need a routing software. If it is about racing around the cans, no need for that.

[jocki]

Nico,
thanks for your reply. thats what i thought, so do you hav an idea where to get the grib files for deckman? i am doing the new course of the volvo 08/09 race, if you have an idea where to get th weather data from, that would be great!
thanks for your help
Jocki

[nico]

You'll need grib files covering the whole race (both in time and area), I don't think it can be found without paying for it. But if anyone knows where to find it on the web, i would be interested too.

Are you at solent uni?

[jocki]

Nico,
yes i am at solent uni. know the place?....
yes seems to be tricky to bet by that stuff, but will let you know, if i know more.at the moment i will be doing it via excel , should be allright.
thanks for your help
Jocki

[RHough]

Originally Posted by jocki

Nico,
thanks for your reply. thats what i thought, so do you hav an idea where to get the grib files for deckman? i am doing the new course of the volvo 08/09 race, if you have an idea where to get th weather data from, that would be great!
thanks for your help
Jocki

To use routing software you need weather predictions for the time of the passage. I doubt that you will find predictions for the 08/09 route anywhere.

What you can do, is to create the polars for the boat and use pilot chart information (historical data) to route based on average conditions along the route or most frequent conditions along the route.

I'm sure that design offices like Farr et al have very sophisticated models to run polars through. For the layman, Virtual Passage Planner can be used to get an idea of what should work. The program has the pilot chart data for each month, but the polar data is not very detailed. It is limited to four ranges of apparent wind angles, Beat (0-45), Close Reach (45-112.5), Broad Reach(112.5-157.5), and Run(157.5-180). You can enter a polar speed (but not angle) for each Beaufort Number from Force 0 to Force 12.

It does a fair job for under $100 US.

[nico]

Yes i know solent uni, i was there during 2001-2004. And my final year project was a volvo 70 . The method described by RHough is actually the one i used since i didnt have acess to any routing software. (but i used grib files)