Expedition Navigation Software / Reanalysis and the 'Multiple' run process

**Posted by radaroom** 4/16/2025 1:38 am

In the past I have been able to run 'reanalysis' of a course using the Copernicus downloaded gribs - 20years of runs. Great value. Of course I cant remember how I did it
Trying to do the same again and can only get 'No Wind at Start' error message and I have tried a variety of options in the Multiple setup box, to no avail.
I have redownloaded the grib several times to ensure I have the data - about 1.2GB
Can you demystify the process and setup please?
Should I start at year 20 (eg race start at 0900 26/12/2005) and then do hourly intervals over 20years?
Does the start time in Optimal settings have anything to do with this?
Any advice would be gratefully received

**Posted by Nick** 4/16/2025 2:03 pm

Obviously it doesn't have wind at the start time.

You could start a single run from the first start time. It may help.

**Posted by greg.brougham** 7/02/2025 5:17 am

Will did a video that covers the basics a few years ago. Note the optimal setting is not used when doing multiple runs and do use the meteogram functionality to check the wind data as per Nick's comment

https://www.youtube.com/watch?app=desktop&v=kA8H25VUE_4&t=1089s&ab_channel=WillOxley