Expedition Navigation Software / Grib drag and drop time and place

**Posted by christiant** 7/05/2025 4:03 am

I'm interested if this is even a good idea, but i've found with hi-res gribs, that often the weather is correct, but just not in the time and place. I can find the wind we're sailing in "over there", and we still sail into the gribs wind, just not the time and place it has. so twisting the wind or changing strength isn't really what i want, i just want to move the entire data excepting location, over the geographical location, like a drag and drop. interested if this is not feasible or makes no sense, because of other more important considerations i haven't taken into account; especially from those of you more experienced...cheers.

**Posted by christiant** 7/05/2025 4:40 am

(I'm more interested in why this is a dumb idea than it actually being a feature

**Posted by Ernie M** 7/05/2025 7:42 am

Christiant
My opinion on the matter:
What you're describing could be seen as the 'downside' to higher resolution. In a lower resolution model the 'vagueness' might actually work in your favor. The answer is to view several models and see how closely they align. If you have time you can compare the forecast data with observational data from say NDBC (US)

Another aid is to view the reverse isochrones when you Optimise (Optimal/Settings). The smoothness, or lack of, may give a clew as to how critical the resolution of the model is.
Then; observation during the race compared to what you expect allow you to weight your expectations going forward. As far as shifting the forecast lines you'd just be getting into a guessing mode and if you're there, you may as well throw the whole forecast out!
It's all about faith in the forecast compared to the cost of deviating from the direct line.
Best Regards,
Ernie

**Posted by christiant** 7/05/2025 2:57 pm

"The smoothness, or lack of, may give a clew as to how critical the resolution of the model is." That's interesting, i'll think on that.
"observation during the race compared to what you expect allow you to weight your expectations going forward" - constantly doing that
"It's all about faith in the forecast compared to the cost of deviating from the direct line." absolutely.
Thanks for your thoughts Ernie

**Posted by christiant** 7/08/2025 12:36 am

Also @Ernie - nice autocorrect or easter egg on "clew"