What Weather Data is Useful for Passage Planning?

[rebel heart]

Specifically I'm talking about stuff beyond current forecasts and current weather you can download (ssb/satellite). I've got access to a ton of weather data from vessels that have reported wind direction, beaufort, etc. I put a heat map together that sort of shows visually, for any given month, what the general conditions were (blue = light / green = medium / red = bad).

What other things would be handy. Maybe routes other vessels have taken, overlay average wind direction?

[Paul Elliott]

So why are you trying to duplicate the pilot charts? I can see wanting to use more recent data, but the year-to-year variation can be pretty high so I don't know if the prediction accuracy would be improved over the many decades-long pilot chart averages. I'm not convinced that the averages have shifted all that much.

I do know that in the San Francisco to Hawaii run, or even more the Hawaii to San Francisco run, if I used the previous year's weather for this year's routing I would be getting some of it right, but a lot of it very wrong. This is based on my records from five round-trips since 2003.

[colemj]

Aren't you working on a bit North and East from where you are heading?

Mark

[rebel heart]

Originally Posted by Paul Elliott

So why are you trying to duplicate the pilot charts? I can see wanting to use more recent data, but the year-to-year variation can be pretty high so I don't know if the prediction accuracy would be improved over the many decades-long pilot chart averages. I'm not convinced that the averages have shifted all that much.

I do know that in the San Francisco to Hawaii run, or even more the Hawaii to San Francisco run, if I used the previous year's weather for this year's routing I would be getting some of it right, but a lot of it very wrong. This is based on my records from five round-trips since 2003.

I work in software with spatial data so when I think no matter what I just end up naturally messing around with this stuff.

Partially I think the pilot charts are from (and written towards) 300 ton + vessels. I'm also thinking there's a lot more observations to take note of than just overall wind direction spanning huge chunks of sea.

Sort of like a blend between between a cruising guide and sailing directions.

I'm just thinking out loud.