The Offshore Voyaging Reference Site

Q&A—Weather Information In The Southern Hemisphere


Member Terence asked:

When we went to Polynesia, we used Predict Wind. We could get weather in all latitudes. Next year we will again be sailing south of the US Pacific Ocean Prediction Center maps. Need I again use Predict Wind to get what I need? Someone asked the same question about the south Atlantic. I think you did not have an answer. I would like to follow your advice, but I need to figure out how to get information in lower northern latitudes and perhaps south of the equator. Or do I just stay with Predict Wind?


Predictwind is just a tool for downloading and displaying information generated by government models (with some interpolation in inshore areas). So I think it’s easier to first think about the underlying data.

Once we have that sorted we can pick the tools to get and display the information that best meets our needs.

Login to continue reading (scroll down)

Inline Feedbacks
View all comments
Michael Jack

If we are purely talking Americas here then I have nothing to add. The Australian Bureau of Meteorology (with the somewhat appropriate acronym of BOM) has surface analysis charts extending well out into the Pacific and Indian Oceans and down into the Southern Ocean, but most of the charts for those regions say in big letters “No Manual Input” so I am not sure they are any more useful than the Grib files. Their list of surface analysis charts can be found here:

Kit Laughlin

I use the BOM site too, and start at the Antartica map; these are the big systems that drive what we see/feel on the South Coast of NSW. I also use their sea surface temperature map, to see what the East Australian Current is doing—it runs at 4kn South at times and we have used it as an express ride for passages from Brisbane to Greenwell Point.

Once I have seen the big picture (working up from Antartica to the mainland) I use and its various overlays. I feel it’s critical to understand the big scale perspective first, then go in closer.

Taras Kalapun

I bought my current boat in Ushuaia and sailed north on coast of Argentina, Ushuaia and Brazil.
I used GRIBs from GFS and ECMWF. They are pretty accurate, at least no more and no less than In Caribbean.

Terence Thatcher

So, I was not aware that one could get gribs directly from those two sources. My ignorance, again. That is all I got from Predict Wind, at its prices. How does one get those two source gribs directly?

Alan Sexton

Bob Mc Davitt posted a good summary of available weather resources for the Sth Pacific west of French Polynesia
I believe this is largely still current but any particular service should be verified.
NZ’s Metservice ceased Radiofax transmissions on 30 June 2023, BOM Australia to my knowledge still makes Radiofax transmissions but days are probably numbered
The Fiji Met Office (Nadi) still issues its IAC Fleet Code broadcast, OpenCPN has a plug in to decode the number groups
The vast majority of cruisers to/from NZ rely on Predictwind and with the proliferation of Starlink can now tap into all the on line resources. I also use the services of Australia weather router Bruce Buckley for my ocean passages.