Baltic Sea Currents

[Dockhead]

The Baltic Sea doesn't have any tides to speak of, so no tidal charts. However, there are currents, some of them over 1 knot, which makes a huge difference for sailing tactics.

I know that some of these currents are wind-driven, so you can't predict them all like you can tides.

But can we predict them based on wind?

And how about the currents which are not dependent on wind? Is there a decent electronic atlas of these which can be used by Expedition or OpenCPN for routing?

Grateful for any tips.


This seems to imply that it's hopeless: https://www.smhi.se/en/theme/surface-currents-1.12286


But I can't really believe that there is no way to make some predictions.

[Pandor]

The US NGA pilot charts are available in OpenCPN and they make an attempt at a graphical depiction of Baltic Sea currents by month in the North Atlantic volume (Pub 106). I don’t know that you’ll find this helpful due not only to the large scale, but all of the Baltic currents are shown as dashed arrows. The means they are based on sparse data and directional variability. In the Baltic, the don’t even appear to guess at current strengths.

[cagney]

SMHI (Swedish Met Office) issues Baltic current forecasts for about 60 h see...https://www.smhi.se/vader/prognoser/...ameter=current

The Danes has something similar for the North Sea/Baltic Entrance and S Baltic...https://www.dmi.dk/strom/

[Pandor]

Or Windy.com
https://www.windy.com/-Currents-curr...79,7,m:fgragHI

[StuM]

WIndy also forecasts a couple of days:
https://www.windy.com/-Currents-curr...9.052,15.996,5

[cagney]

Windy is based on Copernicus, and seems low resolution and very general, hence contains some garbage values.
Anyone believes this prediction...??
Windy Currents.pdf

The current "arrows" doesn't show up in the pic, but the basically goes across this narrow strait.

[Dockhead]

OK, that's great. Can any of these be downloaded as GRIBs which can be used by Expedition or OpenCPN weather routing?

[cagney]

These German gribfiles should be possible to use in OpenCPN wx routing.
I have not tested it myself though...
I do know that they display OK in O though. There was an issue with the grib2 files. Can't remember the current state of this issue.

https://www.bsh.de/EN/DATA/Currents/...lors_node.html

[StuM]

Originally Posted by cagney

Windy is based on Copernicus, and seems low resolution and very general, hence contains some garbage values.
Anyone believes this prediction...??
Attachment 236684

The current "arrows" doesn't show up in the pic, but the basically goes across this narrow strait.

If you expect a global model to take into account a series of complex 1km wide channels through a group of islands, I've got a bridge you may like to buy

[Dockhead]

Originally Posted by cagney

These German gribfiles should be possible to use in OpenCPN wx routing.
I have not tested it myself though...
I do know that they display OK in O though. There was an issue with the grib2 files. Can't remember the current state of this issue.

https://www.bsh.de/EN/DATA/Currents/...lors_node.html

EXACTLY what I was looking for! Thanks very much!


By the way, this gem of a resource also has current predictions for the Elbe -- invaluable for Kiel Canal transits. The Elbe is an unholy bitch with the stream running as hard as 6 knots downstream, and there are no reliable sources for currents, which vary according to the weather and not just according to the tide. I've been caught with the current turning more than hour before or after it should have.