This is a pre-passage source and decision desk, not a current forecast or clearance to depart. The map is centred approximately on the area, not on your route or a forecast-zone boundary.
Sea-area bulletins and archipelago or fjord conditions have different scales. In season, check ice and sea-level products; in narrow passages also examine current and visibility, not only mean wind.
1. Primary sources
Open current bulletins and warnings for every sea area on the route. These links are starting points, not a promise that each covers the whole location; if unsure, identify the issuer through WMO–IMO.
2. Route and local effects
Open-sea numbers cannot resolve every narrow channel or lee shore.
Swedish skerry sailing can move between a nearly enclosed channel and an outer archipelago in minutes.
Use SMHI sea areas and coastal observations with their precise exposure; compare water level and visibility at the outer section rather than a city wind reading.
How to use this source set
Start with the warning, then the marine text for the exact named area. If the route crosses a zone boundary, obtain both bulletins. Note issue and valid times, wind units and the meaning of wave height. Where a link opens an agency portal, navigate to its current marine product; a homepage is not itself a forecast.
Compare with an exposed station or buoy if available. Check its position and observation time: a sheltered station does not overturn a warning for an open channel. If a bulletin is missing or stale, identify the issuing service via WMO–IMO and defer the decision until current information is available.
Before-passage check
- Mark departure, exposed legs, arrival and feasible diversions; find the responsible named marine areas for each.
- Check warnings, issue and valid times; assess conditions when you expect to reach each leg, not only at departure.
- Compare wind and gusts, waves and swell, visibility, thunderstorms and local effects; do not infer a strait from a sheltered harbour.
- Compare recent observations where available, noting their time and exposure; a mismatch calls for another check.
- Set the next bulletin check, a reassessment trigger, an alternative and a backup communication channel.
Model map — optional
Windy is a third-party model display, not the issuer of official warnings. Choose a layer and check its valid hour and model run. Nothing loads until you click.
Without JavaScript, open the map separately.
If connectivity fails
Before departure, save the current official text bulletin and warning with issue time. Arrange another way to receive updates, such as an appropriate coastal broadcast, NAVTEX or satellite channel. A saved map cannot replace new warnings.
How to choose weather tools · All sailing areas
Scope: Source list assembled 25 September 2026; check its freshness and coverage before use. This public area guide is not a current personalised forecast, navigational notice service or safety verdict. Personalised forecasts with AI and experts are in closed testing; public booking is not open. The skipper makes the decision.
The outer-skerry leg deserves its own weather line
For a Stockholm-archipelago or Swedish west-coast itinerary, label the inner channels, outer-skerry stretch and final anchorage separately. Choose SMHI's sea/coastal area applicable to the actual side of Sweden. A sheltered inner station may help confirm departure conditions but not the wind and wave exposure beyond the skerries. The forecast direction also decides which side of an anchorage can receive waves; the same place is not sheltered from every direction.
- SMHI sea-weather services — Shipping/sea-coast forecasts, coastal observations, water-level/wave and ice products.
Read the level reference before reading the depth
SMHI provides water-level/wave products and coastal observations, and distinguishes level relative to mean water from RH2000. Preserve that label when writing the brief; do not apply a numerical value directly to chart depth without checking compatibility. For narrow channels, visibility, current chart information and actual water level are separate planning inputs. A model wind field cannot resolve a submerged rock, bridge restriction or a local depth margin.
A short inner alternative must actually reduce exposure
When the outer section deteriorates, compare an inside route only if its charting, access and crew capability are confirmed. It may reduce wave exposure while increasing navigation workload or restricting retreat. Reassess when wind direction changes the anchorage, visibility no longer supports the intended visual plan or a level observation is stale. Keep a dated ice check where seasonally relevant, not an assumption that a popular cruising area is always ice-free.
- SMHI sea-weather services
- RYA passage planning — Practitioner guidance on contingency, tides, vessel and crew constraints.
Editorial review of this material: 27 September 2026. This date concerns the page content; check current forecast issue times and validity at the original sources.