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.
National forecast responsibility changes quickly across these coasts and straits. Check the exact marine zone, tropical-system alerts where applicable, visibility and the latest local port or traffic notices.
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
Inter-island straits and coast forecasts should not be treated as one point.
Bali–Lombok legs include open straits and reef or surf-exposed arrivals, not just two island weather icons.
Use BMKG maritime forecasts for the correct sea area; check local current and swell at the planned crossing and arrival with up-to-date navigation information.
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.
BMKG divides the strait into named parts
The BMKG waters catalogue distinguishes northern and southern Lombok Strait and separate Bali and Badung waters. Match the plotted departure, strait crossing and arrival to those named products rather than using a Denpasar or Lombok city forecast. Keep the original Indonesian water name with a checked translation. A longer south-facing leg may need a different product from an island's northern coast.
- BMKG named Indonesian waters — Bali/Lombok subdivisions and Raja Ampat/Misool sectors; select actual route
Current, swell and reef access need separate evidence
A maritime forecast can describe sea and wind but does not establish the local phase of a strait current, reef entrance or surf-exposed harbour access. Obtain applicable hydrographic and current local information before assigning a transit time. Compare incoming swell at the destination with conditions in the strait. A regional current layer, especially without a verified run and resolution, must not be translated into a precise crossing instruction.
A delayed crossing may lose the arrival assumption
Compare departure options at both the exposed mid-crossing and the destination ETA, including a slower passage and daylight. If the later option depends on unverified local-current or entrance conditions, identify that limitation rather than describing it as a better window solely because wind falls. Refresh the next named BMKG product when adding another island; do not carry one strait forecast through the entire itinerary.
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.