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.
A long high-latitude or transoceanic leg crosses forecast responsibilities and update cycles. Separate meteorology from current chart, ice, port and navigation warnings, and plan a dependable offshore receiving channel.
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
Choose the METAREA V and coastal product for the actual leg.
Brazil’s Atlantic coast spans many separate Navy marine sectors and very different coastal approaches.
Choose the Brazilian Navy warning and forecast for the exact sector; compare swell and coastal current with the intended harbour rather than a nearby inland forecast.
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.
Select the CHM sector for the timed coastal leg
Brazil's coast is too extensive for one generic departure number. Select the appropriate Brazilian Navy CHM coastal/oceanic product and preserve its geographical definition. The metocean bulletin links synoptic systems, wind/wave expectations and warning context for METAREA V; it is more than a city forecast near the marina. For a coastal itinerary, keep each exposed stretch and destination approach separate rather than applying the departure sector to the whole route.
- Brazilian Navy CHM metocean bulletin — METAREA V synoptic, wind/wave and warning context; inspect attached issue.
A warning, model and buoy answer different questions
Read the adverse-weather warning alongside the forecast, retaining its start/end and time convention. CHM's warning interface notes that a map summary can use local computer time while the full text stays in UTC. Do not mistake a predicted coastal sea event for a measured harbour condition. A buoy, where available and representative, supplies point evidence; a regional current field is not the actual flow at a river or bar entrance.
- CHM adverse-weather warnings — Warning map summary may use local time; full warning text uses UTC. Direct product verification is limited; obtain the current issue from the issuer.
- Brazilian Navy CHM metocean bulletin
Reassess the front against arrival, not just departure
For a coastal passage with an expected weather-system change, compare the arrival after reduced speed and any waiting period. If the revised warning or wave direction removes the intended refuge, reassess before passing the last confirmed alternative. A long chain of possible harbours is not proof of continuous refuge. Keep local entrance notices and current chart information independent of the attractive offshore wind or current shown by an app.
- Brazilian Navy CHM metocean bulletin
- CHM adverse-weather warnings
- 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.