Forecast methodology
One call, with the evidence left in.
Boat or Nope turns official forecasts, observations, tides, and marine alerts into a pre-departure planning view. Every destination keeps its source identities and links visible so you can check the call against the underlying data.
The short version
- Wind and weather come from the National Weather Service forecast point for the destination.
- Waves combine the available NWS marine grid with nearby NDBC buoy observations.
- Tides and supported current predictions come from NOAA CO-OPS stations.
- Official marine warnings, watches, and thunderstorm wording can hold a comfortable window at Caution or No-Go.
- Missing decision-critical data stays missing; it is not replaced with a made-up safe value.
How the daily call is made
The briefing compares each available forecast hour with the selected boat's wind, gust, and sea limits and the planned time on the water. Gusts default to five knots above the wind limit unless a boat preset sets its own gust limit. Boat or Nope then looks for a continuous window that stays inside those limits. The result is shown as Go, Caution, No-Go, or Incomplete, with a one-line reason beside it.
Active alerts are read from the destination point and from its marine forecast zone, including a separate nearshore zone when one is known. Gale, storm, hurricane, tropical storm, special marine, severe thunderstorm, tornado, tsunami, hazardous seas, and heavy freezing spray warnings are No-Go. Small craft, brisk wind, and dense fog advisories, marine weather statements, and gale, storm, hurricane, and tropical storm watches are Caution. Extreme or severe alert severity is still No-Go, and moderate severity is still Caution, even when the event name is not in those lists. Thunder in the hourly sky forecast is at least Caution. A wind or gust No-Go still counts when sea height is missing.
Where the data comes from
Wind, sky, and marine alerts
The National Weather Service API supplies the point-based hourly forecast and active alerts that intersect the destination.
Waves and observations
NOAA's National Data Buoy Center supplies nearby buoy observations. Where available, the NWS marine grid supplies forecast wave height and period. A buoy wave report newer than three hours can fill a gap in that grid, but the estimate is labeled and cannot produce Go. Reports older than three hours, and backup stations beyond the destination's stored distance limits, are not used.
Tides, water level, and currents
NOAA Tides & Currents supplies tide predictions, recent water levels, and current predictions where the selected station supports them.
Nearby aviation weather
AviationWeather.gov supplies nearby METAR and TAF context. It is supporting evidence, not a substitute for the marine forecast.
Source selection, freshness, and fallbacks
Each destination has named source bindings chosen for its coordinates. The page identifies the selected station, its role, its distance from the destination when known, the reason it was selected, and links to both the source and its documentation.
If a configured station is quiet or unavailable, Boat or Nope may try a reviewed nearby candidate. The source card discloses that fallback. It also reports timing and availability so cached, stale, or missing inputs are not presented as fresh observations.
What Boat or Nope does not decide
The call is planning guidance, not certified navigation, a route plan, or a substitute for seamanship. It does not know every local hazard, inlet condition, visibility change, vessel issue, crew limitation, or notice to mariners. Check official notices and current observations, use local knowledge, and make the final departure decision yourself.
Corrections and questions
If a destination name, source binding, or explanation looks wrong, email ahoy@boatornope.com with the page address and what you found. Todd reads it.