Pressure

Pressure in marine weather is the atmospheric weight of air over the sea surface, usually reported as barometric pressure. It is measured in hectopascals or millibars, and the pattern of high and low pressure areas creates the pressure gradients that drive wind, fronts, squalls and changes in sea state.

For boaters, falling pressure can signal an approaching low, stronger winds or deteriorating conditions, while rising pressure often indicates more settled weather. Track readings in hPa or Millibar alongside Wind Speed to judge whether to reef, delay departure, alter course or choose a more sheltered anchorage.

PredictWind forecast maps and GRIB downloads show pressure patterns from leading models, helping crews understand why the forecast wind is changing along a route. Used with Weather Routing, pressure trends support safer passage planning, better timing and clearer decisions offshore.