Practical marine meteorology for sailors

Turn reading into a working skill

Start with the language of the data, then the decision. Work through chapters 1–8 in order if gusts and mean wind, issue and valid times, or tidal heights and streams are not yet distinct. Do not search for one magic departure number: build the whole picture for the boat, crew and time underway.

Answer before opening the explanation. Each page has our own questions. A useful answer includes the term, the source, a data limitation and a skipper action. Guessing the right answer without a reason does not demonstrate practical competence.

Build three practice briefings. Chapter 12 explores the Aegean, Bay of Biscay and Bahamas/Caribbean using clearly labelled fictional conditions. Repeat the structure with current primary sources for your own area. Never transfer the example numbers into an actual forecast.

Practise observation checks ashore. Record the station, time, sensor height and exposure, and compare only compatible variables. During changing weather, write which observation would force a review. Do not go into adverse conditions for the sake of an exercise.

Keep meteorology and navigation separate. A forecast does not establish depth, absence of rocks, permission to enter, anchorage suitability or vessel condition. Charts, notices, tidal products and local information remain separate necessary checks.

Print without an app. Open a chapter, expand any explanations you want to keep, then use the browser’s Print / Save PDF menu. Core reading and navigation work without JavaScript. Answers and scores appear only on the current page: they are not sent to the server or retained by the service after a reload.

Open the free passage briefing · Choose a sailing area and current sources

Working meteorology glossary EN → RU

Use these terms when reading international bulletins and weather interfaces. These are short orientation notes; confirm the precise variable definition and units in the particular product.

Issue / publication time / Время выпуска / публикации

When the forecast product was published. This may be later than the model reference time; opening the app is a separate retrieval event.

Model run / reference time / Цикл / исходное время модели

The reference time from which the model forecast is timed. It is not necessarily the time the data became available.

Valid time / period / Срок действия

The future time or interval described by the product.

Lead time / Заблаговременность

Valid time minus model reference time. Compare models for the same valid time while retaining each run and lead time.

Observation time / Срок наблюдения

Time of the measurement; later retrieval does not make it newer.

UTC / Всемирное координированное время

A common time reference. Confirm the local offset and daylight-saving rules separately.

hPa / mb / гПа / мбар

Pressure units: 1 hPa equals 1 millibar. Compare pressure at the same reference level.

Isobar / Изобара

A line joining points of equal pressure on a specified chart.

Pressure gradient / Барический градиент

Spatial pressure change; close isobars often indicate stronger wind, not an exact yacht wind speed.

Front / Фронт

A transition between air masses; its movement and structure matter more than a single symbol.

Dew point / Точка росы

Temperature at which cooling air reaches saturation under the stated pressure conditions.

True / apparent wind / Истинный / кажущийся ветер

True wind and the wind experienced on a moving boat use different reference frames.

Sustained wind / gust / Средний ветер / порыв

Averaged wind and a short peak. Averaging and gust definitions depend on the source.

Veering / backing / Поворот по / против часовой стрелки

Clockwise or anticlockwise change in wind direction; neither alone proves that conditions improve.

Fetch / Разгон волны

Length of water exposed to wind in a relevant direction, with duration also affecting the sea.

Wind sea / swell / Ветровое волнение / зыбь

Locally generated waves versus waves propagating away from their generating area.

Significant wave height, Hs / Значительная высота волн, Hs

A statistical description of a wave field, not the height of its largest individual wave.

Peak / mean period / Пиковый / средний период

Different spectral statistics; do not average them together as if they were the same variable.

Set / drift / Направление / скорость течения

Current direction and speed. Tide height does not directly supply either.

Datum / Высотная основа

Reference level for a charted depth or water level; mismatched datums invalidate clearance arithmetic.

Ensemble / spread / Ансамбль / разброс

A collection of forecast realisations and their variation; arbitrary app agreement is not a calibrated probability.

Watch / warning / Заблаговременное оповещение / предупреждение

Official labels have product- and jurisdiction-specific thresholds and lead times. Read the issuer’s definition.

Exposure / shelter / Открытость / укрытие

Conditions at the critical approach or anchorage may differ from a marina observation.

Forecast zone / Прогнозная зона

Defined coverage of a bulletin; coastal, offshore and high-seas zones are not interchangeable.

Review trigger / Условие пересмотра

A pre-agreed event or mismatch that makes the skipper reassess the plan.