Maritime Weather Forecasting

Maritime activities are always risky, but there are many things that mariners and seamen can do to reduce the risks. Weather is one of several factors that cause maritime work and recreation to be risky and dangerous, but forecasting the weather can help prevent accidents that lead to shipping and cargo losses, injuries, and even fatalities.

Weather can be difficult to predict, especially on waterways, but good forecasting can help ships and their crews navigate and make decisions that reduce risks. Bad weather can cause ships and boats to capsize, to run aground, or to collide with other ships or objects. Knowing what kind of weather is coming is extremely important in making maritime activities safer.

Weather at Sea

Weather at sea is not the same as weather over land. The main driving forces are winds, including the trade winds, which blow to the west in the tropical oceans, and the westerlies, which blow to the east in the mid-latitude regions. Winds create surface ocean currents by dragging across the water. In the northern hemisphere, these currents move in clockwise rotations while in the southern hemisphere, they move in counterclockwise rotations.

There are also smaller currents that move along the edges of the major currents, called gyres. The smaller, boundary currents are numerous and include the Gulf Stream, which moves from the Gulf of Mexico, along the eastern coast of the U.S. and Canada, and across the ocean to the British Isles. These currents generate and influence much of the maritime weather that we see across the world’s oceans.

Weather generates waves and swells, which have a big impact on vessels. Winds produce waves in the oceans, and the size of the waves depends on the strength and duration of winds and how far the winds blow without interruption. Swells are groups of large waves that outrun the wind or storm that generated them. Ships at sea may also face rogue waves, unusually large waves among smaller waves. These can cause a lot of damage.

Waves and winds occurring together during storms are particularly dangerous and include hurricanes, also called typhoons and cyclones. These are very large and damaging storms. They are high-speed winds rotating around a calm center, called an eye. Predicting the formation, strength, duration, and path of a hurricane is an important part of maritime forecasting.

Accidents That Can Be Caused by Weather

Maritime weather can be unpredictable, and this is why forecasting it is so important. Forecasting isn’t perfect, but it does give navigators and other crew the ability to make better decisions about routes. The main types of weather that can cause maritime accidents are high winds, storms, and waves or swells. Any of these can cause ships to list heavily, which in turn can cause on-board accidents. Shifting cargo and equipment, falls, and overboard accidents can all result from rough weather and listing ships.

Ships can also get blown off course by severe weather, which can lead to serious accidents. These include running aground in shallow waters or on reefs, which can damage ships, throw crew members overboard, and even cause a ship to sink. Weather can even cause a ship to run into another ship or an object like a bridge, which can cause similar accidents.

Weather Forecasting Methods

Forecasting can be done in multiple ways. Satellites are important for tracking weather across oceans and other bodies of water. Meteorological satellites are dedicated to tracking weather and include those that orbit at the poles of the earth, stationary satellites that monitor just one part of Earth’s surface, and satellites that orbit the entire planet. Satellites can gather information about clouds, temperature of the air and water, currents, dust storms, ice coverage, and more.

Maritime weather is also monitored by weather buoys and weather ships. A moored buoy is a stationary device that can be tethered to one part of the ocean to collect weather information. There are also drifting buoys that track weather as they move across oceans. There are currently more than 1,000 drifting weather buoys across the world, helping to forecast marine weather.

Information taken from these weather stations and satellite is used by meteorologists and computer software to model currents and winds, to track temperatures and storms, and to predict what weather will happen next, where it will happen, and how it may impact ships and other vessels on the oceans.

Weather Forecasting Responsibilities

There are various official organizations around the world that are responsible for tracking and predicting maritime weather and sharing that information with the public and with commercial maritime operations. In the U.S. the National Weather Service of the National Oceanic and Atmospheric Administration tracks and predicts maritime weather, providing maps, forecasts, hazards, warnings, weather and storm models, and many other types of information that can be used by anyone heading out on the water.

Around the world, many countries have their own weather tracking systems and agencies. Internationally, the World Meteorological Organization provides guidelines for how these agencies operate and provide information in international waters.

The Importance of Using Marine Weather Forecasting

The information provided by marine weather forecasting agencies is important for preventing accidents by avoid storms and other weather-related hazards. The consequences of not using that information, of ignoring it, or of misusing or misjudging the information can be serious. One tragic example is the disastrous accident of the El Faro cargo ship.

The El Faro was lost in Caribbean waters on October 1, 2015. A month later the ship was found, sunk, and all 33 members of the crew died. The ship had sailed right into Hurricane Joaquin on its way from Florida to Puerto Rico. The subsequent investigation found that the captain, an experienced seaman, had the forecasting information about the storm but erred when he decided to keep the ship’s course and go right through the hurricane. Even with the best predictive information, crew members can make flawed decisions about weather that lead to disastrous results.

Maritime weather forecasting is an important tool for anyone in the maritime industry, from cargo ship captains to crew on smaller fishing vessels. Weather can be highly unpredictable, but good forecasting can help crew make better choices and avoid the kinds of disasters that can lead to tragic accidents, injuries, lost cargo, ship damage, and lost lives.