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[Wait For Weather] [Long Term Outlook] [Intermediate Forecasts] [Short Term Predictions]

Weather -  trying to avoid the bad stuff - is an all-consuming topic for cruisers.  Resources for predicting it range from long term climate information to direct warnings from satellites overhead.  Pick and area of interest and read on!

Wait For Weather

The basic rule we use for  avoiding trouble is to wait until the weather is the way we want it for the upcoming passage.  Sometimes we want light winds to ease into a trip, other times we want to leave on the tail of a weather system that will help us along for a day or so.  The corollary to this rule is that most forecasts are 50-75% accurate for 2-3 days, beyond that they are unpredictable.

Long Term Outlook

The long term outlook is what we, and most long-distance cruisers, use to plan where we will be during each season: 

• Tropics during the Winter
• Equator or temperate region during the cyclone season
• Move with the trades and seasonal winds. 
• Move between tropics and temperate zones during Autumn and Spring.

This outlook is based on climate observations over many years, and on average, are reasonably accurate.  Of course weather does not always behave like the averages - out of season storms occur or other anomalies may affect this year's cruising, but using this information for planning where to be each season is the still the best approach. 

The cruiser's bible is World Cruising Routes by Jimmy Cornell - information about it and other sources of long-term weather prediction can be found on our Books page.  For those cruising the Pacific, the state of El Ni�o is important, and information can be found at the El Nino site

Intermediate Forecasts

All forecasts observe current conditions and use models to predict what will happen over the next few days.  We have learned a few things about the forecasts and the methods of delivery to the cruiser.

Forecasts

Weather forecasts of interest to most cruisers are produced by meteorological offices of various countries around the world (there are also a few private forecasters).  Accuracy depends on time and the model used. Our experience shows something like: 

• 24 hour     75% accurate, 
• 48 hour     60% accuracy
• 72 hour     <50% accuracy
• >72 hours  indicative information only

The US, Britain, and France have the most widely used models. We have been most impressed by the French models, particularly when we were in New Caledonia - we compared their predictions with actual conditions for approximately 15 days in 1998 and found them very accurate.  As cruisers we have no control over the models used - we get whatever information is available in the cruising area.

Methods of delivery

The forecasts produced by the Met services get to the cruisers by many means.  Some of them are:

Land-Based Cruiser nets

There are a number of radio networks around the world where volunteers provide information or service to cruisers.  Usually they are ham operators or ex-cruisers who operate radio stations on land and perform functions like:

• Track yacht locations
• Relay messages between land stations and yachts
• Relay weather forecasts from Weather Services and other cruisers

The ones with whom we have had experience include:

Short Term Predictions

All of the Sources and Delivery Methods for Intermediate Forecasts can be used for Short Term Predictions since they are usually based on current observations.  In addition there are a few extra assets for short term predictions:

• Direct Download Weatherfax - Polar satellites that circle the earth transmit photographs and infrared imagery as they pass overhead, and this can be received by special VHF receivers connected to a laptop. $US1000 to $2000 can buy a system from Xaxero or OCENS. 
• Direct Observation - By noting wind direction and speed plus cloud formation a reasonable prediction for the next 6 to 12 hours can be made.  Use the guidance in