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A Weather Eye: Part Two

A Weather Eye: Part Two

Plain sailing or battling storms: You chose

By Dick Beaumont

The sailor’s ability to access weather charts during ocean passages via satellite has reduced the probability of running into heavy weather. Undoubtably it improves safety at sea immeasurably. Although it will never be an alternative to a blue water yacht’s liferaft, I believe it to be at least of equal importance.

Twenty-five years ago my trusty Carl Ziess sextant was usurped by a hand-held GPS that gave me an instant position fix, accurate to 25mts or so, anywhere in the world, simply by switching it on. Three or four years later electronics chart chips relegated paper charts to the same locker as my sextant. Both became the backup plan, but while virtually every yacht today has a GPS chart plotter installed, Satellite Communication systems are still considered by many to be a wish list item.

Think again. With weather patterns and seasons becoming far less predictable than they once were, due to the effects of global warming, every blue water sailor should include this equipment and the weather services they can provide on their yacht, as a matter of course. I believe every blue water skipper should know how to use the vital information it will provide.

In preparation for this article, we began downloading grib files for an imaginary ocean passage across the Atlantic from Gran Canaria to Annapolis USA and we got lucky.

The series of weather charts below perfectly illustrates the huge benefit to safety at sea that use of the satellite link and weather charts will provide. 

On this imaginary voyage, we planned to arrive in the Florida sea area around the 1st of November after the end of the supposed hurricane season. We were planning on the basis of a 21-day crossing which averaged 160nm a day. This is a conservative daily run allowance on a 50ft cruising yacht such as a Kraken 50.

These are real charts as downloaded since the 10th of October 2020 via LuckGrib.

Without the accurate and reliable weather forecast charts we show below, if this had been a real voyage, had we had continued on the passage plan we made, as you would normally do without being able to see how the weather systems were changing, we would have run straight into the centre of a very serious storm that developed after we had left port. 

Day one: actual weather chart

This is a weather chart generated by GRIB files on the day of our virtual departure. I’ve input the passage plan or route I had chosen in white. It shows very stable weather conditions which would be perfect for the crossing if it held good. 


Day one: 5-day forecast chart

I normally use weather forecast charts for the period 5 days ahead. Anything further ahead than that often proves unreliable. If the 5-day forecast identifies something of concern I then start loaoking at the shorter and longer-term forecast to get a handle on what might develop. It’s a great time to go. We will follow a route from Las Palmas, Gran Canaria along, or just below latitude 30deg North then at about 10-11 days we will start to swing north as we get closer to Florida. All should be good downwind sailing, most of the way.


Day five: 5-day forecast chart

We’re almost 1,000 miles along and the 5-day forecast is still looking good although we may lose the wind further along.


Day Seven: 5-day forecast chart

Uh oh! The 5-day forecast doesn’t look so good now. I don’t like the look of that depression forming right on our route. Because I have five days and nearly 1,000nm of sailing to run before reaching the forecast position of the depression, we have time to change course and go north keeping the wind behind us and avoid the depression if necessary.


Day eleven: 5-day forecast chart

The five day forecast shows it’s going to be a storm and will continue tracking north and deepening, as expected. I’ll continue further north-west to go well clear north of the storm. I’d be looking at the forecasts for 1-4 days too from now on, so I can see any changes to the forecast.

Note: My original course would be taking me right into the path of the storm.


Day Sixteen: Actual chart

This chart is an actual real-time weather chart for day sixteen. We are now right over the top of the storm. We’ve kept a freshening wind behind us all the way and would have made very good progress.


Day twenty one: actual weather chart

We made it into the Chesapeake Bay on time! The storm passed right through our track, but as you can see, we kept well clear of it throughout our passage.

We sailed around 150nm further, but picked up good following wind, so would have sailed a bit quicker, virtually.

With weather charts at your fingertips, via satellite link, your actual passage making  can be as achievable as this virtual one.

After getting battered by a forming typhoon off the coast of Palawan, on passage to Borneo eight years ago, I installed a Sat Com system and have utilized GRIB file weather forecasts on every passage since.

I’ve had a few bad squalls, caused by local thunderstorms, that produced up to 50 knots of wind for a few hours at most. I’ve also knowingly sailed into winds of 50kts plus when it was abaft the beam, which in a Kraken yacht poses no challenge, but have avoided the head-on heavy weather that populated my ocean sailing before I installed the satellite system onboard Moonshadow, my yacht prior to White Dragon, Kraken’s flagship.

Fair winds.

Dick Beaumont

Chairman, Kraken Yachts

Next Month: Reading the signs, clouds, wave trains and the barometer.

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