Some notes on weather

Some notes on weather

Now that I have crossed into the Southern Ocean and now crossed into the East by crossing the 180th parallel and logged over 9000 miles of open ocean I thought some discussion on weather is due.

As a whole, since I left Seattle the weather and sea conditions have been very good. I would put the seas at following 40%, quartering aft 40%, beam seas 18% and a few times forward of the beam. The average sea is under 10 foot and over 12 seconds. Much of the trip has been in calm seas and some in over 10 foot but again with long period so quite comfortable.

One interesting note; I have the forward master stateroom layout, and there has been much discussion of that layout’s comfort at sea. There have been a few nights were it was bouncy enough to move me to another berth, but I would put that occurrence at less than 10%. The trade off is that I get the large open hatch at anchor, something I have learned to love.

Winds have been well within the comfort zone all the time with a few minor exceptions. Again in general terms; 0-5 knots 20%, 5-10 knots 30%, 10-15 knots 30% and 15-20 knots 18% and a few times over twenty. The top wind we have seen is 30 knots. So it is about like cruising Puget Sound for a summer. I have yet to see weather as bad as a Puget Sound winter gale.

I think I have mentioned this before, the rag “Jerry Doll” that sits on my dash has only fallen from his perch twice since I left Seattle. Once just off the Columbia River and once in a rough albeit short 12 mile crossing from Morrea to Papeete we made to get a crew member to the airport. These are certainly the two roughest times on the whole trip and both were very short.

I have diverted course twice to account for weather and make for a more comfortable ride; once in the Rarotonga to Nuie crossing and once just outside of Fiji. Both were times were we ran into small squalls with head winds, a simple 30 degree course change made for a smoother ride although extended the crossing a bit.

Weather prediction here is fairly easy, there is not the “weather channels” on the VHF we count on so much in the States, and where there are broadcasts they are in French—what did he say? 30 knots? Where? When? Yikes!

The primary source of weather information are the GRIB files downloaded from the SSB through Sailmail or via internet. I have found them to be very accurate in broad terms but sometimes miss the small systems. While within internet range other sources are used, is very good here. I start studying weather about 5 days before a crossing to determine patterns. I, and any captain worth his salt, make my departure date around the weather.

The pattern this time of year—remember it is winter here—is a series of low pressure systems in the southern ocean going from west to east. As they pass below us we get the tail end of the system with rotating winds. The wind picks up and clocks around from the normal SE to S to SW and even NW sometimes. Then it rotates back to the SE trade. For us power boaters the best time to leave is just after the system has passed and the winds are very light. A few days after the passing the trades build back up to the normal SE 10-15.

By following the above plan we usually leave a few days before the sailboats hence our early arrivals at most of the destinations. That makes for a good time as our friends “catch up”. The last crossing was a prime example; we left and cruised two days in flat calm weather, the wind picked up the last day of the trip—that is when our friends left Tonga.

With simple planning and some flexibility, we have managed to cross 9000 miles of ocean and keep “Jerry” happy in his perch.