April 13, 2010

Advisory advice

(Drop by every Monday, Wednesday, Friday, for a new Mainly about Boats column.)

WEATHER FORECASTS were very much on my mind when last I singlehanded down the wilderness coast of British Columbia. Every evening I listened to the pessimistic prognostications and soon came to the conclusion that if I waited for good weather I’d never get anywhere. The main concern, for me, was wind direction. With sheltered anchorages 30 to 40 miles apart, a fair gale was okay. Light headwinds were not.

In my part of the world we get what are called “small-craft advisories” via VHF radio when the weather doesn’t look too good. But there seems to be no agreement on what constitutes a “small boat” or at what wind speed to issue an advisory. Mostly the range is from 22 to 33 knots of wind sustained for at least two hours, though some advisories are issued when the forecast is for 18 knots. It depends on local conditions.

Gale-force winds start at 34 knots (Force 8 on the Beaufort Scale), so if you ignore a “small-craft advisory” you could find yourself on the edge of a fully fledged gale. Nevertheless, if you want to get anywhere when you’re cruising, you have to learn when to ignore these advisories with the benefit of your own experience. There is little more frustrating than being bottled up in port because of a series of adverse weather forecasts, especially when the threatened bad weather never materializes.

The fact that even professional weather forecasts are often wrong is not surprising because forecasting is a very inexact science. There are a couple of useful rules I use when I’m doing my own weather forecasting, and one is never to trust a forecast more than three days ahead. Another is that the weather tomorrow will be more like today’s than yesterday’s. And a third is that the barometer is your best friend.

I know one sailor who learned early on to be her own forecaster. Jennifer Moran, who now cruises extensively in Australia, was a cadet reporter on a Durban metro daily newspaper when I first knew her. Every morning she would telephone the weather bureau to get a one-sentence forecast for the front page, and every morning the weather man would mutter and complain. After about a month of that, Jennifer decided she’d had enough of the grumbling. She figured it was pretty easy most mornings at 7 a.m. to tell what kind of day it was going to be, so she made up her own forecast after looking out of the newsroom windows.

This worked well for about six months, and she was wrong only a couple of times. Then she was wrong two days in a row, and someone complained. Her news editor asked where she was getting the reports from, and she confessed. An investigation revealed that the news editor’s secretary was also phoning the same man at the weather bureau every morning for the extended weather report — just 15 minutes before Jennifer called. Little wonder the weather man was disgruntled.

Anyway, they got it sorted out, and the accuracy of the official front-page forecast naturally declined somewhat thereafter. But Jennifer learned a valuable lesson about reporters’ sources — if they get it wrong, you can blame it on them. And there’s plenty of blame to go around, it seems.

Today’s Thought
Looking out of the window is the most important thing if you want to know what’s going on.
— Harold M. Gibson, Chief Meteorologist, NYC Weather Bureau, 30 Mar 84

Boaters’ Rules of Thumb, #39
Steering error. If your steering, or your compass, is out by 5 degrees, you will be one full mile off course for every 11.5 miles run.

“Bad news, darling — the dog ate your supper.”
“There now, don’t worry, my sweet. We’ll get a new dog tomorrow.”

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