Dear Steve, I have just read your analysis of the Queens Birthday Storm 1994. First of all, I’d like to thank you for your efforts in producing such detailed analysis – they are a wonderful education for relative novices like myself. I do have a question you may be able to help me with.
I agree with your position that the best way to avoid bad weather is to get out of the way – by staying in shelter or sailing fast in a direction which avoids the storm track.
Avoiding the storm track has to rely on knowing which way the storm/low pressure system is likely to be moving. These days, with all the communication aids to obtaining recent surface charts obviously has made this vastly easier than it was 10 or 20 years ago.
However there may well be occasions when you have lost communication and you know, either from before your weather fax went down, or from increasing wind and the barometer going down, that there is potential for bad weather.
You can simply find in which direction the low lies and work out the quadrant you are in.
However, my question is, how reliably can you estimate the potential storm track if you are no longer getting comms? The latitude you are sailing in and in which ocean obviously has a strong bearing as most lows are likely to track NE, E or SE if you are below 25/30 degrees South. Is this true, or can you be more accurate than NE/E/SE, and how?
Cyclones can and do seem to go W – possibly more frequently than they track NE/E/SE? Why is this? And will tropical lows do the same?
There is probably a lot more to this than I realize, but I would be greatly interested in any comments you might have and how if possible can you predict the track.
Best regards, Peter P.S. I have purchased Practical Seamanship – love it, so also just ordered the Cruising Encyclopedia.
Hi Peter: Good question! First, the forecasts and faxes are usually a good indicator of general weather. But often the details on timing, location, and intensity will be off. So your off-the-boat sources need to be confirmed with onboard reality, and if there is a difference, appropriate adjustments made to tactics.
If all outside sources are down, you still have a pretty good idea of what is going on by logging barometric pressure, wind direction and velocity, waves, and cloud type/direction. The trends in this data will usually enable you to forecast the low center and where you are in relation to it.
There are usually trends in how systems behave in various parts of the world, and these can be used to help figure out what is going on. But sometimes weather systems behave differently than the norm. So, you need to be alert to variations.
Tropical lows are usually steered by upper level winds. However, while there are sometimes patterns to how this occurs, there are plenty of atypical situations too.
Our preference is to reduce risk factors by choosing the best season to travel, and avoid being bound by schedules. Taking this approach, together with getting the passage over with as quickly as possible, substantially reduces weather risks. Keep in mind that prior to the last 20 years, very little accurate offshore weather data was available. Regards – Steve
Posted by Steve Dashew (November 30, 1999)
