Squall Tactics for Sailors
Posted by Darrell Nicholson at 05:27PM - Comments: (4)
August 18, 2014
I got a little re-education in squall tactics last week my boys and I took advantage of the last week of summer break with a 160 mile-passage south to the Dry Tortugas from Sarasota, Florida. The trip was aboard the Lost Boyz, an Endeavour 42 that boatbuilder Robert Helmick and his 14-year-old son Cameron are restoring.
The good news/bad news of the trip was a high-pressure ridge (unusual for summer) followed us south, leaving little wind and less than two-foot seas for the voyage. While I would have preferred a long reach, the windless spell offered a good opportunity rigorously test Yanmar’s new 57-horsepower common-rail diesel. Helmick is among a few lucky souls chosen to beta-test the new engine, which performed flawlessly for our trip. (I’ll be giving a more in depth report on the engine in an upcoming issue of Practical Sailor.)
As much as the chug-chug of the diesel grates my nerves, the calm weather took the edge out of the first overnight offshore passage for my sons (ages 10 and 12). It was also the first offshore passage for two other crew on the trip, Andrew Tanner and his 11-year-old son Sebastian. (Tanner is a solar energy specialist from Region Solar www.regionsolar.co who will be helping us with our forthcoming report on solar panels.)
While high pressure ruled most of our week in the Tortugas, some exciting weather squalls and waterspouts moved into the area for the return leg to Sarasota. After a lifetime of boating in the tropics, I thought I had my squall tactics ironed out, but a particularly nasty cell snuck up at sunrise. A jammed furler hampered efforts to reduce sail in time, and we ended up putting an ugly little rip in the leach of Lost Boyz’ 24-year-old 135 genoa. A 150 genoa was already high on Helmick’s list of priorities; and our little mishap no doubt bumped it up a little higher.
I should have known better. My wife Theresa and I lost count of the number squalls that spoiled midnight watches while we were cruising in our 32-foot gaff-rigged ketch, Tosca. The worst we encountered struck near Papua New Guinea, where vicious, but short-lived storms always seemed to arrive on the blackest nights and brought torrential rain. We usually tried to reduce sail early, but if we were caught off guard, our usual tactic was for Theresa to take the tiller and run before first gust, blanketing the jib with our gaff main while I shimmied out on the bowsprit and dropped the yankee. Of course, modern boats with a roller-furling jib make dealing with squalls much easier, but as I found last week, that ease can breed complacency.
The danger in running before the squall (or tacking downwind, a tactic sometimes employed by Transpac racers) is the inevitable wind shift that can cause an accidental jibe. Since squalls are usually short lived, with the strongest winds lasting less than 20 minutes, simply reducing sail to a safe configuration and motoring through is a less taxing approach. What is a "safe" configuration? Gusts much over 40 knots are not common, but some devastating downbursts in excess of 50 knots can occur in volatile areas. (The fatal squall line that struck the fleet in the 2011 Chicago-Mac race is a good example). Theresa and I would go with a single- or double-reefed main and a ready hand on the tiller, but dropping all sail and motoring makes sense when a particularly nasty squall line threatens. The nice thing about the gaff main is we could "scandalize" the sail by dropping the peak, quickly reducing the sail area by about one-third.
While every squall is different, there are a few rules of thumb that can help guide your decision-making process. The following bits are culled from my own experience and a couple of weather books I’ve found helpful over the years, Bill Biewenga’s “Weather for Sailors,” and David Burch’s “Modern Marine Weather.” Burch’s book has some handy illustrations showing the direction of wind flow around a typical squall. I’d be interested in learning the titles of other books that cover squall tactics in detail—most seem preoccupied with hurricanes and winter gales, storms that the average sailor rarely encounters.
If you are the type who benefits from seminars, look for those offered by former NOAA forecaster Lee Chesneau (www. marineweatherbylee.com), author of “Heavy Weather Avoidance.” Chesneau will be doing an article on passage planning for us later this year.
Keep in mind, there are plenty of exceptions to these rules of thumb—but as Burch puts it, you have to start somewhere.
- Taller clouds generally bring more wind.
- Flat tops or “boiling” tops can bring brisk wind speeds and sudden wind shifts.
- Slanted rain generally indicates there is wind. Squalls often move in the direction of (or sideways to) the slant, so don’t assume that the cloud is “dragging” the rain behind it, as it might appear.
- Track cloud/storm movement by taking bearings on the center of the storm (not the edges).
- Watch for whitecaps below the clouds, indicating strong gusts.
- “Tilted” clouds often bring wind.
- The first gust, usually a cool downburst, can strike one-to-two miles before the cloud is overhead, and before the rain starts, so reduce sail early.
- The strongest gusts and the increased wind accompanying the squall generally blow in the direction of the cloud movement, i.e. outward from the “front” of the cloud. However, increased wind blows outward from all sides of the cloud.
- Squalls do not necessarily come from the direction of the mean ambient wind, so squalls to weather are not the ones to worry about. It is the ones to the right of the true wind, about 30 degrees, that are headed toward you (i.e. if a southerly wind is blowing, it is the squalls to the southwest to watch for).
- The strongest wind comes with or just before the light first rain. If the squall arrives already raining hard, the worst winds are usually past, but strong gusty winds are still possible.
- Behind any squall is a unnerving calm.
- If you are faced with a number of successive squalls, they will often follow a predictable pattern, allowing you to fine-tune your tactics.
- If you plan to bathe in the downpour, go easy on the shampoo—you might not get enough rain for a rinse.