Summer Squall Sailing Tactics

Posted by Darrell Nicholson at 05:42AM - Comments: (6)

Darrell Nicholson
Darrell Nicholson

Waterspouts often accompany squalls. This one was moving to the left of the frame. The usual advice is to take bearings and sail or motor 90-degrees to the direction it is moving.

Summer is here and the time is right . . .  for testing your squall-busting tactics.

The comparison of jibe-taming devices in the July 2017 issue of Practical Sailor is an appropriate topic for the summer when afternoon squalls so frequently add a little excitement during the leg back to the marina, or the approach to the next anchorage. 

A tempting response to the sudden increase wind that accompanies a squall is to ease sheets and run before the wind—flatten the boat out and ease the flogging sails. However, the danger in running before a squall (or tacking downwind, a tactic sometimes employed by offsore 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).

The ideal sail plan for dealing with squalls will vary by boat, visibility, sea conditions, and intensity of the squalls. Ideally, the helm is still relatively well-balanced and responsive for whatever point of sail you choose. A moderate amount of of weather helm ensures the boat won't be be overpowered in a gust. Lee helm is to be avoided. Same for excessive weather helm. If you're carrying a mainsail (presumably well-reefed), ease the traveler and be ready to ease the sheets.

At night, when squalls can sneak up on you with little warning, the most conservative approach makes sense. Our gaff-rigged ketch reefed down with a double- or triple-reefed main and staysail could handle about anything and still keep moving on squally night, but our main was easy to scandalize (dip the gaff) if the gusts were particularly intense. On a conventional a Marconi rig, it is not so quick and easy to reduce the area of the mainsail without flogging. However, if you're working to windward in daylight, a well-reefed (double or tripple-reefed) full-batten main can be feathered through a moderate squall with very little flogging as you motorsail.

When reaching or sailing further downwind, a common approach here in Florida is to motorsail with only a reefed. roller-furling headsail (preferably a staysail) which is kept up mainly to steady the boat when there's a sea running. (The headsail be balanced with a reefed mizzen on a ketch.) One caveat to the headsail-only approach is that if you have a masthead sloop with a big 135-150 percent genoa, the furling gear needs to be reliable. The last thing you want is for the furling line to part and this sail to fully open and start flogging during the peak gusts. Better to endure a little rolling while motoring under bare poles rather than risk a shredded a sail.

On a short-handed boat, dropping all sail and motoring is the most conservative approach, and makes sense when a particularly nasty squall line threatens.

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.”



The strongest wind gusts will be at the leading edge of the squall line, with the highest increased winds often arriving before the rain.

Squall Tips

Keep in mind, there are plenty of exceptions to these rules of thumb—but as Burch puts it, you have to start somewhere.

  1. Taller clouds generally bring more wind.
  2. Flat tops or “boiling” tops can bring brisk wind speeds and sudden wind shifts.
  3. 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.
  4. Track cloud/storm movement by taking bearings on the center of the storm (not the edges).
  5. Watch for whitecaps below the clouds, indicating strong gusts.
  6. “Tilted” clouds often bring wind.
  7. 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.
  8. 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.
  9. 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).

10. 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.

11. Behind any squall is a unnerving calm.

12. If you are faced with a number of successive squalls, they will often follow a predictable pattern, allowing you to fine-tune your tactics.

13. If you plan to bathe in the downpour, go easy on the shampoo—you might not get enough rain for a rinse.

Comments (6)

One factor, maybe the most significant In choosing which of the several measure cited above is sea state.

In coastal cruising situations where sea state is mild and squalls are frequently short lived. turning to wind either reefed down or motoring slowly with bare poles works well as seas will usually stay below say 3 to 6 feet. I took this action early morning in the Malacca Straits in the face of an approaching Sumatra. We experienced gusts over 50 Knots but duration was maybe 20 minutes and seas never went above 3 feet.

In contrast, running downwind in typical trade winds of 15 to 25 knots on a tropical ocean passage, seas will already be at least 6 feet, maybe 15 feet. Clearly, it would be folly to turn into wind. Instead, one must remain on the broad reach or run and reef down to the point that the yacht will nor run out of rudder and round up if hit by a gust to perhaps 20 percent above the steady state wind speed. That might mean bare poles or perhaps stay sail or storm jib only. One must recognize that the danger of rounding up and losing control is very real. Indeed, the autopilot or vane steering will almost certainly be overpowered thus the skipper should be hand steering during the episode. A late decision to shorten sail as I made once left me in the position of hand steering downwind with the yacht poised to round up if I allowed the wind angle to move from a straight run to about 20 degrees either way. That was because I really needed reef # 3 in the main to use self steering and could not safely do that until conditions reduced. Oh yes, we always had a preventer rigged.

Posted by: ARGONAUTA I | June 16, 2017 8:33 AM    Report this comment

One factor, maybe the most significant In choosing which of the several measure cited above is sea state.

In coastal cruising situations where sea state is mild and squalls are frequently short lived. turning to wind either reefed down or motoring slowly with bare poles works well as seas will usually stay below say 3 to 6 feet. I took this action early morning in the Malacca Straits in the face of an approaching Sumatra. We experienced gusts over 50 Knots but duration was maybe 20 minutes and seas never went above 3 feet.

In contrast, running downwind in typical trade winds of 15 to 25 knots on a tropical ocean passage, seas will already be at least 6 feet, maybe 15 feet. Clearly, it would be folly to turn into wind. Instead, one must remain on the broad reach or run and reef down to the point that the yacht will nor run out of rudder and round up if hit by a gust to perhaps 20 percent above the steady state wind speed. That might mean bare poles or perhaps stay sail or storm jib only. One must recognize that the danger of rounding up and losing control is very real. Indeed, the autopilot or vane steering will almost certainly be overpowered thus the skipper should be hand steering during the episode. A late decision to shorten sail as I made once left me in the position of hand steering downwind with the yacht poised to round up if I allowed the wind angle to move from a straight run to about 20 degrees either way. That was because I really needed reef # 3 in the main to use self steering and could not safely do that until conditions reduced. Oh yes, we always had a preventer rigged.

Posted by: ARGONAUTA I | June 16, 2017 8:33 AM    Report this comment

One factor, maybe the most significant In choosing which of the several measure cited above is sea state.

In coastal cruising situations where sea state is mild and squalls are frequently short lived. turning to wind either reefed down or motoring slowly with bare poles works well as seas will usually stay below say 3 to 6 feet. I took this action early morning in the Malacca Straits in the face of an approaching Sumatra. We experienced gusts over 50 Knots but duration was maybe 20 minutes and seas never went above 3 feet.

In contrast, running downwind in typical trade winds of 15 to 25 knots on a tropical ocean passage, seas will already be at least 6 feet, maybe 15 feet. Clearly, it would be folly to turn into wind. Instead, one must remain on the broad reach or run and reef down to the point that the yacht will nor run out of rudder and round up if hit by a gust to perhaps 20 percent above the steady state wind speed. That might mean bare poles or perhaps stay sail or storm jib only. One must recognize that the danger of rounding up and losing control is very real. Indeed, the autopilot or vane steering will almost certainly be overpowered thus the skipper should be hand steering during the episode. A late decision to shorten sail as I made once left me in the position of hand steering downwind with the yacht poised to round up if I allowed the wind angle to move from a straight run to about 20 degrees either way. That was because I really needed reef # 3 in the main to use self steering and could not safely do that until conditions reduced. Oh yes, we always had a preventer rigged.

Posted by: ARGONAUTA I | June 16, 2017 8:32 AM    Report this comment

Aim toward the light places on the horizon, not the dark ones!

Posted by: DaveChicago | June 15, 2017 1:40 PM    Report this comment

A rule I have found useful around the Chesapeake Bay is that if there is enough steady wind preceding the storm for reasonable sailing (>10 knots), the wind will increase, but not dangerously. A single reef is probably enough, but reduce farther if it's black and your gut tells you to. I like to reef main and headsails equally, for balance. The steady breeze will prevent deep convention. On the other hand, if the wind has died away to nothing, might as well take in all the canvas, since you're not sailing anyway. The convention will be uninhibited and downdrafts can really blast.

I sail a catamaran, so rolling is not a concern and the risk of sail damage or stretching is simply not worth it to me. I will hoist after the squall is past.

Posted by: Drew Frye | June 13, 2017 5:45 PM    Report this comment

Frontal Strategy
From our experience, the majority of localized fronts are marked by a gray sky transitioning to a definite line of approaching black clouds which will bring winds of 20-35 knots. Once in a great while, we have seen more severe frontal transitions from clear blue sky to a roiling black line of clouds blasting in far higher wind speeds. I cannot imagine any reason to have any part of a main sail up to face an initial slam of localized weather. Many boats will sail well into the 30 knots of wind under a jib or storm jib alone. Even our 40 year old, cruising laden 40', boat will sail at 5 knots powered by the storm staysail and 25-35 knots of cold pelting rain.

We have been caught off guard in such sudden weather flying a full main and jib. The main is the first to be dumped. To get the jib rolled up, we have had to run down wind to ease the pressure on the jib to safely furl it in and keep it from flogging itself into tatters.

With the setting of the storm/staysail, and if we feel the need to get through the weather as quickly as possible, we turn to head bow into the weather so we can just hold our own and let the weather blow on by. Otherwise, if the situation is tolerable, we just continue on our way with the little staysail.

The last thing to have up in a passing localized front is the mainsail. Having to turn into the wind and dump a main while it is trying to flog itself to death is a quick way to add to a boats list of needed repairs. To run off the wind or down wind under main is not a good choice. As the nautical writer Bill Seifert says "It is easier to pull a sailboat than to push it.", meaning the main, with its far aft and off to the side center of effort, will torque a boat around making for demanding steering and increase the risk of jybing. A jib, with its pulling effort far forward, is a much steadier trim for a boat going down or off the wind.

It has been extremely rare for us to see tornadoes at sea. But recently, while passing through a well defined localized front, our boat was surrounded by 5 small but powerful whirling dervishes, which were Hoovering up the ocean along the leading edge of the front. They moved off past our stern with the black line of clouds as our bow headed deeper into the torrential rain in the core of the storm. We did turn on the engine incase we had to make some drastic maneuver to avoid a tornado, but they did not wander about. Luck was in our cockpit.

Posted by: patrick childress | July 9, 2016 12:58 AM    Report this comment

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