Introduction

The forecast called for sustained winds of 15 knots as we prepared to transit Long Island Sound from New London to Port Jefferson. Fifteen knots is manageable for tug and barge operations—routine work we do every week. But buried in the details was a gust forecast of 28 knots, and that changes everything.

Sustained wind speed tells you what the average wind is doing. Wind gusts tell you what happens when things get interesting. That 13-knot difference between sustained and gust isn’t just a bigger number—it’s the difference between a barge that stays where you put it and one that gets pushed sideways during critical alongside operations. It’s the difference between lines that hold and lines that part. It’s the difference between routine and sketchy.

Most mariners check wind forecasts and focus on the sustained speed. That’s understandable—it’s the prominent number, and it represents what the wind is doing most of the time. But professional operations require understanding when gusts matter more than sustained winds, and how to use gust predictions to make better decisions.

In this guide, you’ll learn what wind gusts actually are, when they become critical for operations, how to interpret gust-to-sustained ratios, and how Mariner Studio’s dual wind displays help you plan for the peaks rather than the averages.

Understanding Wind Gusts

Wind gusts are brief increases in wind speed that last anywhere from a few seconds to a couple minutes. When weather models forecast sustained winds of 15 knots with gusts to 25 knots, they’re telling you that the average wind is 15 knots, but short-term bursts reach 25 knots.

The sustained wind speed is calculated as an average over a specific time period—typically two minutes for marine forecasts. The gust speed represents the peak wind observed during that same period. This distinction matters because your vessel responds to both the steady force of sustained winds and the sudden punch of gusts.

Gusts form when turbulent eddies in the atmosphere briefly transport faster-moving air from higher altitudes down to the surface. Think of the wind as a flowing river with swirls and pockets of faster current. When one of those fast-moving pockets reaches down to your position, you experience a gust.

Several factors influence how gusty conditions become. Unstable atmospheric conditions—like cold air moving over warmer water—create more vertical mixing and stronger gusts. Terrain and obstacles create mechanical turbulence that produces gusty conditions. And convective activity, like passing squalls or thunderstorms, generates powerful gusts as downdrafts hit the surface.

When Gusts Become Operationally Critical

Not every gust forecast demands special attention. A forecast of 10 knots sustained with gusts to 13 knots barely registers—that’s normal variability. But when the difference between sustained and gust speeds grows, you need to shift your planning focus from the average to the peaks.

The 50% Rule

I use a simple guideline: when gusts forecast 50% or more above sustained winds, plan for the gusts, not the sustained speed. With 15-knot sustained winds and 25-knot gusts, that’s a 67% increase—well into the range where gusts drive operational decisions. With 20-knot sustained and 35-knot gusts, you’re at 75%—definitely plan for those peaks.

This ratio matters more than the absolute numbers. Ten-knot sustained winds with 18-knot gusts (80% increase) demand more respect than 20-knot sustained with 27-knot gusts (35% increase), even though the second scenario has higher absolute speeds. The first situation indicates unstable, turbulent conditions where the wind varies dramatically. The second shows stronger but more steady winds.

Operation-Specific Thresholds

Different marine operations have different sensitivity to gusts. Here’s when I start planning around gust forecasts rather than sustained winds:

Alongside Operations: Putting barges alongside ships, docking large vessels, or any precision maneuvering in tight quarters—gusts matter whenever they exceed sustained winds by 8-10 knots or more. A sudden 10-knot gust when you’re 15 feet off a ship’s side can push you into dangerous proximity before you can react.

Towing Operations: Towing long tows or light barges offshore—gusts become significant when they reach 20 knots or exceed sustained winds by 40%. Light barges act like sails, and a sudden gust can cause the tow to sheer off course or broach.

Anchoring and Mooring: Setting anchors or picking up moorings—gusts matter when they hit 25 knots or more, regardless of sustained speed. That burst of wind can cause your vessel to overrun the anchor or overshoot the mooring buoy.

Sailing Operations: For sailboats, gusts become a reefing consideration when they exceed sustained winds by 8-10 knots. Rigging that’s balanced for 15-knot sustained winds will be overpowered when 25-knot gusts hit.

Small Boat Operations: Smaller vessels under 30 feet—gusts matter at lower absolute speeds. Fifteen-knot gusts can be challenging for a 20-foot center console, even when sustained winds are only 8-10 knots.

Pro Tip: When gusts forecast at 25 knots or higher, I brief the crew specifically about gust potential. Everyone needs to be ready for sudden wind shifts and increased forces on lines and gear. This is especially critical during alongside operations where there’s no margin for error.

How to Use Mariner Studio’s Gust Forecasts

Mariner Studio displays both sustained wind speed and gust forecasts for every location in your favorites and every point you check on the map. This dual display lets you evaluate both the average conditions and the peaks you’ll encounter.

Reading the Wind Display

Open any weather forecast in Mariner Studio and you’ll see wind data presented with two key numbers: sustained speed and gust speed. The sustained speed appears as the primary number, while the gust speed is shown separately, making it easy to compare both at a glance.

For each hour in the hourly forecast, you see both values. This lets you track not just how wind speed changes throughout the day, but also how the gustiness varies. Some hours might show 18 knots sustained with 23-knot gusts—a relatively steady wind. Other hours might show 15 knots sustained with 28-knot gusts—much more variable and turbulent conditions.

Identifying Problem Hours

When planning a passage or operation, I scan the hourly forecast looking specifically for hours where the gust speed spikes significantly above sustained winds. These are your problem hours—times when conditions will be more challenging than the sustained wind speed suggests.

For a Long Island Sound transit, I might see:

• 0800: 12 kt sustained / 16 kt gusts (steady conditions)
• 0900: 14 kt sustained / 18 kt gusts (still manageable)
• 1000: 15 kt sustained / 22 kt gusts (getting gustier)
• 1100: 16 kt sustained / 28 kt gusts (problem hour)
• 1200: 15 kt sustained / 26 kt gusts (still gusty)
• 1300: 14 kt sustained / 20 kt gusts (improving)

That 1100 hour stands out immediately. The gust speed is 75% higher than sustained—that’s when conditions will be most challenging. If I can shift my departure to arrive at critical navigation points before 1100, or delay until after 1300, I avoid the worst period.

Using Long-Press for Route Planning

The long-press feature becomes especially valuable when checking gust forecasts along your route. Tap and hold on any point—a narrow passage, a harbor entrance, an exposed headland—and you get the complete wind forecast including gusts for that exact location.

When planning that New London to Port Jefferson run, I long-press on Orient Point, the most exposed section of the route. The sustained winds might be forecast at 18 knots, but the gusts show 32 knots. That’s the real number I need for planning—32 knots is what I’ll be dealing with when rounding that point.

Compare that to the forecast for Port Jefferson Harbor, where long-pressing shows 15 knots sustained with 22-knot gusts. The destination is significantly less gusty than the exposed transit, which might influence whether I proceed or wait for better conditions.

Pro Tip: For tug operations in confined waters, I check gust forecasts at three key points: departure location, most exposed section of route, and arrival location. If any of these shows gusts above my operational limits, we adjust the schedule. The most exposed point usually drives the decision.

Real-World Applications

Scenario 1: Alongside Operations in Gusty Conditions

We were scheduled to put a loaded petroleum barge alongside a tanker in New York Harbor. The morning forecast showed 18 knots sustained with gusts to 30 knots—a 67% increase that put us well into the “plan for gusts” range.

The sustained wind of 18 knots was within normal limits for this operation. We regularly work in 20-knot sustained winds without issue. But those 30-knot gusts changed the calculation. When a gust hits during the critical moment when you’re three feet off the ship’s side, that extra 12 knots of force can push you into contact before the engines can compensate.

Using Mariner Studio’s hourly forecast, I scanned for a window when the gust-to-sustained ratio improved. At 1400, the forecast showed 16 knots sustained with 22-knot gusts—still gusty, but only a 38% increase. We delayed the operation two hours, and the approach went smoothly. Those 22-knot gusts were manageable; the 30-knot gusts would not have been.

Scenario 2: Fishing Offshore with Variable Winds

A friend runs a charter fishing boat out of Montauk. He checks Mariner Studio every morning before deciding whether to run offshore. One morning showed 12 knots sustained—well within his comfort zone—but gusts to 24 knots.

That 100% increase in wind speed matters when you’re fishing 20 miles offshore in a 28-foot center console. The sustained winds would produce manageable 3-4 foot seas. But those 24-knot gusts, even if brief, kick up short-period wind waves on top of the underlying swell. The result is confused seas that are much more uncomfortable than the sustained wind speed suggests.

He checked the detailed hourly forecast and saw the gusty conditions would persist through midday before settling in the afternoon. He adjusted his plans, running inshore for sea bass instead of offshore for tuna. By the time he would have been 20 miles out, clients would have been miserable in those gusty conditions.

Scenario 3: Sailing Decisions Based on Gust Potential

Sailing in Narragansett Bay on what appeared to be a perfect day—forecast called for 15-knot sustained winds from the southwest. But the gust forecast showed 26 knots. That’s a 73% increase, signaling unstable, gusty conditions rather than steady breeze.

The sailor had rigged full working sails based on the 15-knot sustained forecast. But when those 26-knot gusts started rolling through, the boat was overpowered and difficult to control. She had to drop sails, reef down, and regroup—all while fighting overpowered conditions.

Had she checked the gust forecast before leaving the dock, she would have started with a reef in the main and a smaller jib. The boat would have been balanced for the gusts, not the sustained winds, making for a more controlled and enjoyable sail. When gusts exceed sustained winds by 50% or more, rig for the gusts.

Best Practices for Using Gust Forecasts

Plan for the Peaks, Not the Averages

When gust forecasts exceed sustained winds by 50% or more, base your operational decisions on the gust speed, not the sustained speed. If gusts forecast at 30 knots, that’s your planning number regardless of what the sustained wind shows. Your vessel, your crew, and your gear will all experience those 30-knot peaks.

Identify Your Personal Thresholds

Every mariner has different comfort levels and operational limits. A commercial tug captain, a recreational sailor, and a charter fishing captain all have different gust thresholds. Know your personal limits:

• At what gust speed do alongside operations become unsafe for your vessel type?
• When do gusts make anchoring difficult?
• What gust speeds require reefing for your sail plan?
• At what point do gusts create uncomfortable conditions for passengers?

Once you know your thresholds, checking gust forecasts becomes a quick go/no-go decision rather than subjective judgment.

Use Hourly Forecasts to Find Windows

Gusty conditions often vary throughout the day. Unstable morning conditions might settle by afternoon. Or calm mornings might give way to gusty afternoons as daytime heating creates convection. The hourly forecast lets you identify specific windows when the gust-to-sustained ratio improves.

Rather than canceling an operation because of gusty conditions, you might just need to shift timing by a few hours to catch a better window.

Check Multiple Locations Along Your Route

Wind gustiness can vary significantly over short distances. A harbor might be relatively calm while an exposed point five miles away is seeing much higher gusts. Use the long-press feature to check forecasts at:

• Your departure point
• Any exposed sections of the route
• Harbor entrances or narrow passages
• Your destination

The most exposed location drives your planning, not the departure or arrival points.

Consider the Cause of Gustiness

Different weather situations produce different gustiness patterns. Cold frontal passages create gusty conditions that typically improve after the front passes. Sea breeze development causes increasing gustiness through the afternoon that settles in the evening. Squalls and thunderstorms produce extreme but localized gusts.

Understanding the cause helps you predict how conditions will evolve beyond the forecast period and make better timing decisions.

Pro Tip: I keep a mental log of how actual conditions compare to gust forecasts for different weather situations in my local area. Over time, this builds intuition about when forecasts tend to underestimate or overestimate gustiness. That experience refines decision-making beyond just reading the numbers.

Common Questions

Q: How accurate are gust forecasts compared to sustained wind forecasts?

A: Gust forecasts are generally slightly less accurate than sustained wind forecasts because gusts result from small-scale turbulent processes that are harder to model. However, modern weather models have improved significantly at predicting gustiness. Mariner Studio’s gust forecasts are reliable enough for operational planning, though they should be combined with real-time observations when possible. If you’re seeing higher gusts than forecast, expect that pattern to continue.

Q: Is it better to plan around sustained winds or gust forecasts?

A: It depends on the gust-to-sustained ratio. When gusts are less than 30% above sustained winds, they represent normal variability and you can plan around sustained speeds. When gusts exceed sustained winds by 50% or more, plan for the gust speeds—those peaks will drive your operational experience. For critical operations like alongside work, I always check gust forecasts regardless of the ratio.

Q: Why do some locations show much higher gust ratios than others?

A: Gustiness varies based on atmospheric stability and local terrain. Unstable conditions (cold air over warm water, strong daytime heating) create more vertical mixing and higher gusts. Locations with rough terrain or significant obstacles produce mechanical turbulence that increases gustiness. Open ocean locations often have lower gust ratios because there’s less surface friction to create turbulence. Coastal areas and harbors can have high gust ratios due to terrain effects and temperature contrasts between land and water.

Q: Can I use historical gust data to improve planning?

A: Absolutely. If you frequently operate in the same area, noting patterns in gust ratios for different weather situations builds valuable experience. You might learn that southwest winds in your harbor consistently show gusty conditions due to terrain channeling, while northwest winds are steadier. Or that morning forecasts tend to underestimate afternoon gustiness when sea breeze develops. This local knowledge refines your interpretation of forecast data.

Q: What if real-time observations show higher gusts than forecast?

A: Always respect what you’re actually observing over what was forecast. If you’re seeing 30-knot gusts when the forecast called for 22 knots, conditions are more unstable than predicted and will likely remain gustier than forecast. Either adjust your plans or build in additional safety margins. The forecast is your planning tool; real-time observations are your validation and should override forecast data when they diverge.

Related Features and Learning

Wind gust forecasts work best when combined with other Mariner Studio features. Here’s how to build a complete wind analysis:

• Barometric Pressure Trends: Rapidly falling pressure often signals increasing gustiness ahead of frontal passages. Check our guide on reading barometric pressure for storm prediction.
• Hourly vs Daily Forecasts: Gustiness often varies significantly throughout the day. Use hourly forecasts to identify the best windows. Learn more about when to use 7-day versus hourly forecasts.
• Weather Map Long-Press: Check gust forecasts at multiple points along your route using the long-press feature. See our weather map long-press guide.
• Weather Favorites: Save frequently-used locations to quickly monitor changing gust conditions. Read our weather favorites setup guide.

For operations requiring precise wind data, combine gust forecasts with real-time buoy observations when available. Historical gust patterns for your local area also help calibrate your interpretation of forecasts.

Conclusion

Wind gust forecasts reveal what sustained wind speeds hide: the peaks and variability that actually drive your operational decisions. When a forecast shows 15 knots sustained with 28-knot gusts, those gusts define the conditions you’ll experience, not the sustained average.

Learning to read and plan around gust forecasts improves safety and timing across all marine operations. For alongside work, those gust numbers determine whether an evolution is feasible or needs to wait for better conditions. For sailing, they guide reefing decisions before you leave the dock. For fishing and cruising, they indicate whether conditions will be comfortable or challenging.

The key is developing personal thresholds based on your vessel, your experience, and your operation type. Once you know your limits, checking gust forecasts becomes a quick, objective evaluation rather than guesswork. Mariner Studio displays both sustained and gust forecasts for every hour, enabling you to plan for the peaks rather than the averages.

Next time you check a wind forecast, look beyond the sustained speed to the gust forecast. That second number might completely change your planning. Always check the gust-to-sustained ratio, and when gusts forecast 50% or more above sustained winds, plan accordingly.