Weathering Through the Yachting Season

Weather conditions are generally what drive the popularity of yachting season around the world. Most voyages are seeking the moderately warm breezes, long days, and pleasant waters.  Suffice to say, no one is pursuing 15 ft waves, freezing temperatures, or torrential rains.  While other determining factors such as cultural events, boat shows, and festivals also factor into intended routes, the weather is the general dictator on the scene.

Global pressure patterns will determine where and how wind patterns work, which ultimately control the associated wave heights and relative positioning of ocean currents.  Much like the phrase “work smarter not harder”, yachting also follows the same train of thought:  work with the elements and not against!  Riding with the currents can often save on fuel and can ensure a speedier ride.  It’s no coincidence that many of the global routes follow the natural flow of the water.

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Transoceanic voyages often follow the major ocean currents

Another major factor is precipitation patterns, as regional monsoon seasons can make for an extended wet ride. A seasonal wind pattern shift, such as ENSO (El Niño Southern Oscillation), is defined as a longitudinal shift in pressure patterns and winds which occur on average, every 2-7 years.

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El Niño typically weaken or reverse the easterly trade winds to become westerly, as seen in this image.  This enhances warmer water to reach the Eastern Pacific, which further increases rain potential.

In the warm phase of ENSO, El Niño, easterly winds weaken or reverse.  This causes the warmer waters to shift from the Western/Central Pacific towards the Eastern Pacific, piling up along the South America coast. The warmer waters instigate thunderstorm development, so in turn, higher precipitation occurs.  Another side effect of the excess water is that it reduces upwelling, which is the ability of the deeper, colder, more nutrient-rich water to make its way to the surface. Ocean currents are related to water temperatures, so this shift alters the local currents.

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La Niña enhances the easterly trade winds, forcing water mass to pile into the Western Pacific. As a result, this elevates precipitation in the Western Pacific.   Meanwhile deeper (cooler) water upwells in the Eastern Pacific, which can limit thunderstorm activity.

Conversely, during the cool phase of ENSO, La Niña, the exact opposite occurs:  The easterly winds strengthen, which piles the warmer waters towards the West Pacific.  This migration of water from the East to the West makes it easier for upwelling to occur along South America.  The repositioned warmer waters over the West Pacific increase thunderstorm activity, and therefore precipitation potential.

Further examination of popular global destinations reveal that prime yachting season aligns with capitalizing on the best weather that each location has to offer:

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Peak months for yachting around the world, often follow the seasons.

The tail ends months of peak seasons tend to be the most financially affordable, as they occur while seasons are still transitioning from undesirable winds/rain/temperatures to the more preferred conditions.  While the weather can still somewhat be iffy, this is generally when dock space, berths, and anchorages are plentiful and tourists are minimal.  As yacht owners and charters seek sublime weather, peak seasonal time also brings overwhelming tourists and limited availability, hence higher prices.

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Global boating tracks, created via OceanPassages

Of course some locations are blessed with a year round type yachting season, such as Florida or the Caribbean, maritime SE Asia, or generally anywhere that is located near the equator.  Approximately 12 hours of daylight bless the equatorial regions, with daylight decreasing as you head north of south of this line.  While that ideally works for most of the year, the real caveat occurs when this excessive heat produces or strengthens tropical cyclones.  Rapid intensification or a change in track may force a yacht to redirect its route with minimal notice, or scurry towards an available hurricane hole.

Predicting and tracking the development and movement of tropical cyclones can be very tricky, as it involves a working knowledge of a four dimensional science: How things are changing 1) from east to west 2) from north to south 3) from the surface of the earth throughout the atmospheric column 4) with time. Recent activity surrounding Hurricane Harvey was a prime example of how a tropical system can intensify in a very short amount of time, as it went from a category 1 [74-95 mph] to minimum category 4 [130-156mph] in less than 24 hours.

The open ocean is a nautical playground for many, to which weather writes the rules.  Knowing the best time to take to the high seas is important, to make the best of your adventure and your time!

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Is Today Spring? It is in MY world!

And no I don’t mean because I live in Florida, the land of hot or not-as-hot.  You may have seen social Media sites buzzing with the mention of spring beginning today, March 01. Don’t worry, you’re not confused.  There are indeed different definitions for spring, depending on whether or not you live in the world of meteorology or elsewhere in the “normal” world.

But before we separate the two, let’s take a step back and review the “anatomy” of the seasons.

Most people assume that the seasons are a result of the Earth’s distance from the Sun.  While this initial thought is indeed intuitive, it’s counteracted with the fact that the Earth is actually closer to the Sun during the Northern Hemisphere Winter, and further from the Sun during the Northern Hemisphere Summer.  Take a look!

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The actual reasons we experience the seasons are a result of the Earth’s tilt. Summer and winter seasons yield the expected temperature extremes because the Earth’s tilt allows the Sun to unevenly concentrate its energy.  Think of it this way: More of the solar “wealth” is given to one hemisphere [summer] at the expense of the other [winter].

Consequentially, spring and fall seasons are considered “transition seasons”; more specifically, where the position and tilt of the Earth occurs in such a way that the Sun’s energy is equally distributed between the Southern and Northern Hemisphere [spread the solar wealth, each hemisphere roughly gets the same].

So now that we share a same page of what seasons actually are, let’s get back to the original question:  When does spring start?  “Meteorological Winter” refers to the usual [climatological] coldest three months of the year, which means December, January, and February.  Therefore “Meteorological Spring” begins right after, or today, March 1st!

The majority of the world goes by the astronomical seasons, which follows the Earth’s position around the Sun.  The beginning of “Astronomical Spring”, also known as the “Vernal Equinox” requires the further understanding of what an equinox actually is.

Let’s take a quick science detour for more astronomical anatomy.  The word “equinox” can be further dissected into its Latin roots; “equi” meaning “equal” and “nox” meaning “night”.  Therefore, the definition of an equinox is when the day and night are of approximately equal times around the planet [roughly 12 hrs each, give or take several minutes depending on how close you live to the poles].  Going back to the “Vernal Equinox”, the position of the Earth around the sun during this time usually occurs between March 19 and March 21, and it kicks off the beginning of the calendar version of spring.

equinox

So “Happy Spring” to all my fellow scientists, and to the rest of you, catch you in a few weeks.

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TL; DR

Meteorological Spring follows the average temperatures and begins on Mar 1.

Astronomical Spring follows the earth’s orbit around the sun and begins between Mar 19 and Mar 21

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