The Rough Guide to Weather

Savour it, ignore it, obsess over it — however you approach weather, it’s a significant part of our daily lives. Since the earliest times when humans scurried into their caves to avoid a storm, people have taken the weather into account. No doubt those same primitive people stood in front of their dwellings a few hours later to admire a rainbow or gaze at a spectacular cloud bank on the horizon.

Vhats changed over the centuries is how people interpret the dance of meteorological elements. Most of us no longer worry, as our ancestors did, about currying favour with those spirits who shuffle the atmospheric cards to punish or reward us. Today, when the weather doesn’t go our way, we tend to look for a more scientific explanation. It’s the fault of the jet stream, a low-pressure centre, or trendy scapegoats like El Nino and the North Atlantic Oscillation — or even global warming.

There is still a lot we don’t understand about weather. We can now predict some aspects of climate as much as a year in advance, but nobody can tell you if a cold front will arrive on your doorstep a fortnight from now, or if a thunderstorm will strike at precisely 4pm tomorrow. We understand the basic physical laws that drive our atmosphere, but were still hampered by our inability to observe every nuance of the present weather and by the finite (though rapidly increasing) speed of the computers that project weather into the future. There’s also another factor restraining our knowledge: even as we learn more about different parts of our atmosphere, the interplay between them can produce something more than the sum of its parts — a crescendo that atmospheric scientists call “non-linear behaviour”.

Where does that leave you, the consumer of weather information? Your cable TV service probably offers weather details on at least one, if not several, of its channels. You can find hundreds of maps and forecasts on the Internet and can dig up enough raw data to satisfy even the most hardcore of atmospheric appetites. But as the gurus of the information revolution keep reminding us, data isn’t the same thing as information. You might be searching for a very specific forecast, say to plan a wedding or to take a boat trip. Maybe you’re heading into the backcountry for a few days and want to know the weather signs that could spell trouble. Or perhaps you’re travelling to a city halfway across the world and you need a sense of the typical weather at your destination, including the worst as well as the best that you might expect.

The Rough Guide to Weather aims to help you get the weather knowledge you’re seekings We’ve collected descriptions and statistics of the weather in dozens of countries and over two hundred destinations around the world. We also take you behind the scenes of the government forecasting centres, the TV studios and other places where your daily dose of weather information is crafted. For all the gains that forecasting has made with the help of computer guidance, humans have not yet been rendered obsolete. Particularly when the weather turns threatening, skilled forecasters can go a step beyond computer guidance and save lives in the process. You’ll learn how the experts decide what to tell you about the upcoming weather and what they may choose to withhold due to limits of time and space, their own uncertainty, politics and other factors. In this second edition of the book, we’ve added key weather events of recent years, such as the 2003 European heat wave and 2005’s disastrous Hurricane Katrina. You’ll find coverage on several new topics, such as the weather on other planets (see p.372). We’ve also enhanced the section on global climate change — a more pressing topic than ever — and updated the city-by-city charts so that they reflect conditions through 2005.

In the end, weather is what people choose to make of it. Every maze of red and blue fronts on the TV screen, every weather warning that crackles across the radio, passes through the filter of our own likes, dislikes, hopes and fears. It’s hoped that this book makes the weather you experience as enjoyable, understandable and as memorable as possible.

The ingredients

As perfectly sculpted as a thunderstorm may look, or as glass-smooth as a blue sky may seem, the endless procession we call weather doesn’t arrive at our doorstep in a static package. The atmosphere around us is crafting weather every second. The detritus from one batch of clouds gets recycled to form another. Air currents loop from one cyclone to the next in endless succession. To understand what drives this pageant, you have to pull back the curtain and take a look at the invisible processes going on backstage. Each player is important — even a molecule of water clinging to a mote of dust, or a proton sailing toward us from the Sun, has a significant role. In its eclectic quest to understand how tiny events add up to weather, meteorology draws from chemistry, physics, mathematics and other disciplines. You don’t have to know the science of weather to understand tomorrow’s forecast, but if you get to know the ingredients, you’ll be drawn to delve deeper into the complex, fascinating, unpredictable world that is weather.

The wild stuff

Some of the most intense and terrifying weather features are among the hardest to decipher. Scientists are still working to understand exactly how a thunderstorm’s energy becomes focused enough to form a tornado, or just how much rain a raging torrent may dump. We do know more than ever about when such events are possible and how to protect ourselves against them. If our fascination with atmospheric trouble has a plus side, it’s the way in which safety messages now make their way into news reports, saving lives on a routine basis. Wild weather has a role to play in basic science, too. When researchers take a closer look at the worst that weather can dish out, they can learn much about how the atmosphere as a whole operates.

Forecasts and how to read them

Professionals discovered long ago that the atmosphere is simply too complex to track without the help of computers — the more powerful, the better. Today, some of the world’s peppiest machines zip through billions of calculations a second in the service of meteorology. They can’t yet follow the wind through every mountain valley and around each building, which is where the human factor enters the equation. Weather presenters on television (whether or not they’re meteorologists) can add local knowledge and translate the statistics churned out by computers into language we understand. The same applies to government forecasters around the world, as well as private firms that serve ever more specialized niches. Common sense and rules of thumb can get you started as an amateur forecaster. You can join other interpreters by taking your own weather readings and digging into the raw data available to all on the Internet.

A primer on climate change

Only half a century ago, the most optimistic of scientists believed we might some day take control of the weather. Science, after all, had harnessed the atom and reined in some of the world’s most destructive diseases. Why not, then, put the kibosh on hurricanes and tornadoes and order up the weather we like.

Little did those mid-century optimists suspect that the 1990s would turn out to be one of the warmest — perhaps the warmest — decade of the millennium. An ever-increasing volume of scientific evidence supports the idea that our industrialized culture is the prime reason for this recent global warming and that further warming is on the cards. Just as we once dreamed, we are now influencing the climate and, by extension, the weather — but, like Dr Frankenstein, we cant quite control the process that we’ve set in motion. For a variety of reasons, all the drama and arguments surrounding global change have taken a long time to produce constructive action. Hopes were high in December 1997, when the world’s governments met in Kyoto, Japan, to draft the world’s first treaty for limiting emissions of greenhouse gases. In the summer of 2001, at a meeting in Bonn, Germany, 178 nations signed the protocol — but not the United States, which produces about a quarter of the world’s greenhouse emissions. That critical no-show left it up to Russia to tip the scales by ratifying the protocol early in 2005, finally making it international law. However, the treaty will only be in force till 2012, and it will cut global emissions only by a few percent, if even that How all of this might affect the weather we experience each day isn’t clear, and that uncertainty is lukewarm comfort in a world that continues to heat up, decade by decade. Below is a quick summary of the science and politics of global climate change. For a more comprehensive treatment, see The Rough Guide to Climate Change.

Weather around the world

Whether you’re looking for unusual weather or (more likely) hoping to avoid it, a broad understanding of the world’s climate is invaluable. You’ll find plenty of background on what actually makes weather happen in the earlier sections of this book. In this particular chapter, the practical conditions you’re most likely to encounter in major countries and cities dotted throughout the globe are discussed. Vital statistics — including annual temperature range and rainfall levels — can be found at a glance on the city graphs supplied here for more than 200 destinations worldwide.

Even without human intervention, Earth’s climate evolves over decades, centuries and millennia. Bear in mind, as you digest the information to follow, that some regions are more variable than others, and it’s a rare day that conforms strictly to the norm. The graphs for each spotlighted city also reveal some of the extremes in temperature observed over the past few years — scenarios that you might want to keep in the back of your mind, if not at the front of your itinerary, as you travel.

Weather on other planets

Earth’s atmosphere certainly has its wild side. But elsewhere in the solar system, you’ll find places that get hotter, colder and windier than our home turf ever does. Each of the other seven planets of the solar system (eight, if you count the recently demoted Pluto … now technically a humble dwarf planet) has a mix of sunlight, chemistry and orbital patterns that leads to its own distinctive set of weather conditions.