0:00:07 > 0:00:13The heat of the sun drives our weather, but water creates its many different faces.
0:00:17 > 0:00:20I'm Donal MacIntyre.
0:00:20 > 0:00:25I am about to follow water's journey around the planet -
0:00:25 > 0:00:29from the oceans to the clouds, from a storm to a flood -
0:00:29 > 0:00:34because I want to experience the awesome power it can unleash.
0:00:34 > 0:00:40I'll meet people who have been at the mercy of some of the wettest, wildest weather on Earth.
0:00:41 > 0:00:44This is Wild Weather.
0:01:15 > 0:01:18We live on a water planet.
0:01:19 > 0:01:2270% of the surface is water.
0:01:25 > 0:01:28Every living thing, including us, is made of it.
0:01:32 > 0:01:38Right now, there are 12,000 billion tons of it, literally hanging above our heads.
0:01:45 > 0:01:51And it's this that fuels the world's weather.
0:01:55 > 0:02:01If you were to divide it by the amount of people that live on the planet,
0:02:01 > 0:02:06this is how much each single one of us would have -
0:02:06 > 0:02:11a cube of water measuring 46m high, wide and deep.
0:02:14 > 0:02:19The same water we bathe in that we drink or flush away.
0:02:20 > 0:02:23It's the same water that rains on us
0:02:23 > 0:02:27that forms the hurricanes and the monsoons.
0:02:27 > 0:02:33It's the same water that's been here since the Earth was formed.
0:02:34 > 0:02:40If all things were equal, this would be your share of the weather.
0:02:45 > 0:02:50This is the same water that fell as rain before life itself began.
0:02:50 > 0:02:57By now, it has probably circled around the planet over eight million times.
0:02:59 > 0:03:05Now I'm going to follow the cycle your bit of water takes around the world.
0:03:07 > 0:03:11Along the way, we'll see how it transforms itself
0:03:11 > 0:03:14into every kind of weather on the planet.
0:03:22 > 0:03:28I'm going to start my journey with water in the wettest place in Western Europe -
0:03:28 > 0:03:32Bergen, city of rain, on Norway's western coast.
0:03:37 > 0:03:41It rains here two out of every three days.
0:03:44 > 0:03:47So what do you need in a city like this?
0:03:47 > 0:03:50Umbrellas - lots of them.
0:03:50 > 0:03:56- We have some special umbrella for little rain, lot of rain and storm. - For every occasion?- Yes.
0:03:57 > 0:04:00This city is so proud of its rain,
0:04:00 > 0:04:03they can it, and sell it to tourists -
0:04:03 > 0:04:07because they've got lots of it.
0:04:10 > 0:04:16Just to give you an idea, if I was to stand here every day and night for the next 16 years,
0:04:16 > 0:04:22I still couldn't capture the volume of water that falls on this city in a single year.
0:04:22 > 0:04:28400,000 Olympic-sized swimming pools of water drench this place annually.
0:04:28 > 0:04:35And crashing down on the roof of the average family house every month is a staggering 18 tons of rain.
0:04:35 > 0:04:38That's 225 tons a year.
0:04:38 > 0:04:41This place is seriously wet.
0:04:46 > 0:04:53Which means that devious tactics have to be employed by weather forecasters to keep people happy.
0:04:53 > 0:04:55Enter the blonde.
0:05:05 > 0:05:10This is TV2, Bergen's local TV station.
0:05:11 > 0:05:18Benedikte Rasmussen has the unenviable job of presenting the weather.
0:05:19 > 0:05:21'It's not that difficult.
0:05:21 > 0:05:28'When the meteorologist says something long and difficult, it's probably just going to rain.'
0:05:30 > 0:05:35The longest period of rain was in 1990, and I know this,
0:05:35 > 0:05:39because I've checked it. It turns out that it was raining
0:05:39 > 0:05:44from the 3rd of January to the 26th of March that year.
0:05:44 > 0:05:47That's about 83 days. And I can't remember,
0:05:47 > 0:05:52but I think I was quite fed up of rain after those days.
0:05:52 > 0:05:55THEY SPEAK NORWEGIAN
0:05:55 > 0:05:58'Prediction is a fine art.'
0:05:58 > 0:06:05- Benedikte, what's happening here? - We're looking at how the weather will be tomorrow, and the days ahead.
0:06:05 > 0:06:13- How's it looking for Bergen?- I'm not sure. I think it's going to be a little bit rainy, but not too bad.
0:06:13 > 0:06:16How are these maps created?
0:06:16 > 0:06:19Um...I don't know!
0:06:21 > 0:06:27Benedikte knows only slightly more about meteorology than I do, but the ratings show
0:06:27 > 0:06:33that her smile and presentation keeps the audience happy and willing to receive
0:06:33 > 0:06:37the somewhat familiar weather forecasts.
0:06:37 > 0:06:42So why is this place so wet? Day after day, warm moist air
0:06:42 > 0:06:49flows in from the Atlantic, hits the surrounding coastal mountains and is forced up.
0:06:49 > 0:06:54As it rises, it cools, and the result is rain, tons of it.
0:06:54 > 0:07:00Right this second, 18 million tons' worth of rain are falling somewhere on the planet.
0:07:00 > 0:07:05And if all this rain from the rooftops is going to join it,
0:07:05 > 0:07:09there is only one way it can go - into the rivers.
0:07:39 > 0:07:44Yesterday, what's cascading around me now was a rain shower in Bergen.
0:07:47 > 0:07:51Before that, it could have been a monsoon rain cloud in India,
0:07:51 > 0:07:54or even a cup of tea from the Ritz.
0:08:03 > 0:08:06Today, it's a river in Norway.
0:08:07 > 0:08:12By tomorrow, it will have joined the North Sea.
0:08:13 > 0:08:20After that, who knows where or what it will next become?
0:08:21 > 0:08:25The water...on our planet...
0:08:25 > 0:08:29connects us all... in truly remarkable ways.
0:08:38 > 0:08:45All this water racing out into the North Sea is about to join a vast weather-making ocean current.
0:08:45 > 0:08:52I'm going to follow its course to see some of the wettest, wildest weather on Earth.
0:08:52 > 0:08:55But, in order to see where this current starts,
0:08:55 > 0:08:58I have to travel north of Bergen.
0:09:20 > 0:09:26There are many currents in the oceans that move water around our planet,
0:09:26 > 0:09:31but there's one, a master current, out there in the North Atlantic,
0:09:31 > 0:09:36that's the drive-belt of our weather systems - the Thermohaline Conveyor.
0:09:37 > 0:09:43Every ocean in the world is connected by the Thermohaline Conveyor.
0:09:43 > 0:09:49It's a 70,000-mile round trip that takes about 1,000 years to complete.
0:09:49 > 0:09:55And, in that time, the water could have been part of every kind of weather,
0:09:55 > 0:09:58in Scotland or on the Serengeti.
0:09:58 > 0:10:05It takes a phenomenal amount of energy to drive this massive engine, the Thermohaline Conveyor,
0:10:05 > 0:10:08so what turns it on, what kick-starts it?
0:10:08 > 0:10:13Of course, to see for myself how it works, I have to get under the ice.
0:10:13 > 0:10:18The secret lies in when this ocean turns to ice.
0:10:42 > 0:10:47At -2 degrees Celsius, sea water begins to freeze.
0:10:47 > 0:10:54But this ice is made of fresh water, because salt doesn't freeze, and it's locked out in the process.
0:10:54 > 0:11:00So, the water around me is very salty, which makes it heavier, so it sinks.
0:11:00 > 0:11:04As all these billions of tons of cold salty water fall,
0:11:04 > 0:11:07they begin to flow south.
0:11:07 > 0:11:12This sucks the warmer tropical waters up north to replace them.
0:11:12 > 0:11:16This action drives a permanent ocean cycle.
0:11:16 > 0:11:20From here, the route it takes is truly global.
0:11:20 > 0:11:24As the cold waters plunge to the depths of the ocean,
0:11:24 > 0:11:29they flow along the bottom and then around the Horn of Africa,
0:11:29 > 0:11:33and after about 500 years, it begins to warm up.
0:11:33 > 0:11:37The Conveyor's first stop is in the Indian Ocean,
0:11:37 > 0:11:40and much later in the Pacific Ocean,
0:11:40 > 0:11:46where the whole system then curves around and the cycle repeats itself.
0:11:51 > 0:11:57It's hard to imagine that the next time anyone sees the water I'm swimming in now
0:11:57 > 0:12:02will be when it rises as a warm current and laps a beach in India.
0:12:17 > 0:12:22After a 6,000-mile journey within the Conveyor,
0:12:22 > 0:12:26the water that fell as rain in Bergen over 500 years ago
0:12:26 > 0:12:32is about to become part of the biggest rainstorm on the planet.
0:12:49 > 0:12:53India hasn't seen a drop of rain for months.
0:12:57 > 0:13:00Life is almost unbearable.
0:13:02 > 0:13:04Well, almost!
0:13:05 > 0:13:08But the monsoon is on its way.
0:13:09 > 0:13:14Every summer, around June 6th, regular as clockwork,
0:13:14 > 0:13:20these clouds sweep in from the Indian Ocean, bringing life and death in their wake.
0:13:20 > 0:13:26How it works is simple. For most of the year, the prevailing winds come from the north,
0:13:26 > 0:13:33then, as summer heats up the country, massive columns of hot air begin to rise and, as they do,
0:13:33 > 0:13:40they suck cool moist air in from the sea. When these moist clouds break over land,
0:13:40 > 0:13:44you get the fury of the monsoon downpour.
0:13:44 > 0:13:48And that cloud there is the beginning of the monsoon.
0:13:48 > 0:13:51In order to see what's going on up there,
0:13:51 > 0:13:54I'm going to take a closer look.
0:13:55 > 0:14:01I'm about to do something that apparently has never been done before in the monsoon.
0:14:01 > 0:14:06I'm going to go up and experience the hot and humid monsoon winds.
0:14:06 > 0:14:09To do that, I have to jump off this.
0:14:35 > 0:14:37Whoo!
0:14:40 > 0:14:47Flying up here with the birds is the most amazing and scary way of seeing the advance of the monsoon.
0:14:47 > 0:14:52On a day like this, 75 billion tons' worth of rain clouds
0:14:52 > 0:14:57will sweep across this coast and a third of that will fall as rain.
0:14:57 > 0:15:03It's staggeringly hard to imagine that amount of rain falling anywhere!
0:15:03 > 0:15:08Some of these clouds are ten miles thick and densely packed with water.
0:15:08 > 0:15:15You don't want to be here when that breaks, so to give yourself a bit of protection and warning,
0:15:15 > 0:15:23you have to know what turns water into rain. To do that, you have to look into the heart of a cloud
0:15:23 > 0:15:27and, right now, that one over there looks promising.
0:15:27 > 0:15:31So how does a cloud produce a raindrop?
0:15:31 > 0:15:36Up close, a cloud is just a swirling mass of water vapour.
0:15:36 > 0:15:41Floating with it are comparatively huge particles of dust and pollen.
0:15:41 > 0:15:45The vapour is attracted to the surface.
0:15:45 > 0:15:50They collide with each other, getting bigger and heavier.
0:15:50 > 0:15:54It takes a million of these droplets to make a raindrop,
0:15:54 > 0:15:57only 2 millimetres wide.
0:15:57 > 0:15:59Gravity does the rest.
0:16:05 > 0:16:10Monsoon downpours are epic. In just a few seconds,
0:16:10 > 0:16:15they can bring inches of water crashing to the ground.
0:16:15 > 0:16:21For this brief period in the year, the monsoon changes everybody's life,
0:16:21 > 0:16:26a welcome relief from the tensions caused by the scorching heat.
0:16:32 > 0:16:38When the rains arrive, India lets its hair down and goes mad for football.
0:16:46 > 0:16:51The rain softens the pitches, making them easy to play on.
0:16:51 > 0:16:57What I can't believe is that I'm 6,000 miles away from home, and I'm still playing in mud.
0:16:57 > 0:17:05I don't know if the monsoon is doing anything for my game, but I know it's doing wonders for my body.
0:17:05 > 0:17:09All this rain can actually make you feel good.
0:17:17 > 0:17:20As water falls through the air,
0:17:20 > 0:17:24be it heavy rain, a waterfall, or even a shower,
0:17:24 > 0:17:29tiny particles in the air, called ions, become negatively charged.
0:17:29 > 0:17:36This makes them sticky, which cleans the air by literally dragging dirt and dust particles to the ground,
0:17:36 > 0:17:39leaving it fresh and clear.
0:17:40 > 0:17:45The cleaner the air, the quicker oxygen is delivered around the body,
0:17:45 > 0:17:49and it's this that makes us feel good.
0:17:51 > 0:17:56Which is why the shower is where most of us have our best thoughts.
0:18:07 > 0:18:12All this clean air has an another effect on the local population.
0:18:12 > 0:18:17To find out what, I went to see my friend Antonio.
0:18:19 > 0:18:26- Now, Antonio, it's raining heavily. I love the sound of this rain. - Oh, yes. It's beautiful.
0:18:26 > 0:18:32When it rains, it's like music. When it rains, you love to stay at home, especially when it rains heavily,
0:18:32 > 0:18:38and a lot of people are...conceived during this time. It's what I feel.
0:18:38 > 0:18:42- So the rain brings babies, too? - Maybe!
0:18:42 > 0:18:44Lots of water babies.
0:18:44 > 0:18:49Nine months after the monsoon, the birth rate leaps.
0:18:49 > 0:18:53It's an intense period, because in a few months' time,
0:18:53 > 0:18:58the monsoon breezes rushing in from the sea will reverse themselves,
0:18:58 > 0:19:02leaving just the merciless heat of the sun.
0:19:05 > 0:19:09India only manages to hold on to 10% of all that rain.
0:19:09 > 0:19:14The rest leaves the country by the thousands of rivers and streams
0:19:14 > 0:19:17that break its shores.
0:19:17 > 0:19:22Every second, billions of gallons pour into the oceans
0:19:22 > 0:19:27to rejoin that great weather-maker, the Thermohaline Conveyor.
0:19:32 > 0:19:36The cycle continues, this time back towards the Atlantic.
0:19:36 > 0:19:41The warmer surface current takes only 50 years to get there.
0:19:41 > 0:19:47This is the same water that fell as rain in the last days of the Raj.
0:19:47 > 0:19:50It's now about to become clouds in the USA.
0:19:50 > 0:19:54But this time, they won't bring any rain.
0:20:05 > 0:20:12This is Texas, land of big skies, and, looking at the crops round here,
0:20:12 > 0:20:19you'd think big rain. But it doesn't rain enough. The clouds don't do what they should.
0:20:21 > 0:20:25In the clouds above the USA and Europe,
0:20:25 > 0:20:29all raindrops start life as ice crystals.
0:20:30 > 0:20:33As they fall, they melt.
0:20:33 > 0:20:37But here, it's so hot and so dry, the rain evaporates
0:20:37 > 0:20:40before it hits the ground.
0:20:54 > 0:21:01The average cloud weighs about 25 tons and contains about seven fire-trucks' worth of water.
0:21:01 > 0:21:08But not all of them will rain. Some just evaporate, and many last only a few minutes.
0:21:08 > 0:21:15Even if there's plenty of water in a cloud, there's often a lack of that extra ingredient to make a raindrop,
0:21:15 > 0:21:18something for the moisture to gather round.
0:21:20 > 0:21:26With just one corn field requiring 4,000 gallons of water each day,
0:21:26 > 0:21:30and a single cloud containing just enough for one acre,
0:21:30 > 0:21:35the question is - how do you tease the rain from the clouds?
0:21:35 > 0:21:39Today, science and big business claim to have solved the problem,
0:21:39 > 0:21:43and they found the answer in a freezer.
0:21:43 > 0:21:51Back in the 1940s, scientists were trying to replicate the temperatures found at high altitude.
0:21:51 > 0:21:55At -20 degrees Celsius, conditions weren't cold enough.
0:21:55 > 0:22:00So to make it colder, they brought in blocks of dry ice.
0:22:00 > 0:22:06At -78 degrees Celsius, the temperature was similar to those high up in the clouds.
0:22:06 > 0:22:11It was then that scientists made a fascinating discovery.
0:22:11 > 0:22:16Whilst moving the dry ice to the freezer, they noticed that the air became so cold
0:22:16 > 0:22:22that the warm water vapour in their breath instantly froze into tiny ice crystals.
0:22:22 > 0:22:25These crystals are exactly the same
0:22:25 > 0:22:30as the ones that form naturally, high up in the clouds.
0:22:31 > 0:22:34HE EXHALES
0:22:34 > 0:22:38They are the frozen seeds of a natural raindrop.
0:22:40 > 0:22:45I can see them sparkling and shining there. It's amazing!
0:22:45 > 0:22:49This chance discovery led the scientists to wonder,
0:22:49 > 0:22:57if they put man-made crystals that imitated the ice into the cloud, would the cloud produce more rain?
0:22:57 > 0:23:00To see if it works, I went to meet the experts.
0:23:13 > 0:23:19In Texas, they spend millions of dollars each year trying to make it rain.
0:23:19 > 0:23:26This is the Hondo Airbase in southern Texas, home to a team from Weather Modification Incorporated,
0:23:26 > 0:23:32the biggest company in the rain business. They've been hired by the water authority
0:23:32 > 0:23:39to boost the dwindling water supplies. If demand from towns and farms continues at its current pace,
0:23:39 > 0:23:45some people predict the water will simply run out in 50 years' time.
0:23:46 > 0:23:50Jeremy Price has been flying this beat for four years.
0:23:50 > 0:23:53We can keep a storm going about 25% longer.
0:23:53 > 0:23:59That's about five minutes, cos the storms only last about 20 minutes.
0:23:59 > 0:24:06- What difference does that make to farmers?- It has a dramatic impact. We increase average rainfall per year
0:24:06 > 0:24:13by a couple of inches. It doesn't seem a lot, but if you think how many millions of acres that's spread over,
0:24:13 > 0:24:15it adds up to billions of gallons.
0:24:15 > 0:24:23- RADIO:- 'OK, it looks like, from your location area, 135 at 20 from your current position.'
0:24:23 > 0:24:26'135 at 2-0 miles. Roger that.'
0:24:26 > 0:24:30What we do isn't magic. There's a lot of science behind it.
0:24:30 > 0:24:37We're not rain creators. We don't bring rain out of nowhere. We go up and see rain that's already there,
0:24:37 > 0:24:44and make it a little bit more. In Texas, usually in the afternoon, we'll get some heavy thunderstorms
0:24:44 > 0:24:51and we'll fly through the updraught. That's where our chemical is most effective.
0:24:54 > 0:25:01As we go in, we look for inflow, which is an updraught, sucking up air and feeding itself moisture.
0:25:01 > 0:25:07We light our burners to produce dust, and the air being sucked into the thundercloud
0:25:07 > 0:25:09seeds and creates the rain.
0:25:09 > 0:25:16The burners release a chemical into the air, which is then sucked up by the storm.
0:25:16 > 0:25:21I'm gonna reach across and turn on the left burner. ..The burner's lit.
0:25:25 > 0:25:28The process is known as cloud-seeding,
0:25:28 > 0:25:32and the seeds are tiny particles of silver iodide
0:25:32 > 0:25:36that mimic the shape of the ice crystals.
0:25:41 > 0:25:47When these particles are sprayed up into a cloud, water vapour freezes onto them.
0:25:47 > 0:25:51They grow in size until they become snowflakes.
0:25:51 > 0:25:55As they start to fall back down, they melt into rain.
0:26:15 > 0:26:22Even if it rains after the clouds are seeded, detractors ask - how do you know it wouldn't rain anyway?
0:26:22 > 0:26:29The rainmakers are shrewd enough not to claim that their techniques work beyond a shadow of a doubt.
0:26:29 > 0:26:35But they provide a service which many satisfied customers happily pay a fistful of dollars for.
0:26:35 > 0:26:41And yet many scientists insist that the evidence for rain enhancement simply doesn't stack up.
0:26:41 > 0:26:46They say it doesn't work. But, faced with water shortages,
0:26:46 > 0:26:50at least people feel something's been done, whether it works or not.
0:26:50 > 0:26:55It's ironic to think that, trapped in the blue skies above us,
0:26:55 > 0:26:57is all the water they'd ever need.
0:27:02 > 0:27:08Just south of here, the people of the Caribbean witnessed the deadly power
0:27:08 > 0:27:13of one of the biggest rain machines on Earth. This one had a name -
0:27:13 > 0:27:16Hurricane Mitch.
0:27:31 > 0:27:37Mitch was born on the 21st of October in the warm waters near the Equator.
0:27:38 > 0:27:42The sun heats the surface of the sea,
0:27:42 > 0:27:47evaporating one trillion tons of water into the air each day.
0:27:47 > 0:27:50So, once in the air, where does it all go?
0:27:50 > 0:27:53At about 2,000 feet up,
0:27:53 > 0:27:59the water vapour cools, condensing back into tiny water droplets.
0:27:59 > 0:28:04This is the dew point - it's where all clouds are born.
0:28:04 > 0:28:09Each cloud is made of billions and billions of water droplets.
0:28:09 > 0:28:13Carried aloft by the rising warm air, they billow upwards.
0:28:13 > 0:28:17If the heat from the sea below is strong enough,
0:28:17 > 0:28:21they grow into massive tropical storms.
0:28:21 > 0:28:26The 22nd of October 1998 began as a normal day.
0:28:26 > 0:28:32At the National Hurricane Centre in Miami, it was a day they would never forget.
0:28:32 > 0:28:37Way out in the Caribbean, a major storm system was building.
0:28:37 > 0:28:43It developed fast after it became a tropical storm. For several days,
0:28:43 > 0:28:47we monitored this cluster of thunderstorms in the Caribbean,
0:28:47 > 0:28:51but we knew it'd be a threat somewhere in the Caribbean.
0:28:51 > 0:28:59In the capital city of Honduras, Tegucigalpa, people were oblivious to the gathering storm out to sea.
0:28:59 > 0:29:05It was hurricane season, and this part of the world is used to it.
0:29:08 > 0:29:13As it spun towards Honduras, sucking up vast amounts of water,
0:29:13 > 0:29:16the wind speeds picked up.
0:29:19 > 0:29:24At 75mph, Mitch officially became a hurricane.
0:29:27 > 0:29:32It was picking up 2 billion tons of water vapour each day,
0:29:32 > 0:29:35which inevitably has to fall somewhere.
0:29:35 > 0:29:41On the 27th of October, it was business as usual in the capital.
0:29:41 > 0:29:45We were in direct contact with the forecast offices
0:29:45 > 0:29:52in Honduras, Nicaragua, Belize, Central America. In fact, it was so large, we knew it would affect,
0:29:52 > 0:29:59with rain and winds, all the north coast of Honduras, so warnings were out 20 hours in advance.
0:29:59 > 0:30:04The next day, Hondurans began to prepare for the worst.
0:30:08 > 0:30:15Out at sea, the warm waters of the Caribbean fuelled the cycle of evaporation and rain.
0:30:16 > 0:30:20By now, Mitch had been rated a Category 5 hurricane,
0:30:20 > 0:30:24the most lethal on the potential-damage scale.
0:30:24 > 0:30:30In Tegucigalpa, Pedro Funez and thousands like him
0:30:30 > 0:30:33were on their way to work.
0:30:38 > 0:30:44By the evening of the 29th of October, Mitch had already reached the northern coast.
0:30:44 > 0:30:49The destructive power now is contained in the very heavy rains
0:30:49 > 0:30:54released as the circulation interacts with a mountainous land mass, here,
0:30:54 > 0:31:01Honduras, and Nicaragua here. It draws in moisture from the Pacific Ocean and Caribbean Sea,
0:31:01 > 0:31:05and the circulation is so large that it's slow to spin down.
0:31:05 > 0:31:10Mitch was so big that, while its centre covered the land,
0:31:10 > 0:31:16its spinning edges sucked up vast amounts of water vapour from the Pacific and the Caribbean.
0:31:16 > 0:31:20It then poured it straight back down onto the land.
0:31:20 > 0:31:27The real disaster is really yet to come in terms of the mud slides and the very great catastrophes
0:31:27 > 0:31:33that occur as a result of several feet of water being deposited over mountainous terrain.
0:31:43 > 0:31:50The water racing down from the mountains was funnelled into the valleys at terrifying speeds,
0:31:50 > 0:31:52wiping out anything in its path.
0:31:57 > 0:32:04Residents watched in horror as friends and neighbours were swept away, with whole neighbourhoods.
0:32:04 > 0:32:08SCREAMING AND SHOUTING
0:32:28 > 0:32:31THEY SPEAK ANIMATEDLY IN SPANISH
0:32:33 > 0:32:39In the capital, Tegucigalpa, mud-slides washed whole shanty towns into the river.
0:32:45 > 0:32:49One of those houses belonged to Pedro Funez.
0:32:49 > 0:32:52And this is all that's left.
0:32:55 > 0:33:00TRANSLATION FROM SPANISH: You could hear people crying.
0:33:00 > 0:33:05People began to scream. It all happened so quickly.
0:33:05 > 0:33:11However much you wanted to take some kind of action, it was very difficult.
0:33:11 > 0:33:14We were almost on the edge of the cliff.
0:33:14 > 0:33:17I think they died quickly.
0:33:20 > 0:33:25When the cliff collapsed, Pedro lost his entire family.
0:33:31 > 0:33:38By the 31st of October, Mitch had disintegrated and the remnants moved out into the Gulf of Mexico.
0:33:38 > 0:33:45The hurricane is both a miracle of nature and a monster. When a meteorologist looks at it from afar,
0:33:45 > 0:33:51he admires it as a thing of beauty, and I think a lot of people, even non-meteorologists,
0:33:51 > 0:33:57would say, "Wow, that's spectacular," but we recognise that, the more beautiful it looks,
0:33:57 > 0:34:01the more potentially destructive it can be.
0:34:01 > 0:34:06From the rubble of his home, Pedro was only able to find one body -
0:34:06 > 0:34:09that of his youngest son, Javier.
0:34:10 > 0:34:15On a quiet hill above the city, survivors pay their last respects.
0:34:15 > 0:34:20THEY SPEAK IN SPANISH
0:34:28 > 0:34:32Mitch was the most lethal storm in modern history.
0:34:32 > 0:34:39Over 7,000 people killed, 8,000 missing and over 12,000 injured.
0:34:39 > 0:34:46The death toll in this hurricane ranks with the deadliest hurricanes of all time.
0:34:46 > 0:34:52This was a very, very catastrophic event and one that we hope will not be repeated.
0:34:53 > 0:34:58An entire country had very nearly been wiped out
0:34:58 > 0:35:03by one of the most powerful hurricanes the world has ever seen.
0:35:04 > 0:35:09When it was over, billions of gallons of water drained away
0:35:09 > 0:35:12into the Gulf of Mexico.
0:35:12 > 0:35:17Having brought destruction to Central America,
0:35:17 > 0:35:23this same water is now about to become a key source of the weather in Britain and Europe.
0:35:23 > 0:35:28And this coconut could be rolling onto a beach in Cornwall.
0:35:28 > 0:35:33To understand how, we have to join perhaps the most famous part
0:35:33 > 0:35:36of the Thermohaline Conveyor.
0:35:36 > 0:35:42Drawn out of the warm waters of the Gulf of Mexico by the Thermohaline Conveyor,
0:35:42 > 0:35:49the Gulf Stream runs practically the entire length of the North American coastline
0:35:49 > 0:35:54before reaching out east across the Atlantic towards the UK.
0:35:56 > 0:36:02It's 10 degrees Celsius warmer than the sea around it, so it heats the air above it.
0:36:02 > 0:36:06All that moist, warm air is then picked up
0:36:06 > 0:36:10and carried with the westerly winds to Europe.
0:36:10 > 0:36:16Incredible as it seems, this massive river of warm water gives Britain and Ireland
0:36:16 > 0:36:20the wet and mild climate we enjoy...so much(!)
0:36:24 > 0:36:28We've known for centuries that the Gulf Stream exists
0:36:28 > 0:36:34because, every day, the evidence is washed up on beaches like this.
0:36:46 > 0:36:53Nick and Jane Darke are professional beachcombers and regular visitors to Cornwall.
0:36:53 > 0:36:59After each storm, you'll find them searching along the high tidemark.
0:36:59 > 0:37:01- Hi.- Hello!- Hi!
0:37:02 > 0:37:05These are seeds which we've found.
0:37:05 > 0:37:11- Where's this from?- Central South America. It grew in a rain forest,
0:37:11 > 0:37:13came down the Amazon into the sea.
0:37:13 > 0:37:18The Gulf Stream even brought them a little piece of Honduras.
0:37:18 > 0:37:22Six months after Hurricane Mitch,
0:37:22 > 0:37:26we found an enormous number of seeds on this beach -
0:37:26 > 0:37:30between 400 and 500, all different species,
0:37:30 > 0:37:36which had all come up from Central South America on the Gulf Stream.
0:37:36 > 0:37:39Everybody's at it.
0:37:39 > 0:37:45- We get lobster tags from Newfoundland, from Canada... - Massachusetts.
0:37:45 > 0:37:52- This one is from Newfoundland, which we know took 14 months to cross.- You've tracked this tag?- Yes.
0:37:52 > 0:37:57You can see the year, '99, "Lobster, Newfoundland", and the serial number
0:37:57 > 0:38:01and, from the serial number, we traced the fisherman.
0:38:01 > 0:38:09Some of the tags have telephone numbers, so I phone and tell them that a bit of their gear has come
0:38:09 > 0:38:15from their side of the Atlantic into ours, and they're always absolutely amazed.
0:38:21 > 0:38:27But what the rest of us want to know is what kind of weather the Gulf Stream will bring.
0:38:27 > 0:38:34- 'It's very cold, all day Sunday. - It looks like it's going to be pretty wet across southern areas
0:38:34 > 0:38:39'but northern parts will be dry, bright, with spells of sunshine...'
0:38:39 > 0:38:46For the Met Office, based at the BBC, forecasting the weather and of course, the rain, is not easy.
0:38:46 > 0:38:50The Gulf Stream is not the only influence at work.
0:38:50 > 0:38:56We get reports from some ships and from some buoys in the Atlantic. Weather BUOYS, that is!
0:38:56 > 0:39:04Helen Willetts, an experienced forecaster, is explaining the other forces that make our weather so wet.
0:39:04 > 0:39:11The UK, being in the middle of the Atlantic, surrounded by water, is affected by many air masses
0:39:11 > 0:39:18that attack it, so you have air coming in from the poles - a cold direction - and also we get
0:39:18 > 0:39:22tropical continental air from the warm continent.
0:39:22 > 0:39:24- From Africa, Spain...?- Yes.
0:39:24 > 0:39:30Also, we get our main weather from this tropical maritime air mass,
0:39:30 > 0:39:38a warm source of air coming over the Atlantic, no land in between, picks up moisture, dumps rain over the UK.
0:39:38 > 0:39:43Complicated! So how often do they get the forecast right?
0:39:43 > 0:39:50Weather forecasters aren't famous for getting it right. We feel that you always get it wrong.
0:39:50 > 0:39:55There is some prejudice and people always remember when we get it wrong
0:39:55 > 0:40:02and don't praise us when we get it right. We get it right six days out of seven, which is about 85%.
0:40:02 > 0:40:10But there's that rare moment when they get it badly wrong. October 1987 was one of those nights.
0:40:10 > 0:40:16A woman rang the BBC to say she'd heard a hurricane was on its way. Don't worry, there isn't.
0:40:16 > 0:40:19THUNDER CRASHES
0:40:19 > 0:40:26Later that night, hurricane-speed winds gusting at over 90mph did indeed strike the south of England,
0:40:26 > 0:40:28causing serious damage.
0:40:32 > 0:40:37Even British skies can produce world-class weather.
0:40:44 > 0:40:48And, occasionally, some world-class weirdness,
0:40:48 > 0:40:55as Derek and Adrienne Haythornewhite found out one night at home in Accrington.
0:40:55 > 0:40:58It were just a normal night.
0:40:58 > 0:41:02It was fine. Nice starry night.
0:41:02 > 0:41:07And, uh, there was no wind, no rain...
0:41:07 > 0:41:10Then I heard this thudding sound,
0:41:10 > 0:41:15like someone was shovelling, up in the garden or something.
0:41:15 > 0:41:18Voom, voom, voom - like that!
0:41:18 > 0:41:22Then I went to the back door, opened the back door,
0:41:22 > 0:41:24and, to my amazement,
0:41:24 > 0:41:30I saw these giant...balls coming from the skies, really fast.
0:41:30 > 0:41:35I couldn't tell what they were. They were too big for hailstones.
0:41:35 > 0:41:42- Voom, voom, voom!- I said, "It's raining apples, or something! Something funny's going on."
0:41:42 > 0:41:45And they WERE apples, hundreds of them.
0:41:47 > 0:41:55The garden was absolutely littered. Littered, I mean littered! Over ankle-deep in apples, all sorts.
0:41:55 > 0:41:57They weren't just one type.
0:41:57 > 0:42:02When we examined them, there were Bramleys, Cox's, Granny Smiths,
0:42:02 > 0:42:06russets, all kinds of different apples.
0:42:09 > 0:42:13The only plausible theory about the Accrington apples
0:42:13 > 0:42:20is that they were sucked up into the atmosphere by the spiralling winds of a tornado!
0:42:26 > 0:42:31In the UK, twisters are surprisingly frequent.
0:42:31 > 0:42:35In fact, we get about the same as the USA,
0:42:35 > 0:42:40it's just that ours are small and rarely do any damage.
0:42:40 > 0:42:44The increasing amount of wild, wet weather we get
0:42:44 > 0:42:48is bringing terrible devastation to Britain.
0:42:48 > 0:42:52But the real danger is not in the amount...
0:42:52 > 0:42:56but in the speed it moves.
0:43:02 > 0:43:06This is the Thurcross Dam on the Yorkshire Moors,
0:43:06 > 0:43:13the perfect place to demonstrate that water only a few feet deep can knock you off your feet.
0:43:15 > 0:43:22The force of water is always a shock, as this child and his rescuers found out.
0:43:27 > 0:43:31What it needs is speed.
0:43:32 > 0:43:34Beautiful, isn't it?
0:43:34 > 0:43:37Millions of tons of water...
0:43:37 > 0:43:40Power, waiting to be unleashed.
0:43:47 > 0:43:51And they're going to dump it all on me.
0:43:54 > 0:44:01I was wondering why there were four divers here, stunt co-ordinators, safety wires, pulleys...
0:44:01 > 0:44:07- Then I saw THAT.- We've got 14 tons of water escaping every second.
0:44:07 > 0:44:14That's the force of two cars hitting you, and it'll push you over. That's what people don't realise.
0:44:14 > 0:44:21Water can turn from nothing to THAT in a few minutes. To try and fight it is impossible. Even a metre deep,
0:44:21 > 0:44:24once it gets above your knees, you're finished.
0:44:24 > 0:44:29All water needs is speed and volume, and it has the strength of explosive.
0:44:29 > 0:44:36'What we're going to do now is prove just how powerful shallow water can be
0:44:36 > 0:44:39'when it's on the move.
0:44:40 > 0:44:45'It only takes an hour of heavy rain to produce a flash flood.
0:44:45 > 0:44:49'It's this that can wipe out towns and entire cities.'
0:44:59 > 0:45:02- Good luck!- Thanks.- See you later.
0:45:18 > 0:45:20It's just started -
0:45:20 > 0:45:23our very own little flash flood.
0:45:29 > 0:45:33And it looks scary up there! It looks really scary.
0:45:36 > 0:45:40It's rising about an inch every ten seconds now.
0:45:48 > 0:45:52It's really, really hard just to stand still!
0:45:52 > 0:45:56I'll just see if I can hold my weight...
0:45:56 > 0:46:00for a couple of seconds longer, but I think it's...
0:46:00 > 0:46:02a lost cause!
0:46:15 > 0:46:19It's only about three or four feet off the bottom and, already,
0:46:19 > 0:46:23our very own flash flood has swept me off my feet!
0:46:27 > 0:46:32Right now, there's not a chance that I could stand here,
0:46:32 > 0:46:34let alone swim against it!
0:46:39 > 0:46:41It's freezing cold!
0:46:41 > 0:46:47And there's a constant for... a constant force... I can't talk!
0:46:52 > 0:46:57It was so cold, all feeling had gone from my hands and feet.
0:46:57 > 0:47:03But I was amazed at how strong the force of just three feet of water actually was.
0:47:03 > 0:47:07If this had been real, I'd have had no chance.
0:47:18 > 0:47:22The force of water in a river can be lethal,
0:47:22 > 0:47:26but magnify that a thousand times and apply it to the ocean,
0:47:26 > 0:47:29and the results can be disastrous,
0:47:29 > 0:47:34as residents of Hunstanton, on the Norfolk coast, learnt to their cost.
0:47:38 > 0:47:41On the 31st of January 1953,
0:47:41 > 0:47:45a severe winter storm moved in off the ocean
0:47:45 > 0:47:48and lashed the northern coast of Britain.
0:47:50 > 0:47:56The storm swept around the northern tip of Britain and headed south.
0:47:56 > 0:48:03The icy gale-force winds grew stronger as they were funnelled into the North Sea.
0:48:04 > 0:48:09The sheer force of the wind piled the waters up in front of it,
0:48:09 > 0:48:13causing it to surge like a bow wave. Waves of over 12 feet
0:48:13 > 0:48:20crashed through the sea defences and ploughed inland, smashing everything in its path.
0:48:20 > 0:48:24This storm would be a killer, but it would produce a hero.
0:48:24 > 0:48:28US airman Reis Leeming was called in to help.
0:48:28 > 0:48:32When we arrived on the scene,
0:48:32 > 0:48:35it was night-time and we didn't know the area,
0:48:35 > 0:48:39and, as I looked at this first street,
0:48:39 > 0:48:44people were down in the houses and you couldn't see the houses.
0:48:44 > 0:48:51All you could see was this water. It was like being in the middle of the ocean, really.
0:48:51 > 0:48:53There was water everywhere.
0:48:53 > 0:49:01The winds were gusting at 80mph as Reis struggled through the icy water dragging a rubber raft.
0:49:01 > 0:49:06I took the raft and went through the gate that was here...
0:49:06 > 0:49:13and carried it all the way back to the house, and I could hear the people, but I couldn't see them.
0:49:13 > 0:49:17These people were on the roof, and somehow I got them.
0:49:17 > 0:49:22I just don't know how we got 'em down and into the boat.
0:49:23 > 0:49:27I walked up to this house. I got up to that doorway.
0:49:27 > 0:49:30That doorway was open, as I recall,
0:49:30 > 0:49:35and I took one or two steps inside and felt something on my leg.
0:49:35 > 0:49:38Turned out it was the leg of a man.
0:49:38 > 0:49:45It was a husband and wife, I found out the next day, an elderly couple, and they had drowned,
0:49:45 > 0:49:50almost immediately, I guess, when the sea wall was breached.
0:49:54 > 0:49:57Sure looks different now.
0:49:57 > 0:50:04At the town hall, local nurse Dot Smith was waiting in vain for survivors.
0:50:04 > 0:50:08The first woman they brought in, I didn't know what to do.
0:50:08 > 0:50:11I thought, "If she's dead, the others are."
0:50:12 > 0:50:15And, sure enough, they were drowned.
0:50:15 > 0:50:18Two children were brought in next,
0:50:18 > 0:50:23and I put them all together, on trestles close to each other.
0:50:23 > 0:50:28And...then the father was brought in.
0:50:30 > 0:50:34By the time I got down to this area to get these people off,
0:50:34 > 0:50:39they had been on the roof of those houses since, uh...
0:50:39 > 0:50:454.00 or 5.00 in the afternoon. This was like, 11.30 at night,
0:50:45 > 0:50:50with wind blowing 120 miles an hour, and they were soaking wet,
0:50:50 > 0:50:54and the rain, and freezing water...
0:50:54 > 0:50:56You know, it would be amazing to me
0:50:56 > 0:51:03- if, out of the 27 or 30 people or whatever that- I- got out, that all of them survived.
0:51:03 > 0:51:09After four hours in freezing conditions, the cold finally took its toll.
0:51:09 > 0:51:12I was aware, late in the evening,
0:51:12 > 0:51:17that I was freezing and I was at the point where I couldn't move my legs.
0:51:17 > 0:51:22I remember thinking, "Oh, boy. You're in big trouble."
0:51:22 > 0:51:28I had to hang on to the raft, cos it had people in it, and that's the last I remember.
0:51:28 > 0:51:35I asked the ambulance men, "How long has he been like this?" They said, "We just fished him from the water."
0:51:35 > 0:51:38His wet suit he was wearing had got torn.
0:51:38 > 0:51:45I said to the chaps, "Has anybody got any scissors? We've got to cut the legs off this wet suit."
0:51:45 > 0:51:49Somebody said, "His legs will have to come off."
0:51:49 > 0:51:53And...that was really frightening,
0:51:53 > 0:51:58because I thought, "Oh, boy, this is bad news."
0:51:58 > 0:52:03Despite his injuries, Reis had rescued 27 people.
0:52:03 > 0:52:07A week later, when news of his heroic act had spread,
0:52:07 > 0:52:12he was in front of the newsreel cameras re-enacting it.
0:52:12 > 0:52:16In the days that followed, 60 bodies were recovered.
0:52:16 > 0:52:21Thousands of survivors now found themselves homeless.
0:52:22 > 0:52:25I thought about these people.
0:52:25 > 0:52:31I got a letter from a woman, and she said,
0:52:31 > 0:52:35"You rescued me and my two sons... that night,
0:52:35 > 0:52:40"and we've been trying to find you for 40 years."
0:52:40 > 0:52:45And she said, "You'd be interested in knowing that the two boys..."
0:52:45 > 0:52:47Um... Shit!
0:52:50 > 0:52:56"The two boys... One graduated from Cambridge and is a professor there now.
0:52:56 > 0:53:02"And the other graduated from MIT and HE is a professor of mathematics at MIT."
0:53:02 > 0:53:06So that was neat, you know?
0:53:06 > 0:53:09I never did see Reis again...
0:53:09 > 0:53:13uh...and I never heard from him from America.
0:53:16 > 0:53:21Almost a lifetime later, Dot and Reis are reunited on the seafront.
0:53:21 > 0:53:24Hi there, young lady!
0:53:24 > 0:53:27Oh, my goodness!
0:53:28 > 0:53:31- How are you?- Oh, Reis!
0:53:31 > 0:53:35- Ooh, you've got a beer belly! - Yeah! Exactly!
0:53:35 > 0:53:39How long is it...? '53?
0:53:39 > 0:53:42- '53.- Yeah, when you were 19.- Yes.
0:53:42 > 0:53:50- And a slim little boy.- A skinny kid. - I know how slim you were, cos I took all your clothes off.- I know!
0:53:50 > 0:53:53- And you cut my pant legs. - Oh, yes! Round there.
0:53:53 > 0:53:57And you said... "His legs have to come off."
0:53:57 > 0:54:03- I didn't!- Well... - I did not! I said, "THE legs have got to come off."- Right.
0:54:03 > 0:54:07- Which meant the legs of the wet suit.- Exactly.
0:54:07 > 0:54:13And, for 50 years, I've lived with that fear. I've awoken in the night
0:54:13 > 0:54:20and remembered coming to and hearing somebody saying my legs have to come off, and I thought...
0:54:20 > 0:54:23Well, you weren't very well at the time...
0:54:27 > 0:54:34The memory haunts the survivors, as does their shock at the awesome power the weather displayed.
0:54:35 > 0:54:41Fuelled by water in its many forms, the weather can bring life and death.
0:54:44 > 0:54:49Hurricane Mitch washed away an entire country,
0:54:49 > 0:54:53whilst the Indian monsoon brought the land to life.
0:54:53 > 0:55:00The constant cycle of water that flows around and through us fuels the weather that dictates our lives.
0:55:11 > 0:55:15Back where we started our journey with water,
0:55:15 > 0:55:20the people here have developed a lifestyle that is almost waterproof.
0:55:22 > 0:55:24Bergen, city of rain.
0:55:24 > 0:55:31At the TV weather station, Benedikte is still smiling through the forecasts,
0:55:31 > 0:55:37while out in the town square, these kids are at the annual rain festival.
0:55:37 > 0:55:42The love of a good shower is instilled at an early age.
0:55:42 > 0:55:47Life would be impossible if rain stopped play, so they celebrate it.
0:55:47 > 0:55:51THEY SING "HOKEY-COKEY"
0:55:58 > 0:56:01But today, something's not right.
0:56:01 > 0:56:08It's not raining. Such is their thirst for the stuff, the fire brigade are pressed into service.
0:56:08 > 0:56:12We have a saying in Norway. It goes like this -
0:56:12 > 0:56:17"There's no thing like bad weather, only bad clothing."
0:56:17 > 0:56:22'So, on a wet day, the four-year-old, little Ulrika, has a great time!'
0:56:22 > 0:56:26It doesn't matter what the weather is. They are used to it.
0:56:27 > 0:56:30CHEERING
0:56:30 > 0:56:35The key to life in a wet world is to learn to live with it, love it.
0:56:35 > 0:56:41Without water's endless cycle around the planet, there would be no life at all.
0:56:41 > 0:56:45No weather, no sunny days, no playing in the rain.
0:56:48 > 0:56:56In the next programme, I'm going to take a journey with cold, from the Arctic to the heart of a snowflake.
0:56:56 > 0:57:03I'm going to be buried alive, frozen solid and plunged into the lethal white heart of winter,
0:57:03 > 0:57:08to understand why cold is the weather's biggest killer...
0:57:08 > 0:57:10Agh!
0:57:10 > 0:57:14..and yet, without it, we wouldn't exist.
0:57:47 > 0:57:52Subtitles by Graeme Dibble & Annelie Beaton BBC Broadcast 2002
0:57:52 > 0:57:56E-mail us at subtitling@bbc.co.uk