Rolling blackouts swept across parts of Brazil on Monday as the grid operator ordered select power cuts to avoid a larger crisis, drawing attention to a fragile electric system that is buckling under the strains of record-breaking heat and dryness.

Grid operator ONS said it orchestrated 2,200 megawatts of controlled outages in eight states as the hottest day of the year in Sao Paulo, where the temperature hit 36.5 Celsius (97.7 Fahrenheit), and other southeastern cities led to surging demand from air conditioners and other power-hungry appliances.

Eletronuclear, a unit of state-run power company Eletrobras , said nuclear reactor Angra I powered down automatically at 2:49 p.m. local time (1649 GMT) due to a drop in frequency on the national grid. The company said there were no risks to workers or the environment due to the stoppage.

Brazilian officials have repeatedly denied the need for energy rationing, even as the driest spell in more than 80 years drains hydropower reserves and forces the use of more costly thermal plants. The drought has also raised the specter of water rationing in Sao Paulo, Brazil's business hub and South America's largest metropolitan area.

Shares of electric companies tumbled on the Sao Paulo stock exchange, dragging an industry index nearly 5 percent lower as news of the power cuts spread. CPFL Energia SA fell more than 7 percent, while AES Eletropaulo, Light SA and Copel each lost around 6 percent.

A privately run subway concession in Sao Paulo, ViaQuatro, said it suffered an electric failure at 2:35 p.m. After 90 minutes ViaQuatro said it had restored service to part of the subway line, but two downtown stations remained closed.

ONS said the national grid was back to normal by 3:45 p.m. after controlled outages affecting less than 5 percent of the system's total demand.

Abnormally heavy snowfall is threatening to decimate much of Siberia's unique wildlife including the rare Amur tiger, experts have warned. Parts of the Russian Far East are covered in snow up to one metre deep, burying many animals and leaving others struggling to move or find food.

Conservationists have already noted cases of young animals dying, with fears the situation could be as bad as the 1980s when up to 90 per cent of species died, including 30 tigers. WWF Russia is demanding urgent measures to prevent a similar catastrophe, with the Amur and Moscow branches of the charity in touch with regional hunting estates to ask them to help feed animals in their areas and prevent poaching.

Pavel Fomenko, the Amur branch coordinator at WWF Russia, said: 'I remember a similar winter at the end of the 1980s, when the snow was so deep that we lost 80 per cent to 90 per cent of all ungulates. I was a part of the inspection team and it was horrifying. The whole valley of the Amba and Bikin rivers turned into a gigantic graveyard. Nearly all the roes, wild boars and Siberian stags died'.

'What happened next was even scarier as during the next winter the tigers were left without pray, and so naturally besieged villages and small towns, hunting dogs, cows and other animals. The official data for that winter shows that more than 30 tigers were killed'.

Some buildings in Voss have collapsed under the weight and several municipal buildings are in danger of collapsing.

On Tuesday, civil defense authorities asked for assistance in shoveling massive amounts of snow from roofs on municipal buildings.

As if 1,000 cars on the roof

According officials, the Vossestrand omsorgstun, which has a roof surface of 2,500 square meters, was covered by a half to two meters deep snow.

"Our calculations show that it is 400 kilograms per square meter of snow. It is as if we were placed 1,000 cars onto this roof," said operations Eivind Hovden in civil defense.

There is so much weight that you have trouble opening doors and windows. There is immense power, he adds.

A rare Arctic visitor is getting folk all a flutter in Wester Ross.

A young ivory gull, generally found in the high Arctic, has been spotted at a fish farm near Ullapool.

They have only been reported in the UK as few as 100 times.

The bird was spotted by Wester Ross Salmon employee Matthew Ross when it landed at the fish farm at Ardmair Bay north of Ullapool. Matthew was unsure of the species of bird and sent pictures to a local wildlife tour operator to identify it.

The sighting has caused interest with bird watchers due to its rarity and there is speculation that it may be the same individual that was spotted at Uig Harbour in Skye at New Year and has possibly been blown to the mainland in the recent winds.

Inverness-based Alan Tissiman of RSPB Scotland said: "Ivory gulls are very rare visitors to the British Isles, invariably seen in the winter months after strong north westerly gales. They are usually found far to the north on the Arctic pack ice where they live all year round.

"They are scavengers, never happier than when they find a dead whale or seal to feed on! They are known to follow polar bears and other predators to feed on the remains of their kills.

"They are lovely-looking birds and I would imagine that this individual will have attracted a fair amount of interest from birdwatchers - though they may not wish to enquire too closely into its feeding habits!"

Lake Erie was less than six percent frozen last Tuesday with ice covering only a sliver of the lake's western basin.

But, after a week with frigid temperatures in the single digits, heavy lake-effect snows and high winds, Lake Erie is freezing up fast.

Nearly 60 percent of the lake waters were frozen today, according to graphs by the Great Lakes Environmental Research Laboratory (GLERL).

Most of the western half of the lake is already under ice coverage.

In some areas - the western basin, along the U.S. and Canadian shorelines, near Long Point, Ont. and close to Buffalo - it's nearly 100 percent iced over, according to GLERL charts.

As Lake Erie iced, so too have the Great Lakes at large.

Just a week ago, more than eight percent of the surface area of all of the lakes was frozen.

But by Monday, nearly one-quarter of the Great Lakes were under ice.

These images of drowned cattle are enough to make meat eaters and vegetarians alike shed a tear over the mistake that caused their mass death.

Last week, about 100 cattle wandered onto a South Dakota reservoir covered in six-inch-thick ice while seeking shelter in a severe windstorm.

Their hunt for rest turned tragic when the ice collapsed under their enormous weight of more than 1,000 pounds.

Storm-strength winds are once again hammering parts of Denmark on Thursday and winter is set to truly make its presence felt next week.

After a beautiful blanket of snow hit parts of Denmark on Wednesday and then disappeared again in about an hour, many were left wondering if and when true winter conditions will set in.

Meteorology institute DMI predicts that winter will truly make its presence felt as early as this weekend, with temperatures falling below the freezing point Saturday night and then remaining there for much of the next week.

The national forecast calls for rain to turn to snow on Sunday, with small amounts predicted through the middle of next week. By late next week, DMI's forecast is short and to the point: "Cold, windy and snow showers."

Weatherr Channel UK meteorologist Liam Brown warned: "We should prepare for freezing temperatures and very icy conditions for the coming days, and probably much of next week too.

Blizzards swept across the country yesterday - as Scots were warned that the worst of the wintry weather was yet to come.

The Met Office have issued "be aware" warnings for wind, ice and rain for much of central and southern Scotland for today.

Travel chaos is set to continue as severe gales of up to 80mph hit the country, while heavy rain and a thaw caused by slightly milder temperatures could lead to localised flooding.

Snow is forecast to return from tomorrow, when the mercury will fall again - and by early next week temperatures could plummet to a teeth-chattering -15C.

Weather Channel UK meteorologist Liam Brown warned: "We should prepare for freezing temperatures and very icy conditions for the coming days, and probably much of next week too.

Fierce Storm Rachel has left 1,950 homes without power and sparked travel chaos across the UK after a deluge of snow and torrential rain.

Gale force winds of up to 101mph blasted through Britain today as the churning low-pressure vortex - dubbed Storm Rachel - sparked commuter chaos.

But as the storm caused damage, delays, disruption and power failures, forecasters have warned the worst could still be to come.

Some 149 flood alerts and 32 flood warnings have been issued across Britain this morning, the Environment Agency confirmed.

The Met Office has also cautioned a "be aware" weather warning remains in place across the whole of England, Wales, Northern Ireland and central and southern Scotland for rain and high winds.

The highest recorded windspeed in the UK today is 101mph - reported in Great Dunsell, Cumbria while other exposed and coastal areas documented speeds of 70mph.

A Met Office spokesperson said: "After something of a lull, a further spell of very strong winds, this time from the west, is expected from late Thursday morning onwards into the evening, again with gusts of 70mph or more in places.

Heavy snowfall caused a traffic jam that extended several kilometers in Sa Pa town in the northern province of Lao Cai from Friday night to Saturday morning. Tourists from other provinces have flocked to the area for a taste of tropical snowfall.

The temperature at O Quy Ho Mountain Pass in Sa Pa town dropped to below 0 Celsius degree from 9pm on Friday to past midnight on Saturday, causing snow to fall heavily in many areas, according to Nguyen Van Thanh, a forest ranging official of the province's Hoang Lien National Park.

The snowfall seriously limited drivers' visibility and caused a several-hour traffic jam on National Highway 4D from Sa Pa to neighboring Lai Chau province and the other way around.