Cloudburst

Cloudburst is a extreme rainfall that lasts for very few minutes and leave with heavy damage to the land. It differs from rainfall as pouring water shower from sky from a big vessel of water. Imagine the situation and its effects. After this rainfall remains only the flood and chaos. It seems a simple and very few minute disaster but its recovering needs more time.

El Niño and La Niña

El Niño is a weather event involving the eastward migration of a mass of warm water normally found in the western equatorial Pacific Ocean.

Periodically (usually every three to seven years), the easterly trade winds in the Pacific weaken and allow the pool of warm water to drift from Australia to the western coast of South America, often triggering heavy rains there.


This vast pool of warm water is thought to set off a chain reaction that can affect jet stream and weather patterns around the world, especially in the winter months in the northern hemisphere. El Niño is sometimes referred to as ENSO for El Niño–Southern Oscillation. The Southern Oscillation is a seesaw of air pressures on the eastern and western halves of the Pacific.

La Niña is essentially the opposite of El Niño. La Nina is a migrating pool of cooler-than-usual ocean water. The cool water can suppress rain-producing clouds, which leads to dry conditions.

Peruvian fishermen first noticed the effects of a new El Niño at Christmas ime, when storminess off the coast reduced the supply of fish. "El Niño" is Spanish for "the boy child," and is used to refer to the Baby Jesus. The name La Niña ("the girl child") was coined to deliberately represent the opposite of El Niño.

Because even the most dedicated scientists do not thoroughly understand El Niño and La Niña (we do not know, for instance, why the trade winds suddenly die down and allow the warm water pool to move eastward), we can only describe certain tendencies in the weather.

In the past, El Niño has often brought heavy rains to southern California and to a portion of the South from Atlanta to Cape Hatteras; it can bring relatively mild winter temperatures to the northern third of the country. However, these effects are not consistent in every El Niño event on record.

The stronger the La Niña, the more severe the droughts. Tha La Niña in 2009 is creating severe drought in much of the world, causing an agricultural crisis.


El Niño

The data from TOPEX/Poseidon, and in the future Jason-1, helps us study and understand the complex interactions between the oceans and the atmosphere which affect global weather and climate events. One well-known example of this interaction is an El Niño event.

El Niño was named by people who fish off the western coast of central America to refer to the warm current that invades their coastal waters around Christmastime. El Niño events disrupt fisheries and bring severe weather events worldwide.

In a normal year, the trade winds blow westward and push warm surface water near Australia and New Guinea. When warm water builds up in the western Pacific Ocean, nutrient-rich cold water comes up off the west coast of South America and fosters the growth of the fish population.


During an El Niño event, the trade winds weaken and warm, nutrient-poor water occupies the entire tropical Pacific Ocean. Heavy rains that are tied to the warm water move into the central Pacific Ocean and cause drought in Indonesia and Australia. This also alters the path of the atmospheric jet stream over North and South America.

The effects of El Niño disrupt normal winter conditions throughout the Pacific Ocean, and can persist into May or June. Reliable predictions of an El Niño occurrence will lead to better preparation for its widespread impact.

La Niña

Warm El Niños and cold La Niñas follow each other against the backdrop of the ocean seasons. During a La Niña, the trade winds are stronger and cold, nutrient-rich water occupies much of the tropical Pacific Ocean. Most of the precipication occurs in the western tropical Pacific Ocean, so rain is abundant over Indonesia.

Snow War

Extreme weather warning as Britain braces for snowstorms

Blizzards and up to 15cm of snow expected as arctic temperatures make winter coldest for 13 years

Britain is standing by for more icy weather tonight as snowstorms move in from the North Sea where they have been gathering since early this morning.

Arctic temperatures will accompany a front that looks certain to make this winter the coldest for 13 years.

The Met Office said it was classifying tomorrow's expected snowfall as an "extreme weather event". The warning covers the south-east of England, including London.

"This is likely to be the heaviest and most widespread snowfall across England since January 2003," Tom Defty, the head of forecasting operations at MetService, said.

"Parts of south-east England, including London and eastern England, will see anywhere from 10cm [4in] to 15cm [of snow], and perhaps above 20cm over the higher ground."

He said the worst of the snow would arrive in Kent tomorrow morning before spreading north and west during the afternoon.

Up to 10cm of snow is expected to fall in the eastern parts of Lincolnshire and Yorkshire, where the coastline between Bridlington and Skegness will bear the brunt of the first storms.

Blizzard conditions and drifts may affect coastal areas and close scores of roads if current high winds persist.

"Severe disruption to roads and airports is extremely probable during the peak of the Monday afternoon rush hour," Defty said.

"Through Monday night into Tuesday, a slow thaw will set in across eastern areas as milder air turns falling snow back to rain."

He said further outbreaks of snow were expected throughout the week across Wales, northern England and Scotland."

Forecasters predicted that the gathering strength of the cold front would see heavy falls well inland, with 5cm predicted for Leeds and Bradford, in Yorkshire, before the morning rush hour.

Light snow has already fallen intermittently in London and across East Anglia.
Forecasters are predicting average wind speeds of between 25 and 30mph, with much fiercer gusts. Gale force strengths could be reached as the storms move over warmer land and gather pace.

People across the country were warned to wrap up warm and avoid unnecessary journeys.
Stephen Davenport, of the MeteoGroup forecasting group, said: "In places, it will feel several degrees below because of wind chill."

The AA's spokesman Andy Taylor said: "Don't treat your car as an overcoat. If you break down you are suddenly vulnerable to the weather.

"That especially applies if you are on a motorway, where safety advice is to get out of the car and wait behind the barrier. Unless you have extra clothes, you really could be flirting with hypothermia."

The easterly chill follows a relatively mild spell after the three-week freeze in early January during which lows of –13C (8.6F) were reached. The previous coldest winter was in 1995.

Bookies have cut odds on 2009 being the coldest winter on record from 12/1 to 8/1, but a counter-trend is seeing betting that this summer will be one of the hottest ever.


Source: http://www.guardian.co.uk/weather/2009/feb/01/snow-arctic-britain-weather-blizzards

Excess Rain in Monsoon

Most scientists agree that global warming presents the greatest threat to the environment.

There is little doubt that the Earth is heating up. In the last century the average temperature has climbed about 0.6 degrees Celsius (about 1 degree Fahrenheit) around the world.

From the melting of the ice cap on Mount Kilimanjaro, Africa's tallest peak, to the loss of coral reefs as oceans become warmer, the effects of global warming are often clear.

However, the biggest danger, many experts warn, is that global warming will cause sea levels to rise dramatically. Thermal expansion has already raised the oceans 4 to 8 inches (10 to 20 centimeters). But that's nothing compared to what would happen if, for example, Greenland's massive ice sheet were to melt.

"The consequences would be catastrophic," said Jonathan Overpeck, director of the Institute for the Study of Planet Earth at the University of Arizona in Tucson. "Even with a small sea level rise, we're going to destroy whole nations and their cultures that have existed for thousands of years."

Overpeck and his colleagues have used computer models to create a series of maps that show how susceptible coastal cities and island countries are to the sea rising at different levels. The maps show that a 1-meter (3-foot) rise would swamp cities all along the U.S. eastern seaboard. A 6-meter (20-foot) sea level rise would submerge a large part of Florida.

Uncertainties

Just as the evidence is irrefutable that temperatures have risen in the last century, it's also well established that carbon dioxide in the Earth's atmosphere has increased about 30 percent, enhancing the atmosphere's ability to trap heat.
The exact link, if any, between the increase in carbon dioxide emissions and the higher temperatures is still under debate.

Most scientists believe that humans, by burning fossil fuels such as coal and petroleum, are largely to blame for the increase in carbon dioxide. But some scientists also point to natural causes, such as volcanic activity.
"Many uncertainties surround global warming," said Ronald Stouffer at the U.S. National Oceanic and Atmospheric Administration's Geophysical Fluid Dynamics Laboratory in Princeton, New Jersey. "How much of it would still occur if humans were not modifying the climate in any way?"

The current rate of warning is unprecedented, however. It is apparently the fastest warming rate in millions of years, suggesting it probably is not a natural occurrence. And most scientists believe the rise in temperatures will in fact accelerate. The United Nations-sponsored Intergovernmental Panel on Climate Change reported in 2001 that the average temperature is likely to increase by between 1.4 and 5.8 degrees Celsius (2.5 and 10.4 degrees Fahrenheit) by the year 2100.