Summer of wind and fire ahead for the US

Waves of fire across one side of the country and walls of water buffeting the coasts on the other. As the city of Los Alamos burns, America can look forward to more of the same - and worse - this year.

Waves of fire across one side of the country and walls of water buffeting the coasts on the other. As the city of Los Alamos burns, America can look forward to more of the same - and worse - this year.

La Niña, the phenomenon which is the other side of the climatic coin from el Niño, is expected to bring a vicious crop of hurricanes to America's Atlantic and Gulf coasts, according to the annual forecasts released last week. And it is also, in part, responsible for the fires which are sweeping through the South-west, including that which has wrecked Los Alamos in New Mexico. Firefighters were still struggling yesterday to contain the flames which have engulfed the city and threatened nuclear weapons facilities.

"Everything is being done that can be done," said New Mexico Governor Gary Johnson. "And yet, we may just be seeing the beginning of what is a real catastrophe." The fire started as a deliberate attempt to clear brush, which got out of hand as winds rose and the flames crossed a containment zone. The official who ordered the fire started was suspended from work on Thursday.

America's climatic problem starts with a swath of the Pacific Ocean which is cooler than normal in la Niña years and warmer than normal in el Niño years. The phenomenon was first noticed by fishermen off Peru: in Spanish, el Niño is "the little boy"; la Niña, the "little girl".

The el Niño/Southern Oscillation, as it is known to meteorologists, is one factor in world weather, but it causes changes to climatic patterns across the globe. Last year la Niña brought hurricanes and fires, and the chances are high that this year will be worse. In the winter, the Pacific jet stream is diverted to the north of the US, taking rain into the North-west.

That means less rainfall in the South and South-east, producing drought. In the summer the jet stream's shift north diminishes the strong winds in the mid-Atlantic. These windswould knock the tops off the storms that blow up over the warm ocean and their absence allows hurricanes to form andmake landfall in the Caribbean or on the Gulf and Atlantic coasts of the US.

The impact of those conditions can already be seen. Roughly a quarter of America is already in moderate to severe drought conditions and the water level in the Great Lakes is at 30-year lows.

America suffered three great droughts in the 20th century: the Thirties dust-bowl, another in the Fifties, and the last in 1988. Each was associated not just with crops dying in the fields, but with vast fires. Over a million acres burned in Yellowstone Park after lightning struck in 1988, which was the last big la Niña year. Though it is only May, the signs are that this will be another very dry year, with plenty more fires. Farmland is parched across the Midwest and South, and farmers - already despairing as agricultural markets languish - fear a very bad year.

According to the National Drought Mitigation Center, "The end of April signalled a record six straight months of record low water storage across Texas." In New Mexico and Arizona, conditions are dry and abnormally warm and the fire threat remains very high. The Los Alamos fire is probably just the first of a series of disasters and the dry weather is probably also a harbinger of a wild and wet summer for America's east coast. When it put out its storm forecasts last week, the US National Oceanic and Atmospheric Administration (NOAA) warned that this year's hurricane season could be bad. The last la Niña, in 1988, produced Hurricane Gilbert, a devastating storm which swept across Jamaica and on to the Yucatan peninsula in Mexico. The pressure at the eye of the storm was as low as 888millibars, the lowest pressurerecorded for an Atlantic hurricane..

This year the forecast is for 11 tropical storms, seven of which will be hurricanes, three of them major. The names for the season have been chosen, sosometime this year Debby, Ernesto, Florence or Gordon will bear down on the east coast as thousands flee for safety.

La Niña typically lasts 18months, and this one is showing signs of fading. Dr Ants Leetmaa, the director of the NOAA's Climate Prediction Center, said: "All of the computer weather models agree that most of the US will be warmer than usual, but at least wecan see the end coming for la Niña."