Weather Wise

According to my 1998 Weather Whys and Wonders Calendar (from Accord Publishing Ltd, Denver, Colorado), yesterday was National Weatherperson's Day in the US. To judge from weather reports, however, they must all have been too busy to celebrate it, as California was hit by its first major El Nino storm of the season.

Seven inches of rain fell on the north of the state on Tuesday, forcing thousands to evacuate their homes as rivers burst their banks and sodden hillsides collapsed into torrents of mud. Southern California was hit almost as badly, with mudslides and flooding, and a state of alert around the Pajaro river, which was four feet above flood-warning level.

After a calm Wednesday, emergency services braced themselves yesterday as more winter storms lined up in the Pacific, ready to bring more wind and rain. "We definitely expect flooding, and possibly disastrous flooding," said Dan Keirns of the National Weather Service. "This is not a normal winter pattern. It is a winter pattern that has been all charged up."

El Nino, of course, is the culprit. Its warm water in the Pacific warms the air above it, the currents created by the rising warm air bring wind, and the torrential rain comes as the quickly rising warm air cools and its high moisture content condenses. The general pattern is normal enough, but this El Nino has given it a vast dose of extra energy. A spokesman for California's flood centre said: "In not one of the dozen or so El Nino storms in the past have we experienced this kind of flooding."

Far from all this, in Florida, there was, amid some lesser storms, a piece of good news. The world's biggest deep freeze is open for business again after a $75m renovation. The McKinley Climatic Laboratory has in the past been used mainly for testing whether military equipment will stand up to severe weather conditions. "We can create any type of climatic conditions that you would want to operate in," said the laboratory director, Kirk Velasco, though he qualified that claim by admitting they could not duplicate a tornado or hurricane. Hail, sandstorms, dust storms, 100mph winds or monsoons are no problem, and you can have any temperature you want from -54C to +74C.

Testing of planes has been a major part of the work of the laboratory. The present major reconditioning of the laboratory followed damage caused to an F-117 stealth fighter by an icicle falling from the ceiling of the test chamber. It had formed from humid outside air leaking through the walls. Now icicle-free, the lab is back in business. "Our snow consistency is extremely good compared to what you get out there in the real world," said its director. The wrong sort for testing British Rail trains, then.