After the squall lashed the Capital on Wednesday, Met officials attributed the sudden change in weather to a low pressure disturbances in the neighbouring region.

Few scientific creations have had greater impact on public opinion and policy than computer models of Earth's climate. These models, which unanimously show a rising tide of red as temperatures climb worldwide, have been key over the past decade in forging the scientific and political consensus that global warming is a grave danger. (Editorial)

The India Meteorological Department on Wednesday forecast that the onset of the South-west Monsoon over Kerala is likely on May 29, with a model error of plus or minus four days. In other words, the monsoon could enter the Indian landmass between May 25 and June 2. The normal date of onset over Kerala is June 1. Meanwhile, with the strengthening and deepening of the monsoon winds and widespread rainfall activity, the monsoon has already entered the waters surrounding the country.

MUMBAIKARS looking for some respite from erratic rainfall predictions as experienced on 26/7, are in for a disappointment. Reason: The much-awaited installation of a Doppler Radar for accurate weather forecast continues to be stalled for one reason or the other.

The Environment Ministry and the Japan Meteorological Agency have opened a new website to jointly publicize yellow sand information. The ministry and the agency had previously posted yellow sand information on separate websites, making data access by Web visitors less user friendly.

"Politicians seem to think that the science is a done deal," says Tim Palmer. "I don't want to undermine the IPCC, but the forecasts, especially for regional climate change, are immensely uncertain." Palmer is a leading climate modeller at the European Centre for Medium-Range Weather Forecasts in Reading, UK, and he does not doubt that the Intergovernmental Panel on Climate Change (IPCC) has done a good job alerting the world to the problem of global climate change.

A new paper shows that regional and even global temperatures are being temporarily held down by a natural jostling of the climate system, driven in large part by vacillating ocean currents.

The climate of the North Atlantic region exhibits fluctuations on decadal timescales that have large societal consequences. Prominent examples include hurricane activity in the Atlantic, and surface-temperature and rainfall variations over North America, Europe and northern Africa. Although these multidecadal variations are potentially predictable if the current state of the ocean is known, the lack of subsurface ocean observations that constrain this state has been a limiting factor for realizing the full skill potential of such predictions.

The effects of global warming over the coming decades will be modified by shorter-term climate variability. Finding ways to incorporate these variations will give us a better grip on what kind of climate change to expect.

Extreme rainfall events today pose a serious threat to many populated and urbanized areas worldwide. An accurate estimate of frequency and distribution of these events can significantly aid in policy planning and observation system design. We report here a highresolution (10 km) analysis of heavy rainfall episodes (defined as 24-h rainfall exceeding 250 mm) over the Indian region.