Until a decade ago many climbers favoured the spring season for expeditions on the peaks of the Nepal Himalaya because the weather was more stable than the colder shorter days of autumn.

"There has been a perceptible shift in monsoonal patterns, they start later and stay longer," says meteorologist Ngamindra Dahal, "we don't know whether it is a result of climate change, but it is happening."

But the jet stream which lashes the tops of the mountains is now less predictable, snow is less firm and there is more objective danger from avalanches even in the autumn season. This has influenced major changes in terms of seasonal choice among serious mountain climbers.

"The weather is much more unstable. There is more risk of snow in the spring and the monsoon is more unpredictable. While autumn is drier," says James Frush former president of the American Alpine Club and managing editor of the American Alpine Journal. Frush attempted Makalu in 1983 and has been coming back to Nepal since preferring to go after remote area mountains like the unscaled 6405m Fwaksakang west of Dhaulagiri which he is climbing this season with a team of two other Americans and a German.

This year, the monsoon sputtered out in July and was lingering long after the traditional end of monsoon date of 22 September. Even in the trans-Himalayan areas like Manang, there was little rain till two weeks back and most expeditions were patiently trying to wait out the weather.

Historically, during the age of first ascents in the 1950s, climbers preferred the spring on eight thousanders because the temperatures were higher and there would be less wind. But as climbing gear and clothing improved, many mountaineers switched to the less-crowded autumn season despite the jet stream. Now, because of the shift in monsoonal patterns it seems climbers prefer spring again.

There were a total of 133 expeditions last spring, 141 in autumn and five in winter. Sagarmatha however continues to attract more climbers in spring. There were 64 expeditions in spring 2004 and a phenomenal 101 this year compared to only two last autumn and one this season.

Although the ceasefire has come as a much needed blessing to the trekking and mountaineering industry, there has been no big surge in the number of expeditions this autumn. The royalty to climb from peaks from the Nepal side is much higher than for the same peak from the China so Nepal is losing out to Tibet, even though the high altitude porters and guides there tend to be Nepalis and Kathmandu-based companies do the handling. Last year the Ministry of Tourism even announced a 50 percent discount on all 8000m peaks, but there seem to be few takers.

For example, there are 41 expeditions are headed for Cho Oyu, considered the easiest eight-thousander but all are from the Tibet side this season, even an expedition to mark 50 years of Nepal-China diplomatic relations.

Lakpa Sherpa who is a part of the Nepali delegation is confident about the success of the expedition but has his fingers crossed about the weather. "We are ready, now it is up to the weather," he told us last week before he left for Tibet.