How the Autumn Trekking Season Became Lethal in the Himalayan Mountains
Bright heavens, calm winds and a breathtaking view of Himalayan peaks draped in snow - that is the autumn experience that trekkers on the world's highest peak have grown to adore.
But that appears to be transforming.
Shifting Weather Patterns
Climate scientists indicate the rainy season now stretches into fall, which is traditionally the mountain tourism period.
During this delayed conclusion of monsoon, they have recorded at least one episode of heavy precipitation nearly every year for the previous decade, with mountain weather becoming more dangerous.
Recent Emergency on Everest
Last weekend, a sudden blizzard stranded hundreds of visitors near the east-facing side of Everest for days in freezing conditions at an altitude of more than 4,900m.
Almost 600 hikers were guided to safety by the end of Tuesday, according to sources.
One individual had succumbed from extreme cold and altitude sickness, but the others were said to be in good health.
Similar Incidents Across the Region
This was on the northern slope but a comparable situation had occurred on the Nepal side, where a South Korean climber died on Mera Peak.
The international community found out after some delay because communications were affected by heavy downpours and significant snow accumulation.
Officials calculate that mudslides and flash floods in the country have killed approximately sixty individuals over the previous week.
"It is highly atypical for autumn when we expect the skies to remain calm," said Riten Jangbu Sherpa.
Economic Consequences
Considering autumn represents the favored period, frequent extreme weather events like this have "disrupted our mountaineering and mountaineering industry," he continued.
The rainy period in the Indian subcontinent and the Himalayan nation typically lasts from June to mid-September, but no longer.
"Research demonstrates that most of the annual cycles in the past decade have had monsoons lasting until the second week of autumn, which is definitely a shift," said a high-ranking meteorology official.
Growing Climate Severity
More concerning is the heavy precipitation and snow the tail end of the season produces, like it occurred recently on 4 and 5 October.
High in the Himalayas, such severe weather means blizzards and snowstorms, which represents a huge danger for hiking, mountaineering and tourism.
Personal Experiences
That's what happened recently when the weather shifted quite suddenly - the winds began howling, mercury readings dropped sharply and sightlines dropped significantly.
The road that had comfortably brought the trekkers to what was expected to be a stunning pitstop was now buried in white accumulation and impossible to traverse.
Still, one hiker, who had climbed the Himalayas more than a dozen occasions, reported he had "not once experienced conditions like these" before.
Scientific Analysis
One big factor is the increased quantity of moisture in the atmosphere because of how the world has been warming, researchers say.
This has led to torrential rains over a brief period of duration, often after a prolonged dry spell – in contrast to in the past when seasonal rains were spread evenly over four months.
A Intensified Monsoon
Weather specialists report the rainy seasons in South Asia at times appear to have become stronger because they are more frequently coming into contact with another weather system, the westerly disturbance.
The phenomenon is a atmospheric depression that originates in the Mediterranean area and travels eastward - it carries cold air that causes precipitation and sometimes snowfall to the subcontinent, neighboring countries and the Himalayan region.
Global Warming Effects
Scientists have also discovered that in a warming world, the growing relationship between western weather systems and seasonal rains is producing another unusual outcome.
The warmer atmosphere is pushing the weather systems to greater altitudes, which means these weather systems are now able to pass over the Himalayas and affect Tibet and other areas that previously experienced less as much precipitation in the past.
"What's changed is the reliability of patterns; we cannot presume that conditions will occur the same from season to season," said an experienced expedition guide.
"That means adaptable scheduling, immediate decision-making, and knowledgeable guidance [in the Himalayas] have become even more important."
