October on Everest and the calm before the storm
11:30 a.m. EDT Oct 17, 2003
The word on Everest is that the winds have been low and there’s been no moisture in sight – clear skies above. Transitions – it’s the time when spring teams get the *bluebird skies and ideal summit conditions. So what exactly is going on right now? Well, for one, it’s very clear the monsoon has subsided – this is good news; no monsoon means little if any precipitation, BUT, there is a downside.
About a month ago ExplorersWeb came out with the latest in an ongoing weather analysis of the autumn climbing season (See link to the left ‘Fickle fall forecasts’). With two season’s worth of weather data, nothing is conclusive, but a clear pattern has been evident thus far; we’ve donned it the ‘Monsoonal flip-flop’. As in the spring when the arrival of the Monsoon brings a couple days of great weather, the same thing happens in the fall, except in reverse.
Like a Swiss watch
As the Monsoon subsides in late September and early October it takes the heavy snows and rains with it. Then, soon after the winds start to come – almost as if a light switch was turned on. In the two previous fall seasons this transition happened around the tenth of October.
Well, with one last cough and 7” of new snow this October 11th, the precip disappeared and the skies opened up – like a clock almost. Since then, the skies have been clear and the winds have been low – pretty ideal conditions. The question now remains, how long will this last. That band of yellow in the picture to the left is the jet wind. For the past while it has been hovering just next to Everest, but not quite there. When will it come down? This past spring it chose to sit atop of Everest for some time before clearing north.
Pink fuzzy dice
How drastic is the wind speed transition with the jet wind? It is almost like a knifes-edge. When Richard Branson was into endurance ballooning, one of the concerns his team had was making the transition into the jet wind as the balloon rose through the atmosphere. They feared as the balloon top hit the jet; it would shear right off from the capsule dangling just feet below. While it didn’t sheer the jet took the balloonist for quite the tumble as they entered it; the capsule trailing behind the balloon like a pair of fuzzy dice hanging from the rear view mirror of a Ferrari at full throttle.
Late spring summits = late fall summits?
The picture to the left shows the jet for today (on the left) and for the 22nd (on the right). The blue dots represent Everest and that yellow band indicates 30 to 40 m/s of wind. If the tentative predictions hold correct that band of high wind should be descending on Everest any day now, bringing with it over 30 m/s of wind at the summit. Will this mean the end of summit bid chances? Not exactly, while it may be more difficult, the wind could still subside enough for a summit attempt, although the chances of a windless day at the top becomes very, very low. Remember, the latest fall Everest summit to date was the last day of October over ten days from now. And this past spring several summiteers reached the top on the last day of May equaling the latest spring summit set earlier in the 90’s. Only time will tell as we watch the sole Everest expedition shoot for the top in the upcoming days!
*Bluebird skies – crystal clear, an ideal day
Weather charts of the Everest area of the wind at jet level courtesy of AdventureWeather.com and ExplorersWeb.