ExWeb series - Winter climbing: The BAD chart, part 4 final

Posted: Dec 21, 2004 05:00 am EST

Lately we've run a series about winter climbing in Himalaya. In high mountaineering, there are two ways to define winter; calendar and permit. The Calendar winter starts December 21, whilst a winter climbing permit begins December 1.

The Calendar winter is considered a "classic winter" climb. All first winter accents of 8000ers were made by Polish climbers - in Calendar winter. The first ascent was on Everest in 1980 and the latest on Lhotse in 1988.

But still, what does the reality look like? Let's put calendars and permits aside for a while, and examine the weather only, in order to find the worst time to climb.

Very few people have climbed 8000ers in the winter, and no one has skied to the North Pole or the South Pole in the cold season. This series is divided in 4 parts:

1. Wind Force

2. Temperature, Wind-Chill

3. Humidity

4. The Bad Chart Defining Seasons

Today, part 4, final: The Bad Chart Defining Seasons.

Winter according to Climbers

Climbing an 8000 meter during the winter has been the ultimate trophy, achieved only 31 times (by 25 people). 15 out of those 31 summits where made by Polish and 8 by Spanish (all on Cho Oyu). The other summits where reached by Japan (3), South-Korea (2), Nepal (1), Argentina (1) and Switzerland (1 only female).

Only 7 of the 14, 8000ers have been climbed in winter. All first ascents where made by Polish climbers. Two of the mountaineers (both Polish) are outstanding: Jerzy Kukuczka climbed 4, 8000ers during winter and Krzyztof Wielicki climbed 3, including one solo of Lhotse.

Some climbers have tried to make early winter climbs in the beginning of December taking advantage of milder weather in November. Most climbers have renounced that as winter climbs, insisting that winter officially starts on December 21, disqualifying all summits prior to that as winter.

Some puritans even insist that a winter climb shouldnt begin before December 21, leading to a summit at the height of winter in January.

Winter according to Nature: The Bad Chart

In the earlier articles we have examined Everest winter wind speeds, temperatures, chill factor and humidity. Time has come to bring it all together and add one more line dark hours.

According to the chart the lines jam up and things starts to get really bad during December, worsen slightly in January and stay bad during February.

November is drier and warmer than the winter period and March is warmer and less windy.

Winter according to ExplorersWeb: The exact start and end of Winter

The two most important factors for bad winter weather are cold temperatures and high winds. The extreme winds start already in October and run through February. Temperatures drop constantly during the autumn until Dec 21, when they reach bottom levels.

Temperatures stay low for just over two months until February 28; when Everest starts to warm up again. It is probably no coincidence that the weather charts show winter starting at the exact same date as the winter solstice (darkest day of the year), and the official beginning of winter according to the calendar.

The 6 Weather Periods of Everest

Below is ExplorersWebs definition of 6 distinct weather seasons for Everest and the surrounding 8000ers.

June 7 - Sep 30
Summer: Very Wet, Calm, Warm

Oct 1 Oct 20
Autumn Window: Dry, Calm, Warm

Oct 21 Dec 20
Autumn: Very Dry, Very Windy, Cold, Dark

Dec 21 Feb 28
Winter: Dry, Very Windy, Very Cold, Dark

March 1 May 19
Spring: Dry, Windy, Cold

May 20 June 6
Spring Window: Dry, Calm, Warm

The Rules for a Winter climb.

ExplorersWeb will acknowledge winter climbs as winter when:
A. The summit was reached between Dec 21 and Feb 28.
B. The climb started after Dec 1.

Image 1 (ExplorersWeb): Everest Bad Chart a relative comparison of key weather factors.
Image 2 (ExplorersWeb): 7-day average detail of base camp and summit temperatures on Everest. Period November to Feb.

Data
"BaseCamp" is at Pressure (hPa) 495 or app. 6100m of altitude

"Summit" is at Pressure (hPa) 346 or app. 8750m of altitude

The charts are based on forecasts delivered by SMHI and compiled by the super-computer at ECMWF. The information below is compiled from 868 forecasts from May 1 2002 to Nov 1 2004.

There is no weather station at the Summit of Everest which would have allowed exact readings, but the forecast should be fairly accurate - as it has been used by climbers for 10 Himalayan seasons and hundreds of high-altitude expeditions.

The AdventureWeather 8000 meter forecasting project is free of charge to climbers and sponsored by ExplorersWeb.com and its partners.










Everest Bad Chart a relative comparison of key weather factors (click to enlarge).
7-day average detail of base camp and summit temperatures on Everest. Period November to Feb. Data "BaseCamp" is at Pressure (hPa) 495 or app. 6100m of altitude. "Summit" is at Pressure (hPa) 346 or app. 8750m of altitude. The information was compiled from 868 forecasts from May 1 2002 to Nov 1 2004, based on forecasts by the super-computer at ECMWF. Copyright ExplorersWeb.