Weather

Antarctica is generally warmer (in season) but windier than the Arctic. The wind chill and the altitude close to the pole will be our major challenge in terms of weather. Another major difference is that Antarctica experiences more storms than the North, due to the powerful Katabatic winds which sweep down from the Polar plateau.

The Katabatic winds of Antarctica are amongst the most ferocious on Earth, reaching speeds of  up to 200mph. However the average wind speed that we're likely to experience is 12mph.

Temperature and Snow Fall

The coldest period in Antarctica is usually the end of September.  The coldest recorded temperature ever measured was -128.6F/-89.2C at Vostok base on 21^st July 1983, and the warmest recorded Antarctic temperature was +15C, on 5^th Jan 1974 at the New Zealand Vanda base.

When the winter winds blow across Antarctica the wind chill factor can make the perceived temperature plummet to as low as -150F/-100C. The average wind chill that we can expect when we're going to the Pole is -46C.

To put all of this into perspective, think about how cold it is inside the freezer unit at your house or the supermarket. Frozen foods are normally kept in temperatures no colder than -17C, so you can imagine what it's going to be like!

There is very little precipitation on Antarctica which classifies the continent as, believe it or not, a desert. Precipitation (rain or snow fall) averages less than 2in (50mm) a year. The cold evaporates all humidity and the continent is as dry as the Sahara desert.

During 'expedition season' the sun never comes close to setting.  It travels around the sky in a low circle each day and 'day' is indistinguishable from 'night'. Although the sun remains quite low, the combination of permanent daylight, reflection off the ice, and the lack of ozone in that part of the world mean that sunburn is an ever-present risk which we will prepare for carefully each day.  Indeed sunburn is as much a potential problem as frostbite.

 
The South Pole season is opposite to the North Pole when it comes to polar travel. South Pole adventurers arrive in Antarctica's summer and travel into winter. With the coastal areas being warmer, this means that our warmest period will be at the beginning of the trip, gradually cooling off as the weeks tick by. Because we will be flying in as early as possible, we are likely to catch some cold weather before the summer weather kicks in.  So initially - 20C to -25C is likely, but rising over a couple of weeks to perhaps -5C to -10C.

 As we get closer to the Pole, -40C will become common, particularly as we gain altitude - the Pole being at 9,300 ft.  As we return towards the coast the temperatures will slowly warm again.  However, we are likely to be weakened by this time, with less fat reserves, and so will feel the cold much more.

Reading clouds

Antarctic weather can change extremely quickly.  We are very pleased to have the support of the Met Office which, for the first time, will be providing a private expedition with bespoke daily forecasts to assist in our planning and daily scheduling.  Further daily forecasts from base camp at Patriot Hills and the South Pole station will assist us.

In addition, we can make our own short-term forecasts from the cloud conditions. Cumulus, a low grey blanket, usually means no wind, perhaps some snowfall and warmer temperatures. The light conditions will be no shadow but there may be some contrast.

High, sharp streaks of Cirrus imply high winds and sunshine initially, but can also be a sign of an approaching storm, so we know to watch for further signs and be ready to take action.

Alto Stratus, a white veil of medium high clouds, generally means that we can expect difficult weather conditions with snowfall that could last for days on end, whiteout conditions and generally bad weather which could severely affect our progress.

A more unusual formation is a nasty looking white wall of cloud approaching rapidly with black twisters touching the ice. If we see this we can expect very high winds within 20 minutes of sight. Although the conditions that this brings with it are atrocious and will stop us entirely, the storm usually passes fast, rarely lasting more than 30 minutes or so. The moment we see the signs of this type of storm approaching we will stop, secure all of our gear, and brace ourselves until the storm passes.

Blizzards and Whiteout

Because there is very little new snowfall in Antarctica, blizzards are caused by existing snow, snow that's already on the ground, being picked up and blown around by the high wind. Think of a child's snow-dome toy - the principle is similar.

Conditions like this seriously impair vision, making it impossible to see features further away than the end of our skis.  This makes travel in crevassed areas particularly hazardous.

Whiteout conditions come with  low cloud over a snow covered surface, and cause a loss of depth perception and complete disorientation; the old saying that it is like being inside a ping-pong ball is quite accurate..

On clear days in Antarctica you can see a very long way, but this gives rise to some difficulty in judging distance. Mountain ranges 60 miles away appear knife sharp, looking much closer than they are, especially if we've been experiencing contrasting weather conditions.

Solar phenomenon

In Antarctica, the clear air, sun, ice conditions and air temperatures can combine to create all sorts of entertaining trickery.

'Sundogs' are images of several suns in the sky. Sometimes there are images of pillars and arcs caused by the suns halo. Another phenomenon is known as 'diamond dust' which is caused by ice particles floating in clear air reflecting the suns light.  This is exceptionally beautiful and it seems as though the air itself is sparkling.

In the Antarctic winter the Southern Lights, or Aurora Australis, are quite spectacular. They are caused by electrically charged, high-energy particles from the sun meeting the earth's magnetic field and are seen as multi-coloured giant 'curtains' in the sky and are typically green, white or red.   If we see these, we know we've missed our flight home.