Greeting from McMurdo!
We have been in Antarctica for about 9 days now. So far, a full 6 of those days have had travel restrictions due to weather! In McMurdo, there are 3 conditions of weather: Condition 3, 2, and 1, in order of increasing severity.
The definitions for the three conditions are actually quite broad. You can find the full definitions with good visual aids here but briefly, they are:
Condition 3 – Wind less than 48 knots AND visibility greater than 1/4 of a mile AND wind chill temperature warmer than -75F.
Condition 2 – Wind between 48-55 knots (sustained for one minute) OR visibility between 100 feet and 1/4 of a mile OR wind chill between -75F and -100F (sustained for one minute)
Condition 1 – Wind greater than 55 knots OR visibility less than 100 feet OR wind chill less than -100F
ALL travel is restricted in Condition 1, everyone should shelter in their current buildings. In Condition 2, vehicular traffic is limited to enclosed vehicles (no snow mobiles) with radios and foot traffic is limited to only between buildings.
If you have trouble visualizing what 48+ knot winds are, those are enough to make a grown adult stagger and bobble about in their footsteps! Terry Deschler claims that at 70+ knot winds, you are forced to crawl if you want to move anywhere. So far we have not had the pleasure of testing that statement (and hopefully we won’t have to)!
As you might guess, even in Condition 3 things can be pretty nasty! We have only reached Con 1 once since we landed here but we have had full days of Con 2. I am told this is quite unusual for this time of year. Most of the Con 2 time so far has been due to visibility issues as opposed to wind speed or wind chill issues. There has been an unusual amount of precipitation (snowfall) and any wind whatsoever is enough to cause whiteout conditions.
The good news is that we have had plenty of time to make sure all of our instruments work while we are in a nice, centrally heated lab space. The bad news is that all of the Con 2 time has pushed back our training schedule but we finally did finish that yesterday! Either here or on the FB page we will have a post about all of the training courses we have had to do. Stay tuned for more updates!