Condition 2

The United States Antarctic Program uses a weather classification system to identify when restrictions are put into place at a field camp or station. The classification systems is: Condition 3, Condition 2, and Condition 1. Condition 3 is normal weather conditions without any significant detrimental weather impacts, Condition 2 occurs with moderate weather presenting a concern, and Condition 1 indicates potentially hazardous weather for any form of travel.

The specifics are as follows:

• Condition 3:  Winds less than 48 knots; Visibility great than 1/4 mile; Wind chill warmer than -75F
• Condition 2:  Sustained winds between 48 and 55 knots; Visibility between 1/4 mile and 100 feet; Wind chill between -75F and -100F
• Condition 1:  Sustained winds greater than 55 knots; Visibility less than 100 feet; Wind chill colder than -100F

Only one of the three criteria needs to be met to push the weather into Condition 2 or Condition 1. My experience is that it is the visibility that is the driving factor. The weather conditions are also defined for nine regions in the area around McMurdo Station (e.g. McMurdo, Williams Field, Pegasus Field, Road to Pegasus).

Condition 2 presents restricted pedestrian traffic between buildings and limited vehicular traffic in an enclosed vehicle with required radio checkout at all times and locations. Condition 1 is the most limiting as everybody is confined to their current building or nearest shelter. I have never experienced Condition 1 in Antarctica. In fact, there have only been a few times where I have experienced Condition 2.

During the last two days we had a storm move through the region. For a few hours Thursday evening we went to Condition 2 in McMurdo. I had been watching the storm in the weather forecast model for a few days leading up to the actual storm. The fact that we went Condition 2 for a few hours made it a reasonable storm, although overall there was not much to the storm. About a week ago, we had Condition 2 weather on the drive back from Pegasus but we were the only ones on the road so it was not officially classified as Condition 2. I also experienced a Condition 2 storm at WAIS a year ago.

After a few days off from flying the UAVs, due to the weather and to rest, we are planning on returning to some morning to afternoon flights the next few days. I have also passed the midway point of my time in Antarctica, provided there are not significant delays in the flight back to Christchurch.

Limited visibility due to blowing snow and ice fog on the road going from Pegasus Airfield to McMurdo Station about a week ago.

Signs are placed throughout McMurdo indicating the weather condition. The weather condition is also indicated on the station webpage and a TV channel. This is me in front of the sign for this week's Condition 2.