Antarctica Weather Danger Classification

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The weather in Antarctica can be highly variable, and weather conditions will oftentimes change dramatically in a short period of time. There are various classifications for describing weather conditions in Antarctica; restrictions given to workers during the different conditions vary by station and nation.

McMurdo Station (USA)[edit]

Condition Criteria Example
Condition 3 /
Normal Condition 3
Must meet all of the following criteria:
  • Visibility is either greater than 14 mile (400 m), or it falls to ​14 mile or less for less than one minute at a time
  • Windspeed is either below 48 knots (89 km/h; 55 mph), or it reaches 48 knots or above for less than one minute at a time
  • Air temperature and wind chill are either above −75 °F (−59 °C), or falls to −75 °F or below for less than one minute at a time
Condition 3 McMurdo.jpg
Condition 2 /
Severe Condition 2
Must meet all of the following criteria:
  • Visibility is either greater than or equal to 100 feet (30 m), or it falls below 100 feet for less than one minute at a time
  • Windspeed is either less than or equal to 55 knots (102 km/h; 63 mph), or it exceeds 55 knots for less than one minute at a time
  • Air temperature and wind chill are either −100 °F (−73 °C) or above, or falls below −100 °F for less than one minute at a time

And also must meet one or more of the following criteria:

  • Visibility is less than or equal to 14 mile (400 m), sustained for one minute or longer
  • Windspeed greater than 48 knots (89 km/h; 55 mph), sustained for one minute or longer
  • Air temperature and/or wind chill of −75 °F (−59 °C) or below, sustained for one minute or longer
Condition 2 McMurdo.jpg
Condition 1 /
Severe Condition 1
Must meet one or more of the following criteria:
  • Visibility less than 100 feet (30 m), sustained for one minute or longer
  • Windspeed over 55 knots (102 km/h; 63 mph), sustained for one minute or longer
  • Air temperature and/or wind chill below −100 °F (−73 °C), sustained for one minute or longer
Condition 1 McMurdo.jpg
Sources: United States Antarctic Program - The Antarctic Sun, National Science Foundation - McMurdo Station Guide 2006 & Field Manual for the U.S. Antarctica Program

An air temperature of −75 °F (−59 °C) or below would meet the criteria for Condition 2. And an air temperature of −100 °F (−73 °C) or colder would meet the criteria for Condition 1. However, the coldest temperature ever recorded at McMurdo Station was −51.7 °C (−61.1 °F). So reaching −75 °F (−59 °C) would be unlikely to occur, and reaching −100 °F (−73 °C) would be virtually impossible. However, reaching Condition 2 based on windchill values of −75 °F (−59 °C) or below do happen. And reaching Condition 1 based on windchill values of −100 °F (−73 °C) or colder does occur.

Scott Base (New Zealand)[edit]

Condition Criteria
Weather Condition 3 Must meet all of the following criteria:
  • Severe weather is possible within 24 to 48 hours
  • Visibility is greater than 300 metres (980 ft)
  • Wind less than or equal to 45 knots (83 km/h; 52 mph)
  • Air temperature and wind chill are above −60 °C (−76 °F)
Weather Condition 2 Must meet all of the following criteria:
  • Visibility is greater than 30 metres (98 ft)
  • Windspeed is no greater than 55 knots (102 km/h; 63 mph)
  • Air temperature and wind chill are no colder than −73 °C (−99 °F)

And also must meet one or more of the following criteria:

  • Visibility less than 300 metres (980 ft)
  • Windspeed is greater than or equal to 48 knots (89 km/h; 55 mph)
  • Air temperature and/or wind chill of −60 °C (−76 °F) or below
Weather Condition 1 Must meet one or more of the following criteria:
  • Visibility less than 30 metres (98 ft)
  • Windspeed over 55 knots (102 km/h; 63 mph)
  • Air temperature and/or wind chill are below −73 °C (−99 °F)
Sources: Antarctica New Zealand - Field Manual 2012-2013