Cunnane plotting position

{
  "id": "MLC-T-MET-004800",
  "term": "Cunnane plotting position",
  "field": "Meteorology and atmospheric science",
  "definition": "A formula used in hydrology and meteorology to estimate the exceedance probability of an event from a sample of historical data, such as annual maximum rainfall or streamflow. The formula assigns a probability to each data point based on its rank when the data is sorted in descending order. For a data point with rank m in a sample of size n, the plotting position is calculated as (m − 0.4) / (n + 0.2).",
  "see_also": [
    "plotting position",
    "probability paper"
  ],
  "url": "https://mlchart.com/terminology/meteorology/cunnane-plotting-position/"
}