title: Peak Detection and Event Duration using BigQuery
body: <p>We are trying to implement a peak detection algorithm using BigQuery.  Basically we want to track if there is a threshold exceedance, and then just output the start and end
  time.</p>
  
  <p>For example, with GSOD weather data pick an arbitrary temperature threshold. Basically for a given GSOD location, find the dates where it is above 70 degrees but don't count
  it as an event until it drops back below 70 degrees.</p>