Reporting Criteria

When reporting in to MTR, Skywarn weather spotters should report:

Identify:

  1. Your name and spotter ID
  2. Your location
  3. Significant weather event including location, movement, speed, and direction and distance from a known location as appropriate

What to report:

  • Tornado, funnel cloud, or water spout
  • Thunderstorm (lightning seen or thunder heard)
  • Hail (any size)
  • Flooding
  • Strong winds (35mph or greater)
  • Heavy rain (>1/2”/hr or >2”/6hr)
  • Dense fog (< 1/4 mi – where public safety affected)
  • Snow of any amount
  • Passage of weather front
  • Other things
    • Ominous clouds, e.g. Towering Cumulus (TCu, seen on 9/2/2025 over Central Valley)