Reporting Criteria

Net participants are encouraged to share weather reports from what they’re observing at their location. When reporting information to the net, please use the following guidelines:

  • Tornadoes, funnel clouds, rotating wall clouds
  • Damaging winds that blow down trees and power lines or damage buildings (see below)
  • Hail marble size or larger (0.50”+ in diameter)
  • Flooding of homes, buildings, or major roadways that impedes traffic
  • Whiteout snow conditions with visibility below .5 miles
  • Snowfall rates estimated to be 2”+ per hour.

When reporting, if you’re uncertain of the severity please state that in your report to net control.

Damaging Wind Criteria

Wind Speed (mph)Visual Effect
20 – 30 mphSmall trees in motion.
30 – 40 mphLarge trees in motion, whistling in overhead utility lines.
40 – 50 mphWhole trees in motion; Garbage cans/similar items blown over.
50 – 65 mphTwigs/Small branches break off trees; Damage to fences/shingles
65 – 80 mphLarge branches break off of trees; Shallow rooted trees uprooted.
80 – 100 mphExtensive tree/roof damage; Trailer homes overturned.

Hail criteria

ComparisonMeasured Diameter
Marble0.50”
Penny0.75”
Nickel 0.88”
Quarter1.00”
Half Dollar1.25”
Ping Pong Ball1.50”
Golf Ball1.75”
Tennis Ball2.50”

Snow Measurement Reference

Measuring snow in the winter is not as easy as walking down your driveway with a ruler, there are some things you should keep in mind, especially in Colorado. Winter storms are usually accompanied by wind in our geographic region which can quickly skew snow measurements.

  • Take measurements in a location where drifting does not usually occur
  • Locations sheltered from the weather (close to buildings, under trees) should be avoided
  • Make sure you’re measuring on a flat surface if you don’t have a snow board. Things like picnic table, decks work well. If you don’t have that option, measure on a flat portion of your yard away from your home/garage.