National Weather Service United States Department of Commerce

Upcoming Spotter Training Sessions Info:

(Dates are BelowSevere Storm Spotter Show Slideshow Download)


Current Severe Weather Information


Reference Information


Send in a Report


Reference Information 

  Hail Size Chart: (diameter in inches)

  • Pea Size: 0.25 inches
  • Small Marble: 0.50 inches
  • Penny: 0.75 inches 
  • Nickel: 0.88 inches
    Any hail size below is severe thunderstorm criteria:
  • Quarter: 1.00 inches
  • Half Dollar: 1.25 inches
  • Ping Pong Ball: 1.50
  • Golf Ball: 1.75 inches
  • Hen Egg: 2.00 inches
  • Tennis Ball: 2.50 inches
  • Baseball: 2.75 inches
  • Grapefruit: 4.00 inches
  • Softball: 4.50 inches

Wind Speed Estimate:

  • 25-31 mph: Large branches in motion; whistling heard in telephone wires.
  • 32-38 mph: Whole trees in motion; inconvenience felt walking against the wind.
  • 39-54 mph: Twigs break off trees; wind generally impedes progress.
  • 55-72 mph: Damage to chimneys and TV antennas; pushes over shallow rooted trees.
  • 73-112 mph: Peels surfaces off roofs; windows broken; light mobile homes pushed or overturned; moving cars pushed off road.
  • 113-157 mph: Roofs torn off houses; cars lifted off ground.



 Spotter Training Classes


The 2021 Spotter Training was online! See below for specific times and registering links. Spotter training is also available anytime from our partners at COMET Severe Storm Spotter Show Slideshow Download


Frequently Asked Questions about LIVE ONLINE WINTER Spotter Training Sessions

  1. Do I need to preregister for these sessions? YES. Click on the link specific to the date/time that you plan to attend to register. After registering, you will receive a confirmation email containing information about joining the webinar.  If you do not receive a confirmation email, please check your spam folder in email. If it's not there, then please register again
  2. About how long do the sessions last? Approximately 2 hours.
  3. How many of these training sessions do I have to attend? Just one. All sessions will contain the same content.


Date Click Link to Register For Session
Monday December 6 at 6:00 PM EST
Saturday December 11 at 11:00 AM EST
Thursday December 16 at 1:00 PM EST
Monday December 20 at 6:00 PM EST