National Weather Service United States Department of Commerce

The SKYWARN Storm Spotter Program was created by the National Weather Service (NWS) to improve warning services. The NWS needs real-time reports of hail size, wind damage, flash flooding, heavy rain, tornadoes, and waterspouts to effectively warn the public of inclement weather. Even as new technology allows the NWS to issue warnings with more lead time, spotters will always be needed as links between radar indications of severe weather and ground truth. Storm Spotter volunteers serve as severe weather spotters for the NWS and local emergency management programs, and generally have two things in common - an interest in the weather and a desire to serve their community.

How to Become a NWS Storm Spotter

2023-2024 Local Storm Spotter Training Schedule
1) Local Storm Spotter training classes for Southeast SC and GA. All classes are FREE and VIRTUAL and may be canceled on short notice due to severe weather threatening the area. No prior knowledge of weather or weather observing required.
2) Online Storm Spotter course:  This option is best if you cannot attend one of our in-person training sessions or want to refresh your knowledge. You will need to register on the COMET website to access the training. Be sure to follow the instructions in the Course Description section for how to become an official Storm Spotter for the NWS in Charleston, SC.
3) Storm Spotter training classes outside of the local area Most National Weather Services Offices across the country provide training specific to their local areas of responsibility. Click here for training in other areas of the country.


Severe Weather Reports Needed

  • Tornadoes, waterspouts, funnel clouds, rotating wall clouds
  • Hail (any size)
  • Estimated or measured wind speeds of 50 mph or greater
  • Flooding resulting in closed or impassable roads, property damage
  • Rainfall amounts greater than 2 inches per hour
  • Trees downed by wind (including large limbs)
  • Downed power lines or other structural damage caused by wind

When reporting any of these events, it's very important to tell us WHEN and WHERE they occurred. For geographic reference, an intersection and town are very useful so we can pinpoint the report. If it's a second or third hand report, please give us the source of the original report, along with all the applicable information about what was reported.

See our Weather Spotter Quick Reference Card for a lot of useful information.


Reporting Reference


Hail Sizes

Please report the size of the largest hailstones as they cause the most damage. Also, please do not use the term "marble size" or "ice cube" since these items come in many different sizes.

  • 0.25 inch - Pea
  • 0.50 inch - Dime
  • 0.75 inch - Penny
  • 0.88 inch - Nickel
  • 1.00 inch - Quarter (Severe)
  • 1.25 inch - Half Dollar
  • 1.50 inch - Ping-Pong Ball
  • 1.75 inch - Golf Ball
  • 2.00 inch - Hen Egg
  • 2.50 inch - Tennis Ball
  • 2.75 inch - Baseball
  • 3.00 inch - Tea Cup
  • 4.00 inch - Grapefruit
  • 4.50 inch - Softball

Wind Speeds

  • 25-31 mph: Large branches in motion; whistling heard in power lines.
  • 32-38 mph: Whole trees in motion; inconvenience felt walking into the wind.
  • 39-57 mph: Twigs break off trees; wind generally impedes progress.
  • 58-72 mph (Severe): Damage to chimneys and TV antennas; shallow-rooted trees blown over.
  • 73-112 mph: Surface of roofs peeled away; windows broken; mobile homes pushed or overturned; moving cars pushed off roads.
  • 113-157 mph: Roofs torn off; weak buildings and mobile homes destroyed; large trees snapped and uprooted.
  • 157+ mph: Severe damage; cars lifted off ground.

Amateur Radio Network


NWS Charleston sometimes utilizes the 2 meter amateur radio network across southeast SC and southeast GA to obtain severe weather reports. When a significant severe weather outbreak is anticipated, NWS meteorologists can call in a Net Control to initiate a severe weather net. The Call Sign for NWS Charleston during an organized net is WX4CHS. When calling net control, simply call Charleston Weather. It is not the intent of the net to provide the latest conditions and forecasts. The purpose of the net is to only receive reports. During an active weather net, the operator may monitor the following repeaters (primary repeaters in bold):

  • 146.760 MHz - Awendaw SCHeart Repeater
  • 146.715 MHz - White Hall SCHeart Repeater
  • 147.105 MHz - Charleston SCHeart Repeater
  • 146.790 MHz - USS Yorktown CARS Repeater
  • 146.910 MHz - White Hall CARA Repeater
  • 147.345 MHz - Adams Run TARC Repeater
  • 146.970 MHz - Savannah
  • 147.330 MHz - Savannah

Additional Information


Weather Spotter Guide
NWS Charleston Office Newsletter
NWS Charleston Spotter Quick Reference Card
National SKYWARN Website
SKYWARN Recognition Day
NWS Booklets and Brochures