Primary and Secondary Contacts

It is essential that any spotter network have a clear set of procedures for reporting severe weather and other observations. All networks should have a designated methodology for relaying reports from the field to the local NWS office. There should be a primary contact for activation and operation of the spotter network. It is also suggested that a secondary contact be established for those occasions when widespread severe weather is occurring or when the primary contact is not available.

Amateur radio operators comprise the backbone of many spotter networks. Most amateur radio networks include an operator at the NWS office for quick relay of reports and direction of spotters in the field to "hot spots." This has proven to be an effective, efficient method of relaying severe weather observations. Other operators may be deployed at television or radio stations in the NWS office's county warning area.

Law enforcement and fire department personnel also serve as spotter networks in many areas. Many of these groups report to a dispatcher who, in turn, relays reports to the NWS. These spotter networks should establish a secondary contact (such as the dispatcher of another city/ county agency) for those times when primary communications are impeded.

The dispatchers should also receive at least basic spotter training. Although they are not actually observing the storms in the field, dispatchers serve as a critical link in the severe weather information chain. If they are familiar with thunderstorm and spotting terminology, dispatchers are able to screen out less important observations and quickly relay significant reports to the local NWS office.

In remote or sparsely populated areas, private citizens may have to serve as spotters. While these groups may not be as well organized as the amateur radio or law enforcement-based groups, there should still be established reporting procedures. Local law enforcement or emergency management offices are candidates for contacts in these situations.

Spotter Coordination

Spotting is not a one-person job. It is difficult, if not impossible, for one spotter to accurately observe all aspects of a thunderstorm. Rather, it is necessary for spotters and spotter groups to coordinate and share information (with the NWS and with each other) to obtain the best possible assessment of the storm.

Spotters with two-way radio communications should talk not only with their dispatch/control personnel but with other spotters in the area.

Positioning spotter teams at several strategic locations around a storm, with active communication between the spotters, should enable a great deal of information concerning the thunderstorm to be relayed to the local NWS office.

If two or more spotter groups are working in the same area (i.e., an amateur radio group and a law enforcement group), then these groups should share information regarding their observations. The NWS should also attempt to coordinate between spotter groups. As a storm moves from one spotter group's area to another, the downstream spotter group should be notified well in advance to allow time for their activation and deployment.

Reporting Criteria

There are certain criteria for reporting severe weather. Recall that a thunderstorm is defined as severe if it produces a tornado, hail 3/4 inch in diameter or larger, and/or wind gusts 58 miles an hour or higher. It would be desirable to report events associated with a thunderstorm before they reach these severe levels. Use the following guidelines for reporting weather events.

Report hail occurrences when the hailstones have a diameter of 1/2 inch, and report wind gusts when their speed reaches 50 miles an hour. See tables 1 and 2 for estimations of hail size and wind speed. Obviously, tornadoes and funnel clouds should be reported. A funnel cloud is defined as a violently rotating column of air which is not in contact with the ground. It is usually marked by a funnel-shaped cloud extending downward from the cloud base (hence its name). If the violently rotating air column reaches the ground, it is called a tornado. An important point to note is that the visible funnel DOES NOT have to extend to the ground for a tornado to be present. Instead, look for a rotating cloud of dust and debris underneath a funnel cloud as evidence that the tornado's circulation has reached the ground.