SKYWARN Net Activation Criteria

We are often asked what determines whether SKYWARN nets will or will not be on the air. Truth is, up until recently there really weren't any solid rules. Activations were based on "best guesses" as to what might happen.

After two and a half years of SKYWARN activations, beginning January 1, 2011, a SKYWARN Service Level Commitment (SLC) is in place which specifies the types of severe weather events we will activate our nets for.

You can find the criteria in section 3.1 of the SKYWARN Operations Manual.

During daylight hours -- from 6 AM to 10 PM -- any one or more following criteria must be met for the SKYWARN ham radio team to activate:

• Active Severe Thunderstorm Watch or Tornado Watch and one or more of the following:
• SPC Enhanced Resolution Thunder Risk of 40% or greater
• SPC Day 1 Convective Outlook Damaging Wind Risk at 15% or greater
• SPC Day 1 Convective Outlook Severe Hail Risk at 15% or greater
• SPC Day 1 Convective Outlook Tornado Risk at 5% or greater
• Any Particularly Dangerous Situation (PDS) Tornado or Severe Thunderstorm Watch
• Any Tornado Warning
• Certain severe warned thunderstorms where the storms either demonstrate a history of reported damage or show a high likelihood of producing reportable damage, with or without a watch product in place (generally local discretion).
• Any winter weather event capable of producing icing conditions or sufficient snow or sleet accumulations so as to make travel hazardous.
• Tropical weather events including tropical storms and hurricanes.
• Upon request from the NWS.
• At the discretion of local SKYWARN Net Control Operators and Area Managers.

More restrictive criteria apply to activations between 10 PM and 6 AM.

The SLC is designed to balance the needs of the National Weather Service with the needs and capabilities of the amateur radio community. We have designed the SLC to ensure that we are on the air for significant weather events, avoiding excessive activations for the lower-impact events that historically have not generated enough traffic to even warrant having a net.

Regardless of the SLC criteria, every trained Wakefield SKYWARN Net Controller has the authority to start a net any time they feel one may be needed. Likewise, the National Weather Service has the authority to request amateur radio support without regard for our own criteria.

Any questions about the criteria, or any suggestions can be directed to the Amateur Radio Coordinator.