Taken from the MISA Operating Manual
During activation of Skywarn, the net may operate in one of the following modes:
Skywarn Standby Alert
Severe weather is possible within 30 minutes to 2 hours, but is not imminent. Amateur radio operators may feel free to use the repeater for normal activities, but please try to break up transmissions so that the net control station can break in to provide briefings or activate the net.
Severe weather is imminent or possible within the next 30 minutes. All radio traffic should be directed through net control, and radio traffic should be limited to providing severe weather reports if at all possible.
The severe weather event has passed or no severe weather is expected within the next 2 hours. Normal amateur radio activity may resume on the repeater.