Just like in the winter, the National Weather Service personal need their spotters to be helpful and ready for activiation when severe weather occurs.
They rely not only on the instruments that they have at their hands, but also the timely reports of what the spotter sees.
The severe weather that the spotter sees is very important and so that is why the NWS has set up a criteria of what to report.
This criteria is very cut and straight to the bone, so when severe weather occurs either in the form of tornadoes or damaging severe thunderstorm winds, the NWS spotters know exactly what to report.
The criteria that I have shown below is just a sampling of some of the criteria that they use.
Some NWS offices have a larger criteria while some offices only have a short list of criteria to be reported.
That is why it is best to get the neccassary criteria from your local office.