These are the criteria that many weather nets are looking for. This data is borrowed from the Dayton Skywarn website. This information is subject to updating to NWS updated guidelines.
WHAT TO REPORT
Cloud Formation
• Any questionable cloud formation with or without rotation
• Roll Clouds
• Elongated funnel-shaped clouds with rotation
• Tornado with or without roar and debris
HAIL
• Pea size 1/4 inch or larger Use coin or Ball size description ( dime size, Quarter size, golf ball, baseball )
• Please indicate how much hail is covering the ground.
WINDS OVER 40 MPH
• Damage to buildings, trees, utility poles, any limbs down, and the diameter of the limbs/trees and the direction they fell. Indicate weather a dying or healthy tree.
FLASH FLOODING
• Streams out of bank
• Ponding of water in streets
• Water standing curb to curb
RAIN GAUGE REPORTS
• Immediate: One (1) inch or more within an hour
• After: As measured for the storm
DAMAGE REPORTS
Should you see damage during a storm report it immediately through your county Amateur Radio SKYWARN Net or through the Dayton SKYWARN Sectional Net. If you see damage immediately following the storm, report it to your amateur radio net, or the Dayton SKYWARN Sectional Net, giving the time frame you feel the damage occurred as well as types of damage.
Should you come across damage after the weather event is over and the net has been shut down call the National Weather Service Office in Wilmington, Ohio by phone at 1-800-899-2478 and give them your report, along with the time you feel the damage occurred.
WHAT NOT TO REPORT
Keep in mind that ALL thunderstorms have lightning and all lightning is severe. DO NOT REPORT ANY FORM OF LIGHTNING TO THE NET. The NWS does not use lightning to decide the severity of the storms. (Lightning can kill, take appropriate actions for your safety when lightning is present.)
DO NOT report what police radios / scanners are reporting. they will report directly to NWS themselves.
DO NOT report 2nd had reports of weather from TV or Radio Stations. They are mostly reporting what NWS, PUblic service agencies and Weather net spotter are reporting. Use of their report can only make information conveyance confusing.
The NWS has some great PDF training guides that you can download at this link.