TULSA, Oklahoma - Power companies have a tool to determine how severe an ice storm will thanks to a meteorologist at the National Weather Service office in Tulsa.

The meteorologist in charge there teamed up with a power company expert to gauge how much a storm could impact power lines.

When an ice storm is in the forecast, utilities and government agencies can use the Sperry-Piltz Ice Accumulation Index. The weather tool gives a forecast for communities and utilities to prepare for an ice storm.

The Sperry-Piltz Ice Accumulation Index was created in Tulsa by Steve Piltz, the meteorologist in charge at the National Weather Service office in Tulsa, with the help and guidance of power company expert Sid Sperry as the ice storm forecast rolled out in 2007.

The one through five scale determines how people could be affected by ice storms and power outages.

"If we lose power for a few hours nobody likes that, but if you start getting cold for more than 24 hours, that starts to become more of a serious situation and you plan accordingly based on what the estimate of the index is," Piltz said.

He said the most affected areas could be in the northwest counties in the Tulsa metro.

"Before this, we would tell the emergency managers, 'Hey, this looks bad. Power is going to be out for a while.’ Now, on the briefing that I gave today, I was like, 'Hey, there could be a few folks in parts of Osage/Pawnee County might not have power for several days, you might want to plan that day,’" he said.

Piltz said the index takes into account ice accumulation and winds.

"In the red shading, that's where the interruptions could start lasting more than a day. So, even though that in a lower population area it's still something we wanted to make the emergency managers knew," Piltz said.

The index relies on the forecast models, so if those change so does the index and the ratings.