Finnish firm eyes Stonington as site for lightning detector

STONINGTON – A Finnish company known for its expertise in developing weather measurement equipment is eyeing the town of Stonington as a possible site for a lightning detection station.

The station would be one in a nationwide network designed by the Vaisala corporation of Vantaa, Finland, to provide early detection and warning of severe lightning storms and other weather hazards associated with those storms.

The SAFIR system, as it is called, was developed in France by the French National Aerospace Research Agency, according to Ron Draper, a systems engineer with Vaisala in Boston. It is the third or fourth generation of lightning detection equipment that measures intracloud lightning as a storm builds to locate the storm and forecast potential lightning activity.

Intracloud lightning is the most common type of discharge in a storm and, as the name implies, occurs within one cloud. It also appears early in the development of a storm, and so is “an early and precise revealer of storm development,” according to information provided by Vaisala on the company’s Web site.

“Intracloud activity significantly anticipates the cloud-to-ground lightning phase as well as other severe weather phenomena (intense precipitation, severe turbulence, tornadoes, hail, downbursts),” the Web site added. “It also correlates closely with storm severity.”

Vaisala’s promotional material claims that the SAFIR system can provide efficient early detection of storm cells, accurate tracking information, and advance warning of imminent thunderstorm hazards.

The system relies on a network of stations like the one under consideration for Stonington and other sites in Maine. Draper was unable to name the other potential sites in Maine. The network will include between 200 and 250 stations, depending on where they can be located, Draper said.

Each station consists of an antenna that includes a very high-frequency sensor and a low-frequency sensor, used to locate and identify lightning activity, Draper said. Coverage is made possible by the network of such antennas, each with a range of about 120 miles. The network, using a method of triangulation, requires just two stations to operate.

“We can cross-reference information from the sites and determine where a storm is within 1 kilometer and also where it is going,” Draper said.

Information is gathered at the individual stations and then fed to the company’s operations center, which will be located in Woburn, Mass. There the data are combined and prepared in a form that can be marketed to customers, which could include such agencies as the National Weather Service, the Federal Aviation Administration, Bureau of Land Management and the Weather Channel, according to Draper.

Stonington became a potential site, he said, because it fell within a grid path that projected the possible range of the network. Potential sites must meet certain criteria to be considered and are located generally in rural areas away from primary commercial centers. They can’t be near power plants or radio transmitters, or anything that might interfere with electrical signals from developing storms.

“Our equipment is so sensitive, it can pick up a car ignition,” Draper said. “So we don’t want to be near anybody.”

Despite that sensitivity, the antenna, which is about the size of a normal television antenna, can be located just about anywhere, on a house roof or even on a telephone pole. It does require 360-degree clearance and so needs to be above treetops.

Stonington Town Manager Richard Avery initially suggested the town’s water standpipe as a possible site for the antenna, and Vaisala will consider that and other locations in the area. Avery said that the detection station would require no work on the part of the town.

“Wherever it ends up, whether it’s on town property or a private location, I expect we would agree on a long-term agreement or lease, and it would be up to them to install it,” he said.

For most locations in town, Avery said, the antenna would not require any local permits.

Scouting crews for Vaisala are expected to be in the area within the next few weeks to look at potential sites. The network will be built in phases, with each phase coming on line as it is completed.