Hawaii's 77 real-time rain gauges across the state are aging and due for some modernizing.

Gradual replacement of the gauges are planned in an upgraded and expanded system costing about $1 million over three years, said Jim Weyman, meteorologist-in-charge of the National Weather Service's Honolulu Forecast Office.

The gauges now are checked via phone for weather information once every three hours (or once an hour if needed) and they send alerts when certain thresholds are reached.

In the new system, data will be transmitted by radio, which will allow the weather service to place gauges in areas they couldn't before, Weyman said.

Kevin Kodama, senior hydrologist in the forecast office, said the improved system will use a radio band approved by the Federal Communications Commission for hydrologic purposes.

“;The benefit of that, we're not going to be tied to phone lines,”; he said. “;That's a definite plus. We can go to other locations as long as we have radio line of sight.”;

Repeaters will be set up in different places to link gauges in tough-to-reach spots, he said.

Kodama said the system will be faster with upgraded electronics. “;When you have a big storm event, you could lose your phone lines, obviously. We're not going to be tied to that infrastructure.'

Radio towers will be placed where needed but “;they won't be large ugly towers,”; Weyman said.

The first phase of the modernization program began Oct. 1, setting up the infrastructure and data software processing computers in the office. Eighteen gauges will be replaced in the initial cycle and others will follow, Kodama said.

Ten to 15 gauges will be added to the system over the three years, Weyman said.

The gauges are an important tool for forecasters because they provide rainfall information that's combined with radar data to identify dangerous conditions and specific areas that might be affected by a storm, he said.