Linux has moved into the everyday operations of the National Weather Service (NWS) and is now helping produce local forecasts across the nation and run the agency's Web sites.

After more than two years of work, the Silver Spring, Md.-based agency is about 90% through a planned migration from Unix to Linux, said CIO Barry West. So far, the switch has cost about $10 million for hardware and software, although the NWS sees it as a long-term cost-saving move.

Several years ago, the agency began looking for alternatives to its HP-UX operating system on Hewlett-Packard Co. hardware in an effort to get away from what West called an "exorbitant amount of maintenance costs." After looking at several hardware and operating system options, the NWS chose Linux because it was similar to its existing Unix system.

Although he had no firm figures on how much money the NWS has saved by moving to Linux, West estimated that the new system is two-thirds cheaper than the old HP-UX on HP proprietary hardware.

In addition, agency officials in the past few years have seen that Linux is robust enough for extensive deployment and is being adequately supported by major IT vendors, West said. "That was always a big question with Linux, with support," he said. "Now you can get it through Red Hat or others."

About one-third of the agency's 5,000 workers -- those who do hands-on weather forecasting -- now use Linux. They're using Red Hat 7.3 Linux on Intel-based workstations from IBM in some 122 NWS Weather Offices across the nation, as well as in 12 River Forecast Centers, six regional weather service offices and the agency's training facilities. Linux is also being used in the specialized offices of the agency's National Center for Environmental Prediction, including the National Hurricane Center and the Storm Prediction Center.

Workers at the agency who aren't doing forecasting still use Windows-based machines and Windows office applications. A small number of workers are running Linux on the desktop for testing, but West said there are no plans as of now for a major desktop migration.

IBM mainframes and its AIX operating system are still being used for computer weather modeling done in the preparation of forecasts. But over time, Linux may be considered for even those uses, West said.

"We've had really good success," he said, noting that the NWS is one of the first government agencies to use Linux in its mission-critical systems.

Forecasters use the agency's Advanced Weather Interactive Processing System software to collect weather data, assemble forecasts and weather warnings, and then disseminate the information to the various forecast offices. Twenty years ago, the whole process was done on paper with teletype machines transmitting data to offices around the country.

Linux is finding its way into other enterprise operations. Coincidentally, private-sector Weather Channel Enterprises Inc. in Atlanta moved to Linux in 2000 for its Web content and other operations (see story).

And just two weeks ago, global consumer products company Unilever announced that it will move to Linux from several variants of Unix during the next eight to 10 years as it moves to reduce costs, consolidate servers and improve its IT operations (see story).