In an age when satellites routinely keep track of comings and goings in the atmosphere, the National Weather Service is still looking for a few good earthbound storm spotters -- the kind of people who delight in tracking torrential rains, pelting hail and perhaps a thunderous tornado or two.

In its search for volunteer help in forecasting weather, the service has found people such as Mike Bailey, 28, a resident of Darnestown in upper Montgomery County who says he was a "snow freak" as a youngster and bought his first weather instrument 18 years ago as a Boy Scout. He is one of about 400 spotters in the region; most have been organized in the past year into a network of information gatherers for the weather service.

April to September is the Washington area's severe thunderstorm season, a time when thunder-busting weather fronts sweep through the region, packing high winds and heavy rain that can rip down trees, cause flash floods and play havoc with civil aviation.

The weather service's Washington office, responsible for storm warnings in 36 counties and cities, keeps a close watch on the fronts with a powerful radar at Patuxent Naval Air Station in St. Mary's County and with satellites operated by the National Environmental Satellite Data Service.

But over the years, the service has learned that not even the most sophisticated equipment can match old-fashioned eyewitness observations for accurate weather information, said Richard W. Schwerdt, a weather service meterologist in the Washington office.

"It's good to get these pictures from radar, but you still need to know what's happening on the ground," he said. "We found that reports from people are still the best way to get that."

Bailey, who owns a lawn service, became a storm spotter six years ago. Over the years, he has accumulated $3,000 worth of sophisticated electronic weather equipment, most of which he built himself. He can record rainfall, minimum and maximum temperatures, wind speed, peak gusts, humidity, wind chill and a number of other weather observations.

"If I get a change over from rain to snow and it's not in the forecast, or if the temperature is dropping rapidly, I let them know," Bailey said. "Sometimes they can't believe it. They're shocked because it doesn't show up on their radar," he said.

"But I know a couple of times I've called in with observations of high winds, heavy snow or thundershowers, and they've altered their forecast."

Although Bailey considers himself a serious weather buff, volunteer storm spotters do not need sophisticated equipment or an in-depth knowledge to be of help, Schwerdt said. The weather service provides a packet of information for new spotters that describes weather phenomena to look for and how to spot the conditions that produce it.

"Severe storms, tornadoes and flash floods, they're the main three we're interested in," Schwerdt said. Spotters also try to report high winds -- starting at 50 to 60 miles an hour -- that produce structural damage, and hail of about three-fourths of an inch or larger that could damage crops, he said.

The regional office decided to begin rebuilding its spotter network last year after a decade of benign neglect. The first thing the office did was call weatherman and meterologist Bob Ryan, who works for WRC-TV.

Ryan, a firm believer in eyewitness observations, developed his own extensive network of weather spotters when he came to Washington five years ago. "I don't think there will ever be a substitute for that," he said. "If we see something that looks suspicious on radar, I have it flagged on a map where observers live so I can get a first-hand report."

Last year, the regional office quadrupled the number of volunteer weather watchers who routinely report conditions in their areas, and the result was noticeably better weather forecasting.

"We found that in most cases, the sophisticated-type equipment would indicate that the storm was more severe than was the case," Schwerdt said. "Many of the warnings that were being issued for storms turned out to be false alarms."

Now, forecasters tracking storms by satellite and radar check with a spotter close to the action. Forecasts are based on electronic and eyewitness observations, Schwerdt said.

The regional office is seeking spotters this year in Howard and Baltimore counties for the first time. The service hopes to have spotters in every Maryland county by 1987, Schwerdt said. After that, the service will try to expand its network throughout Virginia, he said. Typically, the office likes to have 25 to 30 spotters in each county, he noted.

The spotter network now covers the District and Montgomery, Prince George's, Frederick and Washington counties, three counties in West Virginia, and 28 counties and cities in northern and central Virginia. The rest of the three-state region is covered by weather service offices in Baltimore, Richmond and Elkins, W.Va.

Most official weather observation posts are located at airports, so volunteer spotters help fill in the gaps, Schwerdt said.

"Counties that are farther west and north are particularly important because severe weather tends to move toward the District from the west, southwest and northwest," he said. "We like to have spotters up to 100 miles from D.C."

"We can always use more spotters. It helps to have more than you need," said Roy K. Smith, a weather service meterologist who also acts as a storm spotter in the District.

Smith also has his own weather instruments and keeps track of such things as temperature changes and rainfall accumulation. In the District, unusual weather usually means pea-sized hail or high winds, he said.

For most veteran spotters, a tornado is the ultimate observation. The weather service typically issues one or more tornado watches for the area during the storm season. The storms rarely touch down, but threatening funnel clouds have appeared on occasion.

Ron Carl of Falls Church had been a spotter for only four months when a tornado touched down two years ago about a 1 1/2 miles from his house.

"Things just didn't seem quite right that evening," he recalled. "Right around 8 p.m. it was dark out, but I heard an almost unmistakable roar. It almost sounded like an airplane in the distance."

A Virgina state trooper was officially credited with sighting the tornado, one of five that did damage in Fairfax County that night.

"I was always afraid of severe storms," Carl said. "I guess I just developed that fear into an interest. The more I learned, the bigger the interest grew. Now it's a great hobby because it's ever changing, and it never grows dull."