Fred Knight used to be a television weatherman. He could talk about "shower activity" and "cloud cover." Knight liked being a weatherman. It only bothered him when people asked, "Fred, what's the weather?" Or, "Hey, Fred, where's the sun?"

Yet, he began to feel another tug. It started as a small voice, but it grew and grew. Finally, Fred Knight couldn't ignore it. This voice said just one thing:

Doughnuts.

Last summer, Knight left his Channel 5 weather job to go full time into the doughnut business. He owns seven doughnut shops and is about to launch what he says is the world's first "doughnutmobile."

"This sounds crazy," said Knight, 52, "but I've never had my creative juices flowing so much as I have in the doughnut business. I just go crazy when I start talking and thinking about the unlimited possibilities of doughnuts."

It was the late '60s when Fred Knight, the working weatherman, felt his entrepreneurial sap rising. He had some extra cash from stock market successes, and he began to look around for a business in which to invest. "I wanted to get a McDonald's," he said, "but I didn't have the bucks. I had a friend in the doughnut business, and he told me about his percentages.

"And I felt that doughnuts would be less complicated than these other operations which require a more varied menu."

He bought a Plain 'N Fancy franchise, but in the early '70s went independent with his own chain of Northern Virginia doughnut stores named PamE K's.

"The name is confusing," he said. "It should have been 'The Donut Queen' or something. But, it's PamE K's. My daughter's name is 'Pammy,' but she spells it 'P-A-M-E.' "

He built up the business, continuing to work as a full-time, then a part-time, television weatherman.

Last summer, with a half-million dollar wholesale doughnut business, and thousands of retail customers (he won't say how many), Knight cut loose from TV.

"I'm having the time of my life right now," he said. "I don't know why it took me so long to get into doughnuts. I should have done doughnuts a long time ago."

Since leaving television, Knight has become hard to track. A call to one of his doughnut stores produces this response:

"Fred? That's a mystery. That's a challenge. He often has no schedule by which to judge his whereabouts at a doughnut store at any particular time."

Finally, he is located, and arrangements are made to meet at the PamE K's store at 9909 E. Main St. in Fairfax City.

It's a high-volume store, next to an automobile transmission shop, and 98 percent of the business is takeout, as opposed to the usual 80 percent.

His wife Suzy designed the interior signs: "Glazed Jelly" and "Donut Holes -- .99 a Dozen."

Sitting on a stool that is purposely uncomfortable to keep out loiterers, Knight says he is going into round-the-clock doughnut production.

"Diet doughnuts? That'll be the day. People don't care. They eat doughnuts. You could put a doughnut store in a desert, and people would come. We have customers who come here every day. There are doughnut freaks in the world."

Like him?

"I'll binge," he said. "I'll eat a lot of doughnuts for a period and then say, 'Look, I'm getting a little bit too heavy. This is not calorie-free.'

"I'm on a doughnut diet right now because I've been eating doughnuts for three or four weeks. I'll eat the hot ones -- you know, when the hot honey-dips come out, and the hot blueberry cakes, and the hot devil's-food chocolates."

He speaks of plans to stock frozen doughnut dough for customers to take home, and of new doughnut contracts. Fred Knight's favorite new idea, however, is his doughnutmobile ("it's going to be red hot"), which he hopes to have on the road March 1.

"This is the first," he says. "The world's first doughnutmobile. Where have you ever heard of another one? It's an old truck that I've put a new engine into. A 1981 Chevy truck that has 150,000 miles on it, and I'm giving it a beautiful paint job and four new tires.

"I'm going to put it at the Ballston station, and I'm going to take it to -- Oh, gosh -- I can't think of the name of the Catholic church over in Springfield, but they have four masses there every Sunday, and I'm going to park it there, put maybe 500 dozen doughnuts in it, and give the church a percentage."

Sometimes, Knight takes doughnuts to his friends back at the television station. "If I don't, they always ask me: Hey, Fred, where are the doughnuts?" And, he still pays attention to the weather forecasts.

"On a drizzly day," he said, "you cannot keep doughnuts in the showcase."