This is the time of year when one who lives in the Washington area must keep flashlights, candles and/or propane lanterns handy.

The arrival of the dog days is always accompanied by the arrival and departure of weather fronts. Fronts move, and in moving cause summer storms. Storms fell trees, felled trees cause power outages. So District Liners have learned to equate summer with dead air-conditioners and refrigerators filled with slowly spoiling food.

Last week's severe thunderstorm went through our neighborhood like an express train going through a whistle stop in the boondocks. As it hit, I lined up all our flashlights and lanterns, and prepared for instant darkness. "I just hope it doesn't blow the roof off," I said to myself. A fellow can keep extra flashlight batteries on hand, but not an extra roof.

For a little while, the storm was a rip-snorter. The huge tree in our front yard swooped up into the heavens, dipped suddenly as if it were curtsying to the queen of England, and then swayed from side to side. The huge tree in our back yard danced in unison with its friend in front.

But nothing bad happened. The trees didn't topple. The roof didn't fly away. Our lights didn't even flicker.

The next day, people who had lost power began writing to me about the good service Pepco repair crews had given them. Later, the letters began saying things like, "These guys had apparently not been to bed for some time, yet they answered our questions patiently and did their work with skill and dispatch." One man indulged himself in a wry joke. "No wonder they're so good at restoring service," he noted. "They have so many opportunities to practice."

My own Food Manager and Superintendent of Culinary Production commented "We must be living right. Our electricity didn't go out this time." I agreed that we had been lucky.

By Sunday, we had forgotten about power outages. We contemplated the light rain that was falling, but saw no lightning, heard no thunder. When I left for work, the rain was so light I didn't even bother with a raincoat.

A little after 1 a.m., I called my wife to tell her that I had finished writing and would be home unusually early. "Oh, wonderful," she said cheerlessly. "You can have a raw potato with your dinner. The power just went out."

When I got home, our entire neighborhood was dark. Our candles had been put back on the top shelf of a closet. The propane lantern had been returned to the basement, and when I brought it upstairs I found that its mantle had disintegrated.

The flashlight my wife had been using didn't appear to have enough juice left to survive a search of the basement for another mantle. "Where is your other flashlight?" I asked. She had dropped that one fumbling for it in the darkness. It was dead.

I used the flashlight from my car to get the candles out of the closet, then used a candle to find a mantle for the propane lantern, and eventually we had three candles and a lantern going in the kitchen.

"Now if only we had a propane stove," I said, "we could cook that potato." Before she could answer, the lights came back on.

Mrs. James E. Cloer, who also endured a power outage, was amused at what she found when she looked up Pepco's phone number in the D. C. book.

Both under Pepco and under Potomac Electric Power Co., the entry reads, "Start or Stop Service Or Report Wires Down Report a Power Outrage , 833-7500."

There are some who might suggest that the "outrate" comes at the end of the month, when the bill arrives.

A final note on summer storms comes from Frank H. Forrester, who tells us how to estimate how far we are from the center of a thunderstorm.

Light from a lightning flash reaches the observer's eye almost instantaneously. "The sound of thunder," Frank says, "travels at only about 1,100 feet per second." To estimate your distance from the lightning, start counting seconds as soon as you see the flash, stop when the thunder is heard.

"Multiply the number of seconds by 1,100 and you have your approximate distance in feet from the lightning stroke." By subsequent timings of the main flashes from the core of the storm, you can judge how fast the storm is moving.

P.S.: Don't stand under a tree or atop a hill to make your observations. The lightning may get to you a couple of seconds before the thunder and turn you into a permanent outage.