Let the rock and roll begin! The season's first visit of winter weather didn't just come knocking last Monday morning, it broke down the door. Some of nature's most awesome and spectacular shows are created when cold air collides with warm moist air. Sunday was marked with a strong south wind that brought air that would have been uncomfortably warm and humid had it not been for the wind itself. This is the air that was in place when the cold front swept in during the wee hours of Monday morning. It was as impressive a night as many people could recollect.

It was a wild party staged in the skies above us, and the hangover lasted for days. The storms trailed off into sporadic rumbles and downpours and by the end of the day, some brightness. Tuesday, Wednesday, and most of Thursday were days of uncertain weather, chill and breezy, peppered by passing rain squalls. It was gray, unstable and uncertain. The skies were grumpy.

The new air that moved in was exceptionally cold air for this time of the year. The different temperatures between the air next to the warm summer earth and the air a mile above it was a whopping 30 degrees, well above the 12 or even 15 degrees that could be considered normal. Warm air rose up into the cold air and couldn't cool fast enough to equalize itself with the air around it. The sky was filled with sharp bumps and towering cumulus clouds. Down low the thermal activity was mixed with the turbulence that is created when the wind stumbles over and around the hills.

To the eye, the most significant weather was the clouds and rain squalls. Lake Ontario almost leapt in to the cold air blowing across it because the water was at a warm summertime 72 degrees, and the temperature a mile above it was only 35 degrees. Under last week's circumstances, a temperature difference of 23 degrees between these two benchmark levels will induce lake effect precipitation, and we had an extreme of 36 degrees difference. It was a week of gray, interspersed with gorgeous cloudscapes and rainbows.

It was a good week for students to learn about the ocean of air that we fly in. Some were genuinely concerned that the weather sometimes held us to low altitudes over the hills, and that sometimes the visibility was only a few miles. To each one I explained that there is a difference between wiggling through valleys near our own airport, and doing the same thing far away from home, in strange territory. More significantly, I had to explain that we were actually flying in weather that was trying to be good. The air itself was crystal clear and once free of any squall areas, we could climb to 3500 feet and see for thirty miles around, making areas of bad weather easy to avoid. It was good weather with easily discernable patches of bad weather, rather than bad weather with "sucker holes" that can close in quickly.

It was the rock and roll that received the most attention from the students though. The northwest flow of air just after a winter cold front is rough. From the moment you taxi away from the hangar until the moment you return, you are fighting with it. Not only is it strong, but it is shifty. It will gust and then diminish, it can be almost north one minute, and then almost west the next. These variations make the windsock twitch like a cat's tail.

By Thursday afternoon, the wind was all worn out, and little white clouds of surrender could be seen in the blue sky. They were cumulus clouds just like the billowing monsters of earlier in the week, but they were the flat "pancake cumulus" clouds of winter. The air had come to terms with itself and with the earth below, and there was little energy left to push updrafts into anything but token patches of white.

The students who flew earlier in the week were calmer too. They had met the growly dog of a winter cold front, and learned how to walk past it without getting bitten. Having experienced bad weather, they were more relaxed with the good weather when it returned. One fellow who had been consistently inconsistent with his landings made his first solo the day after bouncing through under, and around our first winter weather system. The rough air made him learn to take charge of the airplane.

The leaves are only starting to turn, but rock and roll is here to stay. Its time for student pilots to learn to dance or be happy standing at the edges of the party.

To contact Bob Tilden, send an e-mail.