Welcome to our Phase Change Page !! This is where I discuss Precipitation Events in which phase transition events occur (e.g. Rain changes to Snow)!!! ENJOY :)
Have you ever taken the time to just enjoy a snowstorm? There's nothing quite like watching big, fat snowflakes drift down and alight on the ground. Soon, they turn the ground white. Snowfall has a wonderful quality of patience. It just keeps on falling and it piles up, more and more, until an entire metropolis is shut down.
I have personally enjoyed many snowstorms. I have seen storms where the rain changed to snow. I have seen sudden rain-to-snow transitions, and I have seen very slow, gradual rain-to-snow transitions.
I have discovered that observing rain change to snow is fascinating!! Take any rain storm. Let's say there is a Low Pressure area along the North Carolina coast. It's moving up the coast slowly. The counter-clockwise circulation around the cyclone is pulling down colder and colder air from Canada, courtesy of a 1045 mb anticyclone parked over Quebec:)
It's early-February and I am located in northern Virginia, let's say in Woodbridge, for example. The surface temperature is running at 39 degrees, with light to moderate rain falling from a low, dark nimbostratus deck. The surface winds are NNE at 10 mph. The wind chill is 25 degrees. The forecast is for rain, continuing into the evening.
I am kicking back in my car, watching the rain hit the windshield. Rain on a windshield is so soothing. It's mesmerizing, it draws you in, so that you can't stop watching it run down the face of the windshield while other raindrops continue to patter down on the glass surface. The windshield is fogging up. It isn't a good idea to try and wipe the glass with a cloth. That's very inefficient. It's much better to direct the heated air from the car heater onto the windshield. Watch that fog clear up!!!!!
So the rain keeps falling on the windshield. If you want to watch a precipitation phase-change transition, a windshield is a good place to watch it. When the temperatures fall to near 34 degrees, you will begin to see sleet mix in with the rain. Sleet pellets will fall inside raindrops and some sleet pellets will fall by themselves. The sleet will make a tinkling sound as it hits the windshield. Sleet striking a windshield sounds much different than rain hitting the same surface.