What exactly does "lake effect snow" mean?

Lake Effect Snow Warning Lake Effect Snow Warning is a bulletin issued by the National Weather Service in the United States to warn of heavy snowfall amounts that are imminent from convective snow generated by very cold airmass passing over unfrozen lakes. The criteria for amounts may vary signficantly over different county warning areas. Environment Canada's Meteorological Service of Canada issues similar warnings but they are called Snowsquall warnings. http://en.wikipedia.org/wiki/Lake_Effect_Snow_Warning Lake effect snow Lake effect snow, which can be a type of snowsquall, is produced in the winter when cold dry winds move across long expanses of warmer lake water, picking up water vapor which freezes and is deposited on the lee shores. This effect is enhanced when the moving air mass is uplifted by the orographic effect of higher elevations on the downwind shores. This uplifting can produce narrow, but very intense bands of precipitation, which deposit at a rate of many inches of snow each hour. The areas affected by lake effect snow are called snowbelts. This effect occurs in many locations throughout the world, mostly in the Northern Hemisphere, but is most known about in the populated areas of the Great Lakes of North America. The lake effect from the Great Salt Lake in Utah helps to create "The Greatest Snow on Earth". Since the Great Salt Lake never freezes, the lake effect can affect the weather along the Wasatch front year around. If the air temperature is not low enough to keep the precipitation frozen, it falls as lake effect rain. In order for lake effect rain or snow to form, the moving air must be cooler and also less humid than the surface air. Specifically, the air temperature should be 15 to 25°C cooler than the water, and the dew point at the altitude where the air pressure is 850 mb should be 13°C lower than the dew point of the air at the surface. Lake effect of extremely cold air over still warm water in early winter can produce thundersnow, snow showers accompanied by lightning and thunder. http://en.wikipedia.org/wiki/Lake_effect_snow

when the cold air on way to the lake which the water is very warm, the cold air evatorate the water into the clouds, its forming the snow,

The water in the lake is still warm and the cold air picks up this moisture created by the cold air over the warm water and dumps it on the first land it goes across.

Cold air moving over the warmer water of the Great Lakes picking up moisture and dumping it as snow. :-)~

It means that the water in the Lakes is warmer than the air above, thus causing the moisture to rise. When it hits the cold air we get snow and lots of it.

Because of the higher moisture content (humidity) over a large body of water than over the neighboring land a drop in temperature will sometimes cause ice crystals (snow) to form over the lake and adjacent land. This is quite prevalent in the Northwest around the Great Lakes.

Lake effect snow happens around large lakes - obviously. The lakes usually don't freeze over and cause I believe condensation that then turns to snow. I live in Chicago and we get it a little bit on our side of the lake but Michigan seems to get it much much more. Places near upstate NY that are getting like 10 feet of snow are getting pelted because that lake never froze. The really interesting thing is that Buffalo NY only has a little bit of snow right now and usually they have a couple of feet.

As cold air moves across the relatively warm open water of a lake, it draws up that moisture and then quickly dumps it as snow. That's why upstate NY gets so much. Cold air from the north moves across Lake Ontario, picks up the moisture and then dumps it in Buffalo, Rochester, etc. If the lake were frozen over, this would not happen. Because Lake Ontario is relatively deep, it rarely freezes over completely.

Go to the web site below. It explains it pretty well. I live in Cleveland, the heart of lake effect snow in NE Ohio. I love it!!