Lake-effect snow

related topics
{island, water, area}
{math, energy, light}
{rate, high, increase}
{line, north, south}
{disease, patient, cell}
{album, band, music}
{acid, form, water}
{city, population, household}
{area, community, home}

Autumn · Winter

Dry season · Wet season

Thunderstorm · Supercell
Downburst · Lightning
Tornado · Waterspout
Tropical cyclone (Hurricane)
Extratropical cyclone
Winter storm · Blizzard · Ice storm
Dust storm · Firestorm  · Cloud

Drizzle · Rain  · Snow · Graupel
Freezing rain · Ice pellets · Hail

Meteorology · Climate
Weather forecasting
Heat wave · Air pollution

Lake-effect snow is produced in cooler atmospheric conditions when cold winds move across long expanses of warmer lake water, providing energy and picking up water vapor which freezes and is deposited on the leeward shores. The same effect over bodies of salt water is called ocean effect snow, sea effect snow, or even bay effect snow. The 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, often resulting in copious snowfall totals. The areas affected by lake-effect snow are called snowbelts. This effect occurs in many locations throughout the world but is best known in the populated areas of the Great Lakes of North America, and especially Western New York, northwestern Pennsylvania, northeastern Ohio, southwestern and central Ontario, northwestern and northcentral Indiana (mostly between Gary, IN and Elkhart, IN), western Michigan and the Upper Peninsula of Michigan, which can average over 200 inches (5 meters) of snow per year and averages the most snow of any non-mountainous location within the continental U.S.[1]

If the air temperature is not low enough to keep the precipitation frozen, it falls as lake-effect rain. For lake-effect rain or snow to form, the air moving across the lake must be significantly cooler than the surface air (which is likely to be near the temperature of the water surface). Specifically, the air temperature at the altitude where the air pressure is 850 millibars (roughly 1.5 vertical kilometres) should be 13 °C lower than the temperature of the air at the surface. Lake-effect occurring when the air at 850 millibars is much colder than the water surface can produce thundersnow, snow showers accompanied by lightning and thunder (caused by the larger amount of energy available from the increased instability).

Full article ▸

related documents
Mount Vesuvius
Geography of the United States
Climate of the United Kingdom
Sea level rise
Geography of Sri Lanka
Death Valley National Park
Geology of the Alps
Geography of China
Mount St. Helens
Columbia River
Avalanche
Geography of Brazil
Kakadu National Park
Tsunami
Zambezi
Geography of India
Ice age
Dead Sea
Geography of Bolivia
Geography of Canada
Surface weather analysis
Surtsey
Geography of Bermuda
Lava
St Kilda, Scotland
Himalayas
Climate
Sylt
Volcano
Thar Desert