Orographic lift

Effects of orographic lifting

Precipitation

• The Mogollon Rim in central Arizona
• The western slope of the Sierra Nevada range in California
• The mountains near Baja California North – specifically La Bocana to Laguna Hanson.
• The windward slopes of Khasi and Jayantia Hills in the state of Meghalaya in India.
• The Western Highlands of Yemen, which receive by far the most rain in Arabia.
• The Western Ghats that run along India's western coast.
• The Great Dividing Range of Eastern and South Eastern Australia which forces cold, moist westerlies up the inland slopes, originating from the Southern Ocean.
• The mountains of New Zealand, which faces a prevailing westerly flow off the Tasman Sea.
• The mountains of western Tasmania which also face a prevailing westerly flow.
• The southern Andes, which faces a prevailing westerly flow off the Pacific Ocean.
• The Northwestern United States and Canada see prevailing westerly flow off the northern Pacific Ocean. Places on the sea-facing side of coastal mountains see in excess of 140 inches of precipitation per year. These locales are on the side of the mountains which are in the path of storm systems, and therefore receive the moisture which is effectively squeezed from the clouds.

• The ski country region of New York and Pennsylvania, particularly with lake effect snows.
• Transylvania County, North Carolina, which gets the most rainfall of anywhere in the Eastern U.S..
• The Appalachian Mountains in West Virginia.
• The Eastern seaboard of Madagascar.
• Table Mountain, Cape Town, South Africa. The cold Atlantic air mass flows up over the north western face to above sea level and is met by the warm Indian Ocean air mass from the south eastern back side of the mountain forming the famous "Table Cloth".
• Oppland mountain area, Norway.
• The Front Range Foothills of Northern Colorado – west of Boulder to Golden as storms pass by. Winter storms can produce of snow.

  Rain shadowing

• The Himalayas block moisture from the Tibetan Plateau
• The Atacama Desert in Peru and Chile
• Switzerland's Rhone valley
• Areas east of the Cascade Range in the Pacific Northwest
• Areas east of the Olympic Mountains in Washington state,
• The Great Basin of the United States, east of the Sierra Nevada
• Geography of the United States Pacific Mountain System
• Pacific Cordillera
• California's Central Valley
• The Canadian Prairies
• All of the Hawaiian Islands. The entire island of Kaho'olawe is in the rain shadow of Maui
• North East England is in the rain shadow of the Pennines, this combined with Britain's prevailing wind from the South West. This explains the significant differences between the rainfall in the North West and North East.
• The Monaro and South Coast regions in South Eastern Australia; as snow-bearing westerlies are forced upwind the inland slopes of the Snowy Mountains, the coastal plain remains dry, and is significantly warmer than on the inland slopes at equivalent altitudes. This is evident when comparing Batlow on the windward slopes to Cooma on the leeward coastal plain, both around.
• The Judean Desert in the Land of Israel and the Dead Sea.

  Leeward winds

Associated clouds

• Orographic fog is formed as the air rises up the slope and will often envelope the summit. When the air is humid, some of the moisture will fall on the windward slope and on the summit of the mountain.
• When there is a high wind, a banner cloud is formed downwind of the upper slopes of isolated, steep-sided mountains. It is created by the low pressure areas in the downwind vortices drawing in relatively humid air from the lower slopes of the mountain. This reduction in pressure compared to the surrounding air increases condensation, in the same manner as an aircraft's wingtip vortices. The most famous such cloud forms routinely in the lee of the Matterhorn.
• The leeward edge of an extensive mass of orographic clouds may be quite distinct. On the leeward side of the mountain, the air flowing downward is known as a foehn wind. Because some of the moisture that has condensed on the top of the mountain has precipitated, the foehn is drier, and the lower moisture content causes the descending air mass to warm up more than it had cooled down during ascent. The distinct cut-off line which forms along and parallel to the ridge line is sometimes known as a foehn wall. This is because the edge appears stationary and it often appears to have an abrupt wall-like edge. A foehn wall is a common feature along the Front Range of the Colorado Rockies.
• A rotor cloud is sometimes formed downwind and below the level of the ridge. It has the appearance of the ragged cumulus cloud type but it is caused by a turbulent horizontal vortex, i.e. the air is very rough.
• Lenticular clouds are stationary lens-shaped clouds that are formed downwind of mountains by lee waves if the air mass is close to the dew point. They are normally aligned at right-angles to the wind direction and are formed at altitudes up to.
• A cap cloud is a special form of the lenticular cloud with a base low enough that it forms around and covers the peak, capping it.
• A chinook arch cloud is an extensive wave cloud. It has this special name in North America where it is associated with the Chinook wind. It forms above the mountain range, usually at the beginning of a chinook wind as a result of orographic lifting over the range. It appears when seen from downwind to form an arch over the mountain range. A layer of clear air separates it from the mountain.