Washington, WA

Washington is a state in the Pacific Northwest region of the United States. The state is named after George Washington, the first President of the United States.

It is the only U.S. state named after a president. Washington was carved out of the western part of Washington Territory and admitted to the Union as the 42nd state in 1889. In 2006, the Census Bureau estimated the state's population at 6,395,798.

Residents are called "Washingtonians" (emphasis on the third syllable, pronounced as tone). Washington is sometimes called Washington state or The state of Washington to distinguish it from Washington, D.C., the U.S. capital.

Geography

Washington is the northwestern-most state of the contiguous United States. Its northern border lies mainly along the 49th parallel, with the Canadian province of British Columbia to the north.

Washington borders Oregon to the south, with the Columbia River forming most of the boundary and the 46th parallel forming the eastern part of the southern boundary.

To the east Washington borders Idaho, bounded mostly by the meridian running north from the confluence of the Snake River and Clearwater River (about 116°57' west), except for the southernmost section where the border follows the Snake River. To the west of Washington lies the Pacific Ocean.

Washington is in the region known as the Pacific Northwest, a term which often includes part or all of British Columbia in Canada and part of Alaska. Sometimes it refers only to lands within the northwestern United States, including Oregon.

The high mountains of the Cascade Range run north-south, bisecting the state. Western Washington, west of the Cascades, has a mostly marine west coast climate with relatively mild temperatures, wet winters, and dry summers.

Western Washington also supports dense forests of conifers and areas of temperate rain forest. In contrast, Eastern Washington, east of the Cascades, has a relatively dry climate with large areas of semiarid steppe and a few truly arid deserts lying in the rainshadow of the Cascades; the Hanford reservation receives an average annual precipitation of between six and seven inches.

Farther east, the climate becomes less arid. The Palouse region of southeast Washington was grassland that has been mostly converted into farmland.

Other parts of eastern Washington are forested and mountainous. The Cascade Range contains several volcanoes, which reach altitudes significantly higher than the rest of the mountains.

From the north to the south these volcanoes are Mount Baker, Glacier Peak, Mount Rainier, Mount St. Helens, and Mount Adams. Mount St. Helens is currently the only Washington volcano that is actively erupting; however, all of them are considered active volcanoes.

Washington's position on the Pacific Ocean and the harbors of Puget Sound give the state a leading role in maritime trade with Alaska, Canada, and the Pacific Rim. Puget Sound's many islands are served by the largest ferry fleet in the United States.

Washington is a land of contrasts. The deep forests of the Olympic Peninsula, such as the Hoh Rain Forest, are among the only temperate rainforests in the continental United States, but the semi-desert east of the Cascade Range has few trees. Mount Rainier, the highest mountain in the state, is covered with more glacial ice than any other peak in the lower 48 states.

Climate

Washington's climate varies greatly from west to east. An oceanic climate (also called "marine west coast climate") predominates in western Washington, and a much drier climate prevails east of the Cascade Range.

Major factors determining Washington's climate include the large semi-permanent high pressure and low pressure systems of the north Pacific Ocean, the continental air masses of North America, and the Olympic and Cascade mountains.

In the spring and summer, a high pressure anticyclone system dominates the north Pacific Ocean, causing air to spiral out in a clockwise fashion.

For Washington this means prevailing winds from the northwest bringing relatively cool air and a predictably dry season.

In the autumn and winter, a low pressure cyclone system takes over in the north Pacific Ocean, with air spiraling inward in a counter-clockwise fashion. This causes Washington's prevailing winds to come from the southwest, bringing relatively warm and moist air masses and a predictably wet season.

The term Pineapple Express is used to describe the extreme form of this wet season pattern.

The coastal mountains and Cascades compound this climatic pattern by causing orographic lift of the air masses blown inland from the Pacific Ocean, resulting in the windward side of the mountains receiving high levels of precipitation and the leeward side receiving low levels.

This occurs most dramatically around the Olympic Mountains and the Cascade Range. In both cases the windward slopes facing southwest receive high precipitation and mild, cool temperatures.

In contrast, the leeward slopes facing northeast experience a rain shadow effect, with low precipitation and warmer temperatures. As a result, there are temperate rain forests on the southwest side of the Olympic Mountains while the northeast side has a drier climate sometimes called sub-mediterranean climate.

The San Juan Islands and the city of Sequim are known for their dry climate compared to the rest of the coastal region. The Olympic rain shadow extends into Canada. Terms like "Mediterranean", "sub-Mediterranean", and "modified Mediterranean" are sometimes used to describe the Olympic rainshadow region even though it is quite different from the standard "Mediterranean" climate.

The terms are mainly used to indicate a climate with wet winters and dry summers with regular drought conditions.

The Cascade Range forms a larger barrier than the Olympics and has a correspondingly stronger orographic effect. While the Puget Sound lowlands are known for clouds and rain in the winter, the western slopes of the Cascades receive larger amounts of precipitation, often falling as snow at higher elevations.

East of the Cascades, a large region experiences strong rain shadow effects. Semi-arid conditions occur in much of eastern Washington with the strongest rain shadow effects at the relatively low elevations of the central Columbia River Plateau — especially the region just east of the Columbia River from about the Snake River to the Okanagan Highland.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Washington".