South Valley Surprise of 2002
Encyclopedia
The South Valley Surprise of 2002 was a Pacific
windstorm
that affected the U.S. state
s of Oregon
, Washington, California
, Nevada
, and Idaho
on February 7, 2002.
. The "surprise" was how rapidly the storm organized and matured, and its unanticipated strength. Thus, the public had no idea of the impending storm. There was extensive damage from falling trees, attributable to the rain-saturated ground, which made it easier for the high winds to topple them.
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
windstorm
Extratropical cyclone
Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are a group of cyclones defined as synoptic scale low pressure weather systems that occur in the middle latitudes of the Earth having neither tropical nor polar characteristics, and are connected with fronts and...
that affected the U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
s of Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
, Washington, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
, and Idaho
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
on February 7, 2002.
Overview
The storm underwent rapid cyclogenesis just before coming inland. The circulation was so tight that the winds stayed above 50 mph even while the storm was a hundred miles inland. The South Valley Surprise was second only to the Columbus Day Storm in terms of wind speed for the southern Willamette ValleyWillamette Valley
The Willamette Valley is the most populated region in the state of Oregon of the United States. Located in the state's northwest, the region is surrounded by tall mountain ranges to the east, west and south and the valley's floor is broad, flat and fertile because of Ice Age conditions...
. The "surprise" was how rapidly the storm organized and matured, and its unanticipated strength. Thus, the public had no idea of the impending storm. There was extensive damage from falling trees, attributable to the rain-saturated ground, which made it easier for the high winds to topple them.