Storms move out of the Gulf of Alaska into the Pacific Northwest region of the continent with great regularity, as many as three or four per week during the height of the winter storm season. Quite often, these storms are packed so closely that the Pacific Northwest does not experience the clearing weather break so common over the rest of the continent. I have compared this train of tempests to the roll of a nearly never-ending freight train of nearly uniform boxcars. As each storm rolls by, the clearing break is often no more than a tease, like the daylight seen between the roll of a chain of boxcars. Only rarely in some areas of the coast does a "flat car" appear and the "caboose" may not arrive until spring.
Winter Gulf of Alaska storms typically sport winds in excess of 80 km/h (50 mph) with corresponding high waves. Some storms rival the strength of the great hurricanes/typhoons and would be considered as such if their origins were tropical rather than polar. (In fact, the Hurricane Hunter air squadron often deploys aircraft into these storms to study their structure.) Winds as high as 160 km/h (100 mph) have been recorded with wave heights pushing 20 m (65 ft) or more. Over the years, these storms have taken their toll of fishing and merchant vessels caught in open waters.
When these storms hit the North American coast, they encounter a series of high mountain ranges parallelling the coast from central Alaska southward into California. The mountains force the storm air to great altitudes causing then to dump much of their prodigious moisture content on the coastal mountains as rain and snow. The result is the incredibly dense temperate rainforests that cover the coast from Alaska's Panhandle through British Columbia and into northern California.
In these regions, rain and snow are measured in metres (yards) annually. During the winter, nearly all days report rain or snow somewhere in the region. The wetness sits in the region can be exemplified by Juneau, Alaska - 222 wet days annually; Prince Rupert, British Columbia - 240; Clearwater, Washington - 192; and Astoria, Oregon - 190. The world's record for snowfall in one snow year (which runs from July 1-June 30) was established on Mt Baker in Washington in 1998-99: 2986 cm (1140.0 inches). And North America's wettest year drenched Montague Island's MacLeod Harbor, about 112 km (70 miles) east of Seward, Alaska with 8440 mm (332.29 inches) in 1976.
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