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Bald Eagle
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Annual Precipitation Cross-section

Location

Annual Precipitation (inches)

Elevation (feet)

Skagit Delta

25

30

Sedro-Woolley

46

60

Concrete

67

195

Marblemount

84

300

Newhalem

79

525

Diablo Dam

74

891

Ross Dam

50

1000

Rainy Pass

56

4780

Mazama

19

2150

Winthrop

14.6

1750

     

During the rainy months, weather moves into the North Cascades from the west (left side of the chart above). As the air masses are forced upward by the mountains into cooler air, the air drops its moisture in the form of rain and snow. Air masses descending along the eastern slopes of the mountains have dried up and provide less moisture to these regions. Meteorologists call this process the rainshadow effect.

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