Bellingham, Washington Weather and Climate

Air Masses of the Pacific Northwest

Bellingham, WA and the pacific northwest is mainly affected by air masses that have originated in the Pacific Ocean. Maritime Polar air is brought down by the by the Polar Jet Stream and is directed through the area frequently in the winter and summer months. The Cascade Mountains to the east for a barrier that protects the coastal areas from the continental polar air coming from Canada. Very rarely does an air mass from Canada reach Bellingham. In the summer months the area is sometimes influenced by the Hawaii'an High causing clear skies and warm weather. the air masses mix very well together because of the similarities they share. During La Nina and infrequently in winter the Tropical Jet Stream wanders north and mixes with the Polar Jet Stream causing the "Pineapple Express" to hit northern Washington and causing heavy precipitation.

The subtropical jet sits at the border between the US and Mexico. The polar jet sits between the border between the US and Canada.

http://www.nc-climate.ncsu.edu/edu/k12/.JetStreams

Mid latitude cyclones of the area are caused mostly by cold polar fronts moving south from the Aleutian Low in the North Pacific. The air masses that move into the area are slowed by the mountainous topography to the east and due to orographic uplift, produce large amounts of precipitation. Winds are increased in the area due to a funneling effect of the Vancouver Island Mountains and the Olympic Mountains to the east. The air is funneled through the Straight of Juan de Fuca increasing wind speeds.