Natural Environment of the Pacific Northwest

Rainshadow Effect

Rainshadow Effect

• Agenda– Go over objectives– Take notes on the Rainshadow Effect– Short in-class activity– Finish/turn in chapter vocabulary

Rainshadow Effect

• Objective:– At the end of this lesson I should be able to…• explain the 5 steps of the Rainshadow Effect.• act out the Rainshadow Effect.

Rainshadow Effect

• Overview– Most important climatic phenomenon in PNW– Creates two differing natural environments

Rainshadow Effect

• Five steps

Rainshadow Effect

• First step– Starts with warm ocean currents in the Pacific– Air is warm and moist– Wind blows the warm, moist air into the sides of

the Olympic Mountains and the Coastal Mountains

Rainshadow Effect

• Second step– Warm, moist air hits the western (windward) side

of the mountains– Air rises and cools– Drops moisture on the side of the mountains

Rainshadow Effect

• Third step– Air crests the mountains– Air descends and warms– Less moisture is dropped

Rainshadow Effect

• Fourth step– Air moves across the Puget Sound– Picks up more moisture

Rainshadow Effect

• Fifth step– Air hits the western (windward) side of the

Cascades– As the air rises over the Cascades it drops

moisture again– Repeats process across Eastern WA

Rainshadow Effect

• Results– Western (windward) slopes• More rain• Greener• More people

– Eastern (leeward) slopes• Less rain• Drier• Less people

Rainshadow Effect

• Activity– Each row is going to get a card– The card has one of the five steps– Refer to your notes– Take five minutes to devise a short skit (less than 1

minute)– You will act these out for the class

Rainshadow Effect

• Tomorrow– Turn in vocab (if you have not yet)– West/East of the Cascades – co-teaching