Climate on the Leeward Side

Having just completed the leg by Longmire, it was easy to compare the climate on the Northeast side of the mountain to the climate on the Southwest.  (We had plenty of times where we stopped to compare the climate during our stops on the way up the hill.)  The main difference in the climate is the moisture.

As you can see from the forest photos near Longmire, the understory is much more lush and verdant.  The understory on this side has much debris from the trees, however, very little (comparatively) vegetation.

The prevailing winds at Mount Rainier are from the Southwest, so most of the moisture is dropped on the windward side.  On the leeward side, the soil is drier hence less vegetation.

The other factor is that there is much more ash from the volcano.  As the ash is blown downwind from an eruption, the leeward side will have much larger ash deposits. 

These factors make this portion of the trail dryer and dustier.  It takes longer for vegetation to decompose and it is more susceptible to wildfires.

Overall, though, it was a pleasant walk through the shade.