Hey Ray! What Is Upsloping?

PITTSBURGH (KDKA) -- I got asked, Hey Ray...Explain upsloping? It is a word meteorologists in the area use a lot during winter because winter is the season where upsloping's impacts are most noticeable.

To explain upsloping, let's first quick refresher the water cycle.

In the water cycle, the sun heats water at the surface. The air and moisture rise because they warmer, therefore more buoyant. As that air and moisture climb into the atmosphere, the moisture cools and condenses. Clouds and eventually precipitation form, that precipitation falls to the ground, and we start the cycle over.

Now, upsloping sort of does the same thing, but in a different way.

When you have winds that blow up the ridges, that air is forced higher up in elevation. As that air is forced up, the moisture in that air also cools and condenses. If it is cold enough, that means snow is formed. That is what we call "upslope snow".

So what happens when winds blow down the ridges? That is what we call "downsloping".

When downsloping occurs, or winds blowing down the ridges, the air compresses and warms, causing the air to dry.

Winds out of the east typically blow down the ridges and dry. Winds out of the west or northwest blow up the ridges and create precipitation.

So what is upsloping? Simply, air goes up the mountain, and snow comes down.