The "Snow Eater"

Friday, February 11th 2011, 3:57 pm
By: News 9

How can we go from below zero temperatures one week to 70s the next? I'm glad you asked. It's the Oklahoma version of the Chinook. You may also hear the Chinook wind referred to as the "snow eater."

Southwest, west, and northwest winds in Oklahoma are naturally a descending wind thanks to the slope of the land. The westerly component allows air to end up at a lower elevation the further east it travels. The higher terrain in West Texas and New Mexico provide a nice downhill slide for air when the winds have this westerly component. However, instead of temperatures sliding too, they actually do the exact opposite.

The key to the process I'm referring to lies with the temperature and humidity of air as it rises or descends. Air cools (and moistens) as it rises largely because atmospheric pressure decreases with height. On the other hand, air warms as it sinks and the pressure increases. Air also dries out as it sinks leading to lower relative humidity. The drier the air, the less energy it requires to warm up. So, when you see southwest or west winds in the forecast it will almost always equal a warming trend.

What about the "snow eater?" Thanks for the reminder. As Arctic high pressure, which deliver cold air outbreaks and occasionally snow, moves east Oklahoma winds often shift to the west or southwest. The "snow eater" then has a serious party, and you're all invited!