Category Archives: Phenomena

Lakes freeze from the surface downward to the lake bottom. Ice floats because it is less dense than liquid water.

The density of liquid water depends on the water temperature. The density of water is highest at a temperature of about 40 degrees Fahrenheit. So, why is that important? Continue reading →

If you watch jets fly high above, you may notice that sometimes white clouds trail them. These condensation trails are called contrails. Most clouds form as air rises. Contrails form by a mixing process that is similar to the cloud you see when you exhale and “see your breath”. Continue reading →

Yes! If you were out late on Tuesday night, you might have seen the Northern Lights. The Northern Lights, also called aurora borealis, appear as a diffuse glow or as overlapping curtains of greenish-white and sometimes red light in the night sky. Continue reading →

In heat lightning you see the flash of light from the lightning, but you don’t hear the thunder the lightning produces. All lightning produces thunder when the bolt heats the air around it. This rapid heating causes the air to … Continue reading →

Those types of cloud are called mammatus. They often extend from the bottom of the anvil cloud of a thunderstorm, also called a cumulonimbus cloud, and indicate an intense storm is nearby. This was the case on Tuesday. Mammatus clouds … Continue reading →