Ominous clouds and an approaching storm may be accompanied by the wail of a community siren. Other times they can be heard in the morning on what may be a nice day. What do the different blasts of the siren mean?

Sirens are part of the Public Alert System to let those outdoors be aware of a local or national emergency. Originally designed for civil defense, sirens are also commonly used in the Midwest and other locations to alert people of severe weather.

At the writing of this post on September 2, we are in the average peak week of hurricane activity for the Gulf of Mexico. Remnants of hurricane Ida are drenching the East Coast, and a new hurricane is currently out in the Atlantic.

The Earth’s weather is a complex system of winds, moisture, and heat. Hurricanes are a good example of all of these. They move huge amounts of heat from the hot tropics to the milder middle latitudes.

What makes them form, and how do they move heat? I’m so glad you asked!