Chapter 3 Weather Fronts and Storms Vocabulary Review the boundary between two air masses front a large and often stormy weather system that occurs when air moves around and into a low-pressure center, then moves up to higher altitudes low-pressure system a blinding snow storm with winds of at least 35 mi/hr (56 km/hr), usually with temperatures below 20 degrees F (-7 degrees C) blizzard a large volume of air that has nearly the same temperature and humidity at different locations at the same altitude air mass a rapid rise in the water level in a coastal area that occurs when a hurricane pushes a huge mass of ocean water, often leading to flooding and widespread damage storm surge a scientist who studies weather meteorologist a low pressure-system that starts in the tropics with winds of at least 40 mi/hr (65 km/hr) but less than 74 mi/hr (120 km/hr) tropical storm a violently rotating column of air stretching from a cloud to the ground tornado a generally calm and clear weather system that occurs when air sinks down in a high-pressure center and spreads out towards areas of lower pressure as it nears the ground high-pressure system a storm with thunder and lightning thunderstorm a tropical low-pressure system with sustained winds of 74 mi/hr (120 km/hr) hurricane a line on a weather map connecting places that have the same air pressure isobar