Wednesday 4/11/18 Storm front over Lake Superior (US) Notebook Entry: Think about the work you have done over the past week. You have examined weather maps and studied air masses and fronts. At this point, what would you say is the main cause of changing weather? To give your answer complete this sentence: “The main cause of a change in weather is…. “

Warm Front During Front: -Cloudy with precipitation likely -Stays for several days as it is slow to push out cold air After the Front: -Warmer temps -More humidity in the air http://www.physicalgeography.net/fundamentals/7r.html A moving warm air mass collides with a slowly moving cold air mass. The warm air moves over the cold air. If the warm air is humid showers and light rain might fall where the warm and cold air meet. If the warm air is dry scattered clouds may form. After a warm front passes through an area the weather is likely to be warm and humid. Winter warm fronts bring snow. https://www.windows2universe.org/earth/Atmosphere/tstorm/warm_front.html

Cold Front During Front: -Quick change in the weather -Strong winds and severe storms- heavy rain/snow After Front: Colder, drier air with clear skies http://www.physicalgeography.net/fundamentals/7r.html Moving cold air mass runs into a slowly moving warm air mass, the denser cold air slides under the warmer air and pushes it upwards. If there is a lot of water vapor in the warm air heavy rain or snow may fall. Cold fronts move quickly so they can cause weather changes. After a cold front passes, cool, dry air moves in. https://www.windows2universe.org/earth/Atmosphere/tstorm/cold_front.html

Occluded Front During the Front: -Cooler temperatures -Clouds and precipitation based on amount of water in warm air After the Front: -Cooler temps -No Precipitation A warm air mass caught between two cooler air masses. The denser cool air mass moves underneath the less dense warm air mass and pushes it upward. The warm air mass is cut off (or occluded) from the ground. As warm air cools and its water vapor condenses, the weather may turn cloudy, rainy, or snowy.

Stationary Front During the Front: Clouds & precipitation for MANY days After the Front: -Depends on which air mass wins -May be cooler or warmer

What type of front is headed towards Montana What type of front is headed towards Montana? What type of weather could we expect?