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What is the difference between a cold front and a warm front?
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Hi Alicia,
The difference is the temperature of the air, and usually the amount of moisture contained in the air. Each type of front influences the weather in the location it moves into - but how it moves into the area and what type of weather already exists there also plays an important part in the weather changes that will result.
I'm attaching my own collection of NSTA resources that might help. I cannot sing the praises of, Stop Faking It! ebook. It's a true life saver.
Be careful! Weather is a sneaky topic - it doesn't look every interesting on the surface, but you'll be watching clouds and disagreeing with the Weather Channel before you know it!
Thanks!
Kendra
Meteorology Collection
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A cold front is associated with colder weather and a warm front is associated with warmer weather. Warm fronts occur when cold fronts are crashed into by a warm air mass, causing it to rise. Cold fronts occur when warm fronts and cold fronts collide, and driven upward.
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If the front is moving into an area of warmer air, the front is called a cold front. If the front is retreating and warmer air is moving into an area previously occupied by cool air, the front is termed a warm front.
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Cold fronts occur when a cold air mass replaces a warmer air mass. Meaning, colder air moves in, slides under and displaces warmer air. Warm air cannot displace cold air easily because it is less dense. With a warm front, you have an area of warm air moving in over colder air. Because warm air is lighter than cold air, the warm air will ride over the top of the colder air, where it will cool, condense, and squeeze out moisture. Warm fronts may cause precipitation and fog, wheras, cold fronts may cause thunderstorms and severe weather.
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Interesting topic. Sometimes the difference between warm and cold fronts is more the humidity than it is the temperature. Especially in the summer in the midwest, you might notice a south-westerly breeze one day, and northwesterly the next day. Insignificant change in temperature, but huge change in humidity from damp to dry as the "cold front" passes. The dry air has similar properties to cold air, in that it has a higher density than damp air of the same temperature. Remember that the mass of a molecule of water vapor (18 g/mole) is lighter than either N2 (28 g/mole) or O2 (32 g/mole), so wet air rises just as warm air does.
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The main difference is how the cold and warm fronts are created. Of course, a cold front is associated with cold weather and a warm front is associated with warm weather. I can explain it by using a reverse-type explanation: Warm fronts occur when cold fronts are crashed into by warm air mass, causing it to rise. Cold fronts occur when warm fronts collide and drive upward.
Vicki Carmichael
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The difference between cold fronts and warm fronts is the type of air they bring. Cold fronts bring "cooler" air temperatures and warm fronts bring "warmer" air temperatures. I stress cooler and warmer because students associate cold fronts with cold weather which is misleading. A cold front brings cooler temperatures than before the front occured. For example a location with a temperature of 76 degrees could drop to 70 degrees after a cold front (which is still warm). Also, bad weather is associated with cold fronts moreso than warm fronts due to a greater contrast of air masses associated with them.
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A front refers to where air masses meet.
Cold fronts: as colder air moves forward, warmer air is pushed upwards. Cold fronts are steeper and move quickly. They often bring brief thunderstorms and heavy precipitation.
Warm fronts: as warm air moves forward, it moves over denser, cooler air. It moves slower than a cold front. When the warm air goes over the cool air, it often causes a longer period of light precipitation.
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Finally! After our class I finally understand the difference between a warm front and a cold front. I actually had one of those "lightbulb" moments when we covered this topic. When warm air moves into an area where colder air had existed it is referred to "a warm front." The warm front may lead to more active weather patterns such as storms and precipitation. When a cold front moves into an area previously occupied by warmer air, we say a cold front is moving in. The air seems crisp, clouds tend to dissipate and we have fair , cooler weather. The colder air will move into an area under the warm air mass and push the warmer air up and away. Today, a cold front moved into Atlanta.
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Way to go Tracy! It really helps to experience it!
The next time you experience a cold front, you might notice that as the front is passing, you may experience very turbulent weather. After all, the cold front is relatively steep, and the change in temperature and humidity occurs quickly. Because of this, severe weather is typically associated with severe weather, followed by cooler temperatures, dryer air, and clear skies. Sometimes, at least in the midwest, a cold front may be followed by cooler air, north winds, and puffy cumulus clouds as the storms clear.
In contrast, a warm front moving in occurs over a relatively longer time, and the weather associated with a warm front typically involves a lower stratiform cloud deck. Because warm air is easier to remove than cold air (remember, cold air is heavy and dense), the leading edge is often accompanied by lighter rain, although sometimes thunderstorms can be embedded in the front, if the contrast in temperatures is large enough to cause instability.
So, the next time you experience a warm or cold front, think about the conditions you observed before the front passed. Look at the sky - sometimes you may even see a stark line of clouds at the edge of the cold front, and wispy, high level clouds preceding a warm front. My grandma used to tell me that a halo around the moon meant rain in 24-36 hours (an empirical method of weather forecasting to be sure). The ice crystals from the high level clouds in front of the warm front reflect the light, forming a corona.
Hope that wasn't more information than you wanted. I think it is so interesting to be able to look at the sky and come up with my own forecast. Could also be a fun project for an elementary or middle school class.
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These are great explainations about Cold and Warm Fronts.
I would also add to this a discussion on tornadoes with students. Especially a discussion about the April 2011 outbreak.
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Sounds like a great - and timely - idea, Diane. Last year we had a record number of tornadoes - 15 - in a single day in April. This year has been quite different.
Did you know that you can start a new thread? Just click the "New Topic" button at the Earth/Space Science forum / discussion listing, and start the next discussion. There is so much to learn beyond the misconceptions in the movie "Twister" and recent television shows. I remember one episode of the show "Criminal Minds" where the unsub is carried off into the tornado while the rest of the group watched; the group waited out the tornado in a cellar, only to find devastation when they emerged, but all the vehicles were unscathed. Anything for drama and an easy get-away!
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