Weather fronts, maps and symbols 6.4

maps, weather, high and low pressure areas, isobars, contour lines, weather systems, precipitation, cold front, warm front, stationary front, occluded front, clouds, snow, rain, weather map, symbols

1. Weather Fronts, Maps and Symbols Illustrated by Kella Randolph M.Ed. http://blogs.henrico.k12.va.us/21/files/2012/01/amishasmap.jpg

2. Isobars What do all the lines mean on a weather map? Those are called Isobars. These lines represent different air pressures. The line joins areas with the same pressure and they can show areas with high and low pressure. The two maps show the same area but at different times. https://learningweather.psu.edu/sites/default/files/Lesson2/06Z_surface_analysis_Irene_edited.png

3. Altitude maps use contour lines similar to topography maps. In both maps, the continuous closed lines indicate that inside the line is one specific unit/ air pressure for isobars or height above sea level for topography. Image/Explain polar front top left: https://images.app.goo.gl/NHbAn1hPWcXijmcF9age Image/Contour Lines top right: https://images.app.goo.gl/FRqwuSY56f5Q56g67

4. The Ziggurat of Choga Zanbil Image: https://images.app.goo.gl/37NfFeHenFaA42gV8 The Egyptians had pyramids, the Mesopotamians had ziggurats, which are massive brick structures with raised platforms with successively receding levels. Nobody knows what they stood for, but it’s presumed that they once contained shrines dedicated to the gods and had living quarters for priests. The Great Ziggurat of Ur in Iraq is one fine example of a ziggurat. But Choga Zanbil is one of the few ziggurats that lies outside Mesopotamia, and it’s the largest one among them. The ziggurat stands at the site of the ancient city of Elam, in today’s Khuzestan province in southwest Iran. Text: https://www.amusingplanet.com/2018/10/the-ziggurat-of-choga-zanbil.html Question: could you draw an elevation map to show the levels of the building? Would it be something like the contour map for topography, or like the isobars used to show air pressure in the atmosphere?

5. High Pressure and Low Pressure Symbols The areas of HIGH pressure will be designated with an “H” and areas of LOW pressure are marked with a “L”. Each pressure system will have isobars circling the symbol. These lines show how quickly the pressure CHANGES as you move out from the center of the air mass. https://upload.wikimedia.org/wikipedia/commons/c/ca/Surface_analysis.gif

6. High Pressure Systems High pressure systems often bring CALM and DRY weather whereas Low pressure systems are associated with storms and PRECIPITATION. A high pressure system is a dense air mass that is usually cooler and drier than the surrounding air. In general, areas that experience high atmospheric pressure also experience fair weather. Air usually flows from areas of high pressure to areas of low pressure. https://images.app.goo.gl/Cus2noeQMMTYJRsRA https://images.app.goo.gl/GpfBNqz2tNK7CoCn6

7. Warm front The front is the location at the surface where the warm air mass begins. Typically, the gradient of a warm front is 1 in 400 to 1 in 100, so the front will be in different locations at different heights. In the warm sector behind the front, shallow convective clouds may form, or stratus may form if there is enough rising motion; producing some precipitation. Unlike a cold front, it is thought that a warm front propagates by mixing its way forward. This may explain why warm fronts generally move slower than cold fronts. https://images.app.goo.gl/Runx1oiF2MJaiPBs6 https://www.climateandweather.net/assets/img/warm_weather_front.gif

8. Cold Fronts Cold fronts are shown on weather maps as a BLUE line with blue TRIANGLES pointing in the direction it is moving. A cold front occurs when a cold air mass pushes BENEATH a warmer mass, forcing the warm air up because it is less dense. PRECIPITATION is still possible as the front moves into an area but the amount will vary. On the left is a National Weather Service forecast map from March 24, 2017. The forecast map shows two cold fronts moving southeast over Texas. On the right is an actual GOES-16 image of atmospheric water vapor from the same afternoon. Text and image: https://scijinks.gov/weather-map/ Note: this is just one image .

9. Low Pressure System https://images.app.goo.gl/bdx3PXYu8JW8vMWS6 https://images.app.goo.gl/1dcMevKXu9MPxEAT6 https://images.app.goo.gl/GJYorRoesYFn4X269

10. https://images.app.goo.gl/cmuE4Nb25WtJdmj2A

11. Four kinds of fronts https://images.app.goo.gl/RBu9J7g43Go5jZrE9

12. Stationary Fronts Stationary fronts occur when a boundary forms between two air masses with different air DENSITIES. Neither air mass is advancing so the front is considered STATIONARY - stays in one place. If the air masses have a lot of water vapor, it could mean severe ice storms or rain that causes FLOODING. https://images.app.goo.gl/ymZJ9pJBLzarDMVv9 https://images.app.goo.gl/fJq7M5nSsDMhju69A

13. Which is which? Stationary Front Occluded Front https://images.app.goo.gl/88h6i5ADiUGrkeAL9 https://images.app.goo.gl/Ati3JUnGKargzUA76 Occluded front symbol: https://images.app.goo.gl/TVjTftcS4UXfNDmV6

14. Occluded Front At an occluded front, the cold air mass from the cold front meets the cool air that was ahead of the warm front. The warm air rises as these air masses come together. Occluded fronts usually form around areas of  low atmospheric pressure .  (Remember:  Air masses flow from High to Low...) Image left:https ://taylorsciencegeeks.weebly.com/blog/occluded-fronts Image center: https://images.app.goo.gl/GPDp7rw28TUwv8qo6 Image right: https://images.app.goo.gl/Bx7nyTFf52joZsVE9

15. Four kinds of weather fronts Symbols above: https://images.app.goo.gl/26eYaRCz245JYtHQ7 Chart right: https://images.app.goo.gl/tEuKbELMNhJ1U7fm8

16. https://images.app.goo.gl/SyMvksbpLg7u44ud7