Meteorology Final Exam 12/13/13In low-pressure regions, the wind circulates counterclockwise and inward, converging at the surface and diverging aloft. Low pressure systems are characterized by clouds, precipitation and/or thunderstorms. In regions of high pressure, the wind circulates outward and clockwise, with divergence at the surface and convergence aloft. High pressure systems bring clear, calm and dry weather conditions.p. 9, 260The advantages of infrared satellite imagery are: 24-hour availability, cloud and surface temperature information in bright areas. The advantage of visible satellite imagery is that it provides detailed images of clouds, but a major disadvantage is that the images are only available during the day.p. 14We call the current atmospheric conditions in a given place weather: it is something we observe in the short term and can vary greatly from one day to the next. Daily or weekly weather forecast is useful for planning what to wear or for working outdoors, etc. Climate is the long-term average of weather variables such as precipitation, temperature, and humidity (just to name a few) for a region. It is consistent throughout the seasons and determines the overall picture of the region, such as the type of crops grown and how cities are built. A typical weather observation for Cleveland, Ohio is "Temperature: 29 F, Wind Speed: NE 6 mph, Dew Point: 17 F, Barometer: 1024.8 mb, Overcast, Snow Showers Expected" (the weather tonight). This is consistent with Cleveland's Dfa (humid continental mid-latitude) climate, which has warm summers, cold winters, and year-round precipitation. The four main divisions of the atmosphere from the surface are: 1) Troposphere: begins... .... middle of paper ...... called orographic uplift.p. 188 It is possible for thunderstorms and tornadoes to form when the lower troposphere is conditionally stable when the air is cloudy. Conditional stability means that for clear air the atmosphere is stable; but with cloudy air the atmosphere becomes unstable, causing the lift needed for thunderstorms.p. 184,369 In northeast Ohio, lake-effect snow develops in early winter/late fall, when the surface of Lake Erie is warm relative to an arctic airflow arriving from the north or northwest. Water molecules quickly evaporate in the cold air flow, and giant snow clouds form parallel to the shore. The colder the air relative to the lake surface temperature, the stronger the effect. Southeastern lakeshore areas are affected by lake-effect snow because they are in the direct path of Arctic winds.p. 269-271