Weather (pgs 51-59) Flashcards
What is an anticyclone?
An anticiyclone is an area of high atmospheric pressure. It is typically shown as a series of closed, ascending isobars enclosing an H. The wind around the high pressure zone moves counterclockwise. They usually bring fine weather, clear skies, and light but variable winds.
What is a depression?
A depression is an area of low atmospheric pressure. It is typically shown as a series of closed, descending isobars enclosing an L. The wind around the low pressure zone moves clockwise. They usually bring clouds and rain.
What is a barometer?
An instrument used to measure atmospheric pressure. If the pressure is rising, a high pressure system (anticyclone) is approaching. If the pressure is dropping, a low pressure system (a depression) is approaching.
What is an air front?
It is the boundary between air masses that are different temperatures because they have come from different regions (i.e. the tropics versus the pole)
What is a warm front?
A boundary where warm air slides up over cold air, causing layered stratus clouds. It brings light, persistent rain. The clouds will lower and the chance of rain increase as the front passes. The front tends to pass slowly.
What is a cold front?
A boundary where cold air undercuts and lifts warm air vertically, causing heaped cumulus or cumulonimbus clouds. It can bring heavy rain, hail or thunder. As it passes, there may be squalls and a rapid drop in temperature. It may pass quickly.
What are land and sea breezes?
Land and sea breezes are generated by the relative temperatures of the earth and water. During the day, the land heats faster than the sea, causing a wind towards the shore. During the night, the land cools faster than the sea, causing a wind away from the shore.
Where can you get marine weather forecasts?
At home, you can get them on the internet, TV, radio, etc via MetService. At sea, weather forecasts are announced on VHF 16 at 0533, 0733, 1033, 1333, 1733 and 2133. Coastguard weather stations also transmit continuously on channels 20, 21 and 23. 21 is our local channel?
