2. An air mass is a vast pool of air having similar temperature and moisture characteristics over its horizontal extent. An air mass occupies thousands of square miles of the Earth's surface. Air masses are born in a source region where they take on their characteristic temperature and moisture content.
3. The jet stream flows from west to east in wave-like patterns. west east
4.
5.
6. Meteorologists agree that jet streams may act as a barrier between cold air in the north and warm air in the south. During their meandering, the streams appear to allow some cold air to flow southward and warm air to flow northward. These flows undoubtedly affect the formation of cold and warm air masses.
12. Cold Fronts Cold fronts are those where moving cold air slides under warm air. Friction slows the advancing cold air causing a steep slope to the front. The steep slope pushes the air ahead of it rapidly upwards and vertically developed clouds (cumulus) are produced along the front.
13. Warm Air Cold Air Heavy Rain often occurs. Cold front Symbol
14. With greatly contrasting air masses on either side of the front and potentially unstable conditions, violent weather can form. Towering cumulonimbus clouds are common along cold fronts producing intense downpours of rain lasting for a relatively short period of time. Tornadoes can form under the most extreme conditions ahead of an advancing cold front.
15.
16.
17.
18. Warm Fronts A warm front is where moving warm air pushes over cold air. As with a warm front, you experience a drop in the atmospheric pressure as the front approaches. The warm front slopes gently up into the troposphere that has a direct bearing on the kinds of clouds that are produced. As the warm air behind the front collides with the cooler air ahead, the warmer less dense air is forced to glide upward.
19. Warm Air Cool Air Light or moderate Rain often occurs. Warm front Symbol
20. Once the warm front passes your location you'll notice an increase in temperature and air pressure. Soon the stratus clouds of the warm front give way to broken and clearing skies. As the warm sector moves into your location you will notice an increase in the humidity of the air
