Frontal Systems and Weather Patterns

1) Frontal Systems (12 Marks)

You notice some high cirrus clouds in the sky, and later your location is covered by low level nimbostratus clouds with light, persistent rain. Then you notice the wind direction veers in a clockwise direction from southeasterly to southwesterly, and the temperature increases but the rain ends.

a) Explain what just happened at your location (3 Marks)

The high cirrus clouds in the sky indicated that a frontal system was approaching. As the front approached, the wind direction veered in a clockwise direction from southeasterly to southwesterly. This indicated that the front was approaching from the southwest. The temperature increased, which is consistent with an approaching warm front. The rain then ended, which is typical when a warm front passes through.

b) Explain what just happened at your location (3 Marks)

After a day or two of nice, clear air with warm temperatures, you hear thunder in the distance and notice extensive towering cumulus and cumulonimbus clouds. This indicated a thunderstorm complex developing, often associated with a low pressure system. The presence of lightning nearby suggested the risk of additional thunderstorms.

c) Did the center of the low pressure system pass to the south of you or to the north of you? (2 Marks)

The center of the low pressure system passed to the north of my location.

d) Draw a rough sketch of the isobars of the system, along with an "L" for the center of the low, an arrow to indicate the rough direction of the movement of the low pressure system, and your location (Use an "X") when you first noticed the cirrus clouds. (4 Marks)

The isobars indicate a low pressure system with a well-defined center. The "L" in the sketch marks the center of the low pressure system. The arrow shows the southwest direction of movement of the low pressure system. The location where the cirrus clouds were first noticed is marked with an "X".