Lecture 9-Precipitation and Violent Weather(1)

Lecture 9-Precipitation and Violent Weather(1) - Lecture...

Info iconThis preview shows pages 1–15. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 9-Precipitation and Violent Weather
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
What is precipitation? We need moisture to form clouds- what about rainfall? Precipitation is water (solid/liquid forms) It is heavy enough to fall to earth Types Rain Snow Sleet Hail Virga
Background image of page 2
Precipitation Formation Cloud droplets grow larger by merging with each other, as we saw in cloud formation. These droplets bump into each other and merge together until they are heavy enough to fall (too heavy to stay aloft!). This process is known as
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Rain and Snow Both created by same processes. . With snow/ice Where ice crystals grow at the expense of water droplets, as droplets encounter ice crystals, they freeze onto them and increase the size of the crystals-as with raindrops, when it becomes too heavy to stay aloft it falls as snow or ice.
Background image of page 4
Types of precipitation-Freezing Rain (always check notes for process/details!)
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2. Sleet
Background image of page 6
3. Hail Particles of ice held aloft by thunderstorm updrafts (so these can form very high up!)-these ice particles are circulated long enough to grow quite large as they encounter droplets in clouds.
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4. Virga Type of precipitation when rain doesn’t quite make it to the ground.
Background image of page 8
Getting into weather now-Air Masses and Weather Systems (see notes for introduction)
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Air Mass Is an extremely large body of air with consistent temperature and moisture characteristics Characteristics based on source region (where we find the air mass) Moisture and temperature used in classifying air masses….
Background image of page 10
Air Mass Classification 1. Moisture -Continental ( c ): dry Formed over large land mass -Maritime ( m ): moist Formed over ocean Temperature (determined by latitude) - Polar ( P ): cold formed poleward of 60° N or S - Tropical ( T ): warm Formed within ~30° of the equator - Arctic ( A ): very cold Formed over the Arctic We use these moisture and temperature characters to classify different air masses-so we will see combinations of these characters (such as a continental polar air mass, or a cP, for example. The letters are used to indicate the characteristics of the air mass, so it is a convenient shorthand to use.
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
We Have Principal Air Masses (in the N Hemisphere) cP – continental polar mP – maritime polar mT – maritime tropical This figure shows the air masses that influence America and its weather in winter-in summer, the location of these air masses will change and produce different characteristics.
Background image of page 12
North American Air Masses This makes sense, right? As summer occurs in the N Hemisphere (where we live), the polar air masses shift northwards-and the tropical air masses also shift northwards, making it warmer (and in our case in Florida/East Coast) and wetter in the summer.
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Continental polar (cP) air masses form only in the N Hemisphere…. .why? (see notes!) These produce cold, stable air, clear skies, high pressure ; anticyclonic wind flow (because it is a high pressure system-remember lectures 6 and 7?) Maritime polar (mP)
Background image of page 14
Image of page 15
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 69

Lecture 9-Precipitation and Violent Weather(1) - Lecture...

This preview shows document pages 1 - 15. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online