Download Basics of Weather notes (smitherman)

Basics of Weather
-Clouds form when air masses rise and cool condensing water vapor into small
droplets
Based upon height
-Cirro – high clouds, above 6000 m
-Alto – middle clouds, between 2000 and 6000 m
-Strato – low clouds, below 2000 m
Shape
-Cirrus – latin for “hair”, wispy, stringy clouds
-Cumulus – latin for “Pile, heap”, puffy, lumpy clouds
-Stratus – latin for “layer”, featureless sheets of clouds
-Nimbus – latin for “cloud’, low grey rain clouds
Air Masses – large body of air that takes on the characteristics of the area where it
forms
-Form over land or water
-Over land they are drier, over water they contain more water vapor
Main types of air masses
1) Warm and dry
2) Continental tropical
3) Warm and humid maritime
4) Cold and dry continental polar
5) Cold and humid maritime polar
Jet Streams
-Wind pattern that greatly affects the weather of North America
-There are actually 4 jet streams that span the entire continental US
Fronts
-Cold front
-Dense cold air displaces warm air forcing it to rise rapidly
-Forms thunderstorms
-Warm front
-Warm air is displaced up as it meets a cold air mass and creates a
gradual sloping boundary
-Forms slow gradual rain
-Stationary front
-When two air masses meet and neither mass advances
-Rarely have cloud cover or heavy precipitation
-Occluded front
-When a cold front overtakes a warm front forcing it upward and two
cold fronts then collide
Atmospheric Pressure
-Describes the weight of air above you at any given point
-Low Pressure Systems
-Have low pressure
-Warm air
-Stormy, rainy weather
-High Pressure Systems
-Have high pressure
-Cold air
-Clear skies