Clouds What they tell us about the weather Spring funnel cloud over Willard, Utah 2003
Cloud coverage 581-586
How to show Cloud Coverage On a weather map meteorologists use circles shaded differently to show the cloud coverage.
Determine Cloud Coverage 1 st Way: look out side 2 nd Way: Satellite Imagery Infrared Visible Water Vapor
Infrared Satellite Imagery Measure the heat/energy from the clouds Strong thunderstorms tops will appear cold.
Water Vapor Satellite Imagery Measure the water vapor in the upper atmosphere. Highest humidity will be the white areas and the lowest humidity areas are the dark regions. Predict heavy precipitation
Visible Satellite Imagery The Sunlight bouncing off the clouds making them appear white (sunrise hasn t happened in parts that are dark).
Cloud Types
Why learn about clouds The purpose of learning about clouds is to understand what type of weather is associated with each. Knowing the clouds will help you predict what type of weather is coming or could happen. When could you use this? Boating Camping
Cirrus White, feathery, wispy First sign of an approaching warm front
Cirrostratus Sheet like Cover entire sky When light pass through the ice crystals it can produce a ring or halo. Sign that a warm front is getting closer
Cumulus Puffy, flat base Form when moist, warm air bubbles vertically from Earth s surface
Cumulonimbus Top shaped like an anvil Very dense with water Weather Hail, lightning, tornadoes, thunder, and heavy rain Altitude: A few hundred meters to 12,000 meters
Stratus Gray color and flat Develops horizontally, covers entire sky Little or no precipitation
Altostratus Gray looking Dense sheet like layers, see sun through it
Nimbostratus Dark, gray Continuous precipitation
Air Masses
Air Mass Types and locations Air Mass: Large body of air of similar temperature and humidity By putting the symbols together you are able to describe both the temperature and moisture of the air mass Symbol Name Type c Continental Dry m Maritime Wet P Polar Cold T Tropical warm
When two air masses meet Frontal zone/front: the area where two air masses of different temperatures meet What happens when a cold and warm air mass meet? Which will go over the other and why? The warm air mass will always go over the other because the cold air is more dense. Warm air goes over the cold. Uplifting of warm air (which may contain much moisture) causes warm air to cool, which leads to condensation and the possibility of precipitation along the frontal boundary.
Weather Fronts
Cold Front Cold dry stable air mass displaces moist unstable subtropical air mass. Symbol is blue triangles, arrows point the direction the front is moving.
Weather Elements Prior to Front Contact with the Front After front passes Temperature Warm Cooling suddenly Cold and getting colder Atmospheric Pressure Decreasing steadily Leveling off then increasing Increasing steadily Cold Front Winds South to southeast Variable and gusty Precipitation Showers Heavy rain or snow, hail sometimes West to northwest Showers then clearing Clouds Cirrus and cirrostratus changing later to cumulus and cumulonimbus Cumulus and cumulonimbus Cumulus
Warm Front Warm, subtropical, moist, air mass replaces a slower moving cold, dry, polar air mass Symbol: red line with red semi-circles, semi-circles point to the direction the front is moving.
Weather Element Prior to the front Contact with the Front Front has passed Temperature Cool Warming suddenly Atmospheric Pressure Decreasing steadily Leveling off Warmer then leveling off Slight rise followed by a decrease Warm Front Winds Precipitation South to southeast Showers, snow, sleet or drizzle Variable Light drizzle South to southwest None Clouds Cirrus, cirrostratus, altostratus, nimbostratus, and then stratus Stratus, sometimes cumulonimbus Clearing with scattered stratus, sometimes scattered cumulonimbus
Occluded Fast moving cold front overtakes a slower moving warm front Two types Cold: air behind the front is colder than the air ahead of the front. Warm: air behind is warmer than the air ahead of the front. Symbol: mixture of purple triangles and semi-circle
Stationary Boundaries Frontal zones where air masses are not moving against each other Wind blow towards the front from opposite directions Symbol: mixture of blue triangles and red semicircles
Tornados Movie How they work