Transcript Weather Unit

Mrs. Qualls
2012
What is weather?
How is weather predicted?
Weather Tools
•Thermometer: measures the temperature in
the air.
•Barometer: measures the air pressure
•Rain Gauge: measure the amount of
precipitation.
•Anemometer: measures the wind speed.
What is a meteorologist?
Weather Map
Look at the map above and see what kind of fronts you can find.
Weather Graph
Which month received the most rain?
How much more rain occurred in May then in January?
What is the title of the graph?
What kind of graph could we make
with the data we have collected?
Thermometer: measures the
air temperature.
What does it mean when
they say “it feels like” a
different temperature then it
really is?
(Heat Index and Wind Chill)
They can look different, but
they all do the same job!
Barometer: measures the air
pressure.
What does low pressure mean? Lows are usually associated with high
winds, warm air, and atmospheric lifting. Because of this, lows normally produce
clouds, precipitation, and other bad weather such as tropical storms and cyclones.
What does high pressure mean? Pressure increases are because more air
fills the space left from the low. It also evaporates most of the atmosphere's water
vapor so high pressure systems are usually associated with clear skies and calm
weather. Unlike areas of low pressure, the absence of clouds means that areas
prone to high pressure experience extremes in seasonal temperatures since
there are no clouds to block incoming solar radiation or trap outgoing
radiation at night. Thus such areas have higher high temperatures and
lower lows.
Rain Gauge: measures the
amount of precipitation.
Rain gauges come in all shapes and sizes, some are
decorative and some are very scientific. No matter what
there appearance is they all are set out to “catch” falling
precipitation and measure how much.
They can look different, but
they all do the same job!
Anemometer: measures wind
speed.
Anemometers all do the same job and that is to measure
the speed of the wind.
What are clouds?
Do different looking clouds mean anything?
Cirrus:
Cumulus:
Stratus:
Cumulo-Nimbus:
Brain
Pop
video
Cirrus clouds are high altitude feathery clouds. They are usually quite thin and
often have a hair like appearance. The curled up ends as shown in this picture are
very common features. They are associated with fair weather and they often
indicate that rain or snow will fall within several hours.
Cumulonimbus, as shown in this photo are the clouds that can produce
lightning, thunder, heavy rains, hail, strong winds, and tornadoes. They are
the tallest of all clouds that can span all cloud layers and extend above
60,000 feet. They indicate that the atmosphere is quite unstable and can
also be an indicator of impending severe weather.
Cumulus are usually puffy and white and often have very distinct edges
and flat bottoms. They often have a popcorn-like appearance. They are
associated with fair weather, but watch out if they start to get dark on
the bottom!
Stratus are usually the lowest of the low clouds. They are smooth and gray
clouds that cover the whole sky. Stratus often appear as an overcast day
and can block out direct sunlight. They are associated with light rain and
drizzle.
Types of Precipiation
Hail is a form of solid precipitation. It consists of balls
or irregular lumps of ice, each of which is referred to
as a hail stone.
Fronts
A front is a boundary between air masses of different temperature
and humidity. It is usually called a warm front or a cold front.
High and Low pressure air masses
Just like a front, it is a boundary between air masses of different
temperature and humidity.
You see it displayed like this on
weather maps
Types of Storms
Thunderstorms:
Thunderstorms form when an air mass becomes so unstable that it overturns violently.
"Unstable" means that the air in the lowest layers is unusually warm and humid, or that
the upper layers are unusually cool, or oftentimes, both.
Hurricanes:
The two essential ingredients in every hurricane are warm water and moist warm air.
That’s why hurricanes begin in the tropics. Warm moist air is drawn into the developing
storm and more heat is transferred from the surface of the ocean to the atmosphere. This
continuing heat exchange creates a wind pattern that spirals around a relatively calm
center, or eye, like water swirling down a drain.
Tropical depression—wind speeds of less than 38 miles per hour (61.15 kilometers per hour)
Tropical storm—wind speeds of 39 mph to 73 mph (62.76 kph to 117.48 kph)
Hurricane—wind speeds greater than 74 mph (119.09 kph)
Tornadoes: Tornado conditions are caused when different temperatures and humidity
meet to form thunderclouds. (http://www.msnbc.msn.com/id/9007188/ns/weather-weather_news/t/birth-tornado/)
Other weather related
phenomenon
•
•
A waterspout is a column of cloud-filled wind rotating over a body of water.
Despite its name, a waterspout is not filled with water from the ocean or lake. A
waterspout comes down from a cumulus cloud. It does not "spout" from the
water. The water inside a waterspout is formed by condensation in the cloud.
video
Lenticular Clouds
•
•
Lenticular clouds: technically known as altocumulus standing lenticularis, are stationary lensshaped clouds that form at high altitudes.
Where stable moist air flows over a mountain or a range of mountains, a series of large-scale
standing waves may form on the downwind side. Lenticular clouds sometimes form at the
crests of these waves. Under certain conditions, long strings of lenticular clouds can form,
creating a formation known as a wave cloud.
Rainbows
•
Rainbows are spectacular rays of color. Sunlight looks white, but it's really made up of
different colors...red, orange, yellow, green, blue, indigo, and violet. The sun makes rainbows
when white sunlight passes through rain drops. The raindrops act like tiny prisms. They bend
the different colors in white light, so the light spreads out into a band of colors that can be
reflected back to you as a rainbow.
Why can't you ever find the end of a rainbow?
A rainbow is an optical illusion, so you just can't catch up to it. When you move, so does it!
What did you learn about
weather?