Transcript storms - pams

STORMS
Weather jokes?
Shoulder Partner

Describe to your partner the scariest storm
you’ve ever been in and what took place.
Close Encounter!
Types of storms…
Storms – a violent disturbance in the
atmosphere.
 Rain/Snow storms – formed when two
different fronts collide (warm meets cold)
Summer = steady rain
Winter = heavy snowfall
Blizzard = wind must reach 36 km/hr and
be -7 degrees Celsius.
Ice storm = rain freezes instantly.
* Thunderstorms – cold meets warm front
forming heavy rainstorms with thunder and
lightning, has violent down drafts and strong
wind shear.

Face Partner

Which type of storm do you believe is the
most deadly, meaning that is takes the most
lives?
Ice Storms…
Lightning
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Lightning – sudden discharge of static electricity
(cloud to cloud; cloud to ground)
Leading cause of forest fires. Can strike people,
animals, or buildings.
When the air is heated by lightning it expands
quickly resulting in loud sound waves (thunder).
Safety – avoid open spaces outside; don’t go under
trees for shelter, and avoid sinks, bathtubs,
televisions, and telephones while inside during a
lightning storm.
If you hear thunder 3 seconds after a flash of
lightning; the storm is only 1 km away.
Lightning continued…
Table Talk…

What is a cyclone?
Cyclones and Anticyclones?
– any area of low pressure
containing rising warm air. Causes
rainy stormy weather.
 Anticyclones – any high pressure area.
Causes dry, fair weather.
 Cyclones
Now for a laugh!
Hurricanes
Hurricanes – power cyclones
that forms over tropical areas.
 Typhoon – hurricane that forms
over the W. Pacific ocean.
 The rapidly, spinning rising air
forms a donut-shaped wall of
strong winds, clouds, and
rainfall. The eye of the storm is
always calm. (speeds of 74 to
over 155 m/hr)
 Considered the most powerful
of all storms.

Hurricanes and Typhoons
Map of a hurricane…
How are hurricanes
categorized?
The Saffir-Simpson Scale
Storm Chasing
Shoulder Partner…

Would you ever go on a storm chase? Why
or why not?
Tornadoes

Tornadoes – incredibly destructive; a
whirling, funnel-shaped cloud of low
pressure. Develops in heavy cumulonimbus
clouds. Acts like a giant vacuum cleaner,
due to the low pressure. Not sure how they
form, usually in the spring in late afternoons
or evenings. Most common in the United
States.
Map of a
tornado…
Tornadoes continued…
More about tornadoes…
 Great
Plains is “tornado alley”.
 Average diameter of a tornado is .4 km
 Average length traveled – 6 km for
only a few minutes.
 Winds can still reach more than 350
km/hour.
 Measured on the Fujita scale as F0 –
F5. (five being the strongest).
Tornado alley?
Fujita Scale
Precipitation types
and
Clouds
Can weather predict disaster?
Types of clouds…
Cumulus –(cotton balls) are fluffy and white with
flat bottoms. Indicate fair weather.
 Cumulonimbus – (thunderclouds) when cumulus
clouds grow vertically and darken.
 Stratus – gray clouds that cover the whole sky and
block out the sun. Light rain and drizzle are
usually associated with these clouds.
 Cirrus – feathery clouds. Sometimes called
“mare’s tails”. Indicate that it will rain/snow in the
next 24 hours.
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Cumulus
Cumulonimbus
Stratus
Stratus
CirrussCumulus
Cumulonimbus
Cirrus
Odd-shaped clouds
Do you see what I see?
Even more…
Precipitation

When water vapor in the clouds becomes too heavy, it
can fall as rain, sleet, snow, or hail
 Cloud droplets must first increase in size until gravity
pulls them down
 When droplets pass through extremely cold layers of air
as they fall, they freeze and produce sleet
 Snow is formed when water vapor (gas) changes
directly into a solid. Process is called deposition.
 Hail is formed within the cloud.
You are done!