Transcript Storms and Precipitation

STORMS
&
PRECIPITATION
S6E4
Types of Storms:
• Thunderstorm
• Tornado
• Snowstorm
• Hurricane
Watch a Brainpop on
Thunderstorms!
• http://www.brainpop.com/science/weather/
thunderstorms/
Thunderstorm
What is it?
Small storm
with heavy
precipitation,
frequent
thunder &
lightning
Thunderstorm
How does it form?
• When warm air is forced upward along a
cold front & warm, humid air rises rapidly
• In Cumulonimbus clouds (dark, anvilshaped)
• During Spring/Summer
Go to the Online Textbook…
• Watch Active Art…Ch 12…weather fronts
• http://www.phschool.com/atschool/phsciex
p/active_art/weather_fronts/index.html
Thunderstorm rolling in over the city
During a thunderstorm, which
comes 1st
lightning or thunder?
LIGHTNING
MCQUEEN
IS #1!
Thunder always
follows
LIGHTNING…
Watch a Brainpop on
Tornadoes!
• http://www.brainpop.com/science/weather/
tornadoes/
Tornado
What is it?
• Rapidly whirling,
funnel-shaped
cloud, reaching
from the storm
cloud to the
ground
• Brief, but deadly!
Tornado
How does it form?
• In cumulonimbus clouds with
winds at different heights
• In summer/spring
• as warm, moist
air from the
Gulf of Mexico
meets cold, dry
air from
Canada
• 800 or more
tornadoes
yearly in this
area
Tornado Alley
Watch a Brainpop on
Snowstorms!
• http://www.brainpop.com/science/weather/
snowflakes/
Snowstorm
What is it?
• Heavy snowfalls
that block roads
• Trap people in
their cars/homes
• Blowing wind
make people
lose their way
Blinding snow can disorient people
Snowstorm
How does it form?
• Extreme
cold
• Air colder
than 32°F
ALL the
way to the
ground
Watch a Brainpop on
Hurricanes!
• http://www.brainpop.com/science/weather/
hurricanes/
Hurricane
What is it?
• A tropical
cyclone
• Winds 119
km/hr or
higher
• May be 600
km wide
Hurricane
• Forms in the Atlantic,
Pacific & Indian
Oceans
• Called a Typhoon in
the western Pacific
• Hurricane Season in
U.S. from July - Nov
• Eye (center) is calm
Hurricane
How does it form?
• Begins over warm ocean water as a
tropical depression → tropical storm →
hurricane
• Last ≥ 1 week
• Loses strength as it crosses land
– no water = no hurricane
Storms bring precipitation…
5 Types of Precipitation
•
•
•
•
•
Rain
Hail
Snow
Sleet
Freezing Rain
Depend on the temps!
Rain
• Drizzle
• Mist
• Large drops
• Falls when the
temps are
above freezing
(32°F)
Hail
• Round pellets tossed around in
cumulonimbus clouds like a rock tumbler
• During thunderstorms
• Forms at any temp
Snow
• Powdery snow falls through cold, dry air
• Clumps together as it falls through humid (wet)
air
• Temps below freezing
• Water vapor in clouds made directly into ice
crystals → SNOW!
Sleet
• Raindrops
that fall
through air
that is below
freezing point
of water
(32°F)
Freezing Rain
• Happens a lot in
GA in the winter!
• Raindrops fall
through cold air,
then freeze as
they hit frozen
surfaces