Transcript Hurricane - Ramsey Public School District

Storms, Tornadoes, &
Hurricanes
Tutorial: http://news.bbc.co.uk/2/hi/science/nature/4588149.stm
All Storms:
• Low pressure at
center
• Warm air rising,
cooling, and
condensing
• Cumulonimbus clouds
Thunderstorms:
• Cumulonimbus Clouds
• Usually Cold fronts
• Separation of charged particles in
cloud. Dust, salts, etc. Have
charges.
• Top of cloud (+); Bottom (-)
• Lightening = electrons moving
from (-) to (+).
• Thunder = rapid thermal
expansion of air molecules
(follows lightening, sound moves
slower)
Tornadoes:
• Small, intense cyclonic storm
w/ high winds
• Spring season (Colliding air
masses have greatest temp.
difference. Canadian air still cold,
Gulf air has warmed up)
Ingredients:
• Cold fronts & C.nimbus clouds
• Shearing winds & flat land
Hurricanes
Storm system characterized by a large lowpressure center and numerous thunderstorms
that produce strong winds and heavy rain.
Wind speed: 74 mph (before 74 mph, storm is
called a Tropical Storm or Depression)
Season: June 1 – Nov. 30
Peak Season: Late Summer (Aug.& Sept).
(Remember, water heats up slower than land)
Ingredients for a Hurricane
1. Warm tropical waters (80F)
Our hurricanes form off coast of Africa
2. Low Pressure system above warm water
(sucks warm moist air in to create storm)
3. Cumulonimbus clouds form fr. rising warm
moist air that condenses
4. Gentle winds (Tradewinds) ROTATE clouds
and STEER hurricanes.
5. Eye forms from dense cool air sinking into
Low Pressure
Eye: Dense, dry, sinking air from the upper
atmoshere; calm
Eye Wall: is a circle of strong T.storms that
surrounds the eye; greatest wind speeds
;precipitation & wind .
Hurricanes MOVE HEAT in Earth’s oceans.
Move warm tropical water to colder places.
When hurricanes “hit” land (Landfall), they fall apart (lose
moisture).
When hurricanes move to colder water they fall apart
(Low pressure lessens)
Path of Hurricane:
In tropics: Tradewinds move them across the Atlantic from E
W
In temperate latitudes: Westerlies move them from W E.
http://www.nhc.noaa.gov/gifs/DC_16_2001-2005.jpg
States most affected: Gulf States (but East
Coast in general)
http://apollo.lsc.vsc.edu/classes/met130/notes/chapter15/formatio
n.html
http://www.nhc.noaa.gov/gifs/DC_16_2001-2005.jpg
Hurricane Hazards
1. High speed winds (74 mph +) – knock down trees &
power lines
2. Heavy rains (flooding)
3. Coastal Areas – STORM SURGE
Water piles up under the low pressure center. When
the water pile moves inland it causes flooding.
Clouds and Storms:
http://www.youtube.com/watch?v=xk18W2OWZT0&feature=related
Tornadoes:
Nat.geo: http://www.youtube.com/watch?v=-K-z-mZ9Va4
http://www.youtube.com/watch?v=DS0V8itbGEg
http://www.youtube.com/watch?v=a_MuaWDg5Z0&feature=related
Hurricanes
Hurricane Season 2005
http://www.youtube.com/watch?v=X5vsYs2hRNI
Nat. Geo. Podcast
http://www.youtube.com/watch?v=OEPZOC6YHUc
BBC: How Hurricanes are Born
http://www.youtube.com/watch?v=4f45jA5UxB0