severe weather

2. Thunderstorms
Lightning
Tornadoes

3. Hurricanes Blizzards

4.  Weather is the state of the atmosphere in a
specific place and time
 There are many components that affect the
weather
 1. Temperature-How hot or cold the air is
 2. Humidity-The amount of water that is in the
atmosphere
 3. Air Pressure-The amount of force pressing down
on earth’s surface from the gases in the atmosphere
 4. Wind-Air moving in a specific direction

5.  An air mass is a large body of air that has
similar properties to the part of Earth’s
surface over which it develops
 What type of air mass would develop over Africa?
 What type of air mass would develop over
Antarctica?
 A boundary between two air masses of
different moisture or temperature is a front.

6.  Weather that may cause property damage or
loss of life
 Types of severe weather are:
 Thunderstorms
 Tornadoes
 Hurricanes
 Blizzards
 Floods

7.  A heavy storm that is accompanied by
rain, thunder, lightning and strong winds.
 To create a thunderstorm you need
 Moisture: cloud formation & rain
 Unstable air: relatively warm air rises
rapidly
 Lifting: from sea breezes and mountain
interaction
Thunderstorms are measured based on
their wind speeds.

8.  A Severe Thunderstorm Watch can be issued
by the National Weather Service station
 This type of storm has winds of at least 58 mph or
hail at least ¾ inch in diameter
 A Severe Thunderstorm Warning is issued
when a severe thunderstorm has actually
been observed

11.  Go inside and stay away from windows,
doors, and porches
 Stay away from trees and out of boats
 Avoid plumbing fixtures and contact with
electrical fixtures
 Stay off the phone!

13.  A destructive rotating column of air with very
high winds and a funnel shaped cloud in contact
with the surface of the earth
 Tornadoes form when a thunderstorm meets
horizontal winds which cause it to rotate.
 Tornadoes can come one at a time or in clusters
 They can also vary in size, length, width,
direction of travel, and speed

14.  Tornadoes are measured based on their wind
speeds and by using the Enhanced Fujita
Scale
EF 0 65 to 85 MPH
EF 1 86 to 110 MPH
EF 2 111 to 135 MPH
EF 3 136 to 165 MPH
EF 4 166 to 200 MPH
EF 5 Over 200 MPH

18.  Tornado Watch: weather conditions are
likely for tornadoes to form in our area
 Tornado Warning: A tornado has been
sighted in our area

20.  Tornadoes can occur in any state and any time of
year
 They typically occur from March to August
 The most common tornadoes are in “Tornado
Alley”
 “Tornado Alley” - Arkansas, Iowa, Kansas,
Louisiana, Minnesota, North Dakota, Ohio,
Oklahoma, South Dakota, and Texas

21.  Seek shelter immediately when a tornado
warning is issued
 Underground shelter is best
 If not available, find an inside room, hallway, or
closet on the lowest floor and away from windows
 Listen to the radio or watch TV for updates
on the storm

23.  A severe storm that develops over tropical
oceans and whose winds are stronger that 120
km/hr that spiral in to an intense low pressure
center
 Hurricanes begin when warm moist air over the
ocean rises rapidly
 When moisture in this rising air condenses a
large amount of heat is released
 The released heat increases the force of the
rising air

24.  They form when they gather heat and energy
through contact with warm ocean waters
 Water evaporates from the water and the
moisture produces a storm
 They can also form when a wind pattern
occurs near the surface of the ocean and
spirals inward

25.  Measured using the Safir-Simpson Scale
 3 factors are considered
 Wind Speed
 Central Pressure
 Storm Surge

26.  Hurricanes can occur during any time of the
year
 Hurricane season is from June 1st
to
November 30th
 They can form in the Atlantic Ocean,
Caribbean Sea, Gulf of Mexico, and in the
eastern Pacific Ocean

30.  Know if the location you are in is a safe zone
or whether evacuation may be needed
 Protect windows and glass with plywood
 Turn off utilities
 Have a supply kit including first aid, water,
canned goods, battery powered radio,
blankets, etc.
 After evacuation, do not return until it has
been declared safe

31.  A Hurricane Watch occurs when a hurricane is
possible within 36 hours
 The storm is being tracked to predict where it may
hit
 A Hurricane Warning is issued when it the
storm is expected to hit within 24 hours
 Evacuation may be needed

32. Two sources of
forecasting weather
 Data collected from
upper atmosphere
 Data collected on the
Earth’s surface