Transcript Weather - Images

What is weather?
Refers to the state of the atmosphere at a
specific time and place.
The one thing that you can talk to anybody
about, it affects all aspects of life
If you don’t like the weather just wait
around it will change
What are some of the factors that affect the
weather?
Air Temperature
Temperature is the
measure of the
average amount of
motion in particles.
Wind
a natural movement of
air of any velocity;
especially : the earth's
air or the gas
surrounding a planet in
natural motion
horizontally
Humidity
The amount of water vapor present in the air
Relative Humidity -is a measure of the
amount of water vapor present in the air
compared to the amount needed for
saturation at a specific temperature
Clouds
 Masses of small water droplets or tiny ice
crystals that float in the air.
 Three main types are cirrus, cumulus, and
stratus.
 Other clouds are a mixture of these three
main types.
Types of Clouds
based on Shape and Altitude
MAIN SHAPES
 Cirrus
 Cumulus
 Stratus
THREE ALTITUDE Groups
 Low Clouds
 Middle Clouds -start with prefix “Alto”
 High Clouds - start with prefix “Cirro”
Cirrus
 Cirro- means “curled” or “feathery”
 Form highest in the sky; are made up of ice
crystals; and appear as curls, tufts, or wisps.
 Usually signal the end of clear weather.
 High level clouds 18,000 to 30,000 ft.
Cumulus
 Cumulo- means “heaped” or “piled”
 Cottony clouds with flat, usually gray bases,
and puffy, bright tops.
 Usually signal good weather, but if
atmosphere is unstable, can build into
towering clouds that produce showers and
thunderstorms.
 Low level cloud 1,000 to 18,000 ft.
Stratus
 Strato- means “layer-like” or “sheet-like.”
 Low-lying, dull-colored clouds that form in
layers or sheets.
 Usually bring drizzling rain or light-falling
snow.
Alto
 A prefix meaning “middle range of clouds “
and used to describe clouds that lie from
6,500-18,500 ft. (1,980-5,640m).
Precipitation Clouds
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Nimbostratus – rain, sleet, and snow
Stratus - drizzle, light rain
Cumulonimbus - rain, snow, sleet and hail
Altostratus – light rain (rarely)
High Cloud Types
Cirrocumulus
Cirrus
Cirrostratus
Condensation Trails
Middle Cloud Types
Altocumulus
Altostratus
Low Cloud Types
Cumulus
Stratus
Stratocumulus
Nimbostratus
Nimbostratus
Cumulonimbus
Precipitation
 Water that falls from the clouds
 Air temperature determines the form of
precipitation that falls
 4 main types of Precipitation: Rain, Sleet,
Snow and Hail
Types of Precipitation
Rain
Sleet
Snow
Hail
Air Masses
 A large body of air that has
properties similar to the
part of the Earth’s surface
over which it develops.
Types of Air mass source regionsMaritime (m) – forms over water and is moist (wet)
Continental (c) - forms over land and is (dry)
Polar (P) – forms over polar- regions and is (cold)
Tropical (T) – forms in tropical regions and is (warm)
Arctic (A) – forms over the poles and (very cold)
Air masses that effect the U.S.
Continental Polar (cP) – cold dry air
Maritime Polar (mP) – moist cold air
Maritime Tropical (mT) – moist warm air
Continental Tropical (cT) – dry hot air
Continental Arctic (cA) – dry very cold air
Air Mass Map
Fronts
 A boundary between two air
masses of different density,
moisture, or temperature.
Types of Fronts
Cold Front
Warm Front
Occluded Front
Stationary Front
Severe Weather
Thunderstorms
Lightning
Tornadoe
More Severe Weather
Hurricanes
Blizzards
Severe Weather Safety
 Watches- conditions are favorable for
formation of severe weather
 Warnings- severe weather has formed and
has been observed by a sighting or by
RADAR
 Examples of Severe Weather WarningsTornadoes, Flash Flooding,
Severe Thunderstorms, Blizzards,
Wintery Mix (snow and ice), High Winds,
Tropical Storms and Hurricanes
THUNDERSTORMS
 Form only in Cumulonimbus clouds
 Can produce rain, snow, hail, Lightening,
thunder, high winds and tornadoes
 Forms individually by convection or multiple
storms along a frontal system
 Super cell thunderstorms exceed 40,000 ft.
Thunderstorm formation
Lightning
20,000 ft +.
32ᵒc
10,000 ft.
TORNADOES
 Form only in Cumulonimbus clouds
 Average life span 5-15 minutes
Super cell tornadoes may last up to two hours
 Small scale storms average 100 yards across,
Largest recorded 2 miles wide 2013 in OK.
 Wind speeds 65 to 300 mph
 Forms over land- if formed over water it is
called a Waterspout and is generally weaker
Tornadoes
Tornado Alley
Fujiti Scale
FUJITA SCALE
DERIVED EF SCALE
OPERATIONAL EF SCALE
F Number
Fastest 1/4-mile
(mph)
3 Second Gust
(mph)
EF Number
3 Second Gust
(mph)
EF Number
3 Second Gust
(mph)
F0
40-72
45-78
EF0
65-85
EF0
65-85
F1
73-112
79-117
EF1
86-109
EF1
86-110
F2
113-157
118-161
EF2
110-137
EF2
111-135
F3
158-207
162-209
EF3
138-167
EF3
136-165
F4
208-260
210-261
EF4
168-199
EF4
166-200
F5
261-318
262-317
EF5
200-234
EF5
Over 200
HURRICANES
 Forms over warm tropical water
 Large scale storms average 300 miles in
diameter Largest typhoon Tip 1,800 mi. dia.
 Wind speeds 75-200 mph
 Losses strength when moves over land and
warm moist air is cut off from oceans
 Generally moves east to west with deflection
to the right due to Coriolis effect
 Average life span of 10 days
 Longest was Hurricane Ginger 31 days
Hurricanes
Hurricane cross section
Eye
Descending air
Outflow
Hurricane Scale
 Two sources of
forecasting weather
– Data collected from
upper atmosphere
– Data collected on the
Earth’s surface
Weather Balloons
 Collects a vertical profile of the atmospheres
temperature, relative humidity, air pressure, wind speed
and direction and transmits the information to a
meteorologist
on the ground
Weather Satellites
 Provides visual data of weather systems
and helps track weather located in distant
locations.
Weather RADAR
 Locates Fronts, precipitation and severe
weather.
Surface Weather Data
Thermometer
Rain
Wind Sock
Gauge
Barometer
Anemometer
Wind Vane
Weather Station Model
Station Model Map
Isobars
 Isobars- line of equal
pressure
 The closer the Isobars
are to each other the
higher the wind speed
1016
Pressure Systems
10
16
1020
1016
1016
1012
1024
1008
FRONTAL SYSTEMS
H
L
Composite Weather Map with
Satellite and Radar