Forecasting Weather Now that Meteorologists understand the factors that affect weather they must put all of this together to create weather maps and to determine weather patterns Together weather maps and weather patterns are very helpful in ID: 504748
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Slide1
Forecasting WeatherSlide2
Forecasting Weather
Now that Meteorologists understand the factors that affect weather they must put all of this together to create
weather maps
and to determine
weather patterns
.
Together weather maps and weather patterns are very helpful in
forecasting
the weather.Slide3
Weather Maps
Graphically show temperature, barometric pressure, wind speed/direction, cloud cover and relative humidity.
Also shows:
A
ir masses
Fronts
hazardous conditions
Created by putting together
data
from thousands of
weather stations
from all across the
world
.Slide4
Weather MapSlide5
Map Symbols
Map
symbols
are used to help
identify
the
conditions
reported from each weather station.Slide6
Other SymbolsSlide7
Weather Movement
Weather moves
from
areas of
high
pressure
to
areas of
low
pressure within
air masses
.
A huge body of
air
that has similar
temperature
,
humidity
and
air pressure
throughout it.
Classified by two characteristics:
Temperature
humidity
Warm or cold air masses depend on the
temperature
of the
region
over which the air mass
forms
.Slide8
Air Masses
4 general air masses
Polar
(P)
From the
poles
to
60°
N or S latitude.
Very
cold
air mass.
Tropical
(T)
From the
equator
to
25°
N or S latitude.
Warm
to
hot
air mass.
Continental
(c)
Over any large
land mass.
Dry
air mass.
Marine
(m)
Over any large
body of water
.
Wet
air mass.Slide9
Combining Air Masses
Maritime Tropical
(
mT
) – warm, humid air masses that form over oceans near the tropics.
Summer = hot and humid weather
Winter = humid conditions that bring rain or snow.
Maritime Polar
(
mP
) – cool, humid air masses that form over the icy cold North Pacific and North Atlantic oceans.
Affect the West Coast more than the East Coast
Summer = cool, humid air brings fog, rain and cool temperatures to the West Coast.Slide10
Combining Air Masses
3.
Continental Tropical
(
cT
) – Hot, dry air masses that form only in the summer over dry areas of the southwest and northern Mexico.
Cover the smallest area of all air masses!
4.
Continental Polar
(cP) – cool to cold and dry air masses that form over central and northern Canada and Alaska.
Winter = clear, cold and dry air to much of North America.
Arctic Air Masses
(A) – bring bitterly cold weather with very low humidity.
Polar VortexSlide11
North American Air MassesSlide12
Fronts
An area where
two
air masses meet and tend to not
mix
due to differences in
temperature
and
density
.
Warm
air masses =
low
densities and
rise
Cool
air masses =
higher
densities and
sink
Colliding air masses often cause
storms
and
changeable
weather.
4 Types:
Cold FrontWarm FrontStationary Front
Occluded FrontSlide13
Front SymbolsSlide14
Types of Fronts
Cold Fronts
– cold air masses meet and push under a warm air mass.
Violent storms
occur followed by
fair, cool
weather.
Cumulonimbus CloudsSlide15
Types of Fronts
2.
Warm Fronts
– warm air masses overtake a cold air mass and moves over it.
Rain
is followed by
hot, humid
weather.
Cirrus
clouds followed by
stratus
clouds. Slide16
Types of Fronts
3.
Stationary Fronts
– warm air mass meets a cold air mass and no movement occurs
Rain
may fall for many
days
.Slide17
Types of Fronts
4.
Occluded Front
– A fast moving cold front overtakes a warm front, lifts it quickly causing large scale precipitation.Slide18
Understanding Weather Maps
X
cPSlide19
Understanding Weather Maps
What is the
temperature
in Pittsburgh?
What is the
wind direction
in NY City?
What type of
front
is moving into
X
?
What weather conditions should they be expecting?
What is the
wind speed
at
X
?
What type of
air mass
is moving into
Pittsburgh?
78°F
SE
Warm
Rain, hot & humid
2
0
cP – Continental PolarSlide20
Cyclones & Anticyclones
Cyclones
– areas of
low
pressure
(
L) that contain
rising
warm air.
Greek for “
wheel
”.
Cooler air will move in and take the place of the warm air causing air currents to spins
counterclockwise
causes
rainy, stormy
weather.
Anticyclones
–
high
pressure centers (H) of cold, dry air.
Winds spiral
clockwise
causing
clear, dry, fair
weather.Slide21
Cyclones & Anticyclones
Cyclone
AnticycloneSlide22
Hazardous Conditions
Causes great
human suffering
and
death
.
Responsible for sever damage to the environment, infrastructure of cities and town and private property.
Types of Hazardous Conditions:
Thunderstorms
Hurricanes
Tornadoes
Winter StormsSlide23
Thunderstorms
Thunderstorms form after
severe heating
of
Earth’s surface
.
Form within large
cumulonimbus
clouds when warm air is forced upward at a cold front.
Causes
convection currents
.
Internal
friction
is created within these convection currents causing
electric charges
in the clouds.
Lightning
is the discharge of the electric charges.
Thunder
is the
sound
that rapidly heated air, from lightning, causes as it
expands
suddenly and explosively.
Mechanical EnergySlide24Slide25
Tornadoes
Develop in
low
,
heavy
cumulonimbus clouds during
spring
and early
summer
often in late afternoon.
Rapidly whirling,
funnel-shaped
clouds that are short lived and develop over land from severe thunderstorms
.
Cyclone – counterclockwise rotation
Over a lake or ocean =
waterspout
Occur
ONLY
in the
United States
The Great Plains has the greatest occurrence of tornadoes and is called “
tornado alley
”.Slide26Slide27Slide28Slide29
Hurricanes
A tropical storm that has winds of
119
km/hr or
higher
and is about
600
km across.
Develops over
warm
water as a
low
pressure area or
tropical
disturbance.
Gets its energy from the warm, humid air at the ocean’s surface.
Winds spiral inward,
cyclone
, toward the area of low pressure.
Lowest air pressure in a hurricane is found in the center,
the eye
.
Storm Surge
– the dome of
water
that is pushed ashore where a hurricane lands.
The cause of most damage and death!Slide30Slide31
Hurricane CategoriesSlide32
Winter Storms
Snow falls when
humid
air cools below
0
°C.
Lake-Effect Snow
is caused when land loses heat
faster
than
water
and a dry, cold air mass it picks up water vapor from the warmer bodies of water.
Oswego, NY
is one of the snowiest cities in the United States.
Receives an average annual snowfall of over
200
”.Slide33
Average Snowfall in New York