Download Storms

Air Masses, Fronts & Weather: How are they related?
When an air mass moves into an area and interacts with other air masses, it causes weather to change. Remember: in the U.S., air masses are commonly moved by the Prevailing
Westerlies & Jet Streams.
A front is the boundary where 2 air masses meet. Air masses of different temps & humidities do not easily mix – like oil & water - the denser air mass will move under the less
dense air mass. Storms & changing weather often happen along fronts as air moves up and/or down in the atmosphere.
A storm is a violent disturbance in the atmosphere caused by sudden changes in air pressure.
Thunderstorm
Lightning
Tornado
Hurricane
(view from side)
(view from top)
Def:
Small storm with heavy precipitation,
frequent lightning & thunder
Def:
Positive & negative electric charges
build up in the air. When they jump
between clouds or between clouds &
the ground we see the flash as bolt of
lightning
Def:
Rapidly whirling, funnel-shaped cloud
that reaches down from a storm cloud
over land
Def:
A tropical cyclone fueled by warm, humid
tropical ocean water
Formation:
On hot, humid days (low pressure) & along
cold fronts (where high pressure meets low
pressure)
Formation:
During thunderstorms from heated
(up to 30,000°C or 54,032°F!) air
that expands suddenly & violently.
We hear the sound as thunder that
follow the faster moving flash of
lightning.
Formation:
Spring & summer mostly, when a cold,
dry (high pressure) air mass from
Canada meets a warm, humid (low
pressure) air mass from the Gulf of
Mexico (in “Tornado Alley” – mid U.S. &
“Dixie Alley” through the South)
Formation:
In the Atlantic Ocean (that affect us) from June
1-Nov 30. Begins over warm ocean water
(≥80°F) as a low pressure system or tropical
depression, then may develop into a tropical
storm, adding heated water and winds to
become a hurricane
Parts:
Cumulonimbus clouds, rain, lightning &
thunder
Parts:
Electric charge with high temp
Parts:
Vortex: center (core), very calm, little
wind, no debris flying
Parts:
Eye: calm center, very little wind surrounded
by clouds
Clouds:
Cumulonimbus
Clouds:
Cumulonimbus
Clouds:
Cumulonimbus
Clouds:
Warm, humid air rises from the ocean’s
surface, growing larger over a week or more
Weather:
heavy rain, hail, lightning, thunder
Weather:
Happens during thunderstorms
mostly over land
“Water Spouts” look similar over
water
Weather:
winds w/speeds up to 500mph, heavy
rain
Weather:
winds of 119mph-320mph & 600 miles wide,
loses strength over land & cold water
Dangers & Safety Needed:
Flooding & Lightning strikes
Stay indoors or inside car, away from water
& conductors!
Dangers & Safety Needed:
May cause fires or serious injuries
from electrical shock
Dangers & Safety Needed:
Damaging winds
Stay away from windows & doors, duck &
cover!
Dangers & Safety Needed:
Very high winds, heavy rains & heavy flooding
around a calm center “eye” which can fool
people into thinking that the storm is over,
storm surges, evacuate the area!
Measured by:
Measured by:
Measured by:
Measured by:
Radar & Lightning Meter 
Lightning Meter
EF Scale (Enhanced Fujita Scale)
Based on wind speed
Saffir-Simpson Hurricane Wind Scale
Based on wind speed
Looking at cloud formation:
Tornado Alley
National Lightning Detection:
May include storm surge & damage info
Dixie Alley
Beaufort Wind Scale