Air Masses, Fronts & Weather: How Are They Related?

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
(view from side) / Hurricane
(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 lowpressure 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:
Radar & Lightning Meter 

Looking at cloud formation:
/ Measured by:
Lightning Meter

National Lightning Detection:
/ Measured by:
EF Scale (Enhanced Fujita Scale)
Based on wind speed

Tornado Alley

Dixie Alley
/ Measured by:
Saffir-Simpson Hurricane Wind Scale
Based on wind speed

May include storm surge & damage info

Beaufort Wind Scale