When a prior passes over an area, it means a adjust in the weather. Numerous fronts cause weather occasions such together rain, thunderstorms, gusty winds, and also tornadoes. In ~ a cold front, there might be dramatic thunderstorms. At a warm front, there might be short stratus clouds. Usually, the skies clear when the front has actually passed.

You are watching: Place where 2 air masses meet

What is a Weather Front?

A weather former is a shift zone in between two different air masses at the Earth"s surface. Every air fixed has distinctive temperature and humidity characteristics. Regularly there is turbulence at a front, i m sorry is the borderline wherein two different air masses come together. The disturbance can cause clouds and also storms.

Instead of leading to clouds and also storms, part fronts just cause a readjust in temperature. However, some storm fronts begin Earth"s biggest storms. Dry waves are fronts that construct in the dry Atlantic ocean off the shore of Africa. These fronts can build into dry storms or hurricanes if conditions allow.

Fronts move throughout the Earth"s surface over many days. The direction of motion is regularly guided by high winds, such as Jet Streams. Landforms like mountains can also change the path of a front.

There are 4 different types of weather fronts: cold fronts, heat fronts, stationary fronts, and occluded fronts.

Cold Front


A side check out of a cold former (A, top) and how that is represented on a weather map (B, bottom).

Credit:Lisa Gardiner

A cold front develops when a cold air mass pushes into a warmer wait mass. Cold fronts can create dramatic transforms in the weather. They relocate fast, as much as twice as fast as a heat front. Together a cold prior moves right into an area, the more heavier (more dense) cool air pushes under the lighter (less dense) heat air, bring about it to climb up right into the troposphere. Lifted warm air ahead of the prior produces cumulus or cumulonimbus clouds and thunderstorms, choose in the image on the left (A).

As the cold former passes, winds come to be gusty. There is a sudden drop in temperature, and additionally heavy rain, sometimes with hail, thunder, and lightning. Atmospheric pressure transforms from fallout’s to climbing at the front. ~ a cold prior moves with your area, you may an alert that the temperature is cooler, the rain has actually stopped, and also the cumulus clouds are replaced by stratus and stratocumulus clouds or clean skies.

On weather maps, a cold former is represented by a solid blue line through filled-in triangles along it, choose in the map ~ above the left. The triangles are prefer arrowheads pointing in the direction that the front is moving. Notification on the map the temperatures at the floor level change from warm to cold as you cross the front line.

Warm Front


A side watch of a heat front (A, top) and also how that is represented on a weather map (B, bottom).

Credit: Lisa Gardiner

A warmth front creates when a heat air mass pushes into a cooler air mass, displayed in the picture to the best (A). Heat fronts often lug stormy weather as the heat air mass at the surface ar rises over the cool air mass, do clouds and storms. Heat fronts move an ext slowly than cold fronts because it is more complicated for the warm air to push the cold, dense air throughout the Earth"s surface. Heat fronts often form on the eastern side the low-pressure solution where warmer waiting from the south is moved north.

You will regularly see high clouds prefer cirrus, cirrostratus, and also middle clouds prefer altostratus ahead of a warmth front. This clouds kind in the warmth air the is high above the cool air. As the front passes over an area, the clouds end up being lower, and also rain is likely. There deserve to be thunderstorms about the warmth front if the air is unstable.

On weather maps, the surface ar of a warm front is represented by a heavy red line through red, filled-in semicircles follow me it, choose in the map top top the appropriate (B). The semicircles show the direction the the front is moving. They space on the side of the line whereby the front is moving. Notice on the map the temperatures in ~ ground level are cooler in prior of the front 보다 behind it.

Stationary Front


A stationary former is represented on a map by triangles pointing in one direction and semicircles spicy in the various other direction.

Credit:Lisa Gardiner

A stationary front develops when a cold former or warm front stops moving. This happens when two masses the air space pushing against each other, yet neither is powerful enough to move the other. Winds punch parallel to the front instead of perpendicular can help it stay in place.

A stationary front might stay placed for days. If the wind direction changes, the front will start relocating again, coming to be either a cold or warmth front. Or the front might break apart.

Because a stationary front marks the boundary between two air masses, there are often differences in wait temperature and wind top top opposite political parties of it. The weather is often cloudy along a stationary front, and also rain or snow often falls, particularly if the prior is in an area of low atmospheric pressure.

On a weather map, a stationary front is displayed as alternate red semicircles and blue triangles like in the image at the left. Notification how the blue triangles suggest in one direction, and also the red semicircles allude in opposing direction.

Occluded Front


An occluded front is represented on a weather map by a violet line with alternative triangles and semicircles.

Credit:Lisa Gardiner

Sometimes a cold front complies with right behind a heat front. A warm air massive pushes into a chillier air massive (the heat front), and also then one more cold waiting mass pushes right into the heat air massive (the cold front). Because cold fronts move faster, the cold former is likely to overtake the heat front. This is well-known as one occluded front.

At an occluded front, the cold waiting mass native the cold prior meets the cool air that was front of the heat front. The warm air rises together these wait masses come together. Occluded fronts usually kind around locations of short atmospheric pressure.

There is frequently precipitation along an occluded front native cumulonimbus or nimbostratus clouds. Wind changes direction together the front passes and also the temperature one of two people warms or cools. After ~ the prior passes, the skies is commonly clearer, and the wait is drier.

See more: Why Does My Kenwood Radio Say Protect " Mode", Solved: Kenwood Deck Flashing (Protect)

On a weather map, shown to the left, an occluded prior looks choose a purple line with alternate triangles and semicircles pointing in the direction the the former is moving. It ends at a low pressure area shown with a large ‘L’ ~ above the map, starts at the other finish when cold and also warm fronts connect.