Where are the particular regions of the world that frequently experience such air mass collisions and frontal weather?
The middle climate zone known as the temperate zone is the area of Earth that gets the most mix of weather patterns due to the clashing of air masses.This climate zone is located from approximately 23.5 degrees to 66.5 degrees in both the Northern and Southern Hemispheres.
A front is nothing more than the leading edge of an air mass. Since air masses are categorized based on their temperature and humidity content, the source region will determine the type of air mass to move into an area. The temperate zone is more unique in that the air masses in the middle latitudes from both the Tropical and Polar (or arctic) zones clash and meet in the middle.
The classification of air masses is done according to where they form. For example, there are tropical air masses as well as Arctic air masses. Whether they form over land or sea also gives them a designation.
Storms, collisions or unstable weather forms for a variety of reasons in all parts of the world. It depends on cold fronts, warm fronts and the temperatures in the atmosphere and on the surface area below.
The two links below give detailed explanations of air masses and their locations
The second link is very graphic, it provides charts to understand how the fronts move around the world.
This type of violent weather can be seen in some parts of Alaska, Canada and also the Greenland, mostly the colder regions on Earth. The Gulf of Mexico is also another location that experiences air mass collisions and frontal weather. Northern American is also part of that region.