You've heard about warm fronts and cold fronts, but what in the world are ana fronts and kata fronts?
To start, one should know that the front currently stretching from the Great Lakes to Texas is an ana front. This is the same front which is producing beneficial rains over the southern Plains.
An ana front is a frontal boundary in which the main shield of clouds and precipitation is located behind the actual frontal boundary.
This is because cold air located behind the front moves rapidly, pushing against the warm air out ahead of the front. Because cold air is more dense than warm air, the surging cold air causes the warm air to lift upward along the front.
Therefore, clouds and precipitation that form end up inclined rearward with height due to the advancing cold air at the surface.
That causes the main zone of cloudiness and precipitation to develop behind the actual frontal boundary.
For a current example, you can see that the cold front over the southern Plains is located over central Texas but a lot of the steadier rains are over northern Texas and Oklahoma, while more scattered thunderstorms lie to the south of the front. This is a great example of an ana front.
There is also a kata front, which is basically the opposite of the ana front.
In this case, an intrusion of dry air moving in behind the front ends up restricting the upward flow of warm air. Due to the dry air aloft, you end up with lower cloud tops; therefore, the clouds and precipitation slant forward with height.
This leads to the main zone of cloudiness and precipitation developing in front of the surface frontal boundary.
For more information and analysis, click on the WeatherWhys video below.
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