Ana or Kata? It's Kata Dave...Added : Tuesday at 14:15 You probably know the difference by now between a warm front and a cold front. But, meteorologists go one further and when a frontal system approaches we also figure out whether the front is Ana or Kata. This is an important aspect, even though a cold front subsequently brings colder air, we also need to know what type of transition it will be.
If you look at the forecast chart for rainfall tomorrow morning then you can clearly see the frontal system across Central areas, stretching from Northeast England to Southwest England :-
But, if you look ahead of the front, you can also see some heavy showers developing as the front approaches.
If you think of a cold front as the head of a broom as it moves along the floor, then as the brush head moves through, the air ahead of it is lifted up. In an Ana cold front, the air then rises and is lifted up over the top of the broom head and the whole thing is tilted back in the angle of the handle.
Ana cold fronts tend to bring an active band of rain, sometimes with a squall line where this lifting process actually occurs.
Now, imagine the same process, but with air blowing over the top of the front near the broom head. This creates a "rotor" effect just ahead of the front, a bit like an old style lawn mower with rotating blades.
This is a kata cold front and the activity tends to be ahead of the front with some heavy showers developing and running ahead of it. AROME also shows this up well with the front moving Southeast, but heavy showers ahead moving from Southwest to Northeast ahead of it :-
At the end of the day it's a cold front and means rain for most, but if heavy showers with the odd rumble of thunder develops ahead of it before the colder air arrives, then now you know why...
METEOROLOGIST : MARSH |