How do cold fronts produce stormy weather?
Well, it is not the front that creates stormy weather. That is; if we agree that by ‘stormy’ you mean a lot of wind. The isobar gradients is what produces wind. The tighter, the more wind it will be. An old seafarer rule of thumb says that if the barometer falls 10 mb in 8 hours, a gale force wind can be expected. But while the entire low pressure may be ‘stormy’ the cold front is also what seafarers fear mostly. It is then interesting to see that the quickly rising barometer is more dangerous than the falling one. And that for several reasons. First, a cold front with – as you write – cold air pushing the warm sector upward, is always in unstable air masses. That is, the temperature gradient is lower than the dry adiabatic cooling with altitude. The air then keeps rising up to the point that thunderstorms may appear. But a thunderstorm is only fearful in Holywood movies. In reality it doesn’t pose a problem and it is hardly called a strom by seafarers. True, it may be preceeded by str
