How do cold fronts produce stormy weather?

Question

Warm moist air ahead of the front is uplifted as the front passes, causing the moisture to condense and precipitate.

Cold air behind the front causes the water vapor to evaporate, producing the storm.

The warm air mixes with the cold air along the front, creating low pressure and storms.

The cold air holds more water vapor than the warm air, thus it must precipitate out as rain or snow.

Answer 1

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 strong wind gusts but the don't last long. True, they may be preceeded by a squall line but I have myself experienced several of those in tiny sailboats and if you lower the sails, it won't have time to create a critical sea.

What is unpleasant with a cold front is exactly that: shifting and gusting winds. But, for seafarers, the problem is also that usually you have the low at your north and as the front moves, the wind veers and creates a cris-cros of waves coming from different directions.

Answer 2

Why did you ask a question and then answer it yourself?

EDIT: Thanks Michel for pointing that out. Thumbs up for you.