Now we know that cold fronts have warm air behind them.
When the reflective ice and snow layer is stripped away, it leaves a dark blue sea which absorbs the sun’s rays and aids the heating process. As the ocean gets warmer it is in marked contrast with the polar air above. The heat from the ocean flows up into the polar air, creating a high pressure system. This forces the polar air to move and then pushes frigid air down into Europe and across the globe.