Hi John, Thanks for your help with this. I have spent a few days looking at fronts, dew points, wind directions, and precipitation and I can correlate fronts with sharp dew point gradients, veering winds and precipitation. I have noted that the correlation isn't always that good, especially around the center of lows and the fingers of the fronts (The ends away from the low center). This is actually quite helpful because I am trying to establish which parts of the forecast can be relied upon and which parts can't. I have read the airmass and Frontal Depression guides but I am still not able to create a 3D picture of a frontal depression in my mind. I can visualise the plan view with warm and cold air initially running parallel to each other and a frontal wave disturbance (e.g. jetstream?) causing an unstable vortex which deepens and a frontal depression is born with winds circulated anti clockwise around it. I can also visualise a section through a low where air currents flow up, out and down but I can't put the two together. I can't visualise how a packet of air might be travelling up and around at the same time. I assume the air in the warm sector stays in the warm sector but circulates in some way. If this is the case, a packet of air behind the cold front stays their but gains on the warm front, pushing the warm air upwards. Again, if this is the case, the wind generated by the pressure gradient and geostrophic force is actually a component of the whole depression moving and rotating not winds circulating around and around the low like a merrygoround. Perhaps I am confusing the timeing of the plan and section views. Do you know of a video, animation or explanation that might give a 3D representaion in time? As I say I am trying to establish the confidence level of the forecasts and have a couple of questions but I will start a new thread on that to keep things tidy. PeggySue