Hi,
What you have asked here are very important questions.
When convection bubbles develop further, as you would know, they can form thunderstorms. When thunderstorms do develop, there still usually is more air pusching the cloud tops upwards. This is called the updraft air. Now if this updraft air is coming from the ground, what is taken away from the ground has to be replaced. This comes from anywhere on the side usually where the wind is coming from. This is the simplest way to explain inflow - the air rushing into the storm.
Now take that enormous thunderstorm growing. It cannot grow forever. Something has to give. At this point, a nice dark base has formed because there is so much material in the cloud covering the sun. This is called the rain free base (some Australian chasers nicked named this to be RFB and have caused confusion to many others).
If the updraft cannot support the weight of the mass of moisture particles in the cloud including the hailstones that may have formed, precipitation begins to fall. This massive of air and moisture or even hail descends (goes down) toward the ground and is called the downdraft. Most of the rain we get from thunderstorms come from the downdraft.
Now we have an interesting interaction here. You have the air going in and up inflow and the outflow air coming down. If the air coming down which is cooler, spreads out and pushes the inflow air out of reach, the storm begins to die. It needs to breathe. Pulse storms that go straight up and hardly move basically die after half to one hour period because the outflow air has spread out so far that the inflow is cut off.
Now with severe storms, the updraft and the downdraft are a little more organised. Depending on the winds pushing the storms and what is going in BEFORE the storm develops, that tells meteorologists and storm chasers which storms are organised enough to chase. In other words, most severe storms besides pulse storms can last much longer and produce much more severe weather. This is because:
- the updraft is stronger and can hold far more moisture and hail in the air including larger hailstones
- the outflow in some storm types does not cut off the inflow as fast so the storm can last longer
- the downdraft can fall at such a pace that they can cause more storm updrafts on the side (although this can occur with non-severe storms)
- the rain free bases are often far more impressive
So the thing to look out for the next time you watch storms develop is the cycle - how the updraft first grows, rain begins to fall and then the rain with the downdraft can begin to cut off the inflow and the storm looks weaker and mushy. The lightning activity also may decrease during and after this stage.
So to answer your question? The updraft and downdraft are within the storm. Where they are located DEPENDS on how the storm formed in the first place based on the winds flowing if there was any! For instance, if there was an easterly wind and the winds were above were from the west, the updraft cumulus tower will rise and tilt forward a little from the west. The whole cloud will begin moving based on the speeds at the different levels. How the downdraft falls depends on the tilt and where the rain free base forms and where the rain falls. This is where you can see the visible part of the downdraft. Sometimes, the air falling down may not be so visible or even invisible. If you are near the downdraft though you will feel the cooler air.
Regards,
Jimmy Deguara
