How a Meteorologist Looks at a Cumulonimbus: A thunderstorm is actually a cumulonimbus cloud which is comprised of an updraft (yellow) and a downdraft (blue arrows). At my home, we could feel the rain-cooled outflowing air from the storm that spreads out once hit hits the ground (just like the water spreads when you spill it on the kitchen floor).
You cannot see this thunderstorm's anvil since I'm looking toward the east, but it shows up nicely on the satellite picture (arrow).
Finally, here is the radar image of the storm at the same time (8:00pm). The orange arrow denotes the thunderstorm in the above two images. The green arrows highlight the light green line which is the rain-cooled air from the storm.