How to predict when and where a thundery will appear. I used to rely on this when I was bush flying in the Kimberley (Australia).
Things I would look for.
Season. Wet or Dry. Has the met bloke predicted thunderies for the day. (summer/winter/etc)
Topography. Mountains, hills, cities, lakes, near ocean etc. A ridge will provide some lifting. As you know, you need that to kick off cu cloud and therefore (if conditions are right, a TS)
Weather. Humid, windy, front, clouds formed already.
Frontal cells will form up around the front. (yeah obvious. It pays to know what front (warm or cold) as to when they'll form.
Air mass. Usually in the arvo, peaking around 2-4pm. Usually dissipates at night unless very tall.
Monsoonal. Big version of the above. Can get them at any time of the day. Less chance in the morning but don't bet on it.
So, when flying around and there's no thunderies forecast, note where the Cu is forming any way. Odds on there's something lifting the air and kicking off the cu. If the conditions are right then it's a really good bet that there's where the TS will form up. This is especially true for air mass sparklers.
The books are great but it's useful to watch what's going on around you and pay attention to the weather report on tv.
