Context / technology level:
- I have a more-or-less Age of Sail airship. It is not intended to be entirely self-sufficient, but it should be able to make long trips with small stops to restock/repair; analogous to a naval sailship.
- There is magic which allows it to overcome the problem of an airship being unable to move relative to the wind.
- The same magic also enables the sailing airship to reasonably control its altitude without routinely jettisoning ballast or lifting gas.
- There is a fantastical material available to use for the gasbags; greatly reducing passive leakage and allowing one fill of lifting gas to last a long time.
- The magic and the fantastical material do not make the ship itself sturdier against weather or other causes of damage.
Motivation for the question:
Given the technological context, it seems to me that the limiting factor for such a vessel's range between stops would be drinking water. The range could therefore be (significantly?) extended if the ship were able to collect water from rain or clouds while in-flight. It is mentioned in passing on Wikipedia that collecting rainwater in an airship is/was done as a redundant buoyancy compensation system. While I haven't (yet) been able to find detailed information about the setup of the system, it's enough for now to take it for granted that it's possible.
However, it seems to be common knowledge that airships are highly vulnerable to bad weather (expressed clearly in this answer), and just steering for the nearest cloud to harvest rain from it might not always be a good idea.
Given that my Age-of-Sail airship will not have weather information updates by radio, and will be relying primarily on visual observation and instruments that give temperature, air pressure and altitude, how can it best determine which weather formations are safe for water collection?
In your answer, please specify, to the best of your ability:
- Types of weather formations that ought to be avoided, and why they are a threat (what might go wrong if we entered them?).
- Types of weather formations that ought to be useful for rain collection, and why you are convinced they are safe.
- Enough context or scientific terminology that I will be able to research your indicated weather formations to identify where and when one can expect them to form.