What´s the deep meaning of this sentence?
Note it is probably Tempestati parendum (without the space before ti). Literally it means: The weather/season/storm must be obeyed. The grammatical construction (gerund+dative) is similar to an example given in A&G:
Lēgibus pārendum est. The laws must be obeyed.
It is hard to comment on "deep meaning" of this motto, as this can be adapted for slightly different usages; the context is important. At any case a natural interpretation is that one should yield to higher powers and not to fight them.
In Speculum Imaginum Veritatis Occultae it indeed seems to be the suggested meaning:
Id est, voluntati divinae parendum, et fortunae nimis iniquae concedendum. (we must obey to the divine will, and yield to the exceedingly-unjust fortune.)