Nature is highly sensitive and can tell the observant of an impending event.
Apollo (Celtic equivalent is Belenus) was the patron of prophets and soothsayers. These prophets were experts in revealing the invisible. Although they used theater to spice up the occasion, they were no tricksters, since such people would have been rejected by the peoples they served. In human affairs, like chess, there are certain known outcomes from a move or given pattern, thus an educated guess on which way a matter may turn, or could be better dealt with often proved right.
In non-human matters there was a need to know if a harvest would be good, if nature favoured certain outcomes. The prophet looked to nature to show them signs. Again, patterns in nature can reveal outcomes later on, for instance I have noted in the last few years how spring flowers in Colchester can emerge in a range of February to May depending upon what happens in the winter, and how this impacts what fruits do well in the late summer and early autumn.
Amongst the Basque is the following of ancient giants:
“Perhaps it was because the basajauns admired the humans for their great cleverness that they used to give the shepherds warning of a coming storm by whistling.”
The Basque suffer many storms that gather in the Bay of Biscay, and perhaps an observation of the natural landscape of a whistling sound indicated such a storm coming.
There is a Basque pony called a Pottok that exists in the mountains, that is able to sense coming bad weather, as they move to the valleys before bad weather, and upland when high pressure builds. A Pottok could probably tell the weather better than any British weather man.