How to forecast the weather in discoloration spring in Zuo Lan county?

Discolored Spring: Discolored Spring is located in Xiang Ding Township, Zuo Lan County, Sichuan Province. Spring water gushed from the deep pit surrounded by lime cliff, forming a sky blue pond with an area of about 50 square meters. Whenever the weather turns from sunny to rainy, the water turns black. Before the rain stopped, the water turned pale yellow, and a day later it turned back to sky blue. Local farmers regard it as a natural weather station for observing sunny and rainy days.