Drought in the Yucatan among the Maya started about 800 AD. It corresponds with the medieval warm in northern europe that started at the same time. Whereas the medieval warm caused a population explosion among the vikings and sent their population all over europe and russia—the same medieval warm caused drought in central america and population collapse.
In the mississipi valley there was a period of lessened rainfall that enabled indians from the plains to settle on some of the richest farmlands in north america in southeast illinios where they built the earth pyramids there.
The climate became colder and wetter starting in the 1300’s. The jungles grew over the mayan homelands. The vikings were forced out of greenland. The cahokia pyramid builders were flooded out.
The southwest at this time experienced drought—according to the article. So I’m not sure how that fits.
/bingo