noun, plural neph·a·nal·y·ses [nef-uh-nal-uh-seez] /ˌnɛf əˈnæl əˌsiz/.

a map or chart showing the distribution of types and amounts of clouds and precipitation at a given time.
the preparation of such a map or chart.

Origin of nephanalysis

First recorded in 1940–45; neph- + analysis Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019