You might take a look at the Australian Bureau of Meteorology site on Indigenous Weather Knowledge at http://www.bom.gov.au/iwk/

I've heard stories from stream gaging technicians in New Guinea about local people knowing that increases in streamflow were about to happen. 

The key here is similar to multisensor precip estimation. How and to what extent can certain information add to the quality rainfall prediction.

I would suggest that there might be many local knowledge systems that could be useful in specific locations rather than a single universal system.