I've finally found the source of the lightning strike map for South America: http://wwlln.net/new/map/
To get the data, Windy's ADM need to get contact to:
Prof Robert Holzworth, Earth and Space Sciences, University of Washington
(WWLLN Data available: WWLLN Monthly CDs containing all stroke locations over the whole world for 1 month. Those are mailed to subscribers each month, or they may opt to download the data weekly. Archival data are available for sale from August 15, 2004 to the present. Our site hosts receive a free monthly subscription.
WWLLN Data are available via internet with cadence every 10 minutes for research purposes from the University of Washington, or with a cadence of as fast as every minute (i.e. in realtime) from our commercial reseller. Contact Prof. Holzworth for more info.)