SoAmer_06HR_Dec_2014
--December is the first month of meteorological summer in the Southern Hemisphere. --Most lightning over land is during the day. --The Andes provide a sharp western boundary in a generally NNW-SSE line. --No lightning occurs over the cold water offshore of the Andes. --The equatorial trough, also called the Intertropical Convergence Zone, is well defined just north of the equator over the Atlantic Ocean during much of the month. --At higher latitudes to the south, storms generally move from WSW to ENE. --Almost no lightning occurs over the SE Pacific and South Atlantic except storms that move offshore from South America. --Over interior regions of the Amazon basin, thunderstorms have slow movement, tending to be from the ENE, but change from day to day due to interactions within the storms. --In the southern portion of the continent, clearing of lightning is apparent from south to north as cold fronts and attendant dry sinking air arrives to minimize lightning. ~Ron Holle
Jan 2, 2015 Webmaster Archive
--07 to 11 December: Two active lines of thunderstorms move SW to NE over Argentina, most likely associated with cold fronts. --23 to 24 December: Clearing of thunderstorms from S to N over Argentina reaches farther north than at any other time of the month. ~Ron Holle
Jan 12, 2015 8:16:28 PM Dave Fincher