The winter is usualy dry here, but not enough dry; there's a lot of 'garoa'!!! I use the plastic over the 'sombrite' to keep some orchids completely dry from May to August: Stans lietzei and wardii (a foreign species), Coelogyne cristata and Angulocaste; w/o this 'transitory' protection against humidity they never bloom!
Undergrounder, according to Dr Jenny, Stan embreei comes from western slopes of Ecuador Andean region, and grows without dry resting period, weather is hot and humidy all over the year (mine didn't bloomed yet). Stans tigrina and tigrina var. nigroviolacea for sure don't need dry resting period, mines grow and bloom without difficulties outside (but I'm in a tropical region!; curiously, if I grow lietzei - a native Stan! - outside, without care to cover with plastic in the winter, lietzei doesn't bloom, and tigrinas - mexicans! - bloom easily!