propitious
Meaning: favorable
Usage: The dark storm clouds visible on the horizon suggested that the weather would not be propitious for sailing.
auspicious
Meaning: favorable, indicative of good things
Usage: The tennis player considered the sunny forecast an auspicious sign that she would win her match.
benign
Meaning: favorable, not threatening, mild
Usage: We were all relieved to hear that the medical tests determined her tumor to be benign.