Hi, guys!<br/><br/>In the following sentence, I don't know the meaning of "what with that".<br/><br/>“It was growing darker every minute and what with that and the snowflakes swirling all round him he could hardly see three feet”<br/><br/>I guess it is almost same with 'moreover', 'furthermore', or 'in addition' etc. but I'm not sure.<br/><br/>Please explain to me what it means.<br/>Thank you.