I was also disappointed with how much we pulled in yesterday - granted I'm a much smaller operation than you and much further South. I didn't tap until last week and it sure seems like the season will end quick down by Oneida Lake. 88 taps and I haven't even pulled in 500 gallons of sap yet. Lets hope I break that today.

As far as answering your question I don't have any data, just theories. Saturday and Sunday were cold for us. Saturday had single digit wind chills and Sunday ran about 30 degrees all day. My taps are split pretty evenly between 80-150 year old monsters and a nice 5 acre sugar bush. Friday I pulled in 175 gallons off those 88 taps, yesterday a measly 40 gallons. I thought for sure the cold snap over the weekend would set us up for a good run, but at least down by us, we don't have the snow cover to insulate our ground. It could be as simple as the trees are still froze up, but it was over 45 by us yesterday so you sure wouldn't think so.