It was a strange day for sap flow. I turned on the vacuum at 9:30 this morning when the temperature got to 30. There wasn't anything coming in at that time but with the bright sunshine I figured that it would be running soon. I went back at 12:00 when the temperature was at 48 to check it and the sap was barely dripping off of the releaser flap. It seemed like the sap should have been running but it wasn't. I went back down at 3:00 when the temperature was 54 and it was running better than before but not by much. I had about 30 gallons for the day so far. I went back down at 6:00 and the temperature was 50 and in the 3 hours since the last check I had gotten over 200 gallons. The sap was still coming in good when I pumped the tank a half hour later. It's not supposed to freeze tonight and I'm hoping to find a lot of sap in the morning.