Barometric Pressure and the running of sap

[Cindee]

I have been keeping a spreadsheet including the barometric pressure. The last 3 collections the pressure was anywhere from 29.7 to 29.9 and we have full bags. But we also at the same time had crappy weather, snow, sleet, rain, wind. Temps were mid 30's to 40's. Can someone explain if the barometric pressure whether rising or falling will indicate a good run that day as long as the temp is above freezing during the day.

[happy thoughts]

I don't know if low pressure can be used to indicate a good run but it can definitely increase sap flow and indicate a potential for one. Low pressure is usually associated with crappy weather. Sap flow depends in part on pressure gradients, higher pressure inside the trees in relation to air pressure outside the trees causes sap to flow from an area of high pressure to low.