Mark Twain once said about the vagaries of spring, “I have counted 136 different kinds of weather inside of 24 hours.”

He could have been talking about 2019, particularly in the Northeast, where the weather over the last week or so has toggled from damp and chilly to briefly seasonal and sunny and back to wet and cold, with the possibility of snow Monday night in parts of New England.

What is putting a crimp on spring, which officially started back on March 20, and standing in the way of such seasonal delights as planting a garden and firing up the backyard barbecue?

The culprit is a convergence of soaking wet weather from the South and West and cold air gliding in from Canada, according to Marc Chenard, a meteorologist at the National Weather Service.