A frontal boundary lurking to our south will lift northward over the next 24 hours, assisted by a couple of waves of low pressure, and bring us a good shot at some rain between Wednesday afternoon and Thursday afternoon.
A combination of factors – including deep tropical moisture, winds converging at the surface and strong winds aloft – will yield pockets of very heavy rainfall over parts of Southern New England. I wouldn’t be surprised to see some spots in eastern Connecticut, Rhode Island and Massachusetts pick up over 4 inches of rain.
Here on the Cape we should manage our fair share of rainfall as well, with a good soaking 1 inch or so expected as an average Cape-wide total. Some spots (most likely the Upper Cape?) could pick up closer to 2 inches of rain.
There will also be enough instability around to support some lightning and thunder at times and there is actually a low threat for a brief waterspout or weak tornado across the region.