This evening rain will continue to work in from south to north along the eastern half of New England as temperatures remain on the mild side with lows near 60 closest to the coast, 50s west. A Flood Warning has been posted for the Cape and Islands as persistent rainfall is expected through this evening, on top of the 3-4” of rain that has already fallen there. Now Maine is included in the flood threat as a Flash Flood Watch has been posted for Downeast Maine, including east central areas farther inland, through Thursday afternoon, as 3-4” of rainfall is expected.
The reason for so much rainfall closest to the coastline from the Outer Cape to Downeast Maine is the fact that the front that swept across the region (from west to east) yesterday, met up with the Jetstream, an atmospheric river of strong winds in the upper atmosphere that drives our weather systems, and that front has now stalled over New England, tapping into a line of moisture that stretches down to just off the North Carolina coastline. Plus, a low pressure has developed along this front, which will wrap the rain around by Thursday afternoon, allowing for even more rain with a few embedded downpours, region-wide.
The system finally moves northward and out of the area, and Friday brings a break in the rain. Both Friday and Saturday will be dry, but the next system will be brewing out towards the Midwest and will sweep in by Sunday afternoon west and continue to slide eastward through Sunday evening and lasting into Monday with an additional 1-3” of rain.
Thankfully, this next system slides out before Halloween, but temperatures will be slightly cooler for those trick-or-treaters on Tuesday with highs into the 50s, so it will finally feel like the end of October!
As always, you can get the latest alerts and updates on-the-go with the NBC Boston / NECN app.