A strong cold front will approach the area on Sunday and pass offshore during Monday afternoon. At the same time low pressure will move along this frontal system, quickly intensifying and bringing a burst of wind and rain to the region.
This storm will cross through the area with colder air being dragged down behind it. This transition to colder air will bring snow to northern Vermont, New Hampshire, and parts of western Maine.
There are three elements to this upcoming storm that will impact southern New England. The first is going to be the rain. This will arrive Sunday afternoon from west to east.
By Sunday evening and into early Monday the rain will be coming down heavy at times. There could even be the rumble of thunder as the front passes Monday morning. Notice on the meteogram below the different elements of weather Sunday into Monday.
Most areas will receive anywhere from 1 to 4 inches of rain through Monday, with the heaviest precipitation, around 6 inches, falling in portions of Connecticut and parts of central Massachusetts. This will create street flooding, but I don’t expect much in the way of river issues.
Wind will be another factor during the storm. For people on Cape Cod and the Islands, the winds could gust over 40 miles per hour and as high as 60 miles per hour in some locations. The strongest winds will likely be over Nantucket as the storm passes. Notice on the loop below you can see the forecast wind gust moving over the region, but the highest winds will occur right along the coastline.
Power outages are not out of the question along the coastline from this weather system. The winds will be strongest in the early-morning hours of Sunday until just after sunrise on Monday morning. Away from the coastline, conditions will be blustery, but the winds will not be damaging and power issues are not likely.
A third element of the storm is coastal flooding. The southerly flow of air means minor coastal flooding is possible at the time of high tide on Monday morning. This will not be a major coastal event, but those roads that are more susceptible to flooding could be closed for a short time.
Snowfall will be relegated to Vermont and perhaps parts of far northern New Hampshire and Maine. The map below is based on probability. Because the timing of the changeover will be so important, this is the most likely scenario based on the current data. If the cold air does not arrive in time, these amounts will be less.
The rest of the upcoming week looks dry with plenty of sunshine and seasonable temperatures in the 40s during the day and 20s and 30s at night.