Significant Weather Weekly Outlook
Periods of Heavy Rain Through Tuesday Possible South of the Mass Pike
Today through Tuesday
A series of weak but moisture laden low pressure centers will pass just south of New England through Tuesday. Weak surface high pressure to the north has helped create a boundary between cooler and much warmer, more humid air in the vicinity of or a little south of the New England south coast. Periods of rain are likely throughout southern New England with the potential for periods of heavy rain, especially across CT and RI and portions of southeast MA. The National Weather Service has issued a Flood Watch across CT, RI, and southeast MA. On the larger, synoptic scale, this is a classic overrunning pattern that produces widespread precipitation across southern New England as warmer, moist air overruns a cooler, denser air mass. During the winter, this would probably yield a widespread moderate precipitation event (rain or snow depending upon temperature). At this time of year, small mesoscale features combined with much higher moisture content will likely set the stage for bands of heavy/very heavy rain embedded in the widespread light to moderate rain shield. Various global and higher resolution regional models depict highly variable rainfall distribution based on varying locations of the heavier rain bands. Even the higher resolution models struggle in the placement of these heavier rain bands. There does seem to be a consensus, however, of the heavier rain falling across CT and RI and then protruding into southeast MA. This is where the NWS has issued the Flood Watch.
It looks as though a series of weak low pressure centers will pass along the boundary just south of New England with the final low pressure wave being the strongest on Tuesday – eventually heading out to sea by Tuesday evening. A low-level moist jet from the southeast and east may be focusing mechanism for some of the heavier rainfall especially over upslope areas of CT, RI, and even portions of the southern Berkshires and Worcester Hills. Further east, the lack of terrain means no upslope of consequence, but something of a coastal front (as moist air from the E or ESE converges through friction just back from the coast) and thus providing another area of possible enhanced rainfall.
The timing of heaviest rain looks to be this afternoon and tonight in CT and late tonight through much of Tuesday in RI and southeast MA.
Total rainfall today through Tuesday looks to be generally 1 to 3 inches along and south of the Mass Pike with possibly one or multiple swaths of more localized 3 to 6 inches of rain across CT, RI, and southeast MA. Localized flooding of urban areas and poor drainage areas are possible especially across CT, RI, and southeast MA. Also, prior rainfall this past weekend across much of CT and RI has resulted in more moist ground conditions to start with. Across much of central and southern CT and southern RI, flash flood guidance indicates the potential for flooding if 3 or more inches of rain should fall in six hours. North of the Mass Pike, lighter amounts of around an inch or less appear likely, although a few models depict locally heavier amounts even in this area. Thus, rain is essentially assured across our region, but there is much less certainty on the location of the more localized heavier rain bands.
Rest of the Week
As far as the rest of the week, warmer temperatures and higher humidity are expected the second half of the week but not to the extent of the extreme heat and humidity of last week. A cold front may help set off scattered showers and thunderstorms Friday afternoon/evening.
Next Message
Will update this blog if the risk of flooding or flash flooding should increase for any portions of southern New England. Otherwise, the next significant weather weekly outlook is scheduled for Monday July 13.
About this Blog and Disclaimer
The National Weather Service monitors the weather 24/7 and updates forecasts, watches, and warnings as necessary. For most of southern New England, refer to your local Weather Forecast Office for the latest forecast/warning information at weather.gov/box. For information from other Weather Forecast Offices, go to weather.gov and click on the location of interest on the map.
The frequency of this blog will depend upon the nature of the weather threat and availability of the author. Thus, for the latest information on weather forecasts and warnings, refer to the National Weather Service, which monitors and forecasts the weather 24/7.
Blue Hill Observatory and Science Center (BHOSC)
The BHOSC maintains a continuous daily observation record that dates from February 1, 1885 without interruption and provides educational information on weather and climate to area students and the community at large. Your support of BHOSC is much appreciated and enables this nonprofit organization to maintain the long-term climate record at the Blue Hill Observatory (longest continuous record in North America) and provide valuable educational resources on weather and climate via outreach to schools, site visits/tours, webinars, and conferences. For more information on the Blue Hill Observatory and Science Center, explore bluehill.org.
Message issued July 6, 2026 by:
Bob Thompson
Retired National Weather Service Meteorologist
Blue Hill Observatory and Science Center Board member
