It is one of those days where it depends upon where you are. There are plenty of people on vacation on the Cape & islands. I am afraid today is just one of those days…as the clouds are locked in and here to stay. We will even have to watch for the risk of more showers with embedded thunder approaching during the mid-late afternoon. The unsettled weather will keep temps cooler in the Lwr-mid 70’s for the Cape, 75-80 for SE MA, including the South Shore, who should remain in the clouds for much of the day as well. Meanwhile, If you head Northwest of Boston, it is a great day as the sun is out and temps will again be warming into the Lwr-mid 80’s with partly sunny skies with warm and humid conditions.
The set up remains the same yet there some slight changes. A slow moving cold front to our west will slowly sag into New England this afternoon, where it will stall over us for Monday-Tuesday. This front may trigger a few showers or thunderstorms in the North and West during the mid-late afternoon. There could be a few brief pulse downpours like yesterday. Also, Upper level winds around the base of a trough, firmly implanted over the Great Lakes, are from the SW and have been steering a plume of moisture up the east coast…which has mostly remained offshore this weekend. A high in the western Atlantic is starting to slide south and push this river of tropical moisture closer to the coast. Heavy downpours appear to be tracking to the Cape and Islands. They will likely remain offshore for most of the day, but by mid late afternoon, I would not be surprised to see some of these showers arriving at the south coast. This will not be fun for those looking for a break in the weather along the south coast. In fact, any downpours will be salt in the wound for those desperate for sun.
The upper level trough will continue to be pushed back westward by the Atlantic high through tomorrow, so this river of tropical downpours will ride right up along this stalled front and produce locally heavy rain and embedded thunderstorms, starting late tonight and last into Tuesday. The deep trough is tapping into moisture from the Gulf and directing it right up into New England for Monday Tuesday, so any downpours will come with heavy rain which could produce a quick 1 or 2 of rain and the potential for more localized flash flooding in any downpours. The trend will be for the risk of thunderstorms to be shifting into the NW by Tuesday…with less of a chance along the coast by that time.
It is a wet humid look which will be in place for the entire east coast as this trough will continue to weaken and pushed back farther inland. Eventually by midweek, the river of tropical moisture will have shifted just wet of us, that we will start to see more ridging with a lessening chance of thunderstorms with each passing day. Warm humid air with increasing sunshine and southerly winds wrapping around the building high offshore will help to push temps into the mid to upper 80’s near 90 to end the week. So while the rain will be less…the humidity will remain. Maybe sometime around July 9th front will push through and give us a little break from the muggy weather. Have a great day…no matter the weather!