DAYS 1-5 (JULY 6-10)
An area of high pressure slides offshore today while aloft the wind blows moderately from the northwest. Your Sunday starts off with moderate humidity and sunshine filtered by high clouds moving through in the aforementioned upper level flow. These high clouds thin out allowing brighter sun, while the offshore high starts to deliver higher dew point air to the region and the temperature heats up as the day goes on, turning what was a comfortable morning into a much less comfortable ending to the day. At least there is zero rain chance, making it a clean sweep of three rain-free days for the holiday weekend. Things are about to change, however. During Monday, high pressure sits offshore to our southeast, continuing to deliver high dew point air. Meanwhile, low pressure moving through the Great Lakes into the St. Lawrence Valley will begin to push a cold front our way. Additionally, tropical moisture from the remains of Chantal (a tropical storm coming ashore this morning in northern South Carolina) will be heading northeastward around the periphery of offshore high pressure. The increase in low level moisture combined with the fact we’ll still be in a fairly hot air mass will lead to the development of tropical showers of the isolated to scattered variety, perhaps a non-severe isolated thunderstorm or two in the region s well during Monday afternoon and early evening. However, these should fade / dissipate with the setting sun Monday evening. Tuesday will be a more unsettled day with more cloud cover, less heat (still fairly warm), high humidity, and much better shower / t-storm chances. Expect a ribbon of moisture associated with the remains of Chantal to bring some heavier showers and potential thunderstorms to southeastern areas of the WHW forecast area, particularly eastern CT, RI, and mostly east of I-95 in MA during Tuesday morning over a period of a few to several hours. This should be followed by a pause, then additional showers and thunderstorms anywhere in the region, but starting to the west and north and moving to the south and east with time, as the cold front moves across the region. This front should get far enough to the southeast to bring this activity to an end by early Wednesday morning after lingering into Tuesday night. The daytime hours of Wednesday look dry, mild, and moderately humid as a very small and weak area of high pressure noses in from the Gulf of Maine. As we head into midweek, the jet stream to our north will sink a little to the south, establishing a weak zonal flow pattern aloft. During this time, the next trough / disturbance will approach from the west, and it looks like a surface low pressure wave will travel along a frontal boundary still to our south, held there by high pressure in eastern Canada. This would be a mainly cloudy, occasionally wet, and cooler set up here for Thursday.
TODAY: Sun filtered by high clouds morning / brighter sun afternoon hours. Highs 88-95 except 80-87 South Coast and 73-80 Cape Cod and the Islands. Dew point rises through 60s. Wind SW 5-15 MPH.
TONIGHT: Mostly clear. Fog patches in low elevations. Lows 68-75, warmest in urban centers. Dew point upper 60s to lower 70s. Wind SW up to 10 MPH.
MONDAY: Partly sunny. Isolated afternoon showers and thunderstorms. Highs 86-93 except 78-85 South Coast. Dew point 70+. Wind SW 5-15 MPH gusts 20-25 MPH.
MONDAY NIGHT: Variably cloudy. Any early isolated showers dissipate. Shower/thunderstorm chances increases especially east of I-95 overnight. Lows 71-78. Dew point near 70. Wind SW 5-15 MPH becoming variable up to 10 MPH.
TUESDAY: Variably cloudy. Showers and thunderstorms likely, favoring eastern CT, RI, and southeastern MA early, then redeveloping from northwest to southeast midday through afternoon. Highs 78-85. Dew point 70+. Wind variable 5-15 MPH.
TUESDAY NIGHT: Variably cloudy. Patchy fog. A shower or thunderstorm possible. Lows 66-73. Dew point middle to upper 60s. Wind variable up to 10 MPH.
WEDNESDAY: Partly sunny. Chance of a shower early in the day, favoring eastern areas. Highs 76-83, coolest coast. Dew point 60+. Wind variable to E up to 10 MPH.
WEDNESDAY NIGHT: Partly cloudy. Patchy fog. Lows 61-68. Dew point 60+. Wind E up to 10 MPH.
THURSDAY: Mostly cloudy. Showers likely. Chance of thunderstorms. Highs 72-79. Dew point in 60s. Wind E 5-15 MPH.
DAYS 6-10 (JULY 11-15)
Continued easterly air flow and unsettled weather with shower chances July 11, then a transition to fair weather over the July 12-13 weekend (still a shower / t-storm chance July 12) with slightly warmer and humid weather. Watching another potential disturbance to the south to bring mild, high humidity, unsettled weather to the region early next week.
DAYS 11-15 (JULY 16-20)
Heading through the remainder of mid July the strongest indications are for a pattern favoring a weak jet stream near or just north of the region, surface high pressure dominant in eastern Canada and low pressure dominant to our south. This leaves the region vulnerable to unsettled weather at times but without sustained major heat being a threat.