DAYS 1-5 (JULY 16-20)
“The heat pump” aka the Bermuda high keeps on going for a couple more days, giving us hot and humid weather through Wednesday. Today’s thunderstorm threat sets up differently than yesterday’s, with fairly quiet weather through the afternoon – minimal chance of a pop-up storm – with most activity forming out in NY State and charging toward New England, but arriving as weakening showers and possible leftover thunderstorms in the WHW forecast area from west to east during the course of this evening. The speed of the activity will determine how far east it survives before dissipating, but in general many areas will end up seeing little or no activity, with the greatest chance of seeing “something” the further northwest you are in the region. We do it again tomorrow with storm threats, but this time the timing is potentially earlier with a pre-frontal trough ahead of an approaching cold front, so thunderstorm chances go up by mid afternoon and continue into evening / night from west to east. There are still details to be figured out for this, so check tomorrow’s update for sure! The front will be a little sluggish to make it all the way through the region, so Thursday morning carries a shower and potential thunderstorm chance at least near the South Coast up to the South Shore of MA into the morning, otherwise look for a transition day to cooler and less humid air from Canada. Friday and Saturday we’ll get the benefit of this air mass as high pressure dominates with seasonable and dry weather – perfect for summer outdoor activities (don’t forget your sun screen!).
TODAY: Any early fog patches dissipate. Sun and patchy clouds. Highs 90-97 except 83-90 South Coast and 76-83 Cape Cod. Dew point upper 60s to middle 70s. Wind SW 5-15 MPH.
TONIGHT: Variably cloudy evening with a shower or thunderstorm possible especially northwest of Boston. Partly to mostly clear overnight but patchy fog forms in lower elevations. Lows 68-75, warmest urban areas. Dew point upper 60s to lower 70s. Wind SW up to 10 MPH.
WEDNESDAY: Partly sunny. Potential afternoon thunderstorms. Highs 88-95, except cooler South Coast. Dew point 70+. Wind SW 10-20 MPH, but can be stronger and variable around any storms.
WEDNESDAY NIGHT: Mostly cloudy. Showers and thunderstorms likely. Areas of fog. Lows 70-77. Dew point 70+. Wind SW to variable up to 10 MPH but can be stronger and variable around any storms.
THURSDAY: Variably cloudy. Chance of showers and thunderstorms, favoring the morning and the MA South Shore to South Coast. Highs 80-87. Dew point lowering into/through 60s. Wind variable to NW 5-15 MPH.
THURSDAY NIGHT: Clearing. Patchy interior lower elevation ground fog. Lows 56-63. Dew point middle to upper 50s. Wind NW up to 10 MPH.
FRIDAY: Sunny – few fair weather clouds. Highs 81-88, but a little cooler in some coastal areas. Dew point middle to upper 50s. Wind variable up to 10 MPH with coastal sea breezes.
FRIDAY NIGHT: Clear. Lows 57-64. Dew point lower to middle 50s. Wind variable under 10 MPH.
SATURDAY: Mostly sunny. Highs 81-88, a bit cooler though in some coastal areas. Dew point middle to upper 50s. Wind variable up to 10 MPH with coastal sea breezes.
DAYS 6-10 (JULY 21-25)
High pressure slides offshore allowing an increase in humidity but still mainly fair weather early in the period. A nearby frontal boundary brings a better chance of showers / thunderstorms mid to late period.
DAYS 11-15 (JULY 26-30)
A push of drier air early period then humidity returns again with a few showers / storms possible. No prolonged major heat.