4:06PM
As a splendid summer day comes to an end, we look ahead to the 4th of July holiday tomorrow, and what the weather will bring. Will outdoor plans get messed up? Will fireworks displays go off as scheduled? Though the exact answer to these questions is not answerable yet for every location, the general answer is that outdoor plans will not get messed up too much and that fireworks displays will be a go in just about every location. This is based on the timing of both a warm front crossing the region in the morning and a cold front arriving in the evening, and the weather in between the 2 fronts…
As the sun sinks in the western sky this Tuesday evening you will notice some high clouds out there. This is the leading edge of a warm front that will move across New England from west to east during the Wednesday morning hours. A complex of showers and thunderstorms will be associated with this warm front, and may be quite strong as it approaches the area from the west. My feeling is that the area overall will be weakening as it arrives near or shortly after dawn. It may still be strong enough to bring a threatening sky, some gusty wind, and a round of showers and storms with possible heavy rain. This should then exit west to east by mid morning, and the sky will brighten as clouds break behind it. The key to any afternoon and evening thunderstorms is how much sun occurs between the passage of the warm front in the morning and the arrival of the cold front in the evening. I suspect plenty of sun to the west, over western New England and New York, will ignite a line or 2 of showers and thunderstorms during the afternoon. Some other isolated showers and storms may pop up further east in parts of central and eastern MA, and southern NH, and even RI, but I don’t expect any of these to organize into large areas or linger over any location for very long. Previous experience tells me that lines of storms from the west in this set up will eventually take an east southeast route from western MA across CT and RI. If this is the case, the main activity would miss the Boston area. Also, any storms that do make it into eastern MA may weaken as this area may not have enough sun to become very unstable during the afternoon. One thing is for sure, it will turn warm and rather humid during the day on Wednesday, but highest temperatures should be in the middle to possibly upper 80s, at least below the 90+ readings that would make a humid day very difficult to be outside in.
When we get to Wednesday night, I think any activity that is going on will be moving out by 9PM, in time for most fireworks displays. The rest of the night should be fairly quiet but warm and still on the humid side. It will take until Thursday morning for drier air to work in enough to be felt.
Thursday will be a great summer day as high pressure dominates with warm, drier air. This high pressure area will slide offshore into the western Atlantic Friday and Saturday, allowing heat and eventually humidity back into the region. An approaching cold front later Saturday may set off some thunderstorms, but the timing of this system many days away is uncertain. The front may slow down and keep Saturday storm-free, but make Sunday unsettled. Time will tell. Early next week looks seasonable and dry.
Forecast for eastern MA, RI, and southern NH…
TONIGHT: Clouds increase west to east. Lows 62-67. Wind SW to S under 10 MPH.
WEDNESDAY – INDEPENDENCE DAY: Mostly cloudy in the morning with showers and thunderstorms crossing the region from west to east. Briefly gusty winds and briefly heavy rain may occur anywhere. Partly cloudy from midday through most of the afternoon with only a slight risk of an isolated shower or thunderstorm in a few locations. Variably cloudy late day/evening with another risk of showers and thunderstorms, favoring areas southwest and south of Boston. More humid. Highs in the 80s, some upper 70s Cape Cod and Islands. Wind S 5-15 MPH.
WEDNESDAY NIGHT: Any showers and storms ending early, then partly cloudy. Evening temperatures hanging in the 70s then overnight lows in the 60s. Humid. Wind variable around 10 MPH shifting to N.
THURSDAY: Mostly sunny. Highs 83-88, closer to 80 parts of Cape Cod and Islands and any north-facing coastal areas. Wind N 5-15 MPH.
FRIDAY: Partly cloudy. Low 68. High 89.
SATURDAY: Hazy sunshine. Low 71. High 94.
SUNDAY: Variably cloudy. Chance of showers and thunderstorms. Low 73. High 86.
MONDAY: Sunny. Low 60. High 80.
TUESDAY: Partly cloudy. Low 60. High 84.