Holiday weekends in New England = Murphy’s Law. Hard pressed to remember many that are just pleasant for several straight days with no weather fanfare. This 4th of July Weekend will try, but we’ll be dodging a few storms and tracking hot and humid conditions at times. Typical of summertime, not everyone will see the same outcomes. Storms favor certain areas more than others, and temperatures heat up in some places more than others. So here’s a day by day and region by region breakdown of the days ahead!
The Main Headlines:
In general, we’re looking at a classic hot and humid summer stretch for what’s the start of the hottest time of the year. In fact, Boston’s all-time highest temperature on record of 104 degrees was set on the 4th of July! Temperatures will be in the mid 80s to low 90s for most, Friday right on through Tuesday. So pool and beach plans are looking appropriate. An official heat wave may be reached in areas around Metro Boston (3 straight days of highs 90+) from Friday through Sunday, and possibly into Monday.
Humidity peaks Saturday with dew points near 70F, with just slightly less humid conditions Friday and Sunday. The whole stretch also features southwest winds, which means your ‘cool relief’ spots will be along the South Coast with highs in the 70s to mid 80s.
The Biggest ‘Concern’ Area:
If your plans take you up to northern New England to do some camping or boating, then you’ll want to keep a close eye on the weather. Rounds of storms should be firing up Thursday PM, Friday, Saturday, AND Sunday in this area. None of the days will feature rain all day long, and you’ll get periods of sunshine to enjoy. But the continuous threat of downpours and storms could really add up over time.
A northwest-west flow aloft will help to push rounds of repeated storms across northern New England starting on Thursday and lingering into Sunday morning.
As you can see, June has been a very wet month. Some spots have received over 5″ of rain, so the ground is already pretty wet and rivers are flowing at higher than usual levels for summer. When trying to figure out a flash flood risk, this is an important factor to take into consideration. Any summertime storm can easily put down a quick 1-3″ of rain, which also means several days of storms could lead to some isolated 3-6″ rain totals where places are hit by multiple rounds. Now you’re talking 8-12″ of rain during the course of a month, and across rocky northern New England that can easily cause problems.
Flash flood guidance shows that Vermont is most prone to flooding at the moment, with only 2-3″ over a 6 hour period needed for some rivers and streams to come out of their banks. This is also where the highest storm risk is Thursday through Saturday, and so this is where campers in particular should be most vigilant. I wouldn’t rule out a localized flash flooding risk in the White Mountains region of New Hampshire, either. So please take extra care in monitoring the weather and plan accordingly if you’re spending the holiday in these spots!
Area Of Least Concern:
Good news for beach bums – it’s the Cape and the Islands! Summer storms often thrive across the interior but wilt as they approach the bridge. Much like the morale of a weary traveler after hours of traffic. Why? A southwest wind is the popular direction of choice this time of year, which brings in cooler and more stable air off the ocean. Storms that are driven by surface instability don’t do well across southeastern Massachusetts, and that’s what we have going this holiday weekend. There’s a good chance all the action misses the Cape & Islands Friday and Saturday, leading to some great beach weather albeit gusty. Winds should top 20 knots both days, so plenty of wind in the sails for boaters. Plus, you avoid the worst of the heat. Highs will be in the 70s to mid 80s through the weekend (you can’t escape the humidity though!).
If this region gets in on some showers/storms, Sunday is the day as a front crosses the area. Won’t be an all-day thing, but some scattered action may push through. Back to dry and beautiful weather Monday, and 4th of July Tuesday looks fantastic at the moment as well! Looking like a win with a trip to the Combah or local ice cream joint in order.
In The Middle:
Most of the region from central Mass to Metro Boston will live in a forecast between the storms and the sunshine. This will also be the hottest part of the area and feature the best odds of an official heat wave.
For getaway day Friday, we’ll be watching out for scattered strong to severe storms. The areal coverage will probably not be as widespread as this past Tuesday’s storm bonanza, but anything that pops could feature torrential downpours, damaging gusts, and some small hail. Highs will reach the 85-90 degree range.
Saturday looks best for beach and pool time. Bright skies and temps soaring up into the low 90s with humid conditions. Most storms that manage to pop should stay NW of a line from Worcester to Cape Ann. The highest rain risk locally will focus toward the Berkshires.
Sunday brings more cloud cover and a higher chance of scattered storms. If we can get enough sunshine, we’ll have another shot at 90 degrees. At the least, 80s for highs.
Monday into Tuesday both look warm and less humid. A trailing disturbance could bring a few more showers or brief rumbles on Monday, but most of the day looks dry. And Tuesday currently looks fantastic…80s and fairly dry air. The one thing we’ll be monitoring as we get closer is how the flow buckles heading into late Tuesday-Wednesday, and if the chance of storms starts to look higher during that time. Being several days out, we can’t lock in a completely dry forecast through evening fireworks on the 4th just yet.