It’s a soaker today especially north and west of Boston where the heaviest rain should fall. Drenching downpours will yield some sudden flooding in poor drainage locations and that is precisely why the National Weather Service has issued a Flash Flood Watch and a Flood Advisory for these areas. While localized intense showers will produce higher totals, the general potential rainfall will range from 2-3″ across parts of northern New England ranging down to 1-2″ mainly north and west of Boston into southeastern NH with an inch or so along the MA Pike into northern CT and northwestern RI with amounts tapering off to under a half inch farther down into southeastern MA and only a quarter to half inch on most of Cape Cod. With minimal instability expected thanks largely to an absence of sunshine, the threat of a widespread outbreak of severe weather, thankfully, is highly unlikely. However, the presence of a low level jet generating some stronger winds just above the surface suggests that a few downpours could transport some strong gusts to the ground. A few of these could be damaging. There is some wind shear so a few isolated brief rotation signatures may be revealed by the radar but, hopefully, they will not turn into any unnecessary tornado warnings! IMO, plain rain is just fine without all of the bells and whistles! Earlier this morning, there was frequent lightning in many cells that were crossing ME. With the present atmospheric setup, additional cells containing nasty cloud to ground lightning bolts are probable anytime the rest of the day. The humidity is on the threshold of being considered oppressive with the dewpoints hovering over or slightly exceeding 70 degrees. This is one of those days when the temperature fails to rise more than a half dozen degrees. Contrast that to last Monday’s delta T of up to 32 degrees in many places due to the very dry, cool air early in the day and a nice warm air mass overhead with 100% sunshine.
An approaching cold front will shift southeastward across NY and New England as the day progresses. For the concert attendees, there is still a risk of spotty lingering showers near the Comcast Center in Mansfield the first part of the evening. The broken shield of showers and storms will be pushed out of the region from northwest to southeast late in the day opening the doors for more comfortable air to seep and flow into the region. A zone of high pressure will build eastward from the Great Lakes so we will transition from soaking weather to splendid weather. It will be an awesome August weekend with dry air and ample sunshine. Expect highs of 84-88 tomorrow and 79-82 on Sunday. It should be decent from the summits of northern New England through the Lakes Region up north and across all of southern New England to the seashore and out over the ocean. There will be a few patches of clouds mainly tomorrow afternoon especially over the mountains. For beach and boating activities, it will be a wonderful weekend with high tides between 2 and 3 pm and low tides from 8-9 am and pm. The sea temperatures at the coastline should be a bit warmer than earlier this week and there might be some leftover small swells from the larger wind waves generated today by the storms. Us body and board surfers are craving for some decent breakers. The wind will be up to 10-20 knots from the north west to west tomorrow then a lighter wind from the west-southwest might become south to southeasterly on Sunday. It should be a fantastic weekend for hiking and climbing up the in the mountains with even drier air up there. It will be ideal for the great Falmouth Road Race on Sunday morning with a race time temperature around 73 degrees and a dewpoint around 54 degrees under a sunny to partly cloudy sky and a light south wind of 5-10 mph.
Looking ahead, it will still be comfortably dry on Monday with sunshine amidst some patchy cloudiness. After that, the next frontal boundary and upper level trough of low pressure will generate additional rounds of showers and storms on Tuesday especially in the afternoon. Beyond that, a healthier high pressure center will build in to provide some delightful conditions the second half of next week. Initially, however, residual instability will likely lead to varying amounts of clouds and perhaps a few spotty showers Wednesday especially over the hills and mountains with highs in the upper 70s. Thursday will be sunny and a bit cooler with highs in the middle 70s followed by a sunny and slightly milder Friday up to the middle to upper 70s.
Don’t forget the Perseid Meteor Shower this weekend. It actually peaks Sunday night/ early Monday morning with the potential of seeing 40-60 so-called shooting stars. The stars are actually a trail of dust particles that the Earth passes through each year that were left behind by the passage of Comet Swift-Tuttle. Click the link for more info. Unlike some years when August has thick haze and some fog or showers, the timing will be perfect this time around as we enjoy a clear sky with great visibility and no moonlight in the 10pm-4am best viewing period.
Joe Joyce posts his blog early this evening and I shall return early tomorrow morning.
Have a happy and safe weekend.