Although changing air in New England this weekend is fairly commonplace for early fall in the Northeast, the clashes and collisions of different air will mean some changeable weather. We start with cool, crisp sunshine Friday and an easterly breeze that will keep the coast a bit cooler than interior, but not by much: after all, the ocean water is 65 to 70 degrees! Nonetheless, the large dome of high pressure that brought Friday morning lows in the 30s for all states in New England except Connecticut and Rhode Island will still exert influence overnight Friday night, meaning many low temperatures in the 40s with some 30s in colder valleys. To our west, a storm center moving east across Southern Canada will induce a southerly wind ahead of it, carrying warmer air toward New England for gradually increasing clouds from west to east late Friday night, after most communities enjoy a view of the full Harvest Moon. While some limited sun is probable in the first few hours of Saturday morning for Eastern New England, clouds will take over for one and all with scattered showers developing in Northern New England during the morning and continuing off and on through the afternoon…while Southern and Central New England see a midday or afternoon sprinkle with the higher chance of scattered showers during the late evening and overnight Saturday night as the Canadian storm passes to our north. After early morning showers depart Cape Cod, sunshine returns Sunday, bumping temperatures through the 70s and even into the 80s for some in Eastern and Southern New England. Expect one more disturbance to carry scattered showers through New England late Sunday night and Monday, then most of next week looks great in our exclusive First Alert 10-day forecast, with a cool shot at midweek and warming by week’s end. The only thing we really have to be careful for is when the door to warmth opens at the end of next week, it’s not impossible to open a door the tropics, as well, so if anything is near the Eastern Seaboard, we’d have to be on guard…so we’ll keep close watch, as always.
Showers and rain are accompanied by a northeast wind carrying cooler air southward across New England, meaning predawn high temperature in the 70s steadily fall until some communities land in the 50s by day’s end, for a raw feeling! The rain is steadiest morning through early afternoon, then breaks up considerably into lingering showers Thursday evening, with enough cool and dry air from the north to promote clearing in Northern New England Thursday afternoon into evening, and continue that clearing trend southward through the remainder of New England overnight Thursday night. Friday will dawn with bright sunshine that lasts through the day for classic fall sun: great blue skies and high temperatures in the 60s. Saturday, on the other hand, will bring classic fall clouds – after all, gray sky certainly can be a classic in New England autumn, as well. Saturday’s clouds develop as warmth tries to move back into New England but collides with our preceding cool air, meaning eventually by Sunday our temperatures will respond and warm up but Saturday’s clouds should hold most of us close to or under 70 degrees with scattered showers in Northern and Western New England, then perhaps a few evening and night showers farther south and east. This opens the door to Sunday warmth as sun returns and temperatures climb into the 80s for many! Another disturbance may deliver showers Sunday night and Monday, but thereafter, the door once again opens to warm air as high pressure – fair weather – builds off our coastline, encouraging a southerly wind. The only thing we need to watch during this period – particularly as temperatures warm even more for the end of next week – is the tropics. With an opening to southern warmth, there is the possibility we open the door to the tropics, so anything near the East Coast around the end of next week will need to be monitored.
Wednesday is the warmest day of the week, owing to a busy southwest wind gusting over 30 mph at times, transporting not only the warmth but also noticeable humidity into New England with dew points rising into the 60s – a sure indication of increased moisture. One disturbance aloft delivered a round of morning rain north and showers south, but the departure of that disturbance and its associated clouds will allow for increasing sunshine from lunch hour through the afternoon, which is when temperatures really make the greatest rise. In the warmth and humidity, some scattered showers and thunder will develop during the early evening, not impacting the majority of New England but we’ll all keep an eye to the western and northwestern sky. Variable overnight clouds will be found as the wind shifts to blow from the north and east by dawn, decreasing humidity in the air by sun-up but also carrying increasing clouds into New England skies from north to south by Thursday morning. Clouds will be stubborn Thursday – combined with cool air streaming in and abundant clouds, the temperatures will be as much as 20 degrees cooler than Wednesday for some communities, and a disturbance responsible for a tornado in Sioux Falls, South Dakota, Tuesday night will deliver a period of showers Thursday midday to afternoon here at home. Eventually, drier air clears the sky – first in Northern New England late Thursday, then Southern New England Thursday night, giving way to crisp but abundant fall sunshine Friday with highs only in the 60s to near 70! Our current weather pattern features quick and pronounced changes in air from cool to warm and back again, and each clash of air brings clouds and a chance of showers, so we’ll find increasing clouds and some scattered showers Saturday as warmth attempts a return to New England, likely succeeding for a delightful Sunday near 80 degrees. Although one more disturbance may bring showers Monday, most of next week looks exceptional in our exclusive First Alert 10-day forecast, with mostly dry conditions and comfortable high temperatures in the 70s and 80s.
The theme of the next several days – into the upcoming weekend – will be swings in temperature for New England and the results of that changing air. Keep in mind that changes in air and clashes between warm and cool often result in periods of clouds and showers, and we’ll see that playing out over the next few days. Today is the first of the air clashes we’ll see, as warm air just starts to make progress aloft and that’s already prompted plenty of clouds to develop along with pockets of sprinkles and light showers in Southern New England. Between the clouds and sprinkles, we’ll see breaks of sunshine, too, though it’ll take until later in the day for the sun to make a somewhat stronger stand. Meanwhile, a strengthening storm system across the Canadian border not only will deliver rounds of showers to the North Country Tuesday evening and night, but also will turn New England’s winds from the southwest Tuesday night through Wednesday, ushering in warmth and humidity with temperatures climbing into the 80s Wednesday afternoon and dew point temperatures in the 60s to around 70 meaning a true return to sticky, summery air. As the Canadian storm moves east, it will drag an attendant cold front south across New England later Wednesday into Thursday, prompting scattered showers and thunder from north to south later Wednesday, and even perhaps a renewed shower in Southern New England Thursday morning or midday as the cold front slowly settles south, gradually replacing humidity with another shot of cool, dry, fall air. By Friday, even sunshine won’t be able to bump most communities above either side of 70 in the new, fall air. Of course, this means that when new warmth tries to return this weekend, we’ll once again find periods of clouds possible of dropping some scattered showers, particularly by Saturday afternoon. At some point – probably just after one more round of showers Monday – we start transitioning more squarely into warmer and enjoyable weather that we expect to persist for most of next week in our exclusive First Alert 10-day forecast.
A delightful early fall air is in place for New England as we enter a season that features collapsing daylight, declining temperatures but often truly exceptional weather, as well. Nature will deliver on all of those September expectations in the coming days – from crisp nights and early mornings at the start of the week, to warmth at midweek and chances for the warmth to return this weekend and next week. In the short term, the same dry air that allowed for temperatures to drop so much Monday morning is also making for ample Monday sunshine, with some clouds mixing in at times but no raindrops expected. A light and variable wind will tend toward a sea breeze, and as temperatures cool Monday night, the lingering ocean moisture in the air within about 30 miles of the coast may create some pockets of fog and clouds by Tuesday morning, but those should give way to another blend of sun and clouds with just slightly cooler-than-seasonable temperatures around 70 degrees. A strong disturbance moving through Southern Canada Tuesday into Wednesday will first produce showers in Northern New England Tuesday evening into night, then will encourage a strengthening southwest wind across the region Wednesday, boosting temperatures into the 80s for Central and Southern New England with rising dew points meaning increasingly humid air. A cold front attendant to the passing disturbance will march south across New England with scattered showers and thunder Wednesday afternoon and evening, bringing temperatures down a bit Thursday with another shower possible as a second cold front moves through, delivering more substantial cool air Friday. Nonetheless, warmth won’t go far, and while both weekend days feature a chance of showers, that chance of showers comes as warm air starts a return. In fact, in the first half of next week we have returning temperatures around or over 80 degrees in our exclusive First Alert 10-day forecast.