Delightful Weather Follows a Stunning Annular (Partial) Eclipse

V_DISTANCING_4Although high-altitude clouds blocked the view for some, for many with the right tools to control zoom and light exposure for photography, Thursday morning’s annular (partial) eclipse of the sun did not disappoint at sunrise.  As the moon passed between the sun and the earth, the moon’s shadow resulted in a crescent sunrise in a rare confluence that appeared in breaks between clouds spilling south from Canada but not thick enough or widespread enough to completely block the event.  The next annular eclipse that could be seen in New England will occur October 2023, but won’t be nearly as impressive as this one with a much smaller portion of the moon casting a shadow, then a total eclipse is expected in April 2024 but, of course, viewing is always weather pending.  The spectacle in the sky comes as spectacular weather unfolds on the ground: a new, fresh, dry air has swept across New England.  While inland communities will warm to near 80 degrees Thursday afternoon, a freshening onshore breeze will send coastal temperatures backwards after lunch hour, with widespread low temperatures in the 40s and 50s overnight Thursday night, meaning leaving all the windows open in the house probably would mean the house gets TOO cool for a change!  Friday brings dry weather under increasing clouds for most with pleasant air continuing, though Northern New England will find morning sprinkles evolving into afternoon showers with a slow moving disturbance sinking south from Canada that will ease into Southern New England after midnight Friday night, leaving some showers in the southern half of New England Saturday morning.  By late morning to midday, showers should exit and clouds will start to break, affording a brighter afternoon Saturday, with much of the day bright across Northern New England where the showers both arrive and depart sooner.  Sunday sees the return of a south wind, which means warming temperatures and a bit more humidity, though nothing like the sweltering stretch we’ve just cleared.  As the jet stream winds aloft set up into a “trough” – a dip that allows energetic disturbances to collect overhead – scattered showers and thunder become increasingly probable late Sunday, then likely will crop up again Monday, Tuesday and perhaps even a few into Wednesday.  By the end of next week into next weekend in our exclusive First Alert 10-day forecast, a bit deeper heat starts rebuilding into New England.

Scattered Wednesday Storms Ahead of Thursday Fresh Air...and a Sunrise Eclipse!

V_MATTS_MORNING_MEMO (8)The heat may have come down just a touch in New England Wednesday, but humidity remains high and with dew point temperatures – a measure of the amount in the air – still in the 60s to near 70, high temperatures around 90 will feel more like 90-95° Wednesday midday to early afternoon.  Later in the day a sea breeze kicks in to cool the coastline a bit, but scattered thunderstorms are expected in Central and Southern New England Wednesday afternoon and evening ahead of a cold front slowly settling south across New England.  The slow-moving cold front resulted in a few inches of rain along the coast of Maine early Wednesday morning, prompting flash flood warnings, and will drop pockets of heavy rain, frequent cloud-to-ground lightning and isolated damaging wind gusts for areas farther south when they swing through Wednesday.  By late Wednesday afternoon, Northern New England will feel noticeably less humid and that new, fresh air will overtake the remainder of New England overnight Wednesday night, leaving behind an invigoratingly pleasant feeling Thursday with fair sky and highs in the 70s near the coast and around 80 inland with dramatically less humidity.  Thursday dawns with a very special sunrise - a partial eclipse of the sun at our 5:04 AM sunrise will make for a crescent appearance to the sun, reaching its peak around 5:30 AM and while we expect some clouds on the eastern horizon, we're hopeful for enough clearing to allow for a view of this phenomenon! Meanwhile, the new air moving in has staying power – in fact, our First Alert Team sees a brief return of warmth and humidity next week, but not the sweltering heat of recent days.  Along the way, the weather won’t be flawless: we expect showers to move into Northern New England from Canada Friday afternoon and stay into the evening, very slowly settling south with a renewed push of cool, Canadian air but keeping temperatures cool in Northern New England, where some of Maine may be hard pressed to get much beyond 60 degrees Friday!  The showers are likely to be found over Southern New England Saturday morning, but our biggest challenge is determining just how quickly clouds clear behind the showers.  If the clouds stick around, temperatures actually could be quite cool Saturday for much of New England…regardless, we see Sunday as the better of the two weekend days with more sunshine, a lower chance of any showers and temperatures resultantly warmer in the 70s to near 80.  The aforementioned brief return of warmth (not deep heat) and humidity is expected early next week with a mounting chance of showers and thunder before a bit less humid, but still mild, air moves in for midweek in the exclusive First Alert 10-day forecast.

Strong Thunderstorms Expected in Heat and Humidity Tuesday Afternoon and Evening

Be ready to duck inside with storms increasing after 3 PM today!
Details: Just in case you missed NBC10 Boston & NECN this AM, I hit storms pretty hard for today. Potential for lots of lightning, torrential rain, damaging gusts. A potential for rotation inside some storms, as well. Watch the western sky & be ready to head indoors, esp. after 3pm, worst is 4-8pm. During potential severe events, I love to pull clues from our exclusive Forecast System we built here in-house. Starting with the radar swath (sum of all forecast radar images) illustrates quickly and clearly the area of concern in the coming hours. With high dew points - tons of moisture in the air - any showers and storms that develop today will be excellent at making it's not surprising to see some localized amounts of 2-3"+ - localized flooding possible. The wind gust swath product looks exactly like I expect it would today - clusters and pockets of higher wind gusts capable of localized damage. Not a broad wind in the sky today, mostly going to be driven by storm strength. Setups like today where u have relatively light avg wind in the atmosphere can be problematic: if storm grows strong enough, can develop its own environment, begin rotating. Will carefully watch MA Pike corridor where our "Updraft Helicity" product shows weak rotation potential (in blue, the gray areas aren't too concerning). Indications are lightning could be major impact today - strongest signals of cloud-to-ground frequency we've had in the last few weeks. I tweeted about potential for very heavy rain/localized flooding, strong wind & perhaps rotation, but above all: "When Thunder Roars, Go Indoors!" Severe thunderstorm warnings are based on wind or hail. Lightning is NOT a criteria for a warning, so emergency alerts on our phones won't go off for that. Keep in mind hearing thunder means lightning close enough to head to a building or car.

Evaluating Friday Storm Chance: Lightning, Torrential Rain Biggest Concerns in Southern New England

NBCUFS_radarswath NBCUFS_radarswath NBCUFS_radarswath NBCUFS_radarswathWhen I have time, you know I love pulling back the curtain a bit for weather events. Today's (Friday) thunderstorms should mostly focus in the southern half of New England. This round was in Upstate New York yesterday and produced only a few spots of damage, very little overall, but one was a likely tornado touchdown. Similarly, our thunderstorm parameters don't favor widespread severe weather by definition - wind and hail. We all know that lightning and torrential rain can make the storms impactful, though, and there are signals of both, so please watch the northwest and western sky this afternoon and "when thunder roars, go indoors" - be ready to seek shelter if storms approach. Here are a few examples from our exclusive NBC10 Boston & NECN Forecast System I built with my colleague Aaron Perry over the last several years. Items of note: 1) the radar swath shows clearly where strongest storms will form today, 2) the wind gust swath shows rather paltry wind, implying widespread wind damage in storms is unlikely, 3) the "updraft helicity swath" represents forecast rotational tracks - you can pretty much ignore grays but the blues your antenna go up to at least pay attention to storms that enter that zone, today they may rotate but the question is with lots of clouds and temps only near 80 does anything actually grow strong enough to do something like Upstate New York yesterday or is it just a weakly spinning storm, which is actually pretty common. 4) The accumulated precipitation shows some high rain amounts, which makes sense given the humid air, so urban flooding is a possibility from Worcester to Boston area today. Worth noting, even just hours before the time of nature's reckoning, there are still several forecast products showing only a few storms at all in Southern New England today. That extreme seems improbable, but not impossible with our lack of sun and heat today. Putting it all together, today's storm event does not look like a widespread *severe* setup but lightning & downpours on the other hand are more likely & remember strongest storms could still do damage. After this, HEAT! Have a great weekend. Stay weather aware!

Humidity Builds, Showers and Storms Increase Ahead of Likely Heat Wave

LKN_FRONTS_BOSDMA (30)Humid air is moving into New England and not only will be felt by day’s end, but also is visible in the weather changes playing out today: clouds have taken over for most of the six-state region and areas of showers, rain and thunder are ongoing or predicted, depending on location.  Morning rain in Southeast New England includes downpours on Cape Cod and the Islands, with showers extending north to Hartford, CT, and the suburbs immediately south of Boston, with just a few isolated showers and sprinkles expected elsewhere.  For most of Southern and Eastern New England, youth sports Thursday evening can go off without a hitch, but will be played under clouds and in noticeably humid air.  In Western and Northern New England, an approaching disturbance aloft will interact with the increasing humidity to create pockets of rain and thunder Thursday afternoon into evening, with some of those thunderstorms growing strong enough to become damaging in a few spots, while the area of steady rain associated with these storms will grow to encompass much of Western New England during Thursday evening, then inch east across the rest of New England overnight Thursday night with rain, fog, humid air and occasional thunder.  By Friday morning, lingering showers will be tapering for a brief time, but a developing weak wave of low pressure – a weak storm center – may refocus the showers into steadier rain middle to late Friday morning, before a lull around midday in which breaks of sun may emerge, sending temperatures well into the 70s.  The combination of warming temperatures and humidity will raise the chance of afternoon thunder – particularly in Central and Southern New England – and some of that thunder could grow strong. Saturday brings a fair sky and temperatures warming into the 80s until a late day mountain storm may carry south during the night, then deep summer-like heat builds for a likely heat wave – three days or more of 90°+ temperatures – Sunday into the middle of next week.  While thunderstorms would be possible on those days owing to the heat and humidity, they will likely become more focused toward week’s end with an approaching cold front.

Memorial Day Showers Slowly Dwindle on the Cusp of Summery Return

LKN_NEXT_WEEK_JET_ACTIVE (2)The steady rains of the last couple of days have subsided for Memorial Day – at least for most of New England, though Mainers and Northern New Hampshire will see periodic rain and showers persisting as the responsible storm center drifts over the Pine Tree State.  Elsewhere in New England, drying is moving in from the south and west, meaning most of Southern and Western New England will avoid new rain showers Monday afternoon, though communities near and north of the MA Turnpike may still find a few renewed showers between 1 and 3:30 PM before breaks in the clouds emerge from west to east for late day and sunset.  The recent rainfall has sent pollen counts plummeting, which is welcome news for allergy sufferers and the clouds mean sunburns won’t be a problem this Memorial Day!  In fact, with an abundance of clouds, even a change in the wind direction to blow from the west won’t be enough to bump temperatures much above 60 degrees Monday afternoon, but more sunshine and a warmer air Tuesday will afford 70s for most.  Tuesday brings a quick-moving disturbance aloft, capable of touching off scattered afternoon showers in Northern New England but likely only an afternoon isolated sprinkle Central and South.  From Tuesday onward, the exclusive 10-day forecast is essentially broken into two parts: late spring and mid-summer.  The late spring weather Wednesday through Friday comes as warmth and humidity slowly returns to the Northeast, delivering an increasing chance of showers and thunderstorms each day, mostly focused during the second half of the day, while daily high temperatures hover either side of 80 degrees.  As the jet stream winds aloft – the fast river of air, high in the sky, that steers storm systems and separates northern cool from southern warmth – continue to shift north, warmer air will continue to take over and, eventually, as the heat overcomes the warm/cool battle of air, the number of thunderstorms likely will diminish somewhat in mid-summer heat expected Sunday into the middle of next week, until an approaching cold front focuses new thunderstorms as it approaches at midweek.

Onshore Wind Brings Cool Air, Raindrops, Waves for Memorial Day Weekend























Although Thursday began humid for most of Central and Southern New England, drier air from the north has steadily been filtering south on a fresh breeze, dropping the humidity substantially over the course of the day while sweeping away the clouds but leaving enough warmth behind for high temperatures around 80 degrees for many, closer to 70 in the North Country. Dry air cools quickly with the loss of sunshine, though, and overnight low temperatures are expected to drop into the 40s for many with the air turning so cold in Northern New England that frost warnings have been issued by the government for growers to protect plants and crops with lows around and below freezing! There’s no question the dry and cool nature of this air will have a major impact on New England’s holiday weekend forecast: as a series of storms pass to our south and east, moisture will plume north, and when dry air is moistened, it cools. Friday stays dry most of the day but clouds increase markedly from midday onward, holding temperatures in the 60s for most, then rain arrives for Central and Southern New England Friday afternoon, evening and night, generally developing from west to east and continuing through Saturday morning. Although an inch and a half of rain is expected in Southern New England, amounts will drop off significantly from Central VT and NH to Southern ME, points north, where less rain falls. In fact, Saturday afternoon brings drying for many – with clearing late Saturday into Saturday night in Northern New England – though communities within about 20 miles of the coastline will probably still find pockets of drizzle lingering in spots through Saturday afternoon with an onshore, northeast wind blowing cool air across the ocean water. Highs Saturday are only expected to reach the 50s for most, with stubborn clouds and perhaps still some pockets of coastal drizzle overnight Saturday night in Southern New England. The steady onshore wind will churn our coastal waters, building seas as high as ten feet by Saturday evening into Sunday morning, so boaters will need to be experienced and have a big enough boat to handle the seas this weekend outside of our bays, harbors, sounds and inlets. Another developing storm center at the surface, combined with approaching atmospheric energy aloft, will encourage showers to blossom northward on Sunday, arriving to the Cape and South Coast during breakfast and spreading north through the day, lasting into Memorial Day Monday morning. If all goes as planned – and some of these finer details certainly can change in the coming days – Memorial Day may end up totally dry in Western New England, including the Berkshires and Green Mountains, with morning rain giving way to some clearing in the eastern half of New England, allowing temperatures to rebound into the 60s – this is something our First Alert Team will monitor in the days ahead. Of course, as luck would have it, our weather improves immediately after the Memorial Day holiday, though we should see a renewal of humidity and a resultant chance of thunder for the end of next week.

Heat, Humidity & Thunder Expected For Midweek

LKN_SEVERE_OUTLOOK_DAY2_NEWENG LKN_SEVERE_OUTLOOK_DAY2_NEWENGAs New England approaches the full moon this week, tides have been running extra high and extra low – enough that our coastal residents will notice the larger-than-normal swings in ocean level, with some minor coastal flooding or splashover a possibility in typically vulnerable spots at an 11 PM high tide Tuesday night and a midnight high tide Wednesday night.  Otherwise, our weather map features a center of high pressure – fair weather – shifting to the east of New England, past Nova Scotia, and the clockwise flow of air around that center is providing a southwest wind to New England Tuesday, which means sea breezes won’t be a factor and eastern coasts will warm just as much as the interior as high temperatures reach 75 to 80 degrees.  The notable exceptions will be found near south-facing coasts, where a prevailing southwest wind blows across cool ocean water and daytime high temperatures will be cooler than the remainder of our New England communities, and this same phenomenon continues through Wednesday, as the southwest wind continues to blow.  The continued southwest wind has a few other implications, as well: increasing atmospheric moisture will mean pockets of fog developing by Wednesday morning near the South Coast, pockets of low-altitude clouds that will be stubborn near the South Coast and particularly on Cape Cod Wednesday, and an increasingly humid feeling in the air for most of New England.  Combined with temperatures nearing 90 degrees, Wednesday afternoon will feel somewhat sultry and sets the stage for possible strong or damaging thunderstorms from northwest to southeast across New England late day and evening, with the greatest potential for frequent lightning and locally damaging wind gusts found in Central and Southern New England Wednesday evening as a cold front approaches from the northwest.  Our Team has issued a First Alert for Wednesday evening to raise awareness of the potential for some damaging storms in New England.  The passage of the cold front Wednesday night into Thursday opens the door to less humid air and cools New England from hot to warm Thursday…with even cooler air arriving Thursday night into Friday.  Ensuring Friday will be noticeably cooler is an approaching storm center forecast to pass south of New England Friday, delivering a cool rain across at least Southern New England on Friday, though just how much rain – based on just how close the storm center comes – is still uncertain.  The storm track is really important in the holiday forecast, too, because a series of additional storm centers will follow the path of the first, meaning at best a series of days with cool onshore wind flow, variable clouds and a few scattered showers will follow for Saturday, Sunday and Memorial Day (that’s our forecast), but at worst, we’d see periods of cool rain all the way through (less likely, not our forecast, but not impossible).  For now, our First Alert Team follows a somewhat optimistic route of delivering some rain Friday into Saturday morning, then only scattered afternoon showers that may pop up Sunday in a few communities and likely a dry Memorial Day, but we’ll be keeping you posted, of course.  The end of our exclusive First Alert 10-day forecast returns temperatures to near 80 degrees.

Weekend Warmth Builds, Scattered Showers & Thunder

LKN_NBCU_POP_D1_NEWENG (5) LKN_NBCU_POP_D1_NEWENG (5)New England is returning this weekend to a similar weather pattern that we started the week with: multiple disturbances aloft, raising the chance of scattered showers and thunder.  The transition out of our recent dry days is a gradual one as it takes some time for moisture to increase in the atmosphere, but changes were already evident as soon as Friday morning, when clouds and sprinkles dropped south across New England.  Some sun will burn through the clouds Friday midday and afternoon, and this time of the year a little sun can go a long way, so with a south and southwest wind not allowing a sea breeze to develop until late in the day, even our coastlines will warm to near 80 degrees during the afternoon.  Because moisture is still somewhat limited in the atmosphere, a Friday late-day disturbance may result in an isolated shower but unlikely anything more significant.  Overnight Friday night – particularly after midnight – a disturbance aloft coincides with a continuing influx of warmer and more moist air, which is often a favorable combination for showers to develop.  Our First Alert Team expects predawn showers sliding from north to south to linger into the early morning Saturday in the Boston area, and on Cape Cod a bit deeper into the morning, not really giving way to much sun, but even with lots of clouds, many of us will find high temperatures around 80 degrees, warmer where more sun can burn through the clouds.  Expect lots of sun for awhile on Sunday and this will boost temperatures well into the 80s for Central and Southern New England, even closing in on 90 around the Boston, Worcester, Springfield and Hartford metro areas before a powerful cold front sends scattered thunder from north to south across New England Sunday afternoon and evening, opening the door to new, fresh, cooler spring air to start next week.  Next week’s forecast is punctuated by fluctuations in air, from fresh spring air to warmth and humidity, with one spike in warmth at midweek, broken by Wednesday afternoon storms with a cold front, then another spike in warmth possible on Memorial Day weekend, which shows up at the end of our exclusive First Alert 10-day forecast.

Return to Recurring Showers Anticipated By the Weekend

LKN_FRONTS_BOSDMA (28)Another rain-free day is expected across New England, though that will change as soon as this evening for some communities.  Dry air certainly still has a grip on New England, cooling effectively early Thursday morning for a crisp start regionwide, but warming quickly with the help of plentiful sunshine by afternoon, delivering high temperatures Thursday afternoon around 80 degrees, cooler at the coast where sea breezes develop.  Frequent disturbances have still be riding over New England, but none strong enough to overcome the dry nature of the air.  A stronger upper level disturbance drops south into the New England sky Thursday evening and clouds will build across the North Country with scattered Thursday evening and night showers and embedded downpours in Northern VT, NH and perhaps northwest ME, dropping south but weakening to just a few leftover showers by predawn Friday in Central and Western New England.  Variable clouds Friday will still allow for considerable warmth though the chance of showers rises just a bit as the air starts to moisten – not only the possible leftover predawn showers sliding south out of the North Country, but also some new isolated showers for a few communities during the day, though the bulk of the region stays dry.  It’s only a matter of time before the air moistens sufficiently for a return to a similar weather pattern we saw early in the week, where each of many disturbances aloft touch off scattered showers and possible thunder, and it looks like that begins as a round of scattered showers overnight Friday night into early Saturday morning.  The gradual but steady increase in atmospheric moisture will mean more clouds than sun, overall, Saturday, with scattered showers and thunder likely to develop from north to south Saturday afternoon and evening.  Warmth continues to build Sunday and sea breezes relax, meaning 80s by afternoon for nearly one and all with the usual exceptions of Cape Cod and south/southwest facing coasts.  Yet again, scattered showers and thunder are probable Sunday with another jet stream level disturbance aloft, with particular focus during the afternoon to early evening as a cold front enters New England – the leading edge to new, clean, cooler air.  Monday starts fresh with much cooler and drier air cleaning the slate for a storm-free start to the week, though warmth, humidity and a chance of storms will build again by midweek, before another cold front clears the air yet again for a pleasant start to the Memorial Day weekend at the end of our exclusive First Alert 10-day forecast.