In yesterday’s post and today’s broadcasts, we outlined the threat of roof collapses. The Massachusetts Emergency Management Agency follows suit with an advisory today:

MEMA POSTS ROOF COLLAPSE & STORM DRAIN WARNING INFORMATION
Snow Buildup & Subsequent Heavy Rain Can Present Dangers

FRAMINGHAM, MA – “If not reasonably cleared off the heavy, wet snow from the last storm piled on roofs can act as a sponge, absorbing the expected rain, adding weight and stress to structures.” states Massachusetts Emergency Management Agency (MEMA) Director Don Boyce. “Flat, commercial roofs are most susceptible if they are not draining properly. Additionally, MEMA encourages citizens to clear storm drains in their neighborhoods to minimize local flooding problems from this run-off.”

In many cases, roof ice dams can form causing water build-up, leading to interior damage. To minimize the risk of over-stressing a building roof due to accumulated or drifting snow:

· Be on the alert for large accumulating snow build-up on your roofs.

· If roof snow can be removed, from the ground, with the use of a snow rake (available at most hardware stores), do so. Use caution, as metal snow rakes conduct electricity if they come into contact with a power line.

· Try to avoid working from ladders, as ladder rungs tend to ice up. Snow and ice collect on boot soles, and metal ladders.

· Flat roofs can be shoveled clear, but only if it is determined that the roof is safe to stand upon. Exercise care when on the roof to avoid potentially dangerous falls.

· Flat roof drainage systems should be kept clear to minimize the risk of excess roof ponding in the event of subsequent heavy rainfall or melting.

· Large icicles can form on roof overhangs, but do not necessarily mean ice damming is occurring. Icicles overhanging doorways and walkways can be dangerous and should be carefully removed.

· All of the mentioned actions should only be performed by able-bodied adults, as the snow is heavy, and roofs and other surfaces may be slippery. Protective headgear and eye protection is recommended.

This roof collapse alert is issued by the Massachusetts Emergency Management Agency (MEMA), in conjunction with the State Board of Building Regulations and Standards.

The Massachusetts Emergency Management Agency (MEMA) is the state agency responsible for coordinating federal, state, local, voluntary and private resources during emergencies and disasters in the Commonwealth of Massachusetts. MEMA provides leadership to: develop plans for effective response to all hazards, disasters or threats; train emergency personnel to protect the public; provide information to the citizenry; and assist individuals, families, businesses and communities to mitigate against, prepare for, and respond to and recover from emergencies, both natural and man made. For additional information about MEMA and Winter Preparedness, go to the MEMA website at www.mass.gov/mema. Follow further MEMA updates on Facebook and Twitter.

Heavy snow continues to gradually shift northward after dropping up to two feet in some of the Berkshires, and will perform the same feat in the Green Mountains of Vermont, and when all is said and done, perhaps the White Mountains and Mahoosucs, as well.

Of course, my job is to look ahead to what nature will deal us next. I’m concerned with three W’s for Thursday…weight, wind, waves and wet.

1) WEIGHT: Anyone who received over a foot of new snow from Tuesday night/Wednesday’s event needs to be aware of the issue of rooftop weight. The snow was very heavy, as one round of shoveling can quickly attest to, and this snow will add weight to all structures. The concern comes with the inch or more of rain expected Thursday – starting up by mid-morning in some of Southern New England, and encompassing more areas by afternoon. Where a foot or more of snow fell, this new snowpack will absorb that rain and substantially increase in weight, making roof collapses a concern. For those who received over a foot of snow, flat roofs should be cleared before the rain arrives. For those who received over 18 inches, all rooftops should be cleared. Rain is likely even into the mountains.

2) WIND: A very strong storm will intensify quickly just south of New England. The media, in general, is hyping this storm. Let’s be clear that it will not be like the New England “Winter Hurricane” of 2005 that brought 110 mph winds to Cape Cod with thundersnow, with winds consolidated around the core. That was amazing. This storm will also be amazing, but not to the same degree, and will not be the same type of compact creature. Rather, heavy snow will hit New York, New Jersey and Pennsylvania (eventually southwest CT, too) but New England will be dealt the wind. The difference in air pressure from this storm to a fair weather cell in Canada will help to produce wind gusts near 70 mph on the immediate coastlines of Eastern New England Thursday evening, producing damage and churning the seas.

3) WAVES: The strong wind will churn waves to 25-30 feet along the coast of Northern MA, New Hampshire and Maine! This will bring substantial beach erosion from battering surf, Thursday night through Saturday. Storm surge will accompany these waves and wind, and that will mean an increased risk of coastal flooding at each high tide cycle, especially Friday and Saturday.

4) WET: Finally, all of the rain later Thursday and Thursday night will make big puddles for hydroplaning, localized flooding, and perhaps some scattered river flooding where wet snow will melt in Central New Hampshire and Maine. Basement flooding will occur in homes prone to this, as well, thanks to the high water table.

It would appear as though the summit of Mount Washington may still be “Home to the World’s Worst Weather,” but no longer the world’s fastest recorded wind speed. It’s taken since 1996 to surface, but the April 12, 1934, gust of 231 mph atop New England’s highest peak fell to an intense gust of 254 mph at the center of Tropical Cyclone Olivia on Barrow Island, Australia, on April 10, 1996. The site is located just off the northwest coast of Australia, and the wind speed recording instrument (an “anemometer”) was of the three-cup variety, on a site located 210 feet above mean sea level.

The official word on any record must come from the World Meteorological Organization, who recently published their report confirming – to the best of their knowledge and ability to authenticate – the New England record has, indeed, been toppled. The extensive time between the observation and this statement has raised skepticism for some, but it would appear, at least upon initial review, that the observations and process of authentication were not flawed. I spoke with Cara Rudio, spokesperson for the Mount Washington Observatory on Tuesday afternoon, and she describes the sentiment at the Observatory as “bummed,” but acknowledges the validity of the World Meteorological Organization’s work, adding that the WMO was kind enough to provide Mount Washington with a copy of the report, and the summit personnel will be carefully reviewing it in the coming days. Executive Director of the Observatory, Scot Henley, adds, “This doesn’t change the fact that Mount Washington is one of the most fierce locations on the planet…that can’t be taken away from us.” As I mentioned this morning on NECN in my weather broadcast, some interesting items that should be examined meteorologically include the composition of the anemometer (a three cup anemometer typically cannot withstand such strong winds, and should normally break apart at far lesser wind), and the large gap between steady, or sustained, wind and the maximum gust. Additionally, this wind gust represents a 3-second average wind speed, rather than the 10-second wind speed recorded on Mount Washington, which makes a significant difference in the result.

This isn’t the first time Mount Washington’s record has been challenged, but it is the first time it’s been confirmed to have been broken using valid wind measuring tools – Doppler radar estimated 318 mph in a tornado in Moore, Oklahoma, in 1999. This wind speed, however, was hundreds of feet above the earth’s surface, and recorded by Doppler radar, which is not accurate enough to be an official measuring instrument for wind speed. Of course, New Englanders know Mount Washington still is “Home of the World’s Worst Weather” – and from a technical standpoint, still holds the fastest recorded wind speed on earth, outside of a tropical cyclone, and that’s no easy feat! Additionally, Scot Henley reminds me that the Australian site was unmanned, meaning Mount Washington – with the spirit of adventure that was alive in 1934 and still just as strong in 2009 – is home to the fastest wind speed ever observed by man.

The Mount Washington Observatory provided me with a copy of their Press Release, below, which you can read by clicking the “Continue Reading” link of this post. I’m also including the text from the World Meteorological Organization. Want more information on the Mount Washington Observatory? It’s membership supported and non-profit…and I’ve included a link in the documentation.

From the Mount Washington Observatory (www.mountwashington.org):

MOUNT WASHINGTON, NH – For nearly sixty-two years, Mount Washington, New Hampshire held the world record for the fastest wind gust ever recorded on the surface of the Earth. In a report released Friday by the World Meteorological Organization (WMO), that record was toppled in 1996 at Barrow Island, Australia during Typhoon Olivia. According to the report, the new record stands at 253 mph.

News of the new world record was released by a WMO Evaluation Panel of experts in charge of global weather and climate extremes within the WMO Commission for Climatology (CCl). The panel was led by Dr. Randy Cerveny of Arizona State University and CCl Rapporteur of Climate Extremes.

“It was bound to happen, but it’s definitely quite a shock to hear that news,” says Scot Henley, Executive Director of the Mount Washington Observatory. “While we are disappointed that it appears that Mount Washington may have been bumped from the top, at our core we are all weather fans and we are very impressed with the magnitude of that typhoon and the work of the committee that studied it.”

Mount Washington’s famous wind gust of 231 mph, recorded on April 12, 1934 at the Mount Washington Observatory, stands as the record for the fastest surface wind measured in the Northern and Western Hemispheres.

“It’s natural to treat news like this with some level of skepticism,” said Henley. “Dr. Cerveny was kind enough to share the panel’s findings in advance of next month’s WMO meeting in Turkey. We’re going to spend some time reviewing the materials to learn more about the instrumentation, calibration, the methods used to calculate the wind speed and everything else that went into their investigation.”

“The new record does not diminish the fact that Mount Washington is one of the fiercest places on the planet,” says Ken Rancourt, Mount Washington Observatory’s Director of Summit Operations. “It remains consistently one of the windiest places on Earth and a location that begs further study of wind, weather and climate.”

“Work continues atop Mount Washington,” says Henley. “Our crew of meteorologists and educators at the Observatory stands ready to measure and study the next big wind, whenever it may come.”

Mount Washington Observatory, which operates within the 59-acre Mt. Washington State Park, is a private, non-profit, membership-supported organization. Since 1932, the Observatory has been monitoring the elements in one of the most extreme locations on Earth, using this unique site for scientific research and educational outreach.

From the World Meteorological Organization (www.wmo.int):

World Record Wind Gust: 408 km/h
Geneva, 22 January 2010 (WMO) – According to a recent review conducted by a panel of experts in charge of global weather and climate extremes within the WMO Commission for Climatology (CCl) the record of wind gusts not related to tornados registered to date is 408 km/h during Tropical Cyclone Olivia on 10 April 1996 at Barrow Island, Australia. The previous record was of 372 km/h, registered in April 1934 across the summit of Mount Washington, USA.

The Panel consisted of the following experts: Dr Pierre Bessemoulin, MeteoFrance and President of CCl; Dr Tom Peterson, NOAA National Climatic Data Center; Dr Blair Trewin, Australian Bureau of Meteorology; Dr Jose M. Rubiera Torres, Cuban Instituto de Meteorología; Dr John (Jack) Beven, USA National Hurricane Center; Dr John King, British Antarctic Survey; Dr Randy Cerveny, Arizona State University and CCl Rapporteur of Climate Extremes.

The panel came to its conclusion after an extensive review and evaluation of instrumental, phenomenological and statistical data.
The WMO Commission for Climatology provides more information about Global Weather and Climate Extremes at: http://wmo.asu.edu/
Hurricanes, cyclones and typhoons are different terms for the same weather phenomenon which is accompanied by torrential rain and maximum sustained wind speeds exceeding119 kilometers per hour. A hurricane with maximum sustained wind speeds exceeding 249 km/h is referred to as Category 5.

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A strong storm has moved across the Great Lakes, and the intense counter-clockwise flow of air around its core has driven deep warmth and moisture northward up the Eastern Seaboard. The change in air was evident early Monday morning, as temperatures rose rapidly into the 50s, with Boston’s Logan Airport recording a 12 degree temperature jump in just one hour from 4 AM to 5 AM! This warmth comes with deep moisture direct from the Gulf of Mexico…

…and we’ve loaded the New England atmosphere with just about as much moisture as you’re going to see this time of the year, so it will rain quite heavily throughout the day, with total rainfall amounts between one and three inches. Highest rainfall totals will be found from the White Mountains to the Mahoosucs Range of Maine, where a south and southeast wind pushing against the mountain faces will enhance cloud development. So much rain, coupled with snowmelt, means imminent street flooding and stream flooding, regionwide. In some smaller rivers of Central and Northern New England – especially the Swift, Pemigewasset and Saco, ice jams are possible as ice breaks up, flows downstream, and may become lodged on bridges or at narrow passages, allowing water to quickly back up behind the jam. Basement flooding is not as likely because the frost depth, according to reliable weather observers, is about eight inches, so water will readily run off the soil, not into it. Those with flood-prone basements know the most common scenario is for the ground water table to rise, which can’t happen if the water can’t penetrate the ground.

Of course, transporting all of this warmth and moisture northward is wind. You can’t very well get 50s or lower 60s in New England in January without a lot of moving air, and there are indications that this air will move at over 100 mph just 6000 feet off the ground by later Monday afternoon. While we don’t expect those kinds of wind speeds to reach the ground, the atmosphere will be more freely mixed where warmer air has arrived, meaning strong wind gusts of over 55 mph are likely. Damage has already been done to our south, across the Mid-Atlantic, where 30,000 people were out of power as of Midday in Southern New Jersey as a line of damaging thunderstorms continued to rip through that location. Meanwhile, winds ripped a scaffolding from a building in Northern New Jersey, and sent a tree limb crashing upon a pedestrian. These damaging winds will sweep from west to east across New England from Monday morning through afternoon, respectively, with the most vulnerable areas found on the western slopes of the Green Mountains in Vermont, the South Coast and Southern New England away from deep snowpack (snow is cold, and stabilizes the air), and a swath of Eastern New England from Eastern MA through the Maine Coast. Downed tree limbs and power lines in these locations will lead to power outages, and similar problems to our friends in the Mid-Atlantic are possible.

The evening commute will be very difficult for most commuters with the combination of heavy rain, snowmelt and gusty wind. After dinner, rain and wind will taper, and cooler, drier air will slowly settle across New England on a steady but not damaging wind overnight. A few patches of black ice are likely Tuesday morning, before breaks of sun team with lots of clouds and a few snow showers as colder air continues moving in. By Thursday, another disturbance will bring increasing clouds and areas of snow, probably mixed with rain in Southern New England. This actually was the day that, last week, we thought would be quite cold, but that cold shot has been delayed 24 hours, meaning Friday now appears to be the beginning of the deep cold that will last into the upcoming weekend.

Any snowstorm threats? One disturbance passes south of New England this coming Saturday and may throw snow onto at least Southern New England, and a stronger, more moist disturbance makes another pass around the middle of next week.

Stay dry!
Matt

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Though the weather will remain fairly quiet for most New Englanders through Christmas, there are some subtle features that will have important localized effects. Additionally, a complex weather map across the nation ensures challenges in the days ahead. For now…

…high pressure will be nudging into New England from the west, and will be strengthening over the Holiday Weekend as it pulls east through Quebec and into New Brunswick. At the same time, the intense Midwestern U.S. storm that has been much anticipated isn’t failing to perform – with copious amounts of moisture riding north from the Gulf of Mexico, prompting severe thunderstorms and tornadoes from Texas to Louisiana, heavy rain northward through Arkansas all the way to Chicago (where some freezing rain fell, as well), and snow on the western side of the storm track, with one to two feet of snow and blizzard conditions from Oklahoma to Minnesota. As a result of the storm, several hundred flights to, or connecting through, the Midwest have been cancelled or delayed. This storm will remain quite slow-moving heading into the Holiday weekend, lodged across the Upper Great Lakes and Midwest by the blocking high pressure dome affecting our New England weather.

While the situation will remain fairly quiet at home, there will be some exceptions. For instance, a north wind lined up with a burst of warmth and moisture aloft on Christmas Eve Day to bring some snow showers to the South Shore and Cape Cod for a brief time, leaving a solid coating for some. Those snow showers died quickly as winds became less favorable and the air warmed further, but the persistent flow of wind dribbling in from the ocean will mean the development of some patchy black ice Christmas Eve, from about 9 or 10 PM through early Christmas morning. Though moisture may increase near the ground Christmas Eve, drier air will move in aloft, allowing for some clearing of the skies through the overnight, and some Christmas Morning sunshine for many New Englanders, though Southeastern MA may dawn mostly cloudy. Throughout Christmas Day, a prolonged and strengthening onshore wind will mean an expansion of the cloud deck across most of Southern New England, and by Christmas Evening through Christmas night, drizzle will develop from east to west. That will be important, because temperatures will be very close to the freezing mark, meaning some freezing drizzle is likely to put a light glaze on untreated surfaces.

This weekend, New England is dealt a piece of the Central U.S. storm, though its arrival has been estimated later and later as we approach the event. Right now, it appears as though some relatively light showers of wintry mixed precipitation that develop on Saturday will be little more than a nuisance for some, perhaps depositing a light glaze through the interior, though unlikely to have much substantial impact. The delay for steadier precipitation to arrive actually will be beneficial to New England, allowing the cold air to lose a bit more of its grasp on New England, meaning the critical freezing line will retreat northward a bit through the day. By the time steadier precipitation arrives Saturday evening and night, into Sunday morning, most of Southern New England will see rain. Even still, over an inch of rain will weigh down flat roofs that have snow on them, which is why it’s so important for flat-roof structures in Southeastern MA, Rhode Island and Eastern CT to be cleared prior to the arrival of the rain. Farther north, along and north of the Route 2 corridor of Northern MA, and in some of the valleys of Central and Western MA, enough cold air will linger for a period of freezing rain before changing to plain rain. This brings a chance of icing, or glaze, with 1/4″ to 1/2″ possible as you head north through Southern and Central Vermont and New Hampshire (away from the coastal plain), as well as interior Maine. This amount of ice would be enough to cause dangerous travel (any amount of ice can do that on untreated surfaces!) and perhaps isolated or widely scattered power outages. The North Country is likely to find snow changing to a wintry mix.

With the slower trend for the storm forecast, we are likely to find rain lingering Sunday morning, but this will move across Northeastern New England by afternoon, with some breaks of sun possible by afternoon in Southern and Western New England, which would actually allow temperatures to climb into the 40s! Monday and Tuesday should be fairly quiet, though deeper cold air returns heading into the middle of next week, and we open a favorable pattern for storms along the Eastern Seaboard throughout the first half of January (see my technical discussion for more details).

Enjoy the weekend – Merry Christmas to One and All!
Matt

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Throughout the week, we’ve been slow to close the door on snow potential for this upcoming weekend. We continue to tow that line. The issue is this: we’ll be watching a somewhat uncommon east to west movement of a large storm over Eastern Canada, and the precise timing of this westward motion, along with its interaction with two other energetic disturbances, will have great impact on New England’s weekend weather.

For the time being, the tune is cold and dry. Arctic air continues spilling southward on a steady northwest wind that has gusted over 40 mph at times, and created Thursday wind chill values of as cold as 30 degrees below zero in the North Country of New England! Winds will slowly subside overnight Thursday night, with gusts to 30 mph, and similar winds will continue on Friday, meaning wind chill values will hover in the single digits to teens from north to south – not comfy, but better than Thursday’s feeling. Dry weather will continue into Saturday – when winds diminish significantly and the “feels like temperature” ends up close to the actual high in the 20s…some 20 degrees warmer than Thursday felt – before we turn our attention to the next storm.

The timeframe we’re watching is late Saturday night through Sunday morning. The storm has already developed, but is in its infancy in the western Gulf of Mexico, producing day-long heavy rain along the Texas coast, and poised to shift east while gathering strength from the warm Gulf waters and available moisture. All the while, the deep, cold storm over Eastern Canada that helped to shove our cold air across the border this week will be slowly moving west, and this will change the atmospheric steering flow. The question for New England hinges upon how quickly this westward movement occurs – faster movement opens the door for the northwest side of the large developing storm lifting out of the Gulf to move through Southern New England. Though there are some uncertainties, there are also a series of parameters I use in composing the forecast, and you can see a streaming video of my technical discussion outlining the potential in the video window on my personal weather page. Suffice to say that if everything lines up correctly, up to a foot of snow would be possible in parts of Southeastern New England, though chances are good reality will fall short of that, and in fairness, one could make an equal case for the storm to miss New England entirely! The weather pattern, though, suggests at least some snow should fall over Southeastern New England Saturday night and early Sunday.

Farther south, an epic snowstorm is likely in the Southern Appalachian Mountains, where more than two feet of snow is possible. If the storm strengthens quickly enough, the stakes for the Mid-Atlantic from New Jersey to Norfolk, VA, would rise to potential blizzard conditions, rather than the milder possible solution of 6″-12″. I’ll keep you posted! -Matt

A strong disturbance in the northern jet stream has been forecasted to drop overhead, carving out a pool of very cold air across the Great Lakes and Northeastern United States, and plunging New England into even deeper cold than experienced last week! On the leading edge to that cold, there has been the possibility that we would see the involvement of a southern stream disturbance, providing moisture from the Pacific and Gulf of Mexico to feed a developing storm. It appears now, however, that the northern and southern streams will remain separate until reaching the Gulf of Maine, where only a weak interaction will occur. This lessens the chance of meaningful snow in most of New England, though leaves the door open for late Tuesday and Tuesday night accumulating snow in Central and Eastern Maine. Regardless, this system still serves as the gateway to deep arctic cold that will surge southward into New England for the middle and end of the week.

That cold is very apparent as of this Monday morning Summary, with temperatures some 10 to 20 degrees below zero from Northern Minnesota through Southern Canada. A chunk of that deep arctic chill will break into New England, starting with increasing winds Tuesday night behind the departing system that delivers lots of Tuesday clouds, but only limited snow showers to primarily Northern New England. As winds increase into Wednesday morning, early morning temperatures in the 30s will fall through the day, paying no mind to the sun that will be poking out between puffy clouds, and assaulting New Englanders with a biting wind chill that will enter a tailspin through Wednesday, landing either side of 10 degrees by late Wednesday! The strong northwest wind carrying this colder air into the six-state region will gust over 45 mph at times, and isolated power outages are possible for a few communities. The bigger effect, by far, will be the brutal wind chill that continues Wednesday night – feeling well below zero throughout New England – and not making it out of a single digit feeling for most on Thursday, as actual temperatures fail to surpass 20 degrees in a sleu of Northern and Central communities.

With so much cold air, it’ll be tough to get any deep moisture into the Northeast, which means a mostly dry stretch aside from scattered mountain flurries and snow showers from time to time. Temperatures will slowly rebound as winds relax on Friday, and lead us to at least an open door for moisture to develop a storm center along the East Coast next weekend, though whether that storm moves close enough to New England to land any precipitation here remains to be seen. In the meantime, we’ll use Monday and Tuesday to mentally prep for the blast of bitter cold en route!

Though Wednesday’s storm is history, the original, parent storm that provided a chunk of energy for its development is still spinning in Southeastern Canada. The counter-clockwise flow of air around this storm has dragged cold air straight from the North Pole into the Northern Plains and Midwest, with Chicago dropping to zero degrees this morning! Though this cold air doesn’t stream directly into New England from Canada, it will arrive with plenty of gusto…

Our strengthening west-southwest wind on Thursday is carrying this air from Chicago, across the Ohio Valley, and into New England. The difference in barometric pressure between the center of this cold dome of high pressure and the strong storm parked to our north will drive wind gusts to 45 mph on Thursday, Thursday night and Friday, and this will ensure cold air makes quick progress through the Northeast, holding morning temperatures steady in the 30s to around 40 throughout the day Thursday, then bringing temperatures into the teens with wind chill values dropping to near and below zero Thursday night. All the while, the wind blowing across Lakes Erie and Ontario will continue producing very heavy lake-effect snow in Upstate New York, especially around Buffalo and Watertown, where the suburbs of those cities may see feet of snow. In New England, that moist air streaming off the lakes will continue to enhance scattered snow showers and squalls in the mountainous terrain of Northern and Western New England, and a moderate strength energetic disturbance moving across New England Thursday evening may carry a few of these snow showers into Central and Southern New England briefly, as well.

Friday will feel brutally cold, largely because this is by far the most substantial blast of cold air of the young winter season. With high temperatures struggling to reach 30 in most communities, and the strong wind continuing, wind chill values will be lodged in the teens to lower 20s at even the warmest time of the day. With such cold air, though, comes dry air, and that means we’re looking at a quiet weekend until the next storm moves to our south Sunday night. At this stage of the game, it appears as though most of the deeper moisture associated with that storm will stay south of New England, with only lightly accumulating snow reaching into Southern and Central New England Sunday night. Having said that, there is still some uncertainty in how the upper level wind pattern evolves, and I do see at least an open door for a band of snow to be locally heavier, if everything comes together right…though at this point the probability of that is low.

I think a better storm chance comes on Tuesday, though again, with an uncertain pattern and lots of energy aloft, I’ve kept a chance of snow showers in for Monday as well. The Tuesday pattern, however, appears to feature a strong and moist southern stream disturbance coming out of Texas, merging with a northern stream system dropping out of the Upper Midwest. Such a merger would occur with cold air nearby and readily available, and sets up a favorable pattern for a coastal storm on Tuesday. For more technical thoughts on this, as well as my thoughts on other storm possibilities December 17/18 and somewhere around the 22nd, check out my streaming technical video discussion.

Hi Everyone! Well after yesterday’s record warmth it may have felt quite a bit cooler today, but the believe it or not temperatures were still running several degrees above average for this time of year. Highs peaked in the upper 40s to middle 50s, a good 10 degrees higher than normal. By tomorrow we’ll fall back into more typical December temperatures with highs in the 30s to lower 40s. Of course, the main thing on everyone’s mind is the storm down in the deep south- the same system that brought earliest snowfall on record in southeast Texas today. It will re-organize in the eastern Gulf of Mexico tonight then round the corner, turning up the east coast tomorrow and passing east of Nantucket tomorrow night.

So while the morning will start dry, the sky will look and “feel” like snow- you know the type of sky I’m talking about. The precipitation will actually start as rain for many areas in the afternoon but quickly transition to snow from northwest to southeast during the evening. Snow will fall heavy at times tomorrow night in southern and eastern New England then end from west to east by morning. The jackpot should be somewhere in interior southern New England- close enough to the storm to receive the heavy precipitation but far enough from the coast to be predominantly snow. Here’s my latest thinking on totals:

It’s a progressive storm – meaning it’s out of here quickly, and by Sunday morning the clearing will begin in earnest. Expect a nice afternoon with plenty of sun and typical December temps- a great day to get out and enjoy the fresh snow!

I’ll be back tomorrow morning with the latest updates and a tweak in the totals if necessary. Have a great night!

The combination of strong energy moving east across the Ohio Valley and deep moisture moving north from the Gulf of Mexico will create a rapidly intensifying storm just off the coast of New England. This storm is likely to “bomb” – or rapidly intensify – on Friday as it moves north across Cape Cod and into the Gulf of Maine through Friday night…

After a quiet but mostly cloudy Thanksgiving Day, winds may shift just a bit to blow from the east Thursday night and bring drizzle and fog back into coastal and far southern areas, in advance of the approaching storm. Rains that develop Thursday night transition to heavy rain on Friday with a widespread one to two inches likely, resulting in wet Black Friday shoppers, and creating areas of urban street flooding and ponding of water on roadways. The rain should taper across Southern New England by middle afternoon Friday, but Central New England – including Northern MA – are likely to find the rain quite stubborn to quit. As the storm bombs and pulls into the Gulf of Maine waters, it will act much like a vacuum cleaner – sucking air directly into its center. This means a northwest wind that will limit any threat for coastal flooding or beach erosion (northwest is an off-shore wind for almost everyone) but will carry cool air southeast. There is very little cold air available in Eastern Canada right now, so we’re not talking about a quick or widespread change from rain to snow. Rather, most valleys will stay as rain and it’ll be the mountains and higher elevations that can cool enough to see a change to snow Friday evening and night. In these locales, however, the combination of heavy snow and winds gusting to 45 mph late Friday night to early Saturday will create near-blizzard or perhaps bona fide blizzard conditions for the mountainous terrain of the North Country, including North-Central Vermont to the Northeast Kingdom, the northern side of the Whites, and the northwest mountains of Maine. Elsewhere, snow is expected in Northern Maine, rain to snow in Central Maine, and some Friday night snow in the Central/Southern Greens and Berkshires. All locales that see snow will have elevation dependency – more on hills and less in valleys. We’re also going to watch Southern Maine and Southeast New Hampshire very carefully – your temperatures will be marginal when you see a continued burst of heavy precipitation the first part of Friday night that may turn to a burst of snow with a quick couple of inches of accumulation. That’s a tenuous circumstance, similar to the snow for the Patriots in Foxboro, MA, back in October. By Saturday, most spots will be drying out but widespread gusts to 45 mph combined with highs only in the 40s will mean a chilly day with a few rain and snow showers scattered about, though periodic snow will continue in the mountains with near-blizzard conditions early. Sunday brings quieter but still cool weather regionwide before another storm brings rain for many – and perhaps some snow in the North – later Monday and Monday night.

For a full video technical discussion, see mattnoyes.net/new_england_weather/ where the discussion is streaming in the video window.

Accumulation Map appears in the video forecast: