MATTNOYES.NET - NEW ENGLAND WEATHER ANALYSIS

Wednesday evening look at The Winter Classic weather

As the NHL's Winter Classic at Fenway Park nears, the forecast is gaining some clarity for the big day. I'm a bit intrigued by a follow-up shortwave early Fri AM, but think it will remain progressive enough and bring light enough precipitation that the ice will be able to recover. Of course, I'm no rink expert...so I'd better stick to the weather! This is the email I sent to the folks I'll be working with at the NHL and Versus network on Thursday and Friday, when I'm reporting live for them from Fenway. Relative humidity is referenced for ice maintenance and quality purposes.

"Hi All,

As the weather comes into clearer view, here are the updates:

Confidence has increased from low to moderate. I expect even higher confidence tomorrow morning, after this evening's model runs appropriately assess the storm that has now made landfall in the Pacific Northwest, and is racing across the nation.

The timing of the Thursday disturbance has sped up by about 4 hours from my previous estimate. Rather than late afternoon, precipitation should begin during early afternoon and be in the form of light snow, mixed with rain at times. Temperatures will still be about 37-38 degrees when precipitation begins (relative humidity 66%), then fall as the snow/rain combo starts. Total liquid equivalent is still expected to be on the order of .10"-.15", and should accumulate a sloppy inch or so. This should pause overnight Thursday night - probably by midnight - with temperatures dropping to about 32 degrees (RH 85%) - and then one more gasp of precipitation will be possible predawn to early morning Friday, once again as wet snow with some rain mixed in, producing liquid equivalent precipitation of about .10" (so, total Thursday to Friday AM precipitation is .20"-.25" liquid equivalent), with accumulations a coating to 3/4 of an inch.

Friday, it's looking more and more like we may get a relative break in the action, with occasional drizzle under cloudy skies and a high temp of about 37 (RH of 72%), as precipitation shifts just north of Boston and the next round gathers strength to our south. Admittedly, this is threading the needle with the snow/rain mix departing soon prior and still expected to be close by, but I remain optimistic provided the game can be played in drizzle/passing light rain showers of only a few hundredths of an inch, with temps of 37 and an RH of 72%.

I still expect much colder air - in the 20s - with a steady wind on Saturday, with snow developing, though timing of that development remains in question.

Looking forward to seeing you tomorow.

Best,
Matt"

A complex forecast for the Winter Classic at Fenway Park...

For those who are interested, this is the email forecast summary I distributed to the NHL, NHL Network and Versus Network regarding the forecast on the Fenway Ice heading into the weekend (I'm working with them as we gear for pre-game coverage Thursday and Friday...I'll be reporting for them on Thursday and Friday).  Relative humidity forecasts have been included for quality-of-ice purposes.  Of course, the big game is Friday at 1 PM, but the NHL says they will delay to Saturday if it's going to rain considerably on Friday...

"The arctic blast obviously has arrived, and the forecast remains unchanged in the near-term.

 

Wednesday:  Early morning temperature of 9 degrees (relative humidity 52%), scattered clouds at varying altitudes but essentially decent sun until the shadows take hold early afternoon.  Cirrus (high cloud) shield moves in mid to late afternoon, filtering sun a bit.  High temp at Fenway of 27 (RH of 42%).  West wind at 10-20 mph with gusts to 30 mph early, then diminishing to 10-15 mph with limited gusts late.

 

Wednesday Night:  Mostly cloudy - middle altitude clouds at several thousand feet.  Overnight low of 24, then slowly rising temperature possible after midnight (relative humidity increases through the night, from 55% early to 74% late).  Southwest wind at 5-10 mph.

 

Thursday:  Most of the day should stay dry, though mostly cloudy skies are likely.  High at Fenway likely to be about 38 degrees (RH of 59%).  Southwest wind at 5-10 mph.

 

Thursday Night and Friday:  Obviously, this is the biggest focus for you.  It continues to be the focus for meteorolgists, as well.  Here's the situation:  you will NOT find agreement in ANY forecast source.  The reason I'm sure of that, is because the disturbance that will be responsible for the evolution of the storm that will develop heading into the weekend is currently located over the Eastern Pacific Ocean, wedged in upper level winds that are blowing at nearly 150 mph.  This combination of a disturbance over the ocean (where we have very limited observations) and in such fast winds, means the computer guidance will NOT accurately analyze the disturbance.  Greatest certainty will be found in the guidance once the strong system moves over land, which will occur midday Wednesday.  By the time this data is fully assimilated into the computer guidance, it won't be until the Wednesday night computer guidance runs (data comes in between 10:30 and 12:30 Wednesday night) before I think you'll find good forecast agreement.

 

Having said that, there are some hints from the overall jet stream pattern:  It seems likely that temperatures will remain above freezing (middle 30s, RH around 75-80%) Thursday night.  The leading edge of the jet stream disturbance mentioned above will approach.  Scattered, mostly light snow showers will develop, mixed with raindrops, and continue into early Friday morning.  On Friday, precipitation will strengthen, but the big question is WHERE this band develops.  Indications are, this may deposit mostly light precipitation on Boston as a rain/snow mix Friday morning (.10"-.15" liquid equivalent precipitation).  But, we're talking about a difference of 100 miles in development of this band, on a system that is currently over the Eastern Pacific Ocean!  Therefore, it's with great caution that I pass along these details, because - as mentioned above - the meteorological guidance really won't be trustworthy in my eyes until Wednesday late evening.

 

Looking out to Saturday, the developing storm is really expected to take shape over the Gulf of Maine, and this will pull cold air back into New England on a west wind, with temperatures in the 20s and wind chill values in the teens.  The intensifying storm northeast of Boston will wrap bands of locally heavy snow into Eastern Massachusetts, but nailing the timing and intensity of these is obviously an exercise in futility, given the inherent uncertainty described above.

 

At the very least, I hope this helps to paint a vague picture of what I'm expecting now...and more importantly, highlights the timeframe when a more educated decision can be made."

Tuesday evening: Quick model preference overview

Just a quick note to share my thoughts on the guidance.  I've reviewed all available products and like the idea of about a 516 polar vortex over Hudson Bay by 12Z Friday, with a trough axis over Western Ohio draped through Alabama and Mississippi, and a ridge axis east of New England, over Nova Scotia.  I also like the indication of a second northern stream shortwave, well-defined over Minnesota.  This means I favor the longwave solutions of the 12Z GFS Ensemble mean, the 12Z ECMWF Operational, the 12Z ECMWF Ensemble (performing the best at 72 hours of all models this season), and the 12Z Canadian (GGEM) Ensemble.  You can peruse these models to see what this mean, but essentially it would mean light precipitation Thursday night as rain/snow mix, strengthening Friday morning while lifting northeast through Central New England, then waiting on significant storm development later Friday into Saturday east of the New England coast.  Unfortunately, even these similar longwave solutions diverge by Saturday, so nailing down location of the storm intensification is difficult, but I do think we favor a location over the western Gulf of Maine, which would wrap localized heavy wrap-around snowbands around the west side of the storm, even into Eastern MA as west winds increase and cold air snaps back across New England.

Matt

Arctic air arrives, but what about the weekend? Storm is likely, rain/snow line forecast unreliable at this point

Arctic air has been blasting in, and is here through the midweek!  Overall, the jet stream pattern looks like it would favor a storm strengthening near New England heading into the weekend.  I think it's important, however, to be very honest about the uncertainty still associated with the forecast, rather than feeding information to viewers that has an equal chance of being wrong as being right...

Snow squalls Monday, arctic midweek blast, winter mess to end the week (and year)

I want to get something out for those of you looking for my thoughts on the upcoming pattern...I've been keeping close tabs on the end-of-week (end-of-year!) forecast, since I'll be reporting live for Comcast's Versus Network and the NHL Network on Thursday and Friday from Fenway Park for the Winter Classic.  Here's what I shared with them in last evening's summary (Sunday eve):

First, Monday of this week will be interesting (many of you are probably reading this on Monday).  A very strong disturbance aloft will move through during the midday to early afternoon (centered around 2 PM), carrying a windswept band of showers and downpours with it, that will mark a sharp wind shift from a south wind to a west wind.  Brief thunder is possible when these swing through, and the burst of rain may end as some snowflakes.  Temperatures during the morning at Fenway will rise from the middle 30s early, to the lower 40s by midday, only to fall back into the middle 30s by late afternoon as the wind gusts to 40 mph behind the showers.

 

Midweek brings deep cold that settles in on the active wind Monday night, and keeps temperatures in the 20s Monday night and Tuesday, with limited sun amidst bubbling clouds.  Winds continue gusting to 40 mph from the west and northwest on Tuesday.  Tuesday night, very cold.  Clear skies, still an active wind, low temps around 10 at Fenway!

 

Wednesday is sunnier, still cold.  Highs around 26.  West-northwest wind at 12-20 mph.

 

Thursday and Friday are not only our main event at Fenway, but also our main event to watch, weatherwise.  I'd mentioned to Sam when we spoke about a week and a half ago that there was a distinct window of opportunity for a coastal storm either side of Friday, and that continues to hold.  Here's what we know:  Substantial southern jet stream energy will carry Pacific moisture - then team with Gulf moisture - to stream a band of precipitation up the Atlantic Seaboard on Thursday.  At the same time, a strong northern stream Canadian disturbance will pivot through the Central Great Lakes, helping to strengthen a developing center of low pressure off the Mid-Atlantic coastline.  The most important and difficult question at this point is timing - the issue is how quickly the northern and southern stream energy merges.  At this point, however, I see decent agreement among the guidance for snow to stream north into Boston Thursday night, continuing into Friday.  The snow may come down heavily at times early Friday morning.  At this point, I'm expecting this burst of snow to taper in intensity by Friday midday, with the potential for light snow lingering through the day.

 

Potential changes to watch:  1) Timing.  I expect little change on the front edge (beginning) of the precipitation Thursday night.  The duration, however, may be extended if the northern stream disturbance can move east a bit quicker than currently forecast.  2) Precipitation Type:  In Boston, when an east wind develops, meteorologists get a bit twitchy, because we have a 46 degree ocean just to our east.  A due east or east-southeast wind, even for a brief time on Friday, would allow for a flip to rain for awhile on Friday.  At this point, I think this is a low-probability scenario, given both the strength of preceding cold air, and the likelihood that the storm center will stay south of Boston, keeping the wind out of the northeast, and meaning snow would be most likely.

While major storm buries Central U.S., subtle features important in New England

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

As epic storm strands motorists, New England gears up for blast of snow

The major weekend storm sweeping up the Eastern Seaboard left a mark early in the game.  Reportedly, hundreds of cars are stranded on Interstate 26 in North Carolina as of this writing, with no hope of getting out, meaning broad scale rescues will be needed - including digging folks out - after the storm moves out of there on Saturday.  Meanwhile, I'm still expecting historic amounts of about two feet of snow in Washington, DC, easily taking the prize as heftiest December snow on record in the nation's capital and rivaling the greatest storm snowfall ever, and one to two feet through most of New Jersey and Philadelphia.

In New England, snow will overspread the region during the afternoon in Southern CT, and during the evening for most of the rest of Southern New England.  We will remain on the northern side of the storm, but it will reach peak intensity while passing south of Montauk Point in Eastern Long Island.  This means blizzard conditions are probable from Eastern Long Island to the South Coast of Rhode Island through the Cape and the Islands.  Blizzard conditions are sustained winds of 30+ mph (or frequent gusts 35+ mph) with visibility below 1/4 mile in falling or blowing snow for at least a duration of 3 consecutive hours.  It seems likely that the highest snowfall amounts in New England will fall just on the cold side of a front that develops about 12,000 feet in the sky, which will set up for the South Shore of MA west to Northern RI.  In this corridor, 12"-18" seems likely, with an isolated 20" amount possible.

For those who follow the guidance products, I feel the GFS has mishandled convection over the DC area fairly early in the period and suffers convective feedback thereafter in its 00Z Sat run.  The NMM, owing to its superior resolution and convective parameterization, seems to handle this much better, and is my model of choice.  As for the snow to water ratio, the atmosphere warms between 800 and 700 mb, and this cuts back on ratios a bit.  Though the deformation band mentioned for some of Southeastern New England will result in more effective snow growth, many of us will see ratios on the order of 12:1.  This yields rough estimates of:

Southern NH (Manchester points south): 2 or 3"

Coast of Maine: 2 or 3"

Lawrence/Haverhill, MA: 5 or 6"

Lynn/North Shore MA: 8 or 9"

Boston, MA: 9"

Most of Southeast MA: 12"-18" (isolated locally higher)

Cape Cod: 12"

Eastern CT and RI: 10-12" (some higher amounts Northern RI)

Worcester: 8"

Berkshires to Greenfield, MA: 2 or 3"

Updated at 12:00 PM: Epic and historic snowstorm to bury Mid-Atlantic...glancing blow will still be significant for Southern New England

A bundle of deep tropical moisture is lifting north out of the Gulf of Mexico and about to encounter deep cold air draped across the Eastern Seaboard.  This will result in an historic East Coast storm that will drop three feet of snow in some of the mountains of Western Virginia, Maryland and Northern West Virginia.  Metropolitan areas of DC, Baltimore, Philadelphia and most of the Interstate 95 corridor will see up to two feet of snow.  Blizzard conditions will occur on the western side of the storm, perhaps as far inland as Washington DC, but more likely from Long Island through New Jersey into Delaware and Eastern Maryland later Saturday.  Snow moves into New England later Saturday afternoon to Saturday evening from south to north, and tapers by Sunday midday with this fast-moving storm.  Accumulation map is included in this video - one thing to add, though...just after this broadcast I added the February 10-12, 1983 reference onto the snow map.  I did this because this storm has such a similar look, and in that storm Southern New England recorded 10"-20" of snow.  While I'm not currently forecasting that with this storm, I want to at least acknowledge that if the similarities continue, higher amounts will occur.

**Noon update:  New guidance is in.  Good agreement with the forecast.  All looks good for now.  Important to note that while I've labeled only the 6-12 and 2-4 areas, that does not mean you're one or the other.  For instance, the MA Turnpike should see somewhere just over half a foot.  Please interpolate for your location between the 2"-4" zone for the NH/MA border (and coast of ME) and the 12" expected along the South Coast.  Overall, currently I'd expect either side of 3" extreme Southern NH, 7" MA Pike, 12" Central CT/RI/SE MA, 15" South Coast.  Blizzard conditions possible very late Saturday night and Sunday morning from Long Island to Cape Cod...

9 AM Broadcast:

5 AM Broadcast:

Still Keeping the Door Open to a Weekend Snow Potential...

Throughout the week, I've been slow to close the door on snow potential for this upcoming weekend.  I 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

Though deep arctic cold still en route, snow chances diminish in the near-term

For a couple of weeks I've been closely eyeing this Tuesday or Tuesday night as a potential storm for New England.  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, I had strong suspicions we would involve 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!  -Matt