Wednesday Forecast

379 Comments

3:39AM

DAYS 1-5 (FEBRUARY 8-12)
The low level cold air moved back into the immediate suburbs of Boston during the night with any wet areas frozen over. This also extends further north, west, and even southwest of Boston into the early morning hours so watch for icy ground and ice-covered vehicles. Allow extra time. As a cold front moves through the region this morning a band of rain will accompany it, and this rain may still freeze on surfaces that remain cold in areas northwest of Boston. There is a secondary trough behind this front that the cold air sits behind, so initially it will actually warm up after the cold front passes, something that is not all that uncommon here. The cold air will move in starting late today and especially tonight as the next storm system approaches. This system will pass just south of New England Thursday, while intensifying, and bring significant snow to the region. It may start as mix/rain south of Boston and especially toward the South Coast, but cold air will overtake this area too and result in mainly snow, though wetter in consistency than the drier snow that will fall deeper in the colder air to the north and northwest. Behind this a shot of very cold air follows for Friday. A weak low pressure system may bring some snow early Saturday but the majority of the weekend looks precipitation-free, until Sunday night when the next system may arrive with some light rain/mix/snow. The timing and precipitation type are uncertain at this time.
TODAY: Mostly cloudy with rain showers ending west to east morning. Partly sunny afternoon. Highs 52-60 by midday then turning colder late day. Wind SW 15-25 MPH with higher gusts, shifting to NW during the afternoon.
TONIGHT: Clouding over. Snow developing southwest to northeast toward dawn except likely starting as mix/rain south of Boston especially South Coast and may be mixed with rain near the South Coast. Temperatures fall through the 30s. Wind NW to N 5-15 MPH.
THURSDAY: Overcast. Snow, heavy at times, with the greatest risk for heaviest snow in the region from northeastern CT and northern RI through southeastern and east central MA. Expected snow accumulation 6-12 inches for most areas but may be under 6 inches in portions of southern NH as well as near the South Coast. Blowing and drifting snow especially north and west of Boston. Temperatures fall into the 20s. Wind N 10-20 MPH with higher gusts from the I-95 belt westward, NE 15-25 MPH with higher gusts elsewhere.
FRIDAY: Partly cloudy. Lows 8-15. Highs 20-28.
SATURDAY: Mostly cloudy. Chance of snow especially AM. Lows 10-18. Highs 28-35.
SUNDAY: Variably cloudy. Chance of snow/mix/rain especially late. Lows 25-32. Highs 35-42.

DAYS 6-10 (FEBRUARY 13-17)
Low confidence forecast here. Most likely unsettled with mix/rain February 13, fair/colder February 14, storm threat February 15-16 with snow/mix potential, and possibly very cold by the end of the period.

DAYS 11-15 (FEBRUARY 18-22)
Low confidence forecast here as well. Leaning toward dry weather and temperature moderation early to mid period and a storm threat toward the end.

379 thoughts on “Wednesday Forecast”

  1. This cold air coming back in during the evening made for a brutal evening at work. I’m not looking forward to my drive home now.

  3. Thanks Tk. Warm and foggy when I left the house this morning . Arrived in Boston around 3am and it was a lot colder .

  4. WINTER STORM WARNING IN EFFECT FROM 6 AM THURSDAY TO MIDNIGHT
    EST THURSDAY NIGHT…

    The National Weather Service in Taunton has issued a Winter Storm
    Warning for heavy snow…which is in effect from 6 AM Thursday to
    midnight EST Thursday night. The Winter Storm Watch is no longer
    in effect.

    * LOCATIONS…Eastern Massachusetts including the cities of
    Gloucester, Foxborough, Norwood, Cambridge, Boston, and Quincy

    1. As of now how early do we think it starts as I’m hearing multiple different times from midnight , 5am to 10 am.

  8. Thanks TK !

    The shallow cold air made it to Boston, wow !! The small scale features in New England truly make the weather so interesting.

    And it’s not like it dropped to freezing, it went several degrees below.

  11. I have never experience thundersnow in my life so I am hoping I could witness that tomorrow. Still looking like a solid 6-12 inch snowfall for SNE.

  16. I honestly can’t remember a short range temperature forecast as bad, with as big of consequences, as what happened last night. That was really, really bad. I don’t think anyone saw it coming, but that’s definitely the sort of event we have to remember and learn from.

  17. I don’t think Brookline even treated their roads once overnight. Streets are an icy mess! Not to mention the sidewalks. Schools in this area were stupid not to have a delay this morning.

    1. Because it wasn’t below freezing all night and the models didn’t indicate the shallow cold air would make it as far south as it did.

  20. Roads were not treated because they were not forecast to be icy. This falls squarely on the meteorologists. Need to first accept that, then ask why.

    Tomorrow: I suspected an eastward trend in overnight guidance, and we did get one, albeit pretty slight. Most indications still support a significant snowstorm tomorrow, and I agree with SAK’s thoughts from last night about the heaviest snow being near I95. It’s possible, however, that the track slides a little further southeast, and the highest totals end up more towards Plymouth to New Bedford. Overall, I agree with TK’s 6-12″, with the possible trimming back of the northern extent, and the possibility that even the south coast shares in the higher totals. 8-10″ should be common totals, but there will be banding so best to leave a wider range to account for some heavy bands and some gaps. Thundersnow very possible.

  23. You know, I really really hate ice and I was all happy because this wasn’t supposed to freeze. I didn’t quite understand why it wouldn’t, and I think I should have a job predicting freezing rain as I am actually quite good at it. I did tell my husband to put the car in the garage last night and he laughed at me! Anyway, the roads in Milton towards Boston (Rte 138) seem A-OK, but the sidewalks are pretty bad. Be careful!

  24. Thanks TK. With so many comments this soon I knew something was up

    Sutton has its third …I think…delay. They did treat in night at least twice. I have not known a town to do as good a job as they seem to do

  25. The city streets in Boston seemed ok but the side roads and side walks were terrible. I was skating down the street to the train this morning!

  26. The governor just implemented a 2 hour delay to allow road crews to treat the roads. A little late for this don’t you think?!?!? On my drive back to Sterling from Blackstone to temps were crashing big time. Went from 35 in Blackstone to 28 3 exits up on 146. When I got back to Sterling it was 21.

  27. My commute to work — which involves two MBTA buses and a .75 mile walk — usually takes about 45 minutes. Today I’m up to an hour and a half and I’m only 1/3 of the way there. This ice really had quite a domino effect on everything! The roads are so congested, the buses are packed.

    What was it that made this icing so tough to forecast?

  28. Good morning again. Commute in took about 45 minutes to travel about 3 miles.
    Roads were fine for me, but traffic congestion was ridiculous.

    Re: Ice
    It wasn’t just icy, there was a decent amount of ice accretion over night. It took me
    a fair amount of time to get the car cleaned off. I had to salt the stairs, walks and driveway.

    I heard on the radio that both Storrow Drive and Memorial drive were closed
    for a time. WOW!

    And I concur, WHAT A BUST on the overnight temperatures! Unbelievable!!!
    And with consequences.

    Hope all are OK and at their destinations.

    I took a quick peek at the Euro, NAM, GFS and CMC
    CMC farthest East and the Euro is a tad East, however, the GFS and NAM
    want to SLAM us, especially in a wide swath in Easter SNE, including Boston.

    On the instant maps kuchera method, both had boston in the 12-14 inch zone.

    Will post a few maps shortly. Have to get some runs going at work.

  29. 12Z NAM still wants to get things started in the boston area around
    9 or 10AM, while the GFS wants to start it around 6 or 7AM.

    A tad more than 24 hours out and no agreement on start time????

  30. Question. First, I agree with WxWatcher that we need to learn from this. Second, how did Sutton know the roads needed pretreating. I heard them in the middle of the night and then early morning. They did postpone school by two hours but it was later than usual, although in time to prepare if parents were watching/listening to their phone. That is not always possible with the morning rush.

    So to the real question. What happened that mets should have seen? And could they have seen it?

    1. Yeah it killed me. Left the AC heat on all night since it was suppose to warm up overnight. Obviously it couldnt heat and blew cold air all night and must have cost me a fortune in electricity.

      1. I woke up and turned heat down. And opened my window. I didn’t check temperature but figured it was warming up. Doesn’t your system cycle off if it is warm? I know the one we have will cycle off, but it is a Fujitsu so maybe either different model or newer model.

  31. Couldn’t get to my doctor’s appointment earlier this morning. A part of Storrow Drive was indeed closed for a while. I managed to get back home by driving down an icy side street. I decided not to do a detour as pretty much everything was iced over at that time. Why risk it?

    I’d say that when I left my house this morning only the major roads had been treated. I did see the salters and sanders on side roads a little later on.

    1. Here is the 12Z NAM Kuchera from Pivotal Weather

      http://maps1.pivotalweather.com/maps/models/nam/2017020812/054/snku_acc.us_ne.png

      and Instant Weather Maps

      http://www.instantweathermaps.com/NAM-php/showmap-conussfc.php?run=2017020812&time=PER&var=ASNOWI&hour=045

      I guess what this shows is more significant banding farther N&W from the
      center of circulation as the system is NOT hugging the coast.

      It IS NOT a boundary layer issue as in Boston temps are below freezing
      prior to and during the entire event.

  33. From NWS this morning:

    Hourly snowfall rates of 1-2″ will be common late Thu morning into
    the afternoon. There is even a low risk of higher snowfall rates
    along with thundersnow as both NAM/GFS have 200+ units of Fgen thru
    a deep moist layer and collocated with some instability via negative
    EPV. In addition this could be an efficient snow producer with some
    of the guidance suggesting the bulk of the forcing for ascent
    occurring in the snow growth region. This would result in snow
    ratios greater than 10 to 1.

    NWS snow map, rather modest actually. I thought they would be higher. We’ll see if it changes later today.

    http://www.weather.gov/images/box/winter/StormTotalSnowWeb1.png

  34. Here is my take as a someone responsible for snow and ice operations for a town in Central MA-at a certain point, you cannot rely on the weather forecasts to make your decisions about treatment. You have to look at the real time conditions and make your decision from there. There are plenty of sources out there for information on real time temperatures and trends. And you have to rely on the police on the roads to give you a heads up as to what is happening.

    Regardless of what was predicted for temperatures, you still have to go with what is actually happening. We were out treating till about 9:30 PM. Police called us out around 5:30 AM for treatment. No delays necessary where we were.

    When you blindly put your face in what others are telling what is going to happen, rather than look out the window and see for yourself what is actually happening, then you are setting yourself up for failure.

    I’m actually surprised by the issues with the state highways, as they have much more advanced snow & ice systems than most cities and towns. But a similar situation happened out in Worcester of 290 a couple of years ago. Glaze formed on untreated highways and a 75 car pile up occurred.

  35. HMMM…

    Looking at the qpf from each run, it only averages “about” .75 inch. Some have a tad less and some up close to an inch. With 10:1, we’re only looking at about 8 inches on
    average. With 12:1, then we are looking at 9-10 inches. We’ll need 15:1 to make
    a foot or close to it.

    The Pivotal Weather snow ratio, starts at 12-14:1 at the beginning and at the height of
    the storm it is 16-18:1. These ratios will have to be realized to get totals up over a foot.

    Here is the ratio map for 18Z or 1PM tomorrow

    http://maps1.pivotalweather.com/maps/models/gfs/2017020806/036/ratioku.us_ne.png

  36. Regarding the forecast for temperatures.

    What JRW said above is oh so right.

    Btw, We watched Harvey last night and he stated on air that there was NO WORRY for Boston as temperatures would remain above freezing all night and GO up towards dawn.

    WRONG!

      1. Of course not, However, that being said, I think a little less
        cockiness would be good.

        Something like, “I don’t think the cold will get into Boston, but we’ll have to watch to make sure” Or something to that effect.

        Just confidently stating that it won’t is irresponsible in my opinion.

  38. The only thing that will get the snow totals up there tomorrow is the Ratio combined
    with intense banding. If one does not get into the intense banding for long enough, then
    the totals will be down.

    1. Hmmmm…that snow map….hmmm..

      Let me get this straight —

      Boston at .66 QPF is getting 10.8 16:1

      Lawrence at .64 QPF is getting is getting 14.8 23:1

      Worcester at .76 QPF is getting 16.8 22:1

      Springfield at .78 QPF is getting 14.5 19:1

      Think I will be discounting that snow map and most of the others too.

      Pretty good agreement though of .6-.8 QPF region wide between 12zNAM/00z GFS/00zECMWF most falls in a 6 hour period.

  39. JRW – thank you for your comment. It was exactly what I had been thinking. At some point, it is necessary to just look out the window. I am suspecting the police also called the crews out in Sutton. Or they figured it out on their own as I have said I am very impressed by them. Daughter said they were out in the night at least one more time than I heard – possibly two. We did have a delay as sidewalks to bus stops were solid ice and that is not town responsibility. Although no neighboring towns had delays. I think Sutton is extra cautious…or it knows its roads far better that those of us just looking out the window. I’ve said a million times, I will always ere on the side of caution when it comes to our children.

    1. Re: Looking out the window

      I mentioned this once before, but this is CLASSIC

      Years ago, perhaps early 80s or so when Dick Albert was on Channel 5.
      At the time, he also did a radio broadcast on the old Weei.

      There was a storm approaching with a Forecast of a major snow storm.

      Dick Albert came on the radio during my drive home. He clearly called for a snow storm and said that SNOW would be starting very soon. Guess what?
      It had ALREADY STARTED, BUT the problem was, it was NOT snowing as it
      was RAINING!!!!! We NEVER got the snow storm as it was a RAINORAMA.

      Point being: LOOK OUT THE FREAKING WINDOW!!!!!

    1. Its a little up, more in the .8-.9 (say .75-1.0) range. But it was on the higher edge of the .6-.8 average of the 00z suite of NAM/ECMWF/GFS.

  41. Another limiting factor for this storm is that it moves more ENE by us and cuts
    of the precipitation a bit sooner than if it passed by moving NE.

  42. Just compared the 06z GFS to teh 12z and 12z GFS is a little further west with a stronger low pressure

  43. 12Z GFS Instant Weather Maps Kuchera Method Snow map:

    http://www.instantweathermaps.com/GFS-php/showmap-conussfc.php?run=2017020812&time=PER&var=ASNOWI&hour=045

    This is nearly a COWABUNGA map.

    Let me check Pivotal. Here is the Pivotal Weather Kuchera snow map. It provides a bit more detail as SAK alluded to the other day. (SAK thanks for reminding me about this site. I have it book marked, but keep forgetting to go there. I think it was either Mark or Ace that turned us onto this site)

    http://maps1.pivotalweather.com/maps/models/gfs/2017020812/042/snku_acc.us_ne.png

    1. That represents a pretty substantial snow storm, even IF the ratios are up there. 😀

      I’ll happily take it.

      BTW, GFS still wants to get it started in the boston area around 6-7 AM, which
      is pretty much what TK was indicating.

    2. Yeah, that was me – the Pivotal site is great. However, I think that snowmap is way overdone unless the QPF is up considerably on that run. Wont see ratios that high.

      1. Not necessarily. The GFS shows at minimum a 0.1-0.2 increase in liquid from its prior run. With snow ratios of 15:1, that translates to an increase in snowfall by a few inches so the pivotal seems right under those conditions.

      2. Not sure on the ratios. I know that typically they end up
        lower than forecast. But take a look at the cold feeding into
        this thing. This time around, I “think” that the ratios may
        just be realized or at least something close to it.

  44. Almost 11am and temps havent risen much. Now above freezing in most locales, but its gonna have to hoof it to reach the forecasted mid to upper 50’s

  45. None of what I have seen changes much of what I am thinking.

    Snow starts 4am-8am far west to far east. Heaviest 7am-3pm west to east. General 8-10″

    Some areas well north and west may only get to 6″ and the jackpot area which I still think will end up being south and east of Worcester into Norfolk County up to 12″

  46. One more thing regarding the GFS. At least on the Instant weather maps, it has
    wind gusts over 40 almost up to boston.

    http://www.instantweathermaps.com/GFS-php/showmap-conussfc.php?run=2017020812&time=PER&var=GUSTM&hour=030

    with 50 to 60 mph gust off shore.

    Sustained winds of 30 right along the coast.

    http://www.instantweathermaps.com/GFS-php/showmap-conussfc.php?run=2017020812&time=INSTANT&var=GRDM&hour=030

    In this morning’s discussion, the NWS had this wording: there is a low risk for near white-out conditions for a time Thu as gusty NNE winds combine with
    low vsbys.

    Should be a fun storm to watch and experience.

  47. That 12z GFS is pretty beefed up. All systems go. A quick hitting but significant snowstorm on the way. A forecast for a few selected locales…

    Boston: 11.4″
    PVD: 10.6″
    Worcester: 10.0″

    Should be some jackpot totals of 12-16″, maybe near the Foxboro/Attleboro area, or possibly closer in to the coast like the Blue Hill area.

  48. The QPF on that 12z GFS run definitely was up. A pretty widespread swath of 0.9″ with up to 1.0″ in places across much of interior SNE. Boston was 0.89″ That would certainly lend support for widespread double digit snow totals assuming ratios are greater than 10:1 and they should be.

      1. hmmmmm – just posted it is 46.6 here. Also had forecast spot on here yesterday. Maybe everyone should just move to Sutton and they will smile all the time! 😉

  51. Cold air is dense, it spreads out and has momentum.

    Southern Maine and coastal New Hampshire weren’t just chilly late yesterday, they were very, very cold.

    So, on its own, the cold air wants to spread southward just because of how dense it is.

    Add in to that a mini, small scale low which helped aid in the southward push of this very shallow, cold air and presto …… The temps crashed much further south than expected.

    I put the responsibility on the drivers, partly because of how fast new englanders drive, how they don’t adjust to the current conditions. I’d love to know the speed of the vehicles in each and every crash, I hardly doubt they were going 10 to 20 mph, which is probably what glaze warrants, and that might be too fast.

    This is a unique case that is nearly impossible to forecast unless you want to go against every piece of guidance out there and it requires a little help from the people driving. That’s my rant 🙂 🙂 🙂

    1. People are responsible for them selves in all aspects of their lives . To blame a accident on the meteorologist is irresponsible.

    2. I totally agree with you Tom, some of the onus has to be with the drivers. As a responsible driver you need to be aware of the current conditions regardless of the forecast. How many cars now have external thermometers? If you see its 32 or below you should have expected some icy roads. Then there’s the speed of some drivers. I saw a lot of SUV’s involved in accidents. Having an SUV with all-wheel-drive on black ice is no different than a front wheel drive compact car. You go fast, you will slide.

      1. Completely agree! I had cars flying by me last night at speeds of 75-80 on 190 with freezing rain falling.

  53. Last time I checked, meteorologists study weather. Some of us forecast it.

    I do not believe thinking for other people is included in the profession.

  56. In my neighborhood of Dorchester, not only were the streets treated but the sidewalks as well. The trucks have the traditional spreader in the rear and also guns on the sides that shoot salt onto the sidewalks. An ingenious idea IMO.

    JPD, have you seen these trucks in JP in use over the past few years as well? Just curious.

  58. @ryanhanrahan Pornographic snow growth modeled tomorrow. Big, fluffy, dendrites. #nbcct

    @ryanhanrahan We may have to increase snow totals across the state. All of this is going to happen in a ~6 hour blitz. #nbcct

    Ryan thinks snow ratios of 12:1 to 14:1 for the storm, at least here in CT.

    1. From what I see, “could” be 14:1 to 16:1 and perhaps even 18:1 here.
      We shall see. I wish I had a tool to take a snow sample, melt it and measure it. 😀

    1. Final accumulation maps not quite available, so I did my best adding up
      individual panels, but it looks juicy.

  61. Some thoughts on last night as a meteorologist who was on shift for the night:

    When the coastal front (because that’s what it was (slipped southward into the Merrimack Valley during the evening, temperatures dropped from the mid 30s to mid 20s in an hour, and a client in Tewksbury called us to let us know. I looked at the current obs, and took a glance at the HRRR, RAP, and the forecast we had sent out in the afternoon, and told him that it would likely stay cold for a few more hours, but the front should start heading northward again, and the warmer air would bleed back in overnight. Around 9pm, 2 clients, 1 in Andover and 1 in Concord, MA both called to let us know the same thing had happened, and I told them basically the same thing.

    Fast forward 2 hours – a client in Framingham calls and tells me that the temperature just dropped into the middle 20s and everything iced over “in a hurry”. I pulled up the current temps map and sure enough, the front was now approaching 128. The HRRR still insisted that this was as far south as the colder air gets and that temperatures would slowly drift up overnight. By midnight, when the colder air was starting to move into the Arlington/Woburn areas, I started calling all of our clients in the Boston area to alert them to what was going on. I told them that this was completely unexpected, none of the models had it, and and this point, my expectation was that the colder air would continue pushing southward until it doesn’t any more. I also told them that we weren’t going to warm up until the “cold front” came through mid-morning and shifted the winds into the west.

    When I finally left the office in Nashua at 4:30am, I had to scrape off the ice and snow that encased my car, but it was starting to rain and sleet and the temperature was 19. I cleaned off the driver’s side, then went to the passenger side. By the time I finished that, the driver’s side had completely iced over again. Driving down Route 3 and 128, unless I had my defroster on maximum and the highest hear setting, my windshield was literally icing over while driving down the highway. When I finally got back to Brockton at 6am, the front had come through here, and we were down to 30.

    The blame for the poor roads this morning does lie partially with the meteorologists. We’re paid to alert our clients before there’s a problem, so that they can be ready for it. When they’re all calling and telling me of the problem first, then I’ve failed.

    As for tomorrow’s system. I posted my initial thoughts last night. Since I literally just woke up, I am about to digest the 12z models and write a blog post. I will post the link here when it’s ready.

    1. Thanks matt, good write-up. I agree, the jackpot is still up in the air. Even in the jackpot areas there will be the usual places who get robbed. There will be some serious banding as this storm intensifies and passes.

  63. In my Boston neighborhood the major roads were treated (even so they were icy), but the side streets were only salted when it was already above freezing. I saw one truck salting at 10:45am, which seems like a waste of time and salt. Perhaps they’re thinking ahead to when it freezes over again – the salt will make it much harder for ice to form on the road.

    TK, your point is well taken. We’re responsible for ourselves and shouldn’t rely on others to decide or take action on our behalf. However, mets do inform our decisions. Sometimes they get it wrong, which means our decisions may be less well-informed. The best mets (eg, TK) explain to us post-hoc why an anomalous situation occurred, or why a model was inaccurate, or what the forecast failed to take into account.

    Looks like we’ll get a taste of winter tomorrow. Exciting. Even if it’s just 8 inches, I’m fine with that.

  66. OK, what is going here with the Euro? Convective feedback? Bad run? Or is this thing really going to overperform big time?

  68. Looking at the QPF output on eurowx.com, most of SNE is in the 0.8-1.1″ QPF range and there is a decent swath of 1.1″+ QPF from eastern CT and RI into portions of eastern MA. If ratios 12:1 to 15:1 are realized, we are looking at widespread 10-16″ with isolated higher amounts.

  70. This seems to be trending towards a snow blitz over not that many hours, because while the projected snow totals keep inching up, the pace with which the storm is moving is not slowing down.

    We’ve seen higher snow totals accumulate over longer time periods, but a 10 to 14 inch snowfall in 5 or 6 hrs is a different animal. This could be extreme impact on the roads tomorrow.

  71. I was just called into an executive directors meeting to discuss the snow tomorrow.

    Our Executive Director is leaning towards closing the office tomorrow.
    I told her that the timing of this was bad, but if staff made it into the office they
    would then have a problem getting home.

    1. This is the number one issue I have with companies. Make the damn call…my wife just told me she’s expected to be in tomorrow. Why? To say you were there then not be able to leave or get into an accident?

  72. I talked to my wife at lunchtime and told her to please not go into labor tomorrow….she didn’t laugh

    2. Perhaps you should take a room in town tonight to play it safe??

      Just a thought. Of course you could will the baby to wait, but that doesn’t
      usually work.

        1. Oh, I forgot about that. Perfect. At least then you are only a few miles from the Hospital. I presume it’s the Brigham, but just as easily be the BI.

      2. JP – I am just catching up to comments and was about to suggest the same thing. Ace…nice idea to stay with inlaws.

      1. Some models, in some areas, using some ratios? Yes.

        I really can’t reply to a blanket statement like that in any other way.

        1. Curious to know what you think the ration will be on average in say the Boston Area?

          I have seen maps indicating as high as 16:1 to 18:1

          So, is say 15:1 a reasonable possibility? I sure think so.

        2. You posted the 6z GFS snowmap in your blog which had uniformly lower snow amounts than the 12z runs across SNE. That was the basis of my question. If the QPF on the 12z runs verifies at 15:1 ratios, then your 7-14″ snow area would need to be expanded and the lower end of your ranges increased.

          1. I posted the 6z GFS snowmap because it most closely resembled my thinking, which is why I added the text with my specific thoughtrs for each area. I don’t just pick a model and say “here’s my forecast”. I look at everything and blend it. This is why I always explain everything in my posts and don’t just put up a map and say “here”. People only look at the map and don’t read the reasoning.

  75. Question for the experts. Are snow ratios strictly determined by surface air temperature or are other layers/parameters considered as well?

    1. Im not an expert. But it would be determined by the temperature of the entire column (not just 2m).

  85. 8-14 inches seems to be the popular forecast in CT.
    I could see places getting to that 14 inch mark or higher if they get into the heavier bands and if thunder snow develops. For a quicker hitter this could put down a lot of snow.

  86. I don’t like the pressure trend on this thing, in combination with some higher water content snows near the coastline the first half of the storm. Wet snow + wind = power outages. At least the heart of the storm hits at low tide.

    1. IIRC, you are leaving Friday early, where are you flying out of?
      I am leaving for Florida from RI early Friday.
      Any concerns of Delays for the Airports on Friday?

    1. Duxbury’s already announced, that will start the south shore rolling. I don’t think much of anyone will have school tomorrow in much of Massachusetts.

  91. Tom, saw your comment about wet snow. Is that more at the coast with drier snow inland or is snow expected to be wet throughout the area? Thanks.

    1. Immediate coastline south of Boston.

      Inland, a slight bit of water content at the very beginning, otherwise very powdery.

    2. I saw a projected temperature map posted earlier. I think it was for noon tomorrow. It was in the teens to low 20s inland, but it was still projecting 30F in Marshfield and even a bit milder on the Cape. It seems 5 to 6 inches of wet snow on trees with healthy winds is the magic formula for starting to get snapping branches and then obviously higher amounts to break bigger branches, etc.

      I guess for Marshfield Plymouth and the Cape, it’s up to mid afternoon that I wonder if we accumulate wet snow before the coastal front collapses to the coast. And then, when does the wind crank ?

      In NEMO, most of New England had a powdery snow blitz, but once you got to Hanover, pembroke and close to the coast on the milder side of the coastal front, the tree damage from wet snow was unreal. And ever since then, it’s always on the mind in this area during any northeaster.

      1. and the harbor buoy temp is at 43F so that might just hold relatively milder air along the immediate coastline for a wetter snow a bit longer.

    2. That’s why when I was in school (wasn’t that long ago), very rarely did they cancel the day before, very rarely.

      1. I remember a storm not long ago that was suppose to be big…I remember waking up to the sound of no plows…when I looked it we got zero.

        1. Yup, i think i know exactly the storm you’re referring to. IIRC, there was an outcry from parents that had to stay home or find daycare blasting the schools for closing the day before.

    1. Some lightning showing up in central Kentucky and northern Tennessee.

      Hope it works out for you tomorrow.

      1. Was just gonna mention that Tom, this thing is already juicing up and looks very well organized for being over that part of the country. It sure is hauling too. I wouldn’t be surprised to see the snow start everywhere prior to daybreak tomorrow and be going pretty good by then too.

  102. Tom I have seen just about every type of weather living here in CT including tornado when I was five but never have experienced thunder snow.

  105. 4km NAM is bonkers for my area 20.8 inches. The way this thing will be moving quick I don’t believe it could put down that much snow.

    1. The NAM pretty much all along, and to some extent the EURO, has been showing a jackpot near the NYC area and up into your area of CT

  106. I am practicing to be a TV Met.

    Millions in path; thundersnow will roar through neighborhoods; snowfall rates of 2″ per hour; cancellations everywhere; blizzard warnings issued; flights expected to be grounded; public transportation will be slowed; dangerous walking and driving conditions. Will report on updated forecasts at 6 and 11. Simply an epic storm!

    How am I doing?

  107. AceMaster will see if that pans out. I think the forecast our local tv stations are going with for 8-14 inches should be 10-15 inches.

  108. I am in Watertown the town over from Waterbury. We have had a lot of minor events this winter season where most of the snow melted in a day or two. The biggest snowfall I had was 7 inches back on Dec. 17th.

    1. This ASSUMES 10:1

      IF the ratio is the 15:1 we think it might be, this equates to about 20 inches
      of snow for Boston.

    2. Interesting the RGEM now joining the NAM with more snow north and west and a little shadow along I95

  112. Tom said: February 8, 2017 at 3:52 PM
    the harbor buoy temp is at 43F so that might just hold relatively milder air along the immediate coastline for a wetter snow a bit longer.
    Reply

    Tom mentioned south of Boston. Any thoughts on the immediate coastline north of Boston – e.g. Marbleahead, Beverly? Same concerns for heavy wet snow and falling branches?

    1. I think less of a concern because NNE of you is primarily land (Maine), so I’d think temps on the north shore will fall a bit quicker and earlier than they will on the south shore. On the south shore, a NNE wind is off of water for a decent distance. Our wind has to come around to NNW to really push the cold air in off of land.

      1. Thank you – that makes sense – appreciate this explanation as so often I see the south shore has different weather and it’s not that far away.

  113. This is a big ticket storm. We’ll wipe out most if not all of our seasonal snow deficits tomorrow. And more opportunities should exist down the line, although there will likely be a back and forth between the warm and cold.

    Wish I was home for this one! We should get several inches up here but well removed from the jackpot. Enjoy it guys, this is the one we’ve waited for!

    2. They’re aknowledging the little shadow along I95 that’s been showing up on some models. I’m guessing that’s due to banding and where they think it might set up.

  115. I saw we had the first HOLY CRAP BATMAN from you JPDave of the winter season. Last winter there was no HOLY CRAP BATMAN

  117. I just hope this pans out and if does WOW!!! for a storm that will not be a long duration storm the POTENTIAL to put down the amount of snow the computer guidance is showing.

  118. Tom thank you for your great explanation re heavy vs wet snow. As always thinking of you and the area we love. Which reminds me…time to reserve weeks for this summer

  119. Son is essential so he reports to work no matter. I’m surprised son in law has to go in. He cannot send service people on calls. JPD did you say your office is closed?

    1. Yes, indeed. Office closed.
      We had to do a special recording for our phone greeting indicating
      that we are closed due to the snowstorm. Of course, the phone system wants
      it as a wav file 8 bit mono, ccit, uulaw. That’s a mouthful. It was recorded
      as a windows sound file. I had to convert to a wav and then reconvert that
      to the final format. ALL worth it for a day off in the snow. 😀 I can’t upload it until tomorrow morning. 😀 Yes I can get on my work computer from home.

      Even though we were told in the office, in case some were not there and out on home visits etc, I have to send out a robo call this evening. Yup, I get to do that. Seems it’s too technical for others to do. he he he

  122. Yup big one on the way . We prepped all morning and we will be reporting at 4:30 am till sometime on Friday . Bring it on!!!!!

  123. Some excerpts from the 6:05 PM NWS discussion:

    Right now appears that when the snow
    beginning to approach we could see 1-2 inch/hour snowfall rates
    right at 11-12z. Aside form this slight adjustment, the
    forecast is on track for tomorrow`s event.

    Potent
    shortwave will result in rapid cyclogenesis as low pressure deepens
    about 20 mb in 12 hours as it tracks near the Benchmark on Thursday.
    The overall progressive pattern will prevent a widespread
    blockbuster snowfall, but snowfall rates of 2 to 3 inches per hour
    will be possible for a time.

    The storm will be under going rapid intensification which
    is ideal for heavy snowfall as mid level centers close off to our
    southeast. In fact, the GFS/NAM are both showing a back bent warm
    front at 700 mb with 30 to 50 units of omega in the snowgrowth
    region. This should yield a band or two of 2 to 3 inch per hour
    snowfall rates for a time and perhaps even a rumble of thunder. The
    SREF and NCAR Ensembles are both showing some probabilities of 3″
    per hour snowfall rates which also supports this thinking.

  126. JP Dave (always be old salty to me) you happy with this winter now?

    Just as I was losing faith in my months long prognostication that winter would be 2-3 weeks in February, along comes a reminder to BELIEVE!

    However, I don’t believe in 20 plus to 1 as a storm average

    2. No, I’m not happy with this Winter, however, I may very well be perfectly content with tomorrow’s storm.

      We shall see on the ratios. I have looked at enough to know some
      fairly high ratios are possible. Is 20:1 a stretch? perhaps. I don’t think 15:1 is.
      SREF shows ratios up to 25:1 towards the back end of the storm. With 15:1 or more throughout most of it. Closer to 10-15:1 at the beginning.
      My experience has shown the SREF to be extremely conservative with ratios.
      Often showing 5:1 to 10:1 for areas that actually ended up 12:1. So I just don’t know. I still 15:1 is almost certain with higher definitely possible.

      No matter what, tomorrow is destined to be interesting for sure. 😀

  128. JPD….I am in the same boat as far as getting the phone greeting recorded. However I can only do them via the phone system at this point. Already updated the employee line to say we are opening as normal. We plan to meet at 10:00 to make a determination at that point as to when to close. So all of our employees will probably drive home in the height of the storm. Good times.

    1. That’s too bad. Our director said she did NOT want to put her staff in
      that predicament. Kudos to her. I’m just about to record the reminder
      notice and broadcast. 😀

  129. Hi y’all! Major developments with my plans today which lead to a cancellation of the FL trip. It’s ok don’t worry!

    I will be back in a short while to answer any questions from above and give updated thoughts. And yes WW I’ll be on Zion in a while. 😛

    2. Darn, TK. But certainly better to cancel….hope it is to be rescheduled. …..than get stuck at the airport trying to get out.

    3. Want my ticket to Delray Beach Feb 19-23? You just have to stay with my wife, 8 year old, 5 year old, and in-laws in their 2 bedroom condo. There is a pool and shuffle board down the street….

      2. You deserve kudos for trying so hard to get out of this trip. I think we all need to focus on a major storm to keep you here

  130. Glad to see offices are closing. It’ll make it safer for employees and easier for the crews and also for Those who have to go to work to travel.

    Isn’t it fun how anticipating a snowstorm makes you feel like a kid again.

  131. Wanna bet many schools will be taking a four-day weekend even if roads are plowed in plenty of time for school opening Friday? I wouldn’t blame them though. I am assuming any snow ends by early tomorrow evening.

    1. They shouid be ready for Friday Philip. During snow storms it’s a two part as you have the upkeep during the storm keeping things open and the plan passable. The second is final cleanup when the snow stops .

      1. I wonder about sidewalks in cities such as framingham. There was a time they would not have school if sidewalks were not clear. In some larger areas that sadly doesn’t seem to always matter

  132. We are going to get a significant snow, but the 20-26″ amounts are extreme.

    A) Ratio maxes won’t be for the storm duration.

    B) Storm will move even faster than modeled. That I am
    CONFIDENT on.

    C) Dry slot forming in the CT River Valley

    D) Valley shadows

    E) Lower ratios near coast

    F) Rapid Drying west to east

    Almost none of the above is modeled, but frankly experience is better than a model.

    All the negating factors above, one bonus facto below –

    A) O Lift will allow elevated east facing hills to over achieve.

    1. Thank you. Great information. If it moves faster and we have areas in the range of 14ish inches, there will be some intense snow. It seems to me that intensity with lower amounts can be as dangerous as more snow over a longer period.

          1. Great news…both. And I am doing well also. Although I keep looking out the window which is a bit concerning 🙂

  133. I am kind of curious about at 700mb, the “back bent warm front.”

    I almost visualize something like an occlusion or the less cold, humid air making further inroads north and west at the 700mb level as compared to say, the 850mb level, but I’m not sure if that’s the idea.

    I’ve been looking at the 700mb maps, but I’m not sure if the signature of a back bent warm front is best scene in winds or temperature ??????

    1. I admit that my eyes got wider with each word I read. Please tell me a back bent warm front is a good thing

  135. 00z NAM is yet slightly lower in pressure and it holds the back edge of the snow in ever so slightly longer. Guess with the continued trend of a deeper low, a sign that the closed low and the surface low are really going to phase and perhaps that holds the western edge of the snow shield in ever so slightly longer ????

    At one point, there’s a 70mph sfc wind gust contour not too far from Nantucket.

  137. 2 thoughts ……

    If the NAM’s time frame is correct, the best chance in eastern mass for the heaviest snow is from 1 to 4pm.

    If in easternmost mass, it’s 9am and not a raging snowstorm, the storm isn’t about to underperform. 🙂 🙂 I see some signs on the NAM and on one of the simulated radars Eric was showing at 6pm that the steadier snow might not be in easternmost Mass until a bit after 9am.

  138. If those totals pan out there won’t be any snowfall deficits at BDL Providence and Boston for the season.

  140. Ryan Hanrahan ‏@ryanhanrahan · 14m14 minutes ago
    We’re 1 for 1 tonight with evening models showing a big storm. NAM trends even more impressive.

    Ryan Hanrahan ‏@ryanhanrahan · 1h1 hour ago
    I’m a little concerned tomorrow’s storm pulls a Feb 2006 and produces a narrow band with exceptional snow totals. Worth watching. #nbcct

  143. I was in that narrow band that produced 24-30 inches of snow in 2006. I ended up with 24 inches. Fairfield CT was the winner with 30 inches. That storm I remember started at 6am in the morning and was done at 4pm in afternoon.

      1. No we didn’t end up staying closer to Boston. We chose comfort over convenience. Plus we couldn’t find a dog sitter.

    2. Its like hurricane season, where I think New England has to worry about the middle of the alphabet because we usually don’t get hit until August or September.

  147. NAM looks pretty solid but still think it’s a tad far NW with heavy snow. Widespread 12+ clearly looks good. Will be interested to see where that coastal front sets up like SAK pointed out earlier. DBZ look very intense for sure.

  148. NWS tweet

    [Evening Briefing] new 00z NAM weather model supports blockbuster #snowstorm Thu w/2-4″ hrly #snow rates, #thundersnow psbl & 8-16″ totals.

  149. We shouldn’t lose sight of observations this evening, especially after what happened last night. Still well above freezing in most of SNE. Temps appear a little above most of the short range guidance. Doesn’t look like they’ll be any big plunge in temps overnight, more gradual. Possible that even places as far north as Boston start as rain drops? Would be a quick changeover if so, but temps will matter for ratios. Coastal front location will of course be very important as well when the heavy stuff arrives.

    1. Low ratios would be very short lived. Once the low hits the water and undergoes rapid bombogenesis, NNE winds cause temps to crash and snow ratios to rapidly rise. For the majority of the storm, ratios will be in excess of 15:1 (exception Cape and Islands). I agree that lack of radiational cooling tonight should negate a rapid temperature drop due to cloud cover but colder air is bleeding into New England from a reinforcement approaching from the northwest which should set the stage for snow to develop almost everywhere tomorrow morning.

      1. Coastal front likely to set up from providence to taunton to plymouth. Southeast of this front translates to 10:1-12:1 snow ratios while northwest of this front, temps will be in the upper teens and lower 20s resulting in ratios of 15-20:1.

        1. I can feel the colder air moving in. I was just out and it’s coming. The wind is already picking up.

      1. Only 32 here in Plymouth, NH. Will be slow cooling. I certainly agree with the gist of what arod is saying though. By the time the meat of this arrives, it’ll be snow almost everywhere, with good ratios especially away from the coast. For Logan, whole event totaled, I’ll say ratios around 12:1. Should go towards 15:1, even 18:1 further out.

  151. Couple more tweets from Ryan Hanrahan
    Really interesting theory on @UAlbanyDAES MAP list… mesolow off Carolina coast from SE severe wx event helping sharpen trough moving in.
    End result is a more powerful storm that models are starting to key in on with mesolow well resolved now.

    2. Check out what is cooking in the northwest quadrant of the US on that run. That could be our next mini cold weather maker on Saturday topping off the already impressive snow total with a few additional inches 😀

    1. Yes, we can’t seem to get a run to run stabilization on the pressure. Every 6 hrs, it’s going 1 to 2 mb lower.

      It’s clear that the models are projecting towards one of those “everything is coming together events”.

      I think explosive cyclogenesis is 24mb in 24 hrs ??? If so, this will be close.

      1. Correct! The central pressure is required to decrease by 24 mb or more in 24 hours. I believe they call this a weather bomb which is what we may be dealing with tomorrow.

      2. It should be close to 20mb/12 hours tomorrow. 24/24 is the traditional definition of a “bomb”, which this should do as well, but I learned from a big research project last semester that the criteria is actually latitude dependent. So it’s more like 20mb/24 hours around here.

        2. Thanks Arod and wxwatcher !! That’s pretty cool that it can be latitude dependent.

          I’m a little worried about the short time frame for such a big drop.

    2. Impressive. This is going to be a lot of fun. You may not be able to see the person next to you for a time tomorrow if caught under one of those intense thundersnow bands.

    1. That was from College of DuPage. Not sure why that site is higher?
      Regular NAM had 22 inches for Boston. 😀 😀 😀

    2. Certainly, if all the ingredients come together, a quick 20 inches isn’t out of the question somewhere in southern new england.

  158. When we have a storm forecast to deepen like this one, I always recall the dec 9th, 2005 system with the thundersnow, the few hours of 2-4 inch snowfall rates and the crazy cape cod wind gusts in excess of hurricane force.

    1. Tom when if was mentioned you would not be able to see the person next to you above, that was exactly the storm I thought of. I could not see one neighbors house

      1. We were on the southern edge of that heavy snow. I just remember opening the door to appreciate what was going on and getting startled by thunder and lightning.

        1. I seem to recall We measured six inches in an hour or of much more at one point. That was with the thunder snow

          Amazing storm. Timing wasn’t much different as I recall either with a horrific home commute

  159. I am no expert but I have a feeling that the heavy snow band should set up north west of boston from northern worcester country to nw if Middlesex county and probably sit there for a little bit. Same thing happend in Jan 2015 blizzard. I hope boston doesn’t get shadowed

    1. If you are talking about the late Jan 2015 storm we did quite well here in Hingham…in fact I believe the coastal front was our friend on that one.

  160. I cant post it here but I saw on fb the RAP model, not sure how accurate it is but it shows boston and the north shore getting less snow than the rest of the region. Dry slot? Does anyone think there will be a dry spot in the Boston area?

    1. It’s hard to pinpoint where the heaviest bands will set up, but I don’t see anything that should cause a dry slot over Boston. Now, could Boston or any location be temporarily in an area of lighter snow … Sure. I think the Boston area will do quite well.

      1. For Old Saltys sake, Boston better not have a dry slot.

        On that note…of to sleep. See you all and the snow in the morning Sleep well

  161. I don’t see many areas missing out on 10+ inches. Of course with this type of storm some areas will have jackpots. Though I still think NAM is too far NW with the heaviest axis.

    1. I don’t think any of us are doing that, just blasting out the maps we see.
      😀

      Clearly it’s going to be a fun day.

  163. Regarding WW and Arod’s discussion of the temps in Boston and south of the city. I am a little concerned when I see the temps still in the upper 30s to around 40 from Boston southward along the east coastal areas. That being said I’d be worried more if this were March 8th instead of February 8th. Interestingly enough the 10pm obs over the cape were showing clear to partly cloudy skies which could allow some radiational cooling down there before it clouds over a little later.

      1. The other thing I noted looking at the Wundermap temps is that colder air seems to be seeping in more from the west than northwest right now.

  165. Down to 33 degrees here in Coventry CT as of 11AM and steadily dropping. Should be no issues with precip starting as all snow.

  167. And just like that 12-18 inch band gets bigger, now moved into Merrimack valley according to Wcvb and NBC

  169. Down to 36 here as it slowly cools down. NOT worried about any start as rain.
    It WILL start as snow for sure. 😀

    1. Total qpf for Boston: 1.1811 inch, call it 1.18

      at 10:1 that’s nearly 12 inches
      at 12:1 = 14.2 inches
      at 15:1 = 17.7 inches
      at 18:1 = 21.2 inches

  174. 00z ECMWF now has a 30″ bullseye right over the StormHQ World Headquarters. That’s why I’m staying in a hotel here in Nashua when I finish my shift early this morning. Otherwise, I’ll never be able to get back into the office late tomorrow afternoon.

  175. OK, here’s a good laugh for everyone. The ECMWF, in addition to jumping off the deep end for today’s storm, also blows up the Sunday/Monday storm. I usually don’t like to share maps like this, but this was too funny to not share. Here are the ECMWF snowfall totals for the next 7 days:

    https://goo.gl/photos/pYWCaiErAAxq8MVc9

  176. After you all catch up here, you can head on over to the new post!

    I’ll be on the road around 7:30AM hopefully just beating the snow to my destination, then we’ll see how easy it is for me to return home during the peak of the storm……

    I’ll check in here when I can.

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