Monday Forecast

319 Comments

7:26AM

DAYS 1-5 (MARCH 5-9)
The active weather pattern goes on with one disturbance that dropped a little snow overnight departing now, a break but a gusty breeze today and a more tranquil Tuesday but clouds moving back in ahead of the next storm system which will impact the region Wednesday into Thursday. There will be a rain/snow line with it but it is expected to bring a significant snowfall to a good portion of the region. Early call is that a low pressure are will track northeastward and pass over or just southeast of Cape Cod. An upper level disturbance following this will prolong unsettled weather in the form of a few rain/snow showers on Friday. Forecast details…
TODAY: Mostly cloudy with lingering light snow showers possible through mid morning, then becoming partly sunny. Highs 38-44. Wind N 10-20 MPH with higher gusts.
TONIGHT: Partly cloudy. Lows 28-35. Wind N 5-15 MPH with higher gusts.
TUESDAY: Sunny start. Cloudy finish. Highs 38-45. Wind light variable.
TUESDAY NIGHT: Cloudy. Lows 25-32. Wind light N to E.
WEDNESDAY: Overcast. Snow and rain arriving, with rain most likely Cape Cod and Islands, snow along and west of Boston-Providence corridor, and mix in between. Significant snowfall accumulation expected where it is mostly snow and all snow through the nighttime and overnight, with early call of 6+ inches in all snow areas, 3-6 inches in mix but mainly snow areas, and under 3 inches in mix but mainly rain areas. Highs 32-45, mildest Cape Cod. Wind E to N 15-25 MPH with higher gusts.
THURSDAY: Mostly cloudy. Snow/rain ends early. Breezy. Lows from the upper 20s to middle 30s. Highs from the middle 30s to lower 40s.
FRIDAY: Partly sunny. Chance of a few rain/snow showers. Windy. Lows from the middle 20s to lower 30s. Highs from the middle 30s to lower 40s.

DAYS 6-10 (MARCH 10-14)
Blocking pattern remains in place. Fair and milder weather but a breezy start to the March 10-11 weekend. Storm threat looms for March 12-13, though too early for details. Improving weather March 14.

DAYS 11-15 (MARCH 15-19)
Blocking pattern weakens. One or two systems may impact the region but the overall trend looks like weaker systems and moderating temperatures overall.

319 thoughts on “Monday Forecast”

  5. Thanks TK!

    For a first crack at it, I think the NWS Boston “most likely” map is a good one. I like how they’ve tried to show how sharp the cutoff may be to the east. The GFS is too warm as usual, at least for the track it’s showing. There’s definitely room for that implied rain/snow line on the NWS map to shift in either direction, but if anything I would say it maybe pushes a little closer to the coast.

    It looks like the vast majority of precip is expected to fall in the overnight hours, which is very important this time of year. Combine that with cold 700mb temperatures, and ratios shouldn’t be far from 10:1 even though the surface won’t be very cold.

    1. I agree. And most forecasters will say the peak will be at night and people all over the place will still be wondering why there isn’t a foot (or whatever) on the ground by NOON Wednesday calling it a “bust” etc. Watch… 🙂

  7. Thanks TK !

    Poor pembroke. My dad is still without power. 49F in his townhouse and they got about 2″ of wet snow overnight while it rain/snow mixed at my house.

    1. Tough situation Tom . Quite a bit of snow fell overnight . Still no power in the center area where I live but parts of town had restored overnight . I didn’t check the temp when I left for work but it was 52 at 9:00 when we went to bed . I’m suspecting school will be out tomorrow as well as restoring the power is only part of it .

  8. So is Boston in the 6+ or 3-6 inch range? I imagine Boston will be “on the fence” as usual?

  9. Good morning and thank you, TK

    I think we have set multiple records this season got the longest time snowed with the least accumulation. It is a beautiful morning here, but still just ugly by the coast

    Humarock folks are reporting power in several places with all power possibly on by noon. It seems to me that with the overwhelming destruction that the power companies have done a good job. The comment from Hull IMO was unnecessary.

    If anyone is looking for a place to eat, the bridgewaye is open.

    1. Does the Bridgewaye have power or are they on a generator? I have a friend who lives up on the hill behind the restaurant and he is still without power.

      1. Sue, the reports on the Humarock FB page are spotty. There is power on central ave from Marina towards cliff but not on cliff from what I’m understanding. Another said “Yes by north river beverage/ bridgeway”

        Several said they heard the trucks rolling in last night and it should all be on by noon today.

        1. Now I’m hearing ocean ave down by Franklin has power. So it is coming on in sections rather quickly.

        1. I do not have power. Hoping they make some progress today as there are still lots of trees and wires to address on our little street.

          1. It is such a slow process when that much is in the way. Good luck. May I assume there is no school? Work? I know many of your locations were without power also.

            1. No school for the boys and they are now at my mom’s since she got her power back. I am at work and quite frankly, happy to be here. We only have 3 branches without power today, Scituate, Pembroke, and Chatham.

              1. I’m impressed that all but three are on. Mostly, I am very happy to hear your mom has power restored.

    2. The power crews have there hands filled Vicki . I thanked everyone I saw last night. Crews are here from Canada

  10. someome the other day made a comment the other day about “the big nor’easter they’re saying we’re going to get again this week.” To which I found myself responding. The way the weather works now is First, you pick the desired outcome. Second, search the internet to find the model and accompanying Facebook / web pages that validate the prechosen outcome. Third and lastly check the chosen models and Facebook pages every five minutes until either you are proven right by what actually happens in the atmosphere or you left in a bitter, angry pout screaming “bust,” and “I can’t believe these people get paid to be wrong most of the time!” Unfortunately this phenomenon seems all to prevalent with almost all news these days. I suppose it’s only natural that we all want to be right. I think people always had these conversations? It’s just that now there are so many more and more public ways to hear these voices….

    1. This is why you can find “data” online saying the earth is getting hotter and also find data that an ice age is coming. People pick a side and cling to it regardless of truth and reason.

      1. I would agree with that with one small exception. I’d insert “Irresponsible” as the first word of your second sentence. We have many responsible media outlets. I do believe a person should not use just one. And our own mets did an excellent job with this last storm which we know, from reading here, was anything but simple. I don’t understand why folks would turn anywhere else for weather. And you are right that irresponsible folks do pick a side and gravitate toward anything that supports that view and then stick to it.

  12. So what time does this all start on Wednesday? Afternoon? Is most of the day ok and the evening commute will stink? Thursday morning commute is a nightmare?
    Not sure what to expect here.

  13. 9Z SREF Plumes (ensembles) show an uptic in snow for Boston over the 3Z run.

    Esemble mean: 8.48 inches for Boston
    High: 18.89
    Low: 0.03

    And for once, the ARW and the NMB members are all quite consistent.

    Here are the plumes.

    https://imgur.com/a/DRcAE

  15. The 12Z NAM is coming in TUCKED to the coast. NOT good if one likes snow.
    Very good if one does not like snow.

    Either way, NOT good for the wind.

    2. The sucker is going inland over Eastern NJ!!
      Ok, let’s just bring on Spring. No more Masquerading as Winter.

  20. Well, the 12z NAM got our attention here in Plymouth, NH. Obviously, with that track, you will not get snow in coastal SNE. Lot of people have made this forecast seem like a slam dunk, but as usual, it is not. Bear in mind the Euro/UKMET have been colder and further east. We’ll see in a few hours if that changes at all.

    1. Oh, to be sure. My fear is that the Euro and Ukmet will now also track more
      West. Here’s hoping the NAM is wrong.

      But, hey, If the NAM is correct, a bonanza for Ski country and that
      is a really good place for the snow. Many areas in SNE have no need
      for snow at the current time.

  21. I am wondering if the models are not “seeing” cold high to our north is why their trend is focusing west? TK is insisting that a cold high is not required but are some of the models thinking otherwise? I hope I am explaining myself properly.

    Models are not human mets obviously.

  22. Next storm is a no win situation.

    NAM = quicker phasing, stronger storm, more wind.

    EURO = slower phasing, slightly weaker ….. further eastward tracking storm with less wind but, more wet snow potential in eastern areas.

    1. When you put it that way, I agree 100%.
      But I think If I lived on the South Shore, I’d opt for the snow
      and NOT the wind, but that is just I.

      Given those 2 choices, which would you chose? Just curious.

      One thing good, the regular high tides are much lower
      on 3/7 and 3/8. W ed. night is 9.29 feet and Thursday am is 9.61 feet.
      That will be most helpful.

      1. Yes, I agree. Take my chances on 6 inches of wet snow and 30 mph gusts vs 8 hrs or so of 45 to 50 mph gusts.

        The declining tide heights will be very helpful to the immediate shoreline.

        1. I agree also. They just started working on the downed wires on my street so I am hopeful for getting our power back today. Fingers crossed!

        2. I sure agree with that, Tom.

          Sue, keeping fingers crossed you pop on here VERY soon and say power is back.

  23. With the models trending more west, they are showing one of the concerns I have had. There is nothing keeping the storm from moving further inland. The nam is not in its good spot at the moment. The gfs is the gfs and I think the euro been on this system and been rather consistent. Its again the international models vs the us models.

  24. Hello All.

    Regardless of the type of precipitation on Wednesday, can someone give me an estimate of when it will start in Boston?

    Thank you.

  25. Hi all…
    Looking at the predicted snowfall map for the mid-week event with my untrained eye.
    It’s amazing what a difference of 10-15 miles will make. 2″ in Taunton and 8″ in Foxborough.

    Tom…We’ll be in school until the Fourth of July at this rate! You bring the chicken wings. I’ll bring the potato salad.

    1. If that is the case, I may just go back to school.

      Seriously, though, I’m hoping (against hope I am sure) that with the SOE some of the days may be waived.

      1. You’re right. It is about 30 miles. We have had situations in Middleborough where it’s been raining on the Rochester-Wareham line and heavy snow on the Bridgewater end. It makes it very hard for our super to make a call on school cancellations.

  31. Have been meaning to share these photos with y’all. With some free time on my hands this morning and an understanding of Imgur, here are some photos I shot about three years ago at the Cape Cod Canal and at Onset Beach. The first is one of all-time favorites:
    Either this gull is one of God’s smartest creatures or His laziest:

    https://imgur.com/a/ze0L8

  35. I hope the power is back on real soon, Sue.
    I am also heartbroken for your child’s teacher
    and the tragedy with her husband in Plympton.
    Also, my thoughts are with Hadi, too.

    1. Thank you Captain. Certainly my power issue pales in comparison to what that family is going through. I try to remind myself that when I get frustrated about our situation.

      2. NOT for the coast.
        Has “about” 3 inches for Boston.
        Near 5 for Woburn.
        Have to go NorthWest young man, Northwest.

        Bummer run if you ask me. Total qpf about 1 3/4 inch which isn’t shabby.

        So, we shall see, but clearly not looking so great for snow in Boston. I just hope they get enough to add to the season total
        and get closer to “average”

        Btw, anyone have their total for today and their season total? thanks.

        1. Weatherbell shows alot more for Woburn thought? I noticed the euro totals are different depending on what service you use. But you are probably right. Trend is not our friend anyway. We are still almost 48 hours away. And I have a feeling the west trend is not over. What a bummer. Eastern mass gets shafted yet again in terms of snow

            1. Yea I have been noticing that. I got my hopes up just to be dissappinted at up Dave’s snow map

    1. my service shows much more for areas just outside the city as well as interior southeast mass. I am looking at the QPF for the storm and temperature, shows 10+ for snow for most along and west of I95/128. Talking feet in portions of ski country which is much needed 🙂

      Here is the liqud in the form of snow. This does not put into account any snow ratios, but gives you a general idea.
      Areas outside of 495 into central mass up into northern new england can see up to 2 feet. . with 6-12 the rest of the area along and west of I95 based on this run.
      https://weather.us/model-charts/euro/massachusetts/acc-precipitation-snow-total/20180309-0300z.html

      1. Thanks matt. You posted something like this from the euro a few days ago and im still confused. Is this showing total snowfall in inches? OR is it showing liquid equivalent in inches that falls in the form of snow? It isnt very clear.

        1. the second, its showing the liquid content of the snow. so if you melted all the snow you get, that will be the amount of water you get. So lets say you get 10 inches of snow, and you melted it with no evaporation in the process, and you get 1 inch of water. that one inch of water is what this map is showing.
          This map does not show any snow ratio’s so its a different step, but based on temperatures and the liquid in the form of snow you can get a general idea of snowfall.

          Example based on this map. Water falling in the form of snow, will be around .8 to 1 inch in the city. But in the city its more likely going to be 3-6 due to the lower snow ratio. The same amount of .8 to 1 inch of liquid in the form of snow, out in lets say.Amherst Ma, will be closer to 10 inches. Due to a higher snow ratio.

  38. ALL models have been hot garbage with snowfall amounts this winter outside of 2 days. Wait till tomorrow, it will change

  39. TK….or anyone …I’d sure appreciate advice. We have a meeting Friday just south of Stowe, Vt. I attend remotely, but my business associate had planned to travel wellesley to Stowe on Thursday. I have the sense that might be a difficult drive and maybe Wednesday would be a better departure date.

    I’d appreciate any Input. Thank you!

    1. I am really hesitant to answer a question like this and you should really wait for TK. But my feeling is that neither day would be good Unless your associate
      were to leave rather early Wednesday AM. Like 6 AM or so to play it safe.

      1. Thank you, JPD. It would make sense to me that if he goes Wednesday it should be as you say.

        I’ll repeat the question if this one gets too deeply buried and TK doesn’t see it. Maybe even tomorrow would be an option.

  41. I got an access forbidden message.
    Thank you for trying. There is one more thing you can do.
    Take a screen shot and save it, then upload it Imgur.com

    thanks

      1. No account.
        If you try via mobile, you will have a problem
        From your desktop just put
        imgur.com
        in your browser.
        Click on new post then upload images.
        Select the location where you filed your screen shot
        it will load it and give you an url. Post that url to the blog
        and you should be in business.

        much appreciated. many thanks

        btw, does Weatherbell say it is Kucher Snow? Or some other method?

        thanks

    1. Thank you Kane.

      That represents quite a difference.

      not for nothing,but looking at my services precipitation type map, it
      has mostly snow for Boston with perhaps a brief interlude of rain or mix.
      Therefore, My services numbers do, indeed, appear low.

      I will email the site host. He usually answers me with a well thought out and
      reasonable response. Will let you all know.

      Many thanks again.

        2. Why do you want a good thumping? I’ll shave ice at your front door to save us from snow and to keep you happy. lol

      2. I have emailed my service. Waiting on a response.

        many thanks again. (PS I did not post any maps, just explained
        the discrepancy)

      1. Shows about 11 inches inside 128 down to about 4 inches at
        the airport itself. Best I can tell, that 11 inches goes right
        about to JP, then starts to drop from their to the airport.

        Of course, we’re still 48 hours+ from this event, so nit picking
        over 5-10 miles is absurd at this point. I understand that, merely
        going over what this particular run shows.

  51. Hot off the Press from the NWS at 3:54 PM

    .LONG TERM /WEDNESDAY THROUGH MONDAY/…

    Storm Highlights…

    * Major Winter Storm Likely Wed into early Thu for parts of SNE
    * Potential for 8-16″ of snow northwest of mixed ptype/dryslot
    * High uncertainty near the I-95 on rain vs heavy wet snow
    * ENE wind gusts of 45 to 60 mph possible on the coast

        1. That could be a problem. Could really get interesting.
          Wonder what the gfs will show. The 12z gfs qpf
          was off the chart!

  52. Hi all! I’m only here very briefly. I had a busy day which is not quite done. I won’t be able to catch up until early evening, so if anyone asked me anything and I haven’t responded I may have you re-ask a bit later instead of searching the entire string of comments. 😉

    I’ll be back around 6:30 or so.

  53. Tom, you would k ow where these houses are. I am fairly sure I know but not positive. I do know they are Brant rock. BZ has a video from there. The waves are still splashing over into this. I cannot begin to describe how sick this makes me feel

    https://i.imgur.com/dGkPqUE.png

    1. Yes, that’s Brant rock for sure. A few waves, after hitting the sea wall, the thick splash was still clearing the tops of these houses this afternoon.

  55. Right now I don’t buy the warmer edge of the guidance envelope. I can see the rain/snow line getting to I95, but not much further, and I think it’s possible even the east coast of MA, including the city, sees mostly snow. Southeast MA/Cape is likely more of a rain event. This storm will be in its developing phase as it passes us, meaning some very heavy precip rates are likely Wednesday night. Wouldn’t be surprised to see some thundersnow. Dynamic cooling will definitely be a factor, and with a colder preceding air mass than the past storm, I favor more snow than rain in most areas.

    1. I like your style. Now, I hope you are correct.
      Could get pretty hairy around these parts Wednesday night.

      1. It could. Obviously, if the low center does track farther west, then rain will be much more of an issue. But even with the 18z NAM taking the low center right over Nantucket, it’s still all snow just outside I95. That to me suggests the rain/snow line will struggle to push inland, and future hi-res guidance will likely reflect that if they show a similar or slightly more eastward track than the latest NAM.

    2. What do you think of a dry slot happening in eastern mass? Or is it more likely south eastern mass who gets it?

      1. Eventually the dry slot will move up over the area, more so southeast Mass assuming no big shifts west in the track. Because the low is still developing rapidly as it passes us, the dry slot will be quite small to begin with, and then will expand as it’s passing over us. Any areas along and west of the storm track will get significant (1″+) QPF even if a dry slot eventually works in.

  56. sustained winds or wind gusts consistently 33mph +
    with visibility near white out conditions, for three hours…….
    chance of blizzard conditions I think Portions of Eastern NH and down east Maine. maybe Eastern Essex county….

  57. 18Z gfs is playing its boundary level game again.
    850 mb temps are AOK, yet it shows virtually ZERO snow near the coast.

    I will be checking the 925 mb level when I can see it on pivotal or COD.

    1. both euro and gfs been very consistent with their forecasts, I am going with what all the other models are showing 😉

  58. Presumably this is the reason the gfs has mostly rain along the coast.

    Surface at 60 hours:

    http://maps1.pivotalweather.com/maps/models/gfs/2018030518/060/prateptype_cat.us_ne.png

    925 mb at 60 hours:

    http://maps1.pivotalweather.com/maps/models/gfs/2018030518/060/925th.us_ne.png

    850mb levels are cold enough

    http://maps1.pivotalweather.com/maps/models/gfs/2018030518/060/850th.us_ne.png

    So the GFS says that there will be a warm conveyor coming in from the ocean
    that will change the snow coming down from above to rain.

    NOT BUYING that at the moment.

  59. The GFS boundary layer physics are horrible. We had this discussion, led by the great Lance Bosart, during a map discussion while I was at UAlbany the other day. It struggles, and is in many cases totally unable, to bring the near surface temperature/dew point spread to zero during precipitation events. It’s a fundamental error in the model physics, and it didn’t use to be that way. All the models pretty much have the same track/intensity at this point. Why is the GFS the only one that pushes the rain/snow line into west-central Mass instead of just slightly beyond I95? It’s broken. There is literally no way, with that track, that rain/snow line will go beyond Worcester. To and a little beyond 95, yes, but dozens of miles short of where the GFS takes it. Sure, the rain/snow line will get out there if the track shifts 50 miles west, but not with that track.

    1. euro has 1.2 to 2
      German 1.2 to 2.4
      Canadian 1.2 to 2.4
      nam 1.2 to 2.2
      gfs is obviously broken. and on the juice lol. I am throwing out the GFS all together.

  62. Still no power but there in the neighborhood now . It’s 51 in house with a cold night on tap . We have fire going . Good thing we now can use phones

  63. I truly hope that this next storm gets itself lost. Or if it does not, then it stays clear of the coasts.

    1. I don’t think the coast will be impacted that badly. Whats possibly more impressive is the snow for the interior after a very long period of time of having next to nothing.

      1. Considering they are still being impacted after 7 or is it 8 high tides, I suspect it will not take much. But I sure hope you are right.

        1. It won’t take much as you saw toms post today . Gurnet rd in duxbury is scrambling to get a wall fixed that’s hanging by a support bar — Not good

          1. Humarock is also a mess. I’ve seen back side (front IMO is always ocean facing) but many front sides I’ve seen are really bad.

            1. I’m sure they are . I toured Brant rock yesterday and it’s bad . Still had live wires on roadways believe it or not . I’m hearing reports they have power back which is crazy. We also now have Texas crews here with more crews arriving tonight

              1. I love these crews. We had them from all over the country and Canada back several years ago. We always made sure to meet them and thank them an have a couple of DD big things of coffee and donuts on hand

  64. Another thing with this storm is that people will under estimate the power outage potential as they see much weaker winds, but they forget about the snow factor and it looks to be rather heavy in some locations.

    1. Although, as everyone knows, I never mind a power outage. I am so far in the minority that I might as well be nonexistent and I fully understand that. And I know very well that if wishes were horses, everyone would ride but I just hope those facing the results of this past storm can be spared.

  65. Logan received 0.6″ snow bringing the total to date at 35.9″

    Normal for season = 43.8″

    2. Fairly large disparity there from highest to lowest for the same areas. I said it earlier today and I’ll say it again, all models have been terrible outside of 2 days for snowfall amounts this winter. I won’t take anything seriously until tomorrow’s 12Z runs at the earliest. It does seem though we need things to come together just right for Boston to see a significant snowfall. Margin will be small.

      1. I suspect anyone who is thinking would give it till tomorrow. But, as my youngest said the other day…and I agree…..it is irresponsible for general ranges to be given.

          1. Oh I agree. It’s just that, depending on the source, for my area there’s a low of 2” to a high of 8.” That’s the difference between going to work and working from home for me.

            1. I saw that which is why I said 4-8, but I know it is prelimary. I’ll just plan to worm from home 🙂 🙂 🙂 😉

    3. Thanks Dr. S.

      This is great for lazy people like me. Actually, it’s all part and parcel of my boycott of ALL news stations local or otherwise.

      By the way, where did you get your PHD? LOL.

  68. I’m a bit behind on jeopardy but loved this question. A term I have not heard in years

    The drier side of a mountain is said to be in this ?

      1. Great guess but it is rainshadow. But you win because you were the only one brave enough to guess 😉

  69. 21Z SREF ensemble mean now up to 12.23 inches for Boston
    With low of 1 inch and high of 21 inches. Keeps going up.

  70. Ugh, non-stop meetings today and haven’t had a chance to check in. From what I have looked at so far, everything still looking on track for Wednesday.

    0z NAM is running.

        1. oh yeah, I get between 150-200 per day. out of control. and meetings could be cut by 2/3 by just putting some duct tape on the people in the room trying to derail with showing how “smart” they are.

          1. Oh, you run into that shit as well.
            I like your duct tape comment, But I just want
            grab them by the neck, shake the shit out of them and tell them to shut the bleep up!!

            And our meeting NEVER end on time and typically go over by an hour or more. I sit there the whole time thinking about all of the work I could have completed Instead of WASTING my time)(@!#&(!*@&#(*!@(*#&(*!@&#*^!@(*#&!(*@&#(!*@&#(*!&@*#&!(*@&#(*!@*#&(!*@&#(*!&@#(*!&@(*#&(!*&@#(*!&@#*(!&

          2. We have a GREAT technique. We use a polling system as past of our PowerPoint presentations. Everyone gets a voice. No one is overshadowed. My business associate is a master at facilitation.

  71. I just want to reiterate that there seems to be a tremendous amount of energy available for this system. NAM almost out far enough.

  72. So far, the track of the NAM “appears” to be aok. Watching to make sure
    there is no Westward surprise.

  73. re: 0Z NAM
    I hope my eye isn’t off, but I “think” I detect an ever so slight shift East from
    the 18Z run comparing 0Z at 45 hours with 18Z at 51 hours.

        1. I am hopeful about getting power back tomorrow so I pray the wind is not too bad. Can hairdryers blow the wind back out to sea?

      1. Oh now I see it. I was looking at instant weather maps and it was not visible. When I look at the 32km NAM on Tropical Tid-Bits
        it is readily visible.

      3. could be me talking out my ass too but it was a subtle thing. maybe while it’s strengthening.

    3. We really need a like button for some these comments. I dont care i will say it i hope we get hammered. Obviously as long as it doesnt do any harm to some one.

  80. FWIW, the 0Z run does not appear to be quite as juiced up.
    Perhaps the Eastward shift has something to do with that.

    1. Ah hah, It cranks up big time.
      It is every bit as juiced. This is a BIG TIME RUN!!!

      This should get the 12 inch snows to Boston.

  83. This low is crawling along.

    I think the NAM cutoff is too far north and west with that track.

  84. This thing keep sitting in the Gulf of Maine with
    twin closed off 500mb lows, one almost over us and one to the West.

  86. It might just be myself and captain fantastic blogging next week. Meanwhile, all the other bloggers from WHW may be in the dark for a while if that much wet snow verifies.

      1. Where you are, I’d say almost a sure thing. In Boston,
        there is still a mix/rain wild card. Even on this crushing run,
        it shows a period of rain and/or mix in Boston And yet still lays down about 16 inches. We shall see.

  88. So let me see….this thing starts around NOON on Wednesday and goes till about Midnight/1AM on Friday. Will it go that long?????

    1. We do need to see if the other models also further slow the low’s speed down as it passes Cape Cod.

    2. well, it shows a jump back west when you go from hour 57 to 60. not sure what’s going on but maybe it will be slower

      1. Actually my knuckles are cotton. When I make a hard hit it’s usually easy to take. It’s all in the wording. 😉

        1. I’d rather the brass knuckles. At least I’d be on the ground knocked out. Words hurt more LOL.

  90. Well, all I’ll say is the 12km NAM was coming in with huge snow #’s for areas that got zero snow in the last storm.

    Also, the difference between the 12km and 3km for the 00z run is remarkable. 2 feet for NYC on the 3km. Under a foot on the 12km.

  93. Incredible moisture injection into this system. NAM drops 1.32″ QPF in 4 hours at Logan! If all snow, that’s a good foot in just 4 hours! This thing is juiced.

      1. May need to hedge toward the “higher end” totals if the other models take a step towards the NAM solution.

      2. I’d leave them for now, but they may need to tighten the snow gradient even more with respect to the R/S line.

  95. From a met on AmericanWx…

    0Z RGEM actually slows the thing SW of the NAM and jackpots NYC….it then resumes gaining latitude and gives SNE a major event, but not the HECS the NAM does.

    1. Actually the GFS/RGEM solutions, though likely too warm, are more likely than the astronomical snow amounts on the 12km NAM.

    2. Kane, remember….the GFS has been coming in too warm every time. It has a warm bias. Its thermal profiles at the lower levels are screwed up as was discussed up above and in previous blogs. The track and 850mb temps actually look good.

      Here is the QPF:
      https://www.tropicaltidbits.com/analysis/models/?model=gfs&region=neus&pkg=apcpn&runtime=2018030600&fh=84

      That’s over 2″ QPF for Boston. You are still talking significant snow totals if a lot of that falls as snow.

  99. SAK & I are in agreement at the moment that a good representation of what is most likely is what is shown on the kuchera snow #’s from the 00z 3km NAM, with the exception of the NYC area which is too high.

  101. GFS, CMC and ICON ALL coming in more Wet than white.
    Not staying up for the Ukie or Euro.

    manana. Wish there were more agreement among models.

    1. They look too warm, esp. the GFS/ICON. Doesn’t make sense with the track, cold air in place, and the dynamics this storm will have with the rapid deepening. No way it is gonna rain out to Worcester. No way.

  102. Summary after another consultation with SAK and we are in agreement still…

    GFS too warm.
    ECMWF too cold and a little too much precipitation.
    NAM good temp profile but too much precipitation overall but close on 3km Kuchera for snow (except closer to NYC as noted where we think it’s too high).

    Still some wiggle room left regarding R/S line.

  103. 00z Euro looks good. Nice track and cold with decent QPF. Rain/snow line at its farthest NW advance only makes it to a Providence- Marshfield line briefly before retreating back southeast. QPF is 1.2″-1.6″ across much of NE CT, northern RI and eastern MA which would be good for 12″+ in many places.

    1. I also think this is somewhat an error on this model, although that early-week threat has a better chance of staying more south than recent events.

  106. I’m so confused by the GFS lately. I hear people saying it has a warm bias. I always thought it had a cold bias, no?

    2. It really wants to put it canal/I95. Been pretty consistent with close to coast. I would say climo might favor canal to Nantucket track but TK would have to verify. I think it would also Suggest a real tight r/s line.

  107. yawn…good morning.

    3z SREF down a tad on snow.

    Ensembles mean for Boston: 10.91 inches
    high: 25.24
    low: 1.97

    That is one gigantic spread.

  108. Some Kuchera snow totals

    gfs

    http://maps1.pivotalweather.com/maps/models/gfs/2018030606/090/snku_acc.us_ne.png

    cmc

    http://maps3.pivotalweather.com/maps/models/gdps/2018030600/096/snku_acc.us_ne.png

    nam

    http://maps1.pivotalweather.com/maps/models/nam/2018030606/078/snku_acc.us_ne.png

    nam 3km

    http://maps3.pivotalweather.com/maps/models/nam4km/2018030606/060/snku_acc.us_ne.png

    euro (proprietary modified kuchera)

    https://imgur.com/a/u5aDN

    icon (true snow???)

    https://www.tropicaltidbits.com/analysis/models/?model=icon&region=neus&pkg=asnow&runtime=2018030606&fh=90

      1. I do as well. Please see the response I received from my euro service and also Tom’s comments. Interesting for Boston.
        Can you say CEMENT?

  109. On the 12z runs, we should pay attention to the 700 and 850 mb maps. More than just 850 temps. Vertical velocities and their location as well as 700 mb low track. May help narrow down R/S line forecasts.

  110. I am feeling a big let down for snow in the city. Hopefully boston gets 3 or 4 inches to add to the season total and even that may not be achievable. We shall see.
    Here’s hoping for an Eastward drift, but I fear it will not happen.

    1. They always seem high but maybe that’s a misperception. That’s like me telling my boss I will have something done in one hour or 6 weeks ha.

      1. I was actually about to post the exact opposite. For my county I have a winter storm warning and the text is very generic for what seems like the entire warning area out to western MA. Gives me 12-16” with isolated 20” amounts but the map has me at 10”

        1. Equally as disturbing. I was just comparing Boston, but you are also 100% correct.

          I HATE the way they do these maps and warnings.
          AND they do it by county boundaries, which makes ZERO sense to me. If it cuts a county in half, so be it.

          1. They cut them in half sometimes but more for severe thunderstorm alerts that can be much more isolated. But in this case, dealing with a potentially very sharp cutoff it makes sense

    3. Dynamics …… combined with precip intensity.

      I was just looking at the GFS, plenty enough cold at 850mb. But it’s 925 mb 0C isotherm is all the way to the berkshires.

      But all those dynamics will overcome a great deal of that real estate.

      1. After what I saw on Friday, I wouldn’t be so quick to say that.
        That 925 mb with that warm conveyor off of the ocean will
        be tough to overcome.

        Btw, see the response I received from my euro service and check the euro snow maps. It TOTALLY confirms exactly what you are saying. about 1.5 inch qpf with 4 or 5 inches of snow with
        perhaps a bit of mix. In short, CEMENT!!!!

  112. I feel for that transition zone, probably a very narrow NE to SW zone that gets somewhere between 3 to 7 inches of pure cement. Tons of power issues there.

    I’m just hoping that’s not marshfield, but my guess now would be the immediate interior area of the north shore southwestward through Boston’s immediate suburbs then into western interior south shore.

    1. After what I saw on Friday, I wouldn’t be so quick to say that.
      That 925 mb with that warm conveyor off of the ocean will
      be tough to overcome.

      Btw, see the response I received from my euro service and check the euro snow maps. It TOTALLY confirms exactly what you are saying. about 1.5 inch qpf with 4 or 5 inches of snow with
      perhaps a bit of mix. In short, CEMENT!!!!

  113. I may have to repeat this later, but the following is the response
    I received from Andrew Revering of Convective Development (my euro service)
    regarding their snow algorithm:

    David,

    You cannot compare WeatherBell’s Kuchera or other snow maps such as an ‘Air Force’, “10:1′ or ’13:1′ map to ours for the reason you stated — it’s proprietary. Everything from our precipitation type identification to our ratio calculations. The maps just won’t match up… they are done in different ways. We do not use the snowfall algorithm directly from models for several reasons. They often include sleet in their snowfall totals due to their precipitation type identification not being great, and with different models want to be consistent with our methods. Therefore, we use our own precipitation type method which can identify rain, freezing rain, snow and mixed precipitation with a great deal of accuracy. The mixed precip type for example requires a reduction factor in the snow totals where other algorithms would probably use a ‘yes/no’ in that situation and blanket it with a specific ratio rather than reducing it and making a smoother gradient.

    Also the way we do it might simply think there will be something less than ‘all snow’ such as a mix, freezing rain or even all rain in fringe areas that differ from the raw model output or other sites. So our site might determine it as snow, while another has rain in fringe areas. Additionally we use a ‘modified’ Kuchera algorithm to identify snow ratios. Many sites and raw model output will use a static 10:1 or 13:1 ratio. By looking at the thermal profile at any given location at any given point in time, we can get a dynamic snow ratio that better fits the true atmosphere. Kuchera is great, but we have modified it slightly to fix some biases that we’ve noticed with that process.

    We also apply a ‘compaction’ factor that is rarely if ever considered. In certain situations the snow will compact or perhaps melt during the process of the storm — and we try to take this into consideration when applicable.

    I would encourage you to use all data you see (any site) to make your forecast, but take everything with a grain of salt. Over time you may learn to prefer one site’s methods over another, or better, find biases that allow you to trust one over another in certain situations.

    I would like to see the discrepancy you found between QPF maps. Can you send me a copy of theirs that you’re looking at so I can investigate?

    Pretty detailed explanation, if you ask me.

    I sent along the weatherbell snow map. I’ll share any response.

    2. Awesome insight. I like how they incorporate so many real variables. Regarding compaction, if you’re measuring snow and wipe the board every 2″, that’ll mitigate compaction impact some. A way to account for some of the compaction I suppose.

  114. Some thoughts from Taunton NWS

    Snow Impacts…

    Models are consistent in showing 30 to 60+ units of omega in the
    snow growth region which would support 3 inch per hour snowfall
    rates and even thundersnow. This amount of snow in a short amount of
    time will make travel difficult and result in very low vsbys. Time
    frame for this to occur will be Wednesday afternoon into early
    Thursday morning. Expect the Wednesday evening rush hour to
    significantly impacted.

    We also need to watch the snowfall potential near the rain/snow
    line. Snow ratios will be a lot lower leading to heavy wet snowfall.
    Only a few inches will start to bring down tree limbs and
    powerlines, an issue that southern New England does not need right
    now. Lastly, as the system wraps around we could see some blowing
    and drifting snowfall especially out west by Thursday.

        1. Need to push this eastward, but I fear frustration like last Friday. Hope not, but have to be real.

          Waiting in 12z runs.

  116. I still feel that a cold high would make a big difference and would be all snow regionwide. That ocean is a blowtorch.

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