Wednesday Forecast

228 Comments

7:36AM

DAYS 1-5 (JANUARY 16-20)
And now both systems are in the 5-day range, but for today’s update I’ll put some numbers to event number 1 and stay vague on event number 2 because we may not be through seeing guidance adjustment. If ever the 3-day-rule for guidance and 2-day rule for hard numbers applied, this will be the time. First, a slightly milder day today but becoming breezy as a cold front approaches. This front may bring a shower of mixed rain and snow, or snow, to a few locations this evening but it will be largely a dry passage, returning cold air to the region for Thursday. A minor low pressure system is still set to pass through on Friday with some snow/mix north, mix/rain south (see below for numbers). A break Saturday as cold air returns yet again and sets the stage for a larger winter storm that arrives in the pre-dawn hours of Sunday and lasts much of the day. What remains uncertain is precipitation type, snow/ice/rain areas, and how quickly it moves out. Will try to have a much more solid idea on this for tomorrow’s update.
TODAY: Partly cloudy. Highs 35-42. Wind W 5-15 MPH, higher gusts late in the day.
TONIGHT: Partly cloudy. A passing mix rain/snow or snow shower possible early. Lows 15-22. Wind SW 10-20 MPH shifting to NW with higher gusts.
THURSDAY: Mostly sunny. Highs 22-29. Wind NW 10-20 MPH, diminishing during the day.
THURSDAY NIGHT: Clouding over. Risk of mix south, snow north before dawn. Temperatures rise to upper 20s north, lower 30s south. Wind light variable.
FRIDAY: Mostly cloudy. Mix to rain South Coast, snow ending as mix/rain elsewhere from west to east. Snow accumulation of less than 1 inch South Coast, coating to 2 inches elsewhere with 2 inch amounts most likely southern NH and central MA. Highs 33-40. Wind light variable becoming W 5-15 MPH later in the day.
SATURDAY: Partly sunny. Lows in the 10s. Highs from the upper 20s to lower 30s.
SUNDAY: Overcast with snow/ice/rain likely. Lows in the 20s. Highs from the upper 20s to lower 40s north to south.

DAYS 6-10 (JANUARY 21-25)
Dry, windy, very cold MLK Jr Day Monday January 21. Gradual temperature moderation through mid period with the next event more likely to be mix to rain but far out there so will keep an eye on it. Drier weather returns at the end of the period.

DAYS 11-15 (JANUARY 26-30)
Colder as a broad trough overtakes the weather with a couple clipper type systems bringing snow threats, based on current pattern trends. Still not highly confident about the pattern evolution yet.

228 thoughts on “Wednesday Forecast”

  6. Mark,

    For $5 additional with the F5 service, you get the UKMET, the hrr, the nam, the gfs (FV3 only) and the ACCESS-G Australian. In addition TO THE NAM MOS AND GFS MOS ANS THE GFS, CMC AND EPS ENSEMBLES.

    good deal, I think.

    1. From yesterday’s blog late last night TK posted this:

      Woods Hill Weather says:
      January 16, 2019 at 1:23 AM
      I have not discounted anything yet. It’s not likely we see OTS though. I think the furthest southeast we can see is a grazing, but even that is probably an extreme case at this point.

      Will be interesting to see.

  8. NWS discussion from 7 AM rather wimpish imho.

    Saturday night and Sunday…

    Ensemble data indicated an injection of deeper moisture within
    the phased mid level flow. Still a rather large variance in
    storm track. Consensus track suggests a path NW of the 40N/70W
    benchmark. In addition, downstream high pressure should be more
    of the North Atlantic, rather than SE Canada. Both of these
    suggest a wintry mix, rather than an all snow event. Still too
    early to pin down the details. Have high confidence it will
    precipitate, but only low confidence on the timing of
    transitions between various precipitation types. In general,
    still thinking snow to start some time Saturday night, then
    transitioning to a wintry mix during the day.

  9. Thanks TK.

    My patent pending WHW forecast model shows that we should expect at least a foot of snow within the next week. 150 comments means there’s a good chance for a storm. 250 comments or more means the region can expect or may be currently getting at least 12 inches. A WHW score of 300 would mean you can lock in a foot or more. 350+ means either a blizzard or an even bigger blockbuster snow event.

  13. Cold always wins out in these types of situations. We have seen this many times. It’s on as if we have a massive system churning up the cost and retreating cold and an east wind. My guess cold holds out for majority of the event and the models are starting to see that.

      1. This could possibly be a very significant storm with major impact for a big portion of the area . I’m betting the cold air will win out .

      2. Yeah see that. Still suspect on totals as always 4 days out but liking what the euro has for temps. My guess the massive totals clearly coming form the temp contrast. This could be explosive but as always I think the totals are overdone.

        1. I dunno. Look at the qpf forecast for all models.
          Way up there for sure. Perhaps 26 is high, but
          12-18 is not. We shall see. Finally something, whether it pans out or not remains to be seen.

          1. Once upon a time an 18 inch storm was massive, but now, to me its like ho-hum. Has to be a 2 footer after having 2 of them a few years back. 😀

  14. How do you link a twitter post to this blog on your phone?

    Look for John Homenuk @jhomenuk

    He posted some tweets that would be good to post here.

  15. Probably too early to look at this, but I’m wondering what the atmosphere sounding looks like for the weekend storm and if we’d have an issue with warming up above?

  17. The weather underground app which tried to say we would be getting nine inches on 1/13 is still calling for a dusting: https://i.imgur.com/XycPVC5.png

    This must be why nobody has asked me any frantic questions!

    Speaking of Wunderground – a few days ago I was watching NECN/NBC 10 – and they remarked about the proprietary “in house” guidance and referenced wunderground. Sure enough after googling I found this:

    “For the past five years, our weather team has offered New England’s first – and still Boston’s only – broadcast television 10-day forecast. Over that time, we’ve not only brought together New England’s largest weather team of eight broadcast meteorologists, but we’ve also added the power of our exclusive, built-in-house forecast system, our exclusive Weather Underground observing network and first-of-its-kind Storm Ranger mobile Doppler radar.”

    I don’t know why the above tickles me but I figured I would share this knowledge.

  19. For the appetizer 12z NAM showing a coating to -2 inches across SNE. Bad timing with that one for the Fri am commute as the amount of snow is minor.

  21. 12Z NAM for 7Pm Saturday:

    https://www.instantweathermaps.com/NAM-php/conusncep.php?run=2019011612&var=PCPPRSTMP_2m&hour=084

    500 mb

    https://www.instantweathermaps.com/NAM-php/conusncep.php?run=2019011612&var=VRTHGTGRD_500mb&hour=084

    Does not this show what Bernie was discussing??? ie the Northern trough out ahead
    of the Southern trough, allowing the system to move more East than North.
    Translation: SNOW in SNE?????

    Interesting. I love it that the NAM is now getting into range as we have yet something else to look at.

  25. So far, the 12Z GFS “appears” to be ever so slightly more to the East for the same
    time period. We shall see if that translates into anything or no.

  27. Hope this is the GFS warm bias, but this sucker STILL wants to go over to sleet
    and then rather quickly to plain ole rain with some Really warm surface temps
    just south of the Boston Area.

    https://www.instantweathermaps.com/GFS-php/conusncep.php?run=2019011606&var=PCPPRSTMP_850mb&hour=105

    https://www.instantweathermaps.com/GFS-php/conusncep.php?run=2019011606&var=PCPPRSTMP_2m&hour=105

    I hit the DISLIKE BUTTON!@()#&!@(&#!&@*#(*

    Snow map

    https://www.instantweathermaps.com/GFS-php/conussfc.php?run=2019011612&time=PER&var=ASNOWI&hour=114

    now we wait for the rest of the 12Z runs. 😀

  28. The GFS continues to be the outlier….it is also significantly warmer than the NAM for Friday’s system.

    1. Indeed. I think the GFS is a SHIT BUM Model performing rather poorly
      at the moment. Now watch it be 100% correct!!!!!

    1. I mentioned this last night saying the Mets this week have been talking that . Snow to start with mix or rain in the middle & than back to snow later Sunday .

      1. I think the Mets have actually done a decent job & I’ve seen a lot of there forecasts this week .

  33. I am wondering if the cold air damming will be stronger than what the 12z GFS is showing and not moving that cold air out during Sunday and get those temps way above freezing.

  34. Why can’t we have a mostly snow event like everywhere else? Even the Mid-Atlantic and parts of the southwest haven’t had any mixed events. It’s no wonder that SNE is the hardest area to forecast.

    1. They didn’t? Both areas had PLENTY of mix, especially the Mid Atlantic. Did you see Virginia???

      1. My relatives in VA and NC had all snow, a foot and schools in Richmond were closed for a week last month. DC last weekend had all snow. We have yet to have that. Even the November system changed to rain.

        1. If look very closely you will see that the snow amounts
          in the more Southern areas are up a little bit.
          ie Worcester 14 to 16
          central RI 6 to 7
          etc.

    2. The Euro ensemble mean was a bit SE of the operational so I would not be surprised if it continues to correct SE. TK said last night further shifts on the Euro likely as well.

  40. Back at school today.

    Thanks to everyone above for posting the 12z links, it makes it very easy to get caught up !!!

  41. CMC/UKMET pretty much stay the course but disappointing to see the GFS trend back NW. Not too concerned about that though given its performance and tendency to underestimate cold air damming in these types of setups.

  42. Mark I made that comment earlier wondering if the latest GFS run is underestimating the cold air damming.

  44. So, it seems to me that with the directional approach of the storm, that having cold air entrenched in here will be essential.

    Will the cold air truly get entrenched into southernmost New England prior to the arrival of the system.

    I don’t necessarily see a strong push, more like a slow drain into southern areas. Northern and central New England seem deeper into the cold air.

    This is why a track not quite over the benchmark or there-abouts seems plausible to me. I’d think closer to the temp gradient and thus seeking some path across SE mass ???????

  45. Dave, thanks for the info on the F5 service earlier. I noticed I am not getting all the premium content and am considering upgrading.

  47. Just a little bit more of a shift southeast with those GEFS ensembles and we could bring the all snow area down further south and east. Inside the benchmark looking at an icing potential for the interior after the snow.

  48. I wish this tweet from Ryan Hanrahan was 24 prior to Sunday.
    ECMWF (the euro) with a major snowstorm Saturday night and Sunday here. Sure beats ice.

  49. Here is my service UKMET SNOW MAP:

    https://imgur.com/a/rnbkjcD

    On the precip type maps it NEVER rains in Boston, however, there is a pretty
    lengthy period of SLEET and that is what limits the accumulation to about a foot
    in Boston. Imagine a foot accumulation made up of a ton of sleet as well. WOW!!

    My service isn’t in yet for euro, but looking at 2 frames from Tropical Tidbits, it
    looks to take the low “just” South of Nantucket or thereabout.

    https://www.tropicaltidbits.com/analysis/models/ecmwf/2019011612/ecmwf_mslpa_us_5.png

    https://www.tropicaltidbits.com/analysis/models/ecmwf/2019011612/ecmwf_mslpa_us_6.png

    I think that would allow for mostly snow in boston with perhaps a less lengthy period
    of sleet.

    Dying to see the new snow map!

  50. The models at this point are not locked on to any solution from what I can see. I don’t think we will know that much more 24 hours from now. Tough to know what will happen this far out when a track difference of say hypothetically 50 miles could seriously change the local forecast.

  51. I wonder if the models are taking into consideration the couple inches of snow we’ll have on the ground keeping the ground temp just a bit colder? Good set up for freezing rain if the track stays as is. For mass pike area. Worcester county, northern Connecticut?

  52. The most recent forecast discussion from NWS ~ Kansas City, Pleasant Hill MO for the time frame of the Pats-Chiefs’ AFC championship game:

    Friday evening/Saturday/Sunday: A much stronger system is projected
    to impact the area late Friday into Saturday, with bitterly cold air
    to follow. The forecast remains unchanged, with growing confidence
    of accumulating snowfall for much of the area. Additionally,
    temperatures Saturday evening through Monday morning will be
    unseasonably cold. Model consensus has gradually trended warmer with
    respect to weekend temperatures, but still highs on Sunday are
    projected to remain in the teens as influence from surface high
    pressure and a fresh snow cover in place. Northerly winds
    immediately behind the system will be windy, with gusts up to 35mph
    possible. This may lead to some areas of blowing and drifting snow,
    along with bitterly cold wind chills below zero Saturday night into
    Sunday morning. Those with outdoor plans this weekend should prepare
    for potentially dangerous conditions if being exposed to the
    elements and dress accordingly.

  53. Latest euro gets the mix line up to the mass pike/Boston area. With snowfall 18+ for most in interior mass. The rain line makes it up just south the Providence/Boston line.

  57. Euro really moving towards the sort of scenario I’ve been looking for. Weaker low (still plenty of moisture) and further south.

    1. Yea maybe slightly south. But TK did mentioned yesterday its highly unlikely this storm will graze us but you never know what mother nature has in store for us

    2. Wow. I’ll be happy with half. My concern now is this storm slides too much south and areas like NYC get more snow than us lol

  61. First COWBUNGA from JPDave of the winter!!! Hopefully this will hold and we could get another COWBUNGA or a HOLY CRAP BATMAN!!!
    I just wish this was 24 hours prior instead of today. Lot could change.

  62. Starting to get a little excited….will feel much better once we get past Friday, but it’s nice to finally have something to track.

  64. CALL IN THE AIR NATIONAL GUARD!

    12z EPS looks like it is coming in even further south than the operational. May have two feet all the way to the south coast before this thing is done!

        1. yeah I know, usually what happens when SE mass gets good snowfall, we get skunked up here in the Merrimack valley and other areas in NE mass. I will be pissed off if areas like the south shore/cape get more snow than us up here. I want good snowfall for our area up into ski country. I rather see areas south and east of Boston get rain.

  66. I find myself oddly anxious about this storm. I was actually loving having no massive storms for once.

      1. Hahaha. I think it is because by this time in the year I am usually used to shoveling and car manuevering and whatnot. When it goes this long and 2015 totally blindsided us with so much snow our roof had issues…. it was the worst. I remember the run on roof rakes. Hadn’t even heard of roof rakes before that year.

      1. THAT is how it should be done. Can always count on my old friend and long-time coworker A.J. to do it that way. 🙂

  67. Tweet from Eric Fisher:

    Odds of significant snow and ice this weekend on the rise. Winter has arrived. Tomorrow still the target time for nailing down specific details but should be moderate to high impact

  68. MLK always a watcher or a storm . Pattern continues with what could be a whopper of a storm !!!

  69. Hey all,

    Hope Vicki is OK.

    She has not posted in a while and with the impending storm, one would think she
    would chime in with something.

    Hope it is something as simple as her being too busy with work.

  70. Hmmm, perhaps I am just looking for something, but it looks to me as if
    the NAM is getting a little juiced up for the Friday system. We shall see.

  76. My combined feeling and scientific method make me feel like a colder scenario is becoming the dominant side of the scale .. no astronomical snow totals, but a moderate impact widespread and somewhere a more significant impact depending on a few other factors.

    We already know that the snowfall totals from the European model (referenced in A.J.’s tweet) are vastly overdone. Not happening in an event of this magnitude and duration. I could, however, see some of those GFS #’s being in the ballpark as it stands now. They were far too high yesterday.

    2. So what do you think for boston? 6-9 or so??
      I am thinking 1 foot plus. But then I would, wouldn’t I? 😀 😀 😀

      1. I’ll have #’s tomorrow. I still have this funny feeling about a strung out system and a more dominant southern low and a lot of this moving pretty straight east at a very rapid pace.

  77. I’ve been purposely vague on sensible impacts with this storm outside of my continued preference for a further south/east track. Now that I’m more confident my overall read on the storm has been good overall, and now that we’re only about 3 days from the onset, it’s time to start thinking about impacts, at least in general. I do think this will be a major winter storm for most of SNE. I don’t think we’re done seeing model shifts, and I want to see just how far the south trend will take us. It’s possible the south trend could overshoot and go too far, but I don’t think we’re there yet, and I want to see how the change in the track and the upper level evolution impacts storm structure and QPF. I share TK’s thoughts that it could end up as a more strung out southern stream low. One of my big concerns is icing. The low level cold is going to be hard to scour out. But it’s such a big, broad storm that even with a slightly offshore track there will be plenty of warm advection aloft. So I think sleet/freezing rain will factor in quite a bit, at least within a corridor.

    2. Despite my leaning as indicated above, I still cannot throw this scenario off the table. I’ll be honest. I’m hoping to heck I have a solid idea by tomorrow morning’s update. If not, I may need 2 editions of the blog tomorrow.

      1. GFS outshines the EURO???? I know it happens now and then, but EURO is KING! NO, please say it ain’t so!!

        1. It’s happened a fair share of times.

          On the bright side if that solution is good we may have enough breaks in the overcast by lunar eclipse time to actually see it. 😉

  79. The 18z GFS & NAM 84 hour forecasts are quite different, so there is a nice little contest ongoing between that global medium range and shorter range model.

                1. Doesn’t matter to me. I’m not that hooked on snow that I’d want to miss the celestial event. 🙂 To me that’s just impatience. I’m a very patient person.

  80. Pretty incredible that as the Euro is ticking southeast, the GfS is shifting even further northwest. 3 days from the event and model divergence increasing….

    18z ICON has a beautiful track – near to just outside the benchmark, but still penetrates the mix/rain line well inland to the NH border.

    1. We’ve seen that already this season. I believe the November storm featured a similar model performance almost up until the time it started.

      1. Yes indeed they were underestimating the cold air damming up until about 24 hours before the storm. Hoping for a similar situation here. And it’s January now as opposed to November so we have some climatology on our side this time.

  82. Unless the rest of the guidance shifts toward the GFS, it’s extremely unlikely this blind squirrel has found a nut

    2. It is an outlier given it’s the only one with that extreme a solution. Doesn’t mean it’s going to be incorrect, however. Sometimes the outlier is the winner.

  85. Early thoughts. Friday morning up to 2 inches of snow. But will impact Friday morning commute. Questions for the storm over the weekend. How far north does the warm air make it aloft and how stubborn is the cold air. (rain/sleet,freezing rain and snow lines) In this set up would favor stubborn cold air. I fee that rain will make it up into SE mass https://merrimackvalleyweather796095653.wordpress.com/2019/01/17/small-system-friday-morning-big-storm-weekend/

  90. Here’s why I think southern New England can miss out on big snow totals.

    This system, if I’m correct, seems to me to be significant overrunning as opposed to a compacted, dynamic system.

    So …. in overrunning, I would think the best snowfall amounts would line up along the best temperature contrast. I still feel that contrast is likely to be a bit north and northwest of southern areas.

    Could the best temp contrast end up being further south ? Well, perhaps, but that would require a bit more push from the northern stream. But if the northern stream has to become a bit more dominant in this scenario, then I would think you’d end up getting a quick rush of snow, that ends more abruptly, leaving a handful of inches, and not a foot.

    I feel as though right now, southernmost New England, (i.e. the big cities) are caught in a catch 22.

    1. I don’t know Tom . As Harvey said tonight he’s doing this one on years of experience. He thinks it’s looking cold front end dump with something in the middle sleet , freezing rain than back to snow late too wrap it up

      1. Well, yeah, I can see that too. But that middle could turn an expected 10-15+ into 3-5 or 4-6 real fast. It’s where the middle sleet, ice or cold rain lands in New England. I’m not too enthused about a big back end snow amount.

  91. I don’t think the Boston area sees double digit totals. There should be a good front end thump, but sleet/ice/rain will become involved. Almost unavoidable given the trajectory this storm is coming in with, even if it does end up further south. 4-8” up front before the change in greater Boston? Still a little early for any numbers but that will probably be my opening bid barring any big changes tonight, because by tomorrow you have to take a shot at it. Less further south/southeast. More to the north. Where it stays all snow, potential is there for 1-2 feet. But that’s probably more into central New England and far interior SNE.

  94. My early guess would somewhere around 8-12 in Boston. Still need to see more before going in on the higher or lower amounts.

  95. I was excited, now not soo much. Nam is warmer than before. Gfs is still warm. If euro trends north then this will be a kitchen sink storm for sure. Gut feeling I think Boston will see 4 to 7 inches. I hope I am wrong

    1. A lot seem surprised by kitchen sink this has been discussed all week by Mets & appears in most areas will be the case .

  96. My early guess is 3-6 Boston area …..

    Temp at Logan maxes out at 37F during second half of storm and low-mid 30s in Boston’s suburbs.

    A leftover 2-4 inches of waterlogged snow will be cement like by Sunday evening in the Boston area.

    1-3, 2-4 down here, but it briefly gets to 40F and most melts south of lane drop south Of Weymouth.

    Jackpot of 12-16 inches will be Manchester to Lincoln, NH, also central VT and central ME.

  100. According to Harvey late this evening, still on track for snow & sleet. Only extreme SE gets some rain. LOTS of sleet on Sunday.

  101. Deep thunder model showing 40 inches of snow in Boston lol.

    Anyone have the euro? Looking at the 24 hour panels on tropical tidbits it looks like it’s the same track. Maybe little further south

    1. It’s pretty comical how bad some models actually are with snowfall.

      The Euro is a little further south and a touch colder on the 00z. Pretty much supports the blog that I am going to post in exactly 30 seconds.

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