Winter Forecast 2017-2018

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It’s no secret if you’ve seen my comments around the blog. I have struggled with this forecast more than any over the last few years. Examination of indices that help determine the long term pattern have been mixed to the point where I have not felt confident leaning too much in any direction. In such a case, I place more weight on a correlation of the weather pattern of November helping to determine the upcoming winter overall. This in itself, while a decent correlation, has been nowhere close to usable on many occasions. Taking all this into account, and placing a little faith in the November-to-winter correlation, the following paragraphs are my overall thoughts, month-by-month breakdown, and wrap-up summary of the what I expect to take place during the coming winter.

Drought is not so much a factor now as it was going into last winter. Although we continue to run a long term precipitation deficit, short term moisture was decent enough during a good portion of 2017 and from a couple events during the autumn to eradicate the ongoing drought and then put out a drought “flare up” that occurred during our warm and fairly dry stretch in early to mid autumn. I have examined current and expected indices including ENSO (which is expected to be weak to moderate La Nina), QBO (expected easterly), PDO (expected negative), AO/NAO/MJO among a few others. We can talk more about these as we get into the season on the blog on a daily basis. I also realize that these letters may mean nothing to some of you but just know that they have something to do with the large scale pattern in the atmosphere, and in some cases ocean circulation, and impact weather in certain ways. In addition, fairly rapid advancement of snowcover in Siberia, as well as eastern Canada, sets up plenty of cold air north of the border to be tapped. So even in an overall mild pattern we can tap the cold air and experience brief very cold shots of air behind departing low pressure areas. So these, along with the correlation for November mentioned above, leads me to the feeling that the winter overall will end up not all that far from normal in both temperature and precipitation, with a slight leaning toward the mild side of normal for temperature and a slight leaning toward the wetter side of normal for precipitation. Either of these, especially the precipitation, can be skewed significantly by 1 or 2 significant events. And even though we can say this about any seasonal forecast, I feel that the “bust potential” for this particular winter is a little above the average. How we will arrive at “near normal / near normal” will not be by seeing daily weather that fits the average for the date, but by high variability in temperature and frequent weak storm systems with the occasional larger one. Heading into the first 1 to 2 weeks of meteorological winter it looks like the current pattern will hold, and that is one of fairly dry weather overall with changeable temperatures, mild with brief periods of cold, a little milder overall than November had started out. The tendency for the atmosphere to develop a blocking pattern will be there, especially during the first half of the season. One trigger, stratospheric warming, which then disrupts the stable state of the polar vortex and sends it into fragments that then migrate further south, may very well take place toward the end of the first 10 days of December. With somewhat high stakes my leaning, based on fairly reliable guidance with these types of events, is to forecast a shift to colder with enhanced risk for snowfall during the middle and end of December. This pattern will probably not hold much longer than that and will probably adjust into a more zonal pattern similar to that of the early to mid portion of November, which was on the chilly and fairly dry side. This would be the dominant pattern for January’s early and possibly middle portion, but La Nina is going to want to put more ridging in the Southeast, and over time, we should see the pattern revert to the one that we currently have. Assuming La Nina peaks in late January and February, along with the continued negative PDO, during episodes of zonal flow with no blocking, the pattern would be fairly mild and on the drier side overall. Blocking can still occur with little warning and result in 1 or 2 storm systems of any precipitation type, dependent on air mass in place and synoptic conditions evolving during the event. Even with this leaning toward a milder overall pattern during the second half of the winter, we can still be subjected to brief periods of intense cold as Canada will continue to be on the colder side of normal with extensive snowcover. One last thing I am concerned about is icing events. Of course these can occur in any winter, but if we have a pattern that features mild air aloft and a storm system moving through, or even just a precipitation event with a frontal boundary nearby, the availability of cold air in nearby southern Canada can set up a situation where we have a warm atmosphere in all but the lowest levels, resulting in icing situations. The number, magnitude, and location of such events cannot be determined in the longer range, but just know that the possibility of such events this winter, in my opinion, is a little higher than average.

DECEMBER
Breakdown: Weak La Nina pattern. Zonal pattern overall first 10 days, blocking potential higher middle of month possibly into late month but may relax to zonal but more northwest flow before the month ends. Systems during the first third of the month would be more apt to produce rain versus snow, with the snow threat higher thereafter. A significant amount of the seasonal snowfall can occur in a pattern like the one expected in mid to late December, assuming storm threats line up to produce it.
Temperature: Near to below normal, arrived at by balancing a mild beginning of the month with a colder mid to late month.
Precipitation: Near to above normal.
Snow: Above normal.

JANUARY
Breakdown: If the pattern expected in mid December should try to repeat, as we sometimes see, it would likely be during the first half of the month in an otherwise colder and drier regime as late December’s pattern should be more dominant (zonal northwest flow). With time, expect this to relax and become more of a west southwest flow with milder dominant air and brief shots of cold as more of a ridge occurs in the US Southeast. We can see clipper type systems with the northwest flow, and a couple of Pacific systems when the pattern relaxes. Rain/ice/snow would be determined as always by the conditions in place at the time, but the tendency here would be for a somewhat wetter pattern by month’s end
Temperature: Near normal, arrived at by a balance of a colder start with a milder finish.
Precipitation: Near normal.
Snow: Near normal but high stakes as a big swing between Pacific systems producing rain or snow can mean many inches difference.

FEBRUARY
Breakdown: La Nina in its strongest state at this point of the winter should put a more persistent ridge in the US Southeast with the late January pattern continuing, the mild dominating and the cold shots brief but potentially intense.
Temperature: Near to above normal.
Precipitation: Near normal.
Snow: Below normal.

MARCH
Breakdown: Uncertainty abounds not only from it being several months away but the status of La Nina and other indices being somewhat in question. For now going to lean toward a milder and drier than average pattern, but with low confidence.
Temperature: Near to above normal.
Precipitation: Near to below normal.
Snow: Below normal.

WINTER SEASON OVERALL
Temperature: Near to slightly above normal.
Precipitation: Near normal.
Snow: Near normal.
-Boston 40-50 inches
-Worcester 50-60 inches
-Providence 30-40 inches
-Hartford 40-50 inches

42 thoughts on “Winter Forecast 2017-2018”

      1. Messing up or not, I appreciate your comments as always and thank you for reading! Post as often as you like of course…

    1. Glad you enjoyed. Now let’s hope it’s more non-fiction than fiction when all is said and done. 😉

    1. Something that Judah Cohen said, even if I am not quite on the same page as him regarding snow totals, is that keeping the snow that falls around may be hard if we keep going mild between events. That would help in the roof-raking department, but we all know all it takes is 1 week of storminess, and some persistent cold for an issue. Hopefully anything like that will be short lived if it occurs at all. Highly unlikely we’ll see a repeat of 2015’s roof issues any time soon.

      1. Thanks TK for always taking the time to put together and post your outlooks. They are truly appreciated.

        2015 was definately tough in the roof department and the cold.

        1. You’re welcome. Not sure how this one will work out, forecast-wise… Not too confident this time.

  4. Thanks TK. But what are your qualifications for this? LOL…

    In terms of ice events, are any of the patterns you describe more prone to such in SNE, or is icing going to be mostly dependent on the day to day situations?

    1. Haha!! Sometimes on those pages I’m better off not saying anything. I don’t discourage the enthusiast, but I just want people to understand if the opinion they are reading is coming from someone who has formal education or not. 🙂

      I do worry about icing events. I didn’t really mention it in that forecast above, but with a lot of cold air available in eastern Canada, we know that a mild atmosphere can still have cold air right at the lowest level. Throw precipitation on top of this and……

        1. Better to say something than not is my philosophy. Though people may not always like that answer.

          Thanks for the update on icing. Out in Central MA, the 2008 ice storm has become the benchmark for icing events, and people still have nightmares from that storm. Not that anything can be done to prevent it, forewarned is forearmed. Thanks again TK for the time you provide to all of us.

          1. I suppose you’re right. I would never want to turn an enthusiast away. But I am big on having important information come from informed sources. We have seen far too many people relying on “unqualified” sources and using them as if they are as good at or better than sources like NWS. As much as sometimes we might get frustrated with NWS and other media, they are the best we have. Weather is too uncertain to have inexperienced people giving information that may put someone’s life in immediate danger.

  5. Thanks TK, absolutely one of your best posts IMO. I totally agree with just about everything you said.

    My number for Boston is just under 40″. If I bust, it will likely be because we get more snow, not less. I’ve gone a little conservative basically to price in the possibility that we don’t take full advantage of what should be a favorable mid-late December and early January pattern. If we hit big (20″+) from 12/15-1/10, then, we’ll go 40-50″+ almost certainly. If not, we should be on the lower side and my more conservative number should be okay given the likelihood for a less favorable background state with time.

    I’ve also gone higher on snow numbers for central and northern New England. This is to account for the likelihood, especially in later winter, of messy storms which provide more rain/mix to SNE but more snow to the north. That gets into something else TK talked about, which was the elevated risk of icing events this winter.

    1. seems similar to my thoughts but not thinking its going to be an overly front loaded season which is why I am favoring the lower end of my numbers I posted

      1. That is where my forecast can go wrong really quickly…

        If things don’t materialize a bit later in December and the rest of the forecast is reasonably accurate, my #’s are too high. If all of a sudden we’re snowing with borderline temps later in the winter, my forecast looks like total crap. Stakes are higher than average.

  8. Thank you, TK.

    In recent years, my favorite winter blitz is not the one we experienced in 2015. No, it’s the 2011 6 week period of heavy snows and sustained cold. I love it when the snow and cold stick around, and have an aversion to oscillating temperatures and slush. I realize that without a blocking pattern we’re likely to see our snows come and go and with fleeting cold blasts.

    1. Both of those were remarkable stretches. 2011 stands out because we had not had one like that in a while and having so much snow on the ground by the middle and end of that 6 week period was amazing.

      2015 obviously stands out for the sheer amount of snow in 4 weeks and the magnitude of the cold, even during the big storms. That particular setup was one we don’t see often for more than maybe a week, and it was solid for a month.

  9. Thank you, TK.

    A read packed with enough information to require a few passes

    So much for my “feeling it” for days leading to Dec 9….but it is what it is and I will love whatever

    I see a couple of new names….welcome !!!

  11. Wonderful and comprehensive write-up, TK!
    As long it doesn’t snow or ice this Saturday in Foxboro for the 9 am kick-off of the state championship football game!

    Gillette (Schaefer/Sullivan/Foxboro) Stadium and LaSalette Shrine in Attleboro are the two coldest places on the planet.

  12. Its funny that I see this conversation on here about unqualified and qualifed sources for forecasts as just the other day as I had someone email me/message ask that same question are you qualified.

    When it comes to this. I feel as long as they are not trying to troll or spread false stuff, it is fine.
    I do have a question what do you mean by formal education. That can come into many forms when it comes to understanding how the weather works.

    1. Basically I refer to a degree in atmospheric science or meteorology. I realize there is a grey area here and that you can have someone that may have gone to school, gained valuable experience, never actually graduated to pick up a diploma, and through time learned enough through working to do a decent job in meteorology or a similar related field.

      My issue is with someone who has never taken a meteorology class in their life just passing off forecasts like they are the official word. It’s not a responsible practice and can be downright dangerous, even if they are just very enthusiastic and have all the best intentions. It’s an issue of public safety.
      And it may not be a problem all the time, but all it takes is one person who wet out skating on thin ice or went driving an a snow or ice storm because of a “guaranteed” outcome on a weather forecast.

      And I understand that even the most seasoned professional can mess up too, but an expert in the field is going to give a better forecast far, far more often than someone who is not.

      1. I feel like anyone who relies on just one source is just waiting to be uninformed. I feel like someone should be able to tell the differences between a blog like this and one like mine and one of a person with no background in climate/atmospheric/ meterology classes.

        1. I agree. Unfortunately there are many that apparently cannot.

          Out of respect I won’t mention several I know of by name here, but there are several just in this area (that have Facebook pages) that are run by completely non-professional, non degree-holding, inexperienced people that have a large amount of followers. I have viewed the content of these sites and found them to often be very misleading. Yet the majority of the followers put as much stock, if not more stock, into them than they do a forecast from a trusted source. That concerns me.

          2. It is really sad…however ….You know my fault lies with the followers. If they don’t do due diligence…well, it is their problem.

            1. Agreed Vicki, I to be honest feel like if people only look at one source is also diligence. I for one look here, Noaa, wbz, NBC and Harvey when he is on.

  14. Anyone that may be out later tonight to around dawn, watch for the possibility of snow showers, especially southern NH and adjacent northern MA.

    Exception not rule: May be a quick coating and slippery conditions, favoring southeastern NH.

  15. Thanks TK for your winter analysis. I never thought of ice storms being any real threat. It has been awhile. Hopefully the power companies will be on their toes. They did not do a really good job with that massive wind/rainstorm last month. I am glad that I live in the city of Boston where wires are not as much of an issue like most suburbs. I believe it is fairly rare for a Boston neighborhood to go without power for days or a full week.

    I feel fairly confident about my snowfall for the NNE cities but I think my Boston snowfall may be a bit overdone, not like Dr. Cohen’s but still…oh well. 😉

  16. Thanks TK!
    I have not been posting much in the past year, but do continue to read the blog on a daily basis, and I want to thank TK and everyone else for all the great information shared here!
    I will be moving from Brighton to Kingston mid December. I’m not expecting the weather to change too much from where I live now, except maybe a little less snow considering my new home is 3 miles in from the coast!
    Look forward to some interesting winter weather ahead and reading the blog about it all!
    Happy Thanksgiving to the WHW family!!!

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