40/70 Benchmark

JAN 8 Two Weeks Remaining; Severe Second Half of Winter Grows Imminent Mother nature has managed to deconstruct yet another significant winter storm threat with nothing short of surgical precision, as tomorrow's system, which had appeared relatively ominous last week, looks to pass to our north. Thus the cold will be once again eradicated not long after precipitation commences, sequence that has become all too familiar throughout boreal winter 2018-2019. And after perhaps an inch of snow near the New Hampshire border, with potentially more in the higher elevations of the Berskshires, followed by a period of icy mix tomorrow, the majority of precipitation will fall as rain, especially from the Connecticut river valley points eastward. Then the attention shifts to next weekend, and as of right now, the region of southern New England looks largely to dodge and weave yet another blow from old man winter. This time the system looks to pass by in the other direction, as the most significant impacts look to remain out to sea, however some light to perhaps moderate snowfall remains possible....especially south and east of Boston. Both the GFS ensemble suite: As well as the superior ECWF ensemble mean: largely concur on the ridge axis being just a bit to far too the east to allow the downstream flow to buckle enough to lift the system all the way up the coast. While the EPS ridge axis is a bit better more favorably positioned to the west for more impacts, it is significantly flatter, thus it is even less favorable in the aggregate than its GEFS counterpart. Considering the evolution of the first half of the season, it is exceedingly difficult for the beleaguered calvary of winter aficionados to elude the perception of old man winter as an aging middle aged boxer, flailing away in vain during the final moments of a banal career. However old man winter has el nino in his corner, and he may yet be primed to begin landing a succession of devastating blows to local infrastructure once the bell sounds for the second half. Likely Second Half Blocking Trifecta Despite the fact that PNA ridging is typically favored during el nino events, it remained relatively elusive throughout December, which is one of the elements that acted to limit snowfall potential easily in the season. This was expected, as specified in the Eastern Mass Weather Winter Outlook that was released on November 12th: Negative PNA, vs RNA, Pictured to the Right "As illustrated above, the positive mode of the PNA favors cool, wet toughing over the east, and milder, drier ridging over the west. Conversely, the negative PNA, or RNA, favor inclement weather in the west, and more pleasant sensible weather in the east. Positive phases of both the PDO and PNA are favored due to the forcing regime associated with this modoki el nino event being centered more over the central Pacific". "However since this particular warm ENSO event is late to develop and still in the process of coupling with the atmosphere, as evidenced by the ONI/MEI and AEI values, the early season period during the month of December is most likely to feature negative phases. Both phases should begin to become biased towards positive as we begin the new year, and the fledgling el nino beings to assert itself". -Eastern Mass Weather 11-12-18 Indeed, evidence of the maturation of el nino is beginning to manifest in long term ensemble consensus. Not only are the GEFS and the EPS coming into agreement on blocking over western US, but the recent Sudden Stratospheric Warming and subsequent split of the polar vortex is effectively augmenting typical weak modoki climatology in all but ensuring high latitude blocking both over the Arctic and north atlantic, in the vicinity of Greenland. This "blocking trifecta" was evident in the composite of comparable weak modoki events that occurred during a solar minimum, which was presented in the Eastern Mass Weather Winter Outlook "Fortunately, we here at Eastern Mass Weather in our infinite wisdom, have on hand a composite of weak el nino events that occurred in the vicinity of a solar minimum": Temps: "Note the presence of 1977-1978 on this composite, which is becoming a theme. This season was also a weak modoki el nino with a QBO transitioning into the western shear zone during a solar minimum". Precip: Note the continued emphasis on Miller B formation in this particular composite. H5: Significant degree of high latitude blocking in the vicinity of Greenland Our thoughts remain unchanged from the original presentation last November. "The month of January should average anywhere from 1-2 degrees above normal across New England, and 2-3 degrees above normal beneath the 40th parallel. The month of January looks a lot like 2015 and 2005, and we expect a similar evolution. Complete with a monster Archambault event anywhere from January 20th to February 8th, after which the Atlantic couples with the Pacific to induce cross polar flow and set the stage for a memorable February. "What a tremendous difference a year makes. Winter's main course is where it should be climatologically speaking, during February. The sky is the limit for wintery potential this month, as this is as favorable it as it precarious as it gets, not at all unlike February 1978. This is the window for the mid atlantic to see major storm, especially if el nino grows a bit more potent than forecast. However odds favor the most crippling OF impacts being confined to New England. Intense blocking over Greenland, the pole, as well as Alaska and northwestern Canada. The second window for a historic event adjoins the first window, from February 9th through February 20th. After which the pattern relaxes and blocking relents somewhat. The northeast should average 2-4 degrees below average, and the mid atlantic 3-6 degrees below average". "Blocking may not persist as strongly through March as the model implies, as this portion of the forecast is lower confidence. The PNA looks to wane, and there is very high confidence that the robust negative EPO will remain for the entire winter. Although this is another favorable regime for cold delivery, the source will likely be depleted by this point, and some moderation will be the rule as the airmass grows stale. The month should average out near normal across the mid atlantic, and 1-2F degrees above average throughout New England". -Eastern Mass Weather 11-12-18 In closing, here is a list of snowfall through yesterday, January 6, for Boston during some of the most prominent modoki el nino analog seasons. Followed by eventual seasonal totals to the right. 2015: 4.5" 110.6" 2005: 18.0" 86.6" 1978: 9.7" 85.1" 1969: 6.0" 53.8" 2018: .2" ? Eastern Mass Weather snowfall forecast and prognostications for aggregate December through March readings of some prominent atmospheric indexes. Index Value Predicted '18-'19 DM Value Range Actual '18-'19 DM Value Departure From Verification Pacific Decadal Oscillation (PDO) .40 to .70 Perennial North American Pattern (PNA) .25 to .55 ENSO Weak Modoki El Nino (0.9 to 1.1C ONI) (DJF) (J-M) East Pacific Oscillation (EPO) -1.20 to -1.50 Arctic Oscillation (AO) -.35 to -.60 North Atlantic Oscillation (NAO) -.10 to -.35 City Predicted Snowfall Actual Percent Departure From Forecast Range Boston, MA (BOS) 80-90" New York, NY (CPK) 40-50” Philadelphia, PA (PHL) 35-45” Baltimore, MD (BWI) 20-30” Washington, DC (DCA) 15-25” Albany, NY (ALB) 75-85” Hartford, CT (BDL) 65-75” Providence, RI (PVD) 55-65" Worcester, MA (ORH) 90-100” Tolland, CT (TOL) 80-90” Methuen, MA 90-100” Hyannis, MA 45-55" Portland, ME (PWM) 85-95" Burlington, VT (BTV) 85-95" Concord, NH (CON) 75-85” Posted 16 hours ago by Raymond Spinazola

Mixed results in this area on second year el ninos...87-88 was meh, but 77-78 was great.

+.50" 9.5" on the season.

Here is how the Eastern Mass Weather thoughts laid out on 11/12/18 for the month of December fared. "The current scandinavian ridge should retrograde towards Greenland for the first couple of weeks of December, some significant snows are likely for much of New England". The period of negative NAO did indeed materialize near the onset of the month, but unfortunately the system was forced well to the south of New England by overwhelming confluence. "The PNA may struggle to become established this early, however if it can, the northern mid atlantic may join the fray". The decline of a robust period of PNA to begin the month coupled with the eroding negative NAO to deliver the goods for the southern mid atl and southeast. "The blocking pattern should break down mid month, and there will likely be Grinch storm in the vicinity of Christmas, unlike last season". Temperatures should average out near normal for most of the east by month's end, biased colder early, and milder late. If anything, slightly above average for the mid atlantic, and below average in New England". This was a good call, as evidenced by the monthly departure map below, however truth be told, the gradient was a bit further the north across New England than has been anticipated. Additionally, although a temperature forecast was not put forth for the entire country, the warmth especially across the upper midwest was likely more intense than would have been expected, as the +EPO interlude and associated Pac jet were not expected. This may be due, at least in part, to the MJO amplification through phases 4-6 that was incited by the SSW, which also was unexpected. Although a technical SSW was not forecast, the anticipated evolution for the rest of the winter is not impacted. In fact, it only serves to further buttress confidence on the emergence of NAO blocking later in the month of January . "The NAO blocking breaks down in time for the holidays, go figure, however around this time the Pacific side grows more supportive, so this mid winter break will not be as prolonged, nor as mild as last season, especially across New England. The month should average anywhere from 1-2 degrees above normal across New England, and 2-3 degrees above normal beneath the 40th parallel. The month of January looks a lot like 2015 and 2005, and we expect a similar evolution. Complete with a monster Archambault event anywhere from January 20th to February 8th, after which the Atlantic couples with the Pacific to induce cross polar flow and set the stage for a memorable February".

Zero changes for January, or the balance of winter for that matter, as previously referenced SSW is underway....still looks to finish slightly above average temps in the aggregate, as laid out in November. Everything remains on track for the window of opportunity for severe winter weather to begin on January 20th through approximately February 20, as originally laid out on November 12th. Absolutely zero has/will be altered or "pushed back". It is in fact guidance that had been trying rush said changes adjusting to better fit the the original date of 1/20, as anticipated. Other forecasters who had been predicting a severely cold month of January in the mean are also scrambling to adjust expectations, which has also clouded the perception of the general populous and is creating unwarranted consternstion amongst winter weather aficionados. It is most unfortunate that this concept is lost on some posters. Will update with a more precise comparison of December evolution relative to expectation, but the forecast was a success, in contrast to some other outlooks arguing for a harsher onset to boreal winter 2018-2019.

https://easternmassweather.blogspot.com/2018/12/changes-afoot-for-christmas-severe.html

Quick update...no changes. Ironically enough, it is the southeastern states of Virginia and North Carolina that are receiving the major snows since the PNA did join forces with high latitude blocking, but this is irrelevant in the grand scheme of things. The blocking did indeed materialize, and is on borrowed time, as advertised. Everything seems to be going as planned..too bad the early Dec event didn't work out for most of the east coast. Bad luck. This may sound silly, but I'm ambivalent about December struggling....if you look back at all of our most prolific weak modoki seasons, they all struggled in December snowfall wise, with the exception of one....December 1977. December 2014, 2004, and 1968 were all fairly meager snowfall months. December 1976 was a prolific month during a weak el nino, but it was not a modoki. It is not difficult to envision how this month could have easily verified similarly to 12/77 had a moose fart drifted at a slightly different angle, and the northern stream had synced with that s SW, as opposed to suppressing it. The moral of the story is that December 2018 was largely anticipated to be frustrating from a snowfall standpoint, or at least it should have. My hunch is that something will work out from about most of sne points northward in latitude as the month begins to draw to a close. This will provide the impetus for some unrealistic expectations for the first half of January, which will engender some feelings of unwarranted disappointment, only to be reinvigorated by the real deal as the month ages and the late January/February bonanza ensues. Just my two cents- https://easternmassweather.blogspot.com/2018/12/deceptive-early-season-respite-november.html

+2"

+6.5"

Don't they use 1980-2010 period to derive ENSO anomaly?

I have read that modoki events may be more common place in a warmer world....why, not sure-

Oh, yea its possible......but for now, show me a weak modoki ENSO event and I'll show you an above average seasonal snowfall forecast for SNE. lol

So what are you saying, its a coincidence that we are still getting severe winters during weak el nino events, and they are not manifesting themselves as they have historically ?

Global is one thing, but it looked pretty status quo to me stateside..weak el nino and uber el nino behaved as I expected....but annual precip in the Philippines...maybe.

What I mean is that ENSO related forcing has manfiested itself into the atmosphere as it always has climotalogically speaking.....dependent upon intensity and modoki value, etc..

Enjoy. https://easternmassweather.blogspot.com/2018/11/winter-outlook-2018-2019-return-of.html I have neglected family and friends since Friday night, so bare with me on the questions, but I will do the best that I can.

Try now. BTW, I will be in Methuen this season.

I forget my username and password.

Is this why you were suggestion that some residual impact from Pinatubo may have contributed to the abysmal arctic regime of the 1994-1995 winter?

BTW, I actually started suspecting my area was going to jack just before and as the event started.... 1) It began as rain, which oddly enough excited me because I knew damn well KPYM wasn't going to jack and the system was a bit west and warmer than progged. 2) The death band moved near Montaulk PT, which is a pretty good proxy for systems that nail my area. As an aside, I think this season would have made a run for the seasonal record had a weak el nino developed as I had thought last summer...no way we would have punted Feb.

That, and I was awake for the peak of this one. I crashed at midnight with 1' in the ground in 1997. 3.62LE on 4/1 vs 1.7" on 3/13? No contest, there.

You're right. I just checked the pic...24.7". My bad.

To answer your other question....I think April 1997 was much more impressive, but I enjoyed this one the most.

No, I know.....not at all being defensive. I'm serious.....would like analysis from someone skilled to corroborate.