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

How about January 19th?

May have been 2007.

It's a fraud fact that they haven't, anyway.

The way my call was structured, I would inherently have be close to eating shit in order to verify.

We are going to set up a breathalyzer at your keyboard.

31.5/30.7 Really iced up.

I'll have to look into that.

My Ambient gage blows...perfectly level, and still egregiously under reports. I just look at KASH and KLWM. Temp sensor works well, though.

Wow...about .6" here. Dodged a CJ/Ginxy special.

Apparently when you select an analog, you expect the progression of that season to mirror the current season. That is not how I use them. I include an analog because I believe that there is an element(s) of that season that has a great deal of predictive value for at least a portion of the coming season. The greatest challenge of seasonal forecasting is not selecting the analogs, but rather extracting the value from each analog. This December was not as cold or snowy as 1977, nor did I anticipate that to be the case. 1978 is included because of ENSO and the second half of the winter. This is why I produce a narrative outline explicitly specifying what I anticipate as far as a sensible evolution of the coming season, which you chose to ignore and compare this December to a composite of some of my analogs, instead. I'm not sure what else to tell you....I predicted a near normal temp departure, which is what we got...warmer south vs normal, colder north. Did I expect more snow than next to nothing so far, yes. I don't do national outlooks, but I volunteered that it was warmer than I would have expected due to the Pac jet. I did not expect much Dec neg NAO....just a little early, and that worked out. While we utilized some the same analog seasons, we obviously keyed in on different features because we affixed value differently.

What games? The month of December went exactly as I had outlined...complete with predicted temp departure, cold first half, mild second half, grinch storm, gradient pattern and early winter storm, which was suppressed. I was pretty forthcoming about the fact that I didn't anticipate the PAC jet, which was a short term byproduct of the unexpected SSW. And the fact that figured we would have received some snow from that storm that whiffed.

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

My call so far has done very well..amongst the best I have seen for the northeast. See you at verification.

Just let him go. I've long since given up. Its going to be an awesome modoki winter, and long range guidance is beginning to reflect what we knew several months ago.

+.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".

When there is nothing to discuss people feel the need to pound one another over the head with semantics. It was pretty specifically outlined what the expectations are. No winter is severe wall to wall, so that argument is absurd.

I know a good deal of my posts have an arrogant tone, but I won't try to spin anything...if I'm wrong, I'll admit it and just try to figure why. I will say that after going back over things, My Dec call def. was not perfect...aside from missing out on the early month snow through some misfortune, I did miss the +EPO that was prevalent. I was correct RE the grinch event/monthly NAO behavior, and that the PNA was not strong, but expected pretty much wall to wall EPO this season, so Scott was right when he said that no one nailed that. I said that I did, but I didn't. I think it relates back to what Tom said RE the short term feedback from the SSW. I did not think that we would see a technical SSW, but we are.....so there was some deviation from the expectation. The blocking that will materialize was expected, nonetheless. In the end my monthly departure for Dec were good, so missing the SSW and Pac jet interlude is largely immaterial to the forecast seasonal evolution. I did nail the Dec monthly evolution from a sensible standpoint, as well as the NAO. I'll post about the Dec verification this week.

I posted seasonal numbers in the outlook. But I expect two KU level events with some 20"+ amounts between 1/20 and 2/20.

Honestly...no...I'm not.