40/70 Benchmark

Lots of melts this week as we drop like flies....I went a few days ago, now Tip....

No comments bc its 230am on NYE lol

Legit threat IMO.

Actually, east based la Nina events are not front loaded. Modoki are.

He's always referring to the Hadley Cell

That looks about right.

Agree.

IDK about 4 HA events l, but I could see one moderate phase change snow event...I mentioned early Jan as a slight KU risk in my original outlook, but not feeling that.

To me, the timing is more difficult than hitting the overall character of a season. That is tough.

The mild December could also be a sign that la nina is assuming more east based look, too....which would be good. I am def not confident in an poor outcome for Jan. Bottom line is that at some point we should make ground because this season did not have a poor profile heading in.

Yea, PNA gets pretty aggressive....I could see that working out....2010-2011 followed the Pacific progression, with the RNA December, then handoff from arctic to PNA in January. Its a great ENSO analog so its possible

I see that as pretty much a non factor for January. Its going to be about the ratio between the improving PNA and deteriorating arctic.

Hopefully I continue to off base moving forward...the hope is that the PNA really spikes and/or the PV is elongated.

DEC 30 December Forecast Features Mixed Results But Largely Unsuccessful Pacific Overruled the Arctic While the overall tone of the 2021-2022 Eastern Mass Weather Outlook included a cold phase oriented Pacific, as evidenced by the primary extra tropical Pacific analogs of 2010-2011, 1970-1971, 1974-1975, 1955-1956, 1954-1955, 1964-1965, 2020-2021, 1988-1989, 2011-2012, 1998-1999, 1999-2000, 2007-2008, 2008-2009, 1975-1976, there was support amongst the analogs for a more variable PNA pattern during the early portion of the winter season. Thus the December portion of the forecast called for some variability within the PNA domain, which in conjunction with the forecast high latitude blocking would have ultimately led to an active month of winter weather culminating the week of Christmas. However, while the high latitude blocking did in fact verify, the Pacific volatility did not. Here is the original narrative and forecast composite for the period: December Analogs: 2007, 2000 (x2), 1974, 1970, 1995, 2005 (x2), 2017 (x2), 2008, 1983, 2020 "The polar vortex should take some assaults throughout the latter portion of November and much of December, however, it should remain intact and ultimately intensify and consolidate beyond the new year. This is consistent with basin-wide, mixed-type la nina events. While there may be a mild spell early in the month, it should ultimately turn active with a multitude of moderate snowfalls for the northeast, with the most significant event likely to occur the week of Christmas between the 19th and 26th. A white Christmas is highly likely for the majority of the region and a storm on the holiday itself is a distinct plausibility. Plan accordingly. Although the focus will be on the northeast via a mix of Miller B systems and southwest flow events whenever blocking relaxes, the mid atlantic should receive some snowfall due to a subtle subtropical influx coupled with a variable PNA. The month should not be exceedingly frigid, as the very mild fall has ensured a late developing cold reservoir. Anywhere from near normal close to the coast to as much -2 departures well inland should cover the monthly departures". Although the most prolific winter storm during the month in the northeast did in fact occur near the onset of the identified December 19 through December 26 period, it primarily impacted the northern half of the region, and was mainly rainfall for southern New England. More importantly, this particular event was the only noteworthy winter storm of note for the month in large part due to the development of the poorly forecast record RNA pattern. While the forecast episode of high latitude blocking in the NAO domain did in fact materialize as forecast by the holiday period, its development was concurrent with the formation of the strong ridge of high pressure to the south in response to the historically low heights along the west coast in conjunction with the extreme RNA pattern. This acted to create a very compressed flow between the southern ridge, and high latitude ridge in the vicinity of Greenland, which sheared off storm activity approaching from the active Pacific pattern. Note in the annotation above that the two respective ridges of high pressure were situated at just the right distance from once another, at the appropriate latitude to attenuate the storm systems on approach to the Great Lakes. Although this evolution is similar to the year 1970 from the list of analog composite, which featured near record snows for the month of December, in this instance the heights out west were just so low that heights to the east were elevated enough to be create said compression. Storm systems ejecting out of the PNW were sheared by the compressed flow as they neared the great lakes, so that what we were left with at the longitude of New England was a multitude of minor disturbances, instead of any larger, more discrete, congealed or phased system. This pattern acted to negate what was envisioned last fall as being a very active period with a multiple moderate snowfall events from the period leading up to the holidays and beyond. In turn, the higher heights downstream from the deep trough in the west shifted the core of the warm anomalies from the forecast position in the southwest, into the Texarkana region. It also caused temperatures in the east to be slightly warmer than anticipated. Forecast: Actual: In summary, the most important aspect of monthly forecasting is correctly identifying periods of volatility from the seasonal base state. While this does not show up in the overall DM seasonal composite, it is key to correctly diagnosing the sequential evolution of a season And while the Pacific pattern throughout the month of December was essentially a more amplified version the overall DM forecast base state of the Pacific, it certainly was not the forecast period of variability and perhaps slight variation that was forecast. This essentially rendered the well forecast high latitude blocking a moot point, and the forecast sensible appeal did not materialize. The discrepancy between how the month of December actually evolved and how it was forecast to evolve has some implications to the outlook for the month of January moving forward. January 2022 Preview Here is the forecast from early last November: January Analogs: 1955, 1956, 1971, 1996, 2006 (x3), 2001, 2018, 2012, 1989, 1965, 1976 "There is a slight chance of a KU magnitude, Archambault type east coast snowfall between approximately December 28th and January 11th, as any residual high latitude blocking erodes and heights lower in the vicinity of Alaska and western Canada. Heights will also lower in the western US as the aleutian ridge retrogrades into the pacific and a sustained RNA accompanies the development of an active, zonal pacific storm track. The core of the warmth should center in the northern plains as the pacific jet eradicates the supply of cold from much of the continent, however, the degree of warmth in the northeast should not be prohibitive of some wintery weather during this peak climo period. Although mixed precipitation and southwest flow events should be the rule, and major pure snow events will be difficult to achieve outside of the higher terrain of upstate New York and central/northern New England. The forecast is for monthly departures to range anywhere from +1 to +3 degrees, but the ceiling is quite high and the potential is there for several degree positive departures. This has the potential to bean exceptionally mild month akin to February 2018. It is as we begin to flip the calendar from January to February that changes will be afoot, as a Sudden Stratospheric Warming (SSW) is likely to take place between roughly January 21st and February 14th that should deal a much more damaging blow to the polar vortex. It is likely to be a split, as opposed to a displacement, as per 6/9 the nine examined analogs. This should ultimately ensure that any visions of an early spring are vanquished". The overall tenor of the month locally has not significantly changed, as the most favorable stretch for wintery weather still appears to be in the first half the month, especially centered on the second week, from about the 7th through the 14th. This idea is currently supported by long range ensemble consensus, which all agree on storm system tracking close to the coast, which would imply primarily snowfall for northern New England, and mixed precipitation or primarily rain for southern New England. The key change to the forecast is that the PNA should be ascending, rather than descending, considering that it reached its nadir during December instead of January, as originally forecast. This may serve to shift the warmth for the month for the month of January from its original forecast position in the northern plains, to the southeast. The forecast for the arctic remains unchanged from last fall, as the PV has survived the December assaults as predicted, and will continue to recover through most of January. All of this transition and mass flux is what makes a period of storminess near the end of the first week of the month more likely. PNA (Left) EPO (Right) However, the recovery of the polar vortex means that as said storminess takes place and the Pacific becomes less hostile, the polar domain becomes more hostile for wintery weather in the east. NAO (Left) AO (Right) This implies that the best change for any signifiant snows through mid January continues to appear to be across northern New England and upper New York state, as originally forecast last fall. Thereafter by mid month, the pattern is expected to turn mild with a more zonal flow, and a thaw for any locales to the north that had experienced sustained winter weather. This timeline is supported by the latest MJO composites, which show perhaps a brief flirtation with phase during the second week of January, near the time of the winter storm opportunity. However, it is at this point that the tropical influences will be waning as the MJO becomes less and less of a factor towards mid month. Thus the hemispheric pattern in the mid latitudes will become more heavily influenced by the extra tropics at this point, which will consist of a formidable polar vortex. While the official forecast is for the month to finish anywhere from +1 to +3F across the region, this will likely be modulated by the shape and character of the polar vortex, as an elongated lobe across this side of the pole would make the lower end of said rage more likely. Conversely, a more restricted and compact vortex near the pole would mean perhaps even warmer than the forecast range. As we look towards February, all eyes will be peered to the stratosphere for any signs of disruption.

CFS is actually frigid for Jan, Feb, and March. It was correctly very warm for Dec....

In others news, covid is contagious.

I think by mid month the pattern is shit...short window to work with the week of 1/7-14 and even then may need some luck. Latitude is best. I guess the hope is that we really pop a mid month PNA, like 2011.

My guess it is gets storm near the end of that first of January with all of the mass flux, but really going to need to thread the needle here in SNE due to the fact that the NAO block is gone as the RNA becomes less hostile.

La Nina. Spanish for "F U, little girl"

Maybe that's why its phase 8?

This.

I think sometimes when people often post what the majority doesn't want to hear, they can get labeled as a troll....but its important to not allow that emotion to turn the majority into the trolls. lol

I'm just writing up a review now...while certainly not frigid, I expected it to be near normal to perhaps seasonably cold....but yea, what really killed us was the compression between that stagnant RNA/NAO couplet. The warmth in and of itself was not prohibitive to at least near climo snowfall.

No sarcasm intended...just honestly trying to credit your overall conceptualization, which proved more correct than not.

It just seems common sense to me that an NAO block in conjunction with a record RNA pulse could do that, anyway....I mean, we have always had certain patterns more prone to compression. And what we do know is 1) HC didn't seem to constructively interfere with ENSO last year 2) It doesn't seem to be deconstructively interfering this year. Just some casual observations.