December 2021 Obs/Disco...Dreaming of a White-Weenie Xmas

[WxWatcher007]

Winter of yore 

 

[ORH_wxman]

We had a hell of cold shot at this time in 2017 too...here's how ORH closed the month:

 

[Lava Rock]

0.75"

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[ORH_wxman]

4 minutes ago, ORH_wxman said:

We had a hell of cold shot at this time in 2017 too...here's how ORH closed the month:

 

That stretch actually continued into January...had a reinforcement after the 1/4 blizzard. That was a pretty epic stretch if you look brutal cold sandwiched around a huge snowstorm

[Baroclinic Zone]

18F has been mu low thus far and my only low in the teens.  Pretty pathetic.

[WxWatcher007]

10 minutes ago, ORH_wxman said:

That stretch actually continued into January...had a reinforcement after the 1/4 blizzard. That was a pretty epic stretch if you look brutal cold sandwiched around a huge snowstorm

That’s awesome. I’d love to see some cold like that this winter.

[40/70 Benchmark]

25 minutes ago, ORH_wxman said:

We had a hell of cold shot at this time in 2017 too...here's how ORH closed the month:

 

That was a great winter....even with the huge February warm spell.

[Lava Rock]

5yrs ago

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[Lava Rock]

Tooling around Bridgton while wife is at stylist

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[dryslot]

5 minutes ago, Lava Rock said:

Tooling around Bridgton while wife is at stylist

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Shawnee Peak in the clouds.

[mreaves]

I love that area of Maine.  Decent riding when there is snow?

[dryslot]

2 minutes ago, mreaves said:

I love that area of Maine.  Decent riding when there is snow?

Very good riding actually that whole area.

[Baroclinic Zone]

14 minutes ago, Lava Rock said:

Tooling around Bridgton while wife is at stylist

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Too many memories on and off that mountain.

[40/70 Benchmark]

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.

 

[TauntonBlizzard2013]

Gunna be awesome when Virginia has more snow than all of SNE

[tamarack]

8 hours ago, WxWatcher007 said:

Winter of yore 

 

NYC also had a max of 2 that day; their next lowest max is 4, on 12/30/1880 and 2/5/2018.
Central Park's coldest week, by far, is 12/29/17-1/4/18:
12/29:  8  -6  0.12  2.0
12/30:   2 -13  
12/31:   6  -7
1/1:      10  -4
1/2:      10   2
1/3:      12   0
1/4:      18  -3
Avg:  9.4/-4.4/2.5

The 2017-18 bridge is my coldest 2-week stretch, by far, since Fort Kent.  (15 days included below to catch the Christmas snowstorm.)
12/25:   16     9   0.66   8.0
12/26:   19     3
12/27:     6  -16
12/28:   -3  -14
12/29:   -1  -31   0.01    0.1     (Coldest daily mean so far here)
12/30:    7  -25
12/31:    1   -18
1/1:        1   -24
1/2:       6   -27
1/3:      20  -16
1/4:      22  -10   0.99   13.0
1/5:      22    -7
1/6:      -6   -13
1/7;        6   -20


 

[Sugarloaf1989]

https://www.cnn.com/2021/12/29/weather/kodiak-alaska-december-warm-record-climate/index.html

Record warmth in Alaska,  all time warmest temperatures for the Winter.

Kodiak hit 65F on 12/26. The warmest temperature ever recorded between 10/5 and 4/21.

So a new temperature record for October,  November,  December,  January,  February and March.  That's insane. 

[CoastalWx]

18 minutes ago, Sugarloaf1989 said:

https://www.cnn.com/2021/12/29/weather/kodiak-alaska-december-warm-record-climate/index.html

Record warmth in Alaska,  all time warmest temperatures for the Winter.

Kodiak hit 65F on 12/27. The warmest temperature ever recorded between 10/5 and 4/21.

So a new temperature record for October,  November,  December,  January,  February and March.  That's insane. 

They had some all time cold in AK setting records too in November. So cold that those temps would be too 10 cold even in December. And Denali record snow.  It’s not all warmth either.

[Sugarloaf1989]

3 minutes ago, CoastalWx said:

They had some all time cold in AK setting records too in November. So cold that those temps would be too 10 cold even in December. And Denali record snow.  It’s not all warmth either.

But 5 months of high temperature records being broken is impressive,  and with minimal daylight in Alaska. 

[qg_omega]

3 minutes ago, CoastalWx said:

They had some all time cold in AK setting records too in November. So cold that those temps would be too 10 cold even in December. And Denali record snow.  It’s not all warmth either.

Only the warmth makes headlines

[DavisStraight]

I think it was January 1994 I got zero or below 7 nights in a row. I think that's the year Jerry and Ginxy refer to with Leon. I was in a rad spot back then and got to -20 two nights in that stretch.

[CoastalWx]

4 minutes ago, Sugarloaf1989 said:

But 5 months of high temperature records being broken is impressive,  and with minimal daylight in Alaska. 

That’s just another attn grabbing headline. We know solar matters little there and it’s driven by WAA. Just like we break records at night from that with those cutters. I didn’t see this 5 month stat. We’re warming,  but let’s put things into context too. Anchorage also had a frigid period in the winter and spring 2021. 

[PhineasC]

It’s Alaska. They always have record-breaking extreme weather. LOL

[Sugarloaf1989]

3 minutes ago, CoastalWx said:

That’s just another attn grabbing headline. We know solar matters little there and it’s driven by WAA. Just like we break records at night from that with those cutters. I didn’t see this 5 month stat. We’re warming,  but let’s put things into context too. Anchorage also had a frigid period in the winter and spring 2021. 

 

[Sugarloaf1989]

5 minutes ago, CoastalWx said:

That’s just another attn grabbing headline. We know solar matters little there and it’s driven by WAA. Just like we break records at night from that with those cutters. I didn’t see this 5 month stat. We’re warming,  but let’s put things into context too. Anchorage also had a frigid period in the winter and spring 2021. 

I think with record amounts of snow in Anchorage,  right?

[CoastalWx]

1 minute ago, Sugarloaf1989 said:

I think with record amounts of snow in Anchorage,  right?

I believe so. And yes that kodiak record is impressive. 

[BombsAway1288]

On Sunday and Monday, Fairbanks, AK was raining with temps at 40 degrees. Think it was 1 degree off a record high on one day and a record high on another day.

With warmth in Alaska this time of year usually means cold and storminess here but not the winter of 2021-2022! Looks like it will find a way to torch here this winter no matter what

[NW_of_GYX]

5 hours ago, Lava Rock said:

Tooling around Bridgton while wife is at stylist

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Skied it this morning. Has been a sneaky good week here, with last nights event we managed to pick up 4” since Xmas. 

[Lava Rock]

Skied it this morning. Has been a sneaky good week here, with last nights event we managed to pick up 4” since Xmas. 

Talked to some folks at campfire grille that said skiing was very good today

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[NW_of_GYX]

3 minutes ago, Lava Rock said:

Talked to some folks at campfire grille that said skiing was very good today

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Their mountain ops crew is one of the best in the business. Another 4-6” and the clubs will open the trails here too. Off to a better start than last winter if you can believe it.