2024-2025 La Nina

[40/70 Benchmark]

35 minutes ago, snowman19 said:

I figured with the huge push into a Niña over the last few weeks, it was just a matter of time before the modeling caught on and started dumping -PNA into the west. They are probably rushing it though, don’t think it actually starts until mid-January or more likely just after that point, which would be climo for a front-loaded Nina winter

I was dead-on with the 2008 analog for the late development of La Nina when most were jumping off of the bus. Looks as though my timing for the mismatch was a bit late, though...as its more of December into the first half of January, as opposed to just January. 

[bluewave]

12 minutes ago, 40/70 Benchmark said:

Correct, nor do I think that we will.

I said a while back in one of our great discussions that these next 5 winters would probably determine whether we could at least see one colder winter for a change after the 9 winter warmer streak. You would think after 9 years that even in a warming climate we could at least manage one colder winter every now and then. This winter will be a test case for us since we will carry a small cold departure into the start of January.

[LibertyBell]

11 minutes ago, 40/70 Benchmark said:

Correct, nor do I think that we will.

If it came back like 2018 did in March that would be amazing, but I don't think you see that happening either?

[LibertyBell]

3 minutes ago, bluewave said:

I said a while back in one of our great discussions that these next 5 winters would probably determine whether we could at least see one colder winter for a change after the 9 winter warmer streak. You would think after 9 years that even in a warming climate we could at least manage one colder winter every now and then. This winter will be a test case for us since it has been a struggle for us to at least put up a 6 week colder period against the new warmer means. 

it's difficult to objectively state what's *warmer* vs *colder* when the so-called averages change every 10 years.  I think we should just go by the entire climatological record rather than just 30 year slices of it-- there's no scientific reason to choose 30 as the number of years to use to calculate the average.

[40/70 Benchmark]

2 minutes ago, LibertyBell said:

If it came back like 2018 did in March that would be amazing, but I don't think you see that happening either?

I do see support for a warming strat late in the season, just not quite as glaring as 2018 and 2022....

The Polar Domain 

Primary Modern Polar Domain Analogs: 2022-2023, 2016-2017

Secondary Archaic Polar Domain Analogs: 2007-2008, 1999-2000, 1975-1976, 1970-1971

Influence of ENSO on the Extra Tropical Atmosphere

It is evident in the graphic below that Modoki, or basin-wide La Nina events, such as this one is likely to be, often feature the seasonal nadir for the NAO near the bookends of the season in December and March. In contrast, east-based events are more likely to feature mid season NAO blocking and accompanying cold.

 

The behavior of the NAO is the reason why December is the coldest month of the CP la Nina composite, as the NAO is only moderately positive in the composite, while it is highly positive in January and February. The NAO averages slightly negative in November and March. Contrary to the CP la Nina years, the month of December is the most mild month of the EP composite because the NAO is neutral-negative, and is very negative the rest of the winter before ascending slightly in March. Thus the orientation of La Nina can play a vital role in not only the aggregate NAO value of the winter season, but also the overall progression. This is due both the aforementioned modulation of the Hadley Cell via convective forcing patterns and the oceanic circulation patterns that feedback into the Atlantic via subtropical jet bridges to sustain said forcing patterns. Zhang et al 2014 verify through several atmospheric simulations that CP la Nina favors an extratropical response redolent of a positive NAO configuration across north America and the north Atlantic. And EP La Nina favors negative NAO during the winter season due to a diametrically opposing atmospheric and oceanic circulation pattern. It is suggested that the subtropical jet bridges the connection between ENSO and the NAO. Essentially, the circulation pattern of the CP la Nina strengthens the Pacific subtropical jet, which augments the Atlantic jet and creates an anticyclonic circulation. This circulation configures SSTs in such a manner as to reinforce positive NAO through a wind-evaporation-SST feedback. 

 

The EP event has a diametrically opposed circulation pattern that weakens said subtropical Pacific jet, which in turn diminishes the Atlantic jet and fosters the development of an cyclonic circulation that sustains negative NAO via said wind-evaporation-SST feedback. This likely played a role in why the more eastern biased, strong hybrid la Nina season of 1955-1956 featured both high latitude blocking and poleward Aleutian ridging, while other years within the dataset, such as 1999-2000 and 1975-1976 were so much milder with a notable dearth of blocking. In fact, Zhang even referred to basin-wide events as "hybrid" or "mixed" events, since they often display characteristics of both east-based and Modoki events. Due to the fact that this season is likely to feature a central-based, hybrid event of weak intensity with a moderate ocean-atmosphere interface, odds favor a +AO and NAO consistent with a fairly strong polar vortex in the mean. The months of December and March may be most prone to an episode(s) of -AO/NAO. However, variance in this data set is high, thus it is imperative to consider alternative outcomes. Obviously, weaker SST anomalies present within more marginal La Nina events have a reduced ability to couple with the atmosphere, thus other extra tropical factors play a more prominent role. This means that the correlation of the NAO to the structure of La Nina is reduced in weaker ENSO events. This is also why some weaker CP events, such as the 2008-2009 and 2000-2001 events, did not feature a very prominent positive NAO signal and were thus more prone to episodes of blocking. 

 

 

Likewise, the minor EP event of 2005-2006 was relatively mild, despite some blocking episodes. Note that the extremely positive NAO value reflected during the moderate Modoki season of 2011-2012, which in conjunction with a very consolidated polar vortex and cold phase of the Pacific undoubtedly played a role in the very mild character of that winter. Clearly there are other factors at play with respect to the modulation of the polar domain that are independent of ENSO and are very worthy of consideration in their own right. One such consideration. Quasi Biennial Oscillation (QBO).

 

Role of the Tropical Stratosphere on the Polar Domain

The system of cycles and oscillations that occur throughout the tropical atmosphere extends high above the waters of the ENSO region. And all of it plays an integral role in modulating the atmosphere across the entire span of the globe. The Quasi Biennial Oscillation (QBO) is an atmospheric phenomenon marked by a circuit of zonal winds measured at 30mb and 50mb, which run in dual bands throughout the equatorial stratosphere. Each band oscillates from an east to west direction with height, while propagating downwards until its dissipation at the top of the tropical tropopause. Currently the QBO is ascending and is nearing its westerly peak at both the 30MB and 50MB levels. This past summer, Eastern Mass Weather identified the year 2016, 2020 and 2022 as three primary QBO analogs when considering both the 50MB and 30MB levels and this preliminary analysis remains valid.

 

October 2024 50MB QBO: 9.54 & rising

2022: 5.13 & rising

2020: 6.94 & rising

2016: 4.53 & rising

 

October 2024 30MB QBO: 11.64 & rising 

2020: 10.80 & rising

2016: 12.83 & rising

2022: 10.93 & rising

 

Given that the QBO will be westerly both the 30 and 50mb levels during the 2024-2025 winter season, the state of the tropical stratosphere dictates that blocking is more likely to occur earlier in the season before dissipating by mid season, which is congruent with history concerning hybrid, or "mixed-type" La Niña seasons.

This is evidenced by the December-January 500mb composite for all cool ENSO seasons with a westerly (positive) QBO, similar to this season. Note the slight blocking signature in the vicinity of Greenland, as well as the pronounced poleward ridging near Alaska. This aligns with earlier analysis of the West Pacific.

W QBO/Cool ENSO DJ H5

 

Thereafter, any semblance of blocking vanishes later in the season, like the other composites, which supports the notion of a Pacific driven mid-season MC mismatch period akin to January 2022.

 

W QBO/Cool ENSO FM H5

 

This is why most of the eastern US warms appreciably during the second half of winter in the general W QBO/cool ENSO dataset.

 

W QBO/Cool ENSO FM Temp Anomalies

This same trend for early season blocking is noted with respect to the primary QBO analog composite of 2016, 2020 and 2022.

 

2016-2017, 2020-2021, 2022-2023 DJ H5

Interestingly enough, in the analog composite, while certainly decreased in the aggregate relative to the December-January period, blocking appears to reassert itself late. However, it seems to be largely negated by the very deep Western CONUS troughing that is related to the Western Pacific Warm pool, which doomed last season's outlook. This was alluded to in the extra tropical Pacific analysis, and was wonderfully illustrated during the 2022-2023 season. This more recent tendency for southeast ridging to adjoin NAO blocking is predominately why the aged polar analogs are considered secondary to the more modern day analogs.

 

2016-2017, 2020-2021, 2022-2023 FM H5

 

The subtle trend for the polar vortex to become at least somewhat disturbed once again later in the season is confirmed through a consideration of solar data in conjunction with the aforementioned QBO analysis.

Influences of the Solar Cycle on the Polar Fields

 

The impact of the solar cycle and the stratosphere on the earth's atmosphere continues to be a work in progress and much like seasonal forecasting in general, it is still very much a frontier science. Traditionally, research correlated high levels of solar activity near solar max, such as will be the case for winter 2024-2025, to a stronger polar vortex and thus milder winters for much of North America and Europe. There are a multitude of theories as to why this is the case, however, most of these theories cite drivers such as UV radiation and total solar radiation (TSI), which closely mirror sunspot activity, as responsible for increasing ozone levels and temperature in the equatorial stratosphere. This warmer tropical stratosphere then results in a stronger latitudinal gradient and a cooler polar stratosphere (stronger polar vortex) via a modulated Brewer-Dobson cycle. The issue with these theories is that the peak levels of the aforementioned potential drivers of the solar-stratosphere connection coincide with solar max. And most recent research cites stronger drivers that do not coincide with solar max, such as geomagnetic energy and solar winds, which peak during solar flux or, about one year after solar max in terms of peak UV and TSI . (Maliniemi et al, 2014). Malimiemi et al theorize that geomagnetic energy makes its way into the polar region via the process of energetic particle precipitation, which then produces nitrogen oxides in the the upper atmosphere that have a protracted period of time to descend downward and increase ozone during the polar winter in the absence of any sunlight, which cools the stratosphere and strengthens the PV. This more closely corroborates both with other recent research, which cites drivers that do not peak at solar max as defined by UV and TSI (geomagnetic energy peaks approximately one year after solar max), as well as the research of Malimiemi et al (2014), which found that the declining phase of the sunspot cycle remarkably consistently produces the spacial pattern of surface temperature anomalies related to the positive NAO during the last 13 solar cycles" (Maliniemi et al, 2014). This makes sense since the geomagnetic energy peak that Maliniemi et al cite as the main driver behind the connection between the solar cycle and polar domain lags solar max as defined by UV, TSI and sunspots by approximately one year, which is during the declining phase that so strongly correlates with the +NAO response in their research.

 

 

 This implies that winter 2025-2026 and 2026-2027 will be more favorable for a stronger polar vortex than the impending winter season, which is also consistent with other recent studies of seal level pressure patterns that revealed a +NAO pattern lagging solar max by approximately 2-4 years. The work of Maliniemi et al also showed that this relationship is not at all dependent on overall sunspot activity due to intra-cycle variability. 

 

Mean winter NAO index values for the four cycle phases, averaged over cycles 11 to 23. The red line represents the overall mean value of wintertime NAO (0.05). Bars represent the 95% confidence intervals.

 

Perhaps more germane within the context of the coming winter is that the study found that both the solar max and the ascending portion of the solar cycle are weakly correlated to a colder pattern redolent of the -NAO, although this is more dependent on intra-cycle variability of activity. There is a modest negative correlation with solar minimum, which was the case in the QBO analog year of 2020-2021.

 

 

These relationships between solar behavior and the NAO are evident in the graph above, with reds, denoting +NAO, very evident in the declining phase of the last several solar cycles. And Blue, indicative of -NAO, prevalent in the ascending portion of the cycles. What can also be deduced from the graphic above is that while solar max seasons are not as favorable as the ascending phase of the cycle for incidences of high latitude blocking, nor are they as hostile as the descending seasons. Thus winter seasons such as 2024-2025, which are near solar max, are not entirely devoid of blocking, however, nor is this season as prone to an intense round of late season blocking the magnitude of March 2023 given that the solar cycle was still ascending at that point. Be that as it may, solar max seasons are not entirely hostile to incidences of a disturbed polar vortex and this is evident when considering the best solar analogs of 1970 and 1999.

 

There was a split of the polar vortex on January 17, 1971, a displacement on March 20, 1971 and a displacement on March 20, 2000. While there was an easterly QBO evident during the 1970-1971 winter, the polar vortex displacement that took place in March of 2000 occurred during a westerly QBO, as will be the case this season. Thus the latter displacement seems worthy of more consideration for the coming season. When considering the three primary QBO analogs of 2016, 2020 and 2022 within a solar context, although none took place during solar max, 2022 was the closest, followed by 2016 and 2020, the latter of which is a poor solar match having taken place near solar minimum.

 

Given that the QBO analog of 2020-2021 took place near solar minimum, the early January 2021 SSW  is of least relevance as a viable analog occurrence this season. However, the February 2023 SSW, which is a better solar analog, lends more support to a later season potential polar vortex disruption along the lines of March 1971 and 2000. This notion is supported by research on high solar, westerly QBO seasons, which lends credence to the late winter/early spring displacement scenario.

 

 

 

 

The postulation of a modestly disturbed polar vortex during the month of December, followed by a recovery during the middle portion of the winter, prior to a more substantial displacement of the polar vortex during either February or March is well supported by research on moderate, basin-wide La Niña events taking place near a solar maximum with a westerly QBO. Such an evolution would also be consistent with the 2022 type of preferred mismatch during January 2025, which would be Pacific driven (-WPO/-EPO and/or +PNA and accompanied by a fairly strong polar vortex (+AO/NAO). This preliminary conclusion is based upon a constellation of historic data can be checked against observed, concurrent data in real time.

[40/70 Benchmark]

February 2025 Outlook

February Analogs: 2011, 2008, 2000, 1999,1972

The polar vortex should begin the month very strong, but watch for a potential SSW from about mid month onward.

The pace of moderate storms should increase for the first time all season, just as the warmer weather returns in February, however, a notable difference from many recent months of February is that it should not be prohibitively warm so as to entirely preclude some appreciable snowfall across the majority of the region. The month should finish 1 to 3F above average with near normal to perhaps just below normal snowfall. Northern New England should see above normal snowfall as the cold air source lurks close by in southeastern Canada, which will produce several front-end snowfall for much of southern New England and perhaps even into the northern mid Atlantic at times.

"SWFE"....AKA "Southwest Flow Events-

 

 

 

March 2025 Outlook

March Analogs: 2023x2, 2022, 2021, 2017 2014, 2001,1972

The polar vortex should weaken once again to an extent to close out the season, though confidence is not high in a major episode of blocking. The window for a SSW is through about the 20th of the month, so the impact on winter would largely depend on just how early it can take place. During February or at least the first week of March for maximum impact throughout southern New England. There is another window for a potential KU from approximately March 5 through the 19th, but confidence is low.The cold source should be relatively close by at the very least, not unlike February should major blocking not materialize. Near average to 2F above in the mean with near average precipitation inland and slightly below near the coast.  

 

 

 

[40/70 Benchmark]

6 minutes ago, LibertyBell said:

it's difficult to objectively state what's *warmer* vs *colder* when the so-called averages change every 10 years.  I think we should just go by the entire climatological record rather than just 30 year slices of it-- there's no scientific reason to choose 30 as the number of years to use to calculate the average.

No methodology is perfect, but it makes even less sense to measure today's weather against yesterday's climate...we'd never see a below average season, as difficult as it is using 30 year climo.

[LibertyBell]

8 minutes ago, 40/70 Benchmark said:

No methodology is perfect, but it makes even less sense to measure today's weather against yesterday's climate...we'd never see a below average season, as difficult as it is using 30 year climo.

It seems like we should be placing emphasis on the most recent decade then vs 20-30 years ago then.

Wild, I love how you incorporated solar max lag into your forecasts for 2025-26 and 2026-27.

When we saw that unprecedented northern lights display even down here in October, the first thing I wondered about was..... "hmmm, I wonder how this very rare event will impact Ray's winter outlook!"

One great thing about having 0 rain in October was it being such a great month for astronomy and having such a historic northern lights display was absolutely amazing.

[bluewave]

19 minutes ago, LibertyBell said:

it's difficult to objectively state what's *warmer* vs *colder* when the so-called averages change every 10 years.  I think we should just go by the entire climatological record rather than just 30 year slices of it-- there's no scientific reason to choose 30 as the number of years to use to calculate the average.

The global average temperatures are based on the older averages. This makes more sense for keeping track of long term trends. 30 year climate normals are great in a stable climate. But they mask the warming when they update every 30 years in such a rapidly warming climate. Now that the climate normals are so much warmer, the bar is lower to get a colder than average winter. So it’s possible we could eventually get a colder than average winter in the 91-20 normals, but it could still have been a warmer winter using 81-10 normals. 

[GaWx]

 I’m seeing what appears to be a trend toward the early Jan cold dumping more into the W US vs E US vs what was showing on runs late last week through early yesterday. Hoping that would be temporary and/or the trend is a head-fake.

*Edit: This is especially the case on recent GFS/GEFS more than the others.

 Natural gas, which hit new highs on Fri, has been dropping back some the last few hours and most noticeably since 8AM EST. That market could be considering this recent trend, which would be bearish for NG demand if reflecting reality.

[40/70 Benchmark]

16 minutes ago, GaWx said:

 I’m seeing what appears to be a trend toward the early Jan cold dumping more into the W US vs E US than what was showing on runs late last week through early yesterday. Hoping that would be temporary and/or the trend is a head-fake.

I don't really care to see a January 1996 pattern, anyway TBH....last thing I want is suppression. I'll take my chances with a "flawed" pattern at my latitude...especially in January. 

[mitchnick]

23 minutes ago, GaWx said:

 I’m seeing what appears to be a trend toward the early Jan cold dumping more into the W US vs E US vs what was showing on runs late last week through early yesterday. Hoping that would be temporary and/or the trend is a head-fake.

*Edit: This is especially the case on recent GFS/GEFS more than the others.

 Natural gas, which hit new highs on Fri, has been dropping back some the last few hours and most noticeably since 8AM EST. That market could be considering this recent trend, which would be bearish for NG demand if reflecting reality.

That market really is nothing short of gambling. It has nothing to do with predicting weather and more about predicting models. What a way to pay your bills. 

[GaWx]

14 minutes ago, mitchnick said:

That market really is nothing short of gambling. It has nothing to do with predicting weather and more about predicting models. What a way to pay your bills. 

All commodity markets inherently have high levels of gambling. Not for the faint of heart! I’d say that market typically reacts to already existing model trends more than it predicts model trends. That’s why I like to mention its trends.
 This morning it reacted to what the last few models have shown. Even the latest EPS lost some HDDs.

[snowman19]

21 minutes ago, 40/70 Benchmark said:

I don't really care to see a January 1996 pattern, anyway TBH....last thing I want is suppression. I'll take my chances with a "flawed" pattern at my latitude...especially in January. 

You knew the weenie January, 1996 “analog” was coming. I’m laughing at a tweet I just saw: “January-February 2011 let’s do this!!”. Guess they didn’t bother to actually look at what happened in February, 2011 when the blocking went away and the pattern completely shutdown and never came back again….

[40/70 Benchmark]

Just now, snowman19 said:

You knew the weenie January, 1996 “analog” was coming. I’m laughing at a tweet I just saw: “January-February 2011 let’s do this!!”. Guess they didn’t bother to actually look at what happened in February, 2011 when the blocking went away and the pattern completely shutdown and never came back again….

Well, I mean...we don't live in Barrow....the best seasons have shitty periods. Feb 1996 low-key sucked.

[brooklynwx99]

10 minutes ago, snowman19 said:

You knew the weenie January, 1996 “analog” was coming. I’m laughing at a tweet I just saw: “January-February 2011 let’s do this!!”. Guess they didn’t bother to actually look at what happened in February, 2011 when the blocking went away and the pattern completely shutdown and never came back again….

i mean, the pattern is analogous to Jan 2011. no denying that. probably the best the E US has seen for cold and snow in quite some time

[40/70 Benchmark]

4 minutes ago, brooklynwx99 said:

i mean, the pattern is analogous to Jan 2011. no denying that. probably the best the E US has seen for cold and snow in quite some time

More the European suite than the GFS....

[GaWx]

 

 The MJO forecasts toward weak left side are what make me think the recent GFS suite trend is mainly a head fake or temporary at worst and that the E US will likely be dominated by cold in much of Jan 1-20+. Also, a (near) record +PNA in Dec for cold ENSO is encouraging for Jan +PNA prospects as has been posted about. Fingers crossed

 I found 8 cases of weak left side MJO (similar to the images below) in cold ENSO in Jan with 7 of the 8 cases being concurrently cold dominated (posted in detail over the weekend):

 

 In addition, the early Jan progged -AO is on the side that supports E US cold.

[brooklynwx99]

6 minutes ago, 40/70 Benchmark said:

More the European suite than the GFS....

pretty good agreement overall

[LakePaste25]

Yep, that february ‘11 outcome is not just a possibility, but probably leans more likely than not barring any serious SPV warming. But most won’t care if they can score a big storm or two in January to hit average. Just like how a winter with a decent amount of cold, but with low snow might get rated poorly. 

[snowman19]

15 minutes ago, GaWx said:

 

 The MJO forecasts toward weak left side are what make me think the recent GFS suite trend is mainly a head fake or temporary at worst and that the E US will likely be dominated by cold in much of Jan 1-20+. Also, a (near) record +PNA in Dec for cold ENSO is encouraging for Jan +PNA prospects as has been posted about. Fingers crossed

 I found 8 cases of weak left side MJO (similar to the images below) in cold ENSO in Jan with 7 of the 8 cases being concurrently cold dominated (posted in detail over the weekend):

 

 In addition, the early Jan progged -AO is on the side that supports E US cold.

1/1-1/20+? Beyond 1/20? Not sure about that one. I can see it lasting to mid-month but not locking in for the entire month. I don’t think we get very far beyond mid-January before we start seeing -PNA dumping into the west. The GEFS is probably rushing it, but the signs are growing that it’s going to happen

[mitchnick]

12 minutes ago, snowman19 said:

1/1-1/20+? Beyond 1/20? Not sure about that one. I can see it lasting to mid-month but not locking in for the entire month. I don’t think we get very far beyond mid-January before we start seeing -PNA dumping into the west. The GEFS is probably rushing it, but the signs are growing that it’s going to happen

If we get that type of "pattern change," it's often preceeded by a decent sized storm. Plus, if that Hudson Bay blocking fails to completely decay, a -PNA won't be the death knell for east coasts snow threats.

[PhiEaglesfan712]

42 minutes ago, snowman19 said:

You knew the weenie January, 1996 “analog” was coming. I’m laughing at a tweet I just saw: “January-February 2011 let’s do this!!”. Guess they didn’t bother to actually look at what happened in February, 2011 when the blocking went away and the pattern completely shutdown and never came back again….

The pattern came back again for the last week of March. Turned a +4 temperature departure for the first 3 weeks to near normal. Of course, it was too late for snow here at PHL, but places more north got snow in late March 2011.

PHL:

2011-03-23	43	38	40.5	-5.2	24	0	0.23	0.0	0
2011-03-24	44	33	38.5	-7.5	26	0	0.02	T	0
2011-03-25	45	28	36.5	-9.9	28	0	0.00	0.0	0
2011-03-26	43	27	35.0	-11.8	30	0	0.00	0.0	0
2011-03-27	46	30	38.0	-9.1	27	0	0.00	0.0	0
2011-03-28	47	28	37.5	-10.0	27	0	0.00	0.0	0
2011-03-29	52	31	41.5	-6.4	23	0	0.00	0.0	0
2011-03-30	51	33	42.0	-6.2	23	0	T	0.0	0
2011-03-31	44	39	41.5	-7.1	23	0	0.05	0.0	0

 

NYC:

2011-03-23	40	32	36.0	-8.8	29	0	0.87	T	0
2011-03-24	44	30	37.0	-8.2	28	0	0.09	1.0	1
2011-03-25	42	28	35.0	-10.5	30	0	0.00	0.0	0
2011-03-26	40	26	33.0	-12.9	32	0	0.00	0.0	0
2011-03-27	45	28	36.5	-9.7	28	0	0.00	0.0	0
2011-03-28	45	26	35.5	-11.1	29	0	0.00	0.0	0
2011-03-29	49	31	40.0	-6.9	25	0	0.00	0.0	0
2011-03-30	53	36	44.5	-2.8	20	0	0.01	0.0	0
2011-03-31	43	37	40.0	-7.7	25	0	0.13	T	0

 

BOS:

2011-03-20	40	30	35.0	-4.2	30	0	0.00	0.0
2011-03-21	41	34	37.5	-2.0	27	0	0.16	0.3
2011-03-22	44	35	39.5	-0.3	25	0	0.00	0.0
2011-03-23	40	32	36.0	-4.1	29	0	0.00	0.0
2011-03-24	39	31	35.0	-5.4	30	0	0.01	0.2
2011-03-25	45	30	37.5	-3.2	27	0	0.00	0.0
2011-03-26	41	26	33.5	-7.5	31	0	0.00	0.0
2011-03-27	45	27	36.0	-5.4	29	0	0.00	0.0
2011-03-28	48	28	38.0	-3.7	27	0	0.00	0.0
2011-03-29	49	32	40.5	-1.5	24	0	0.00	0.0
2011-03-30	55	34	44.5	2.1	20	0	0.00	0.0
2011-03-31	44	33	38.5	-4.2	26	0	0.35	0.6

[40/70 Benchmark]

18 minutes ago, mitchnick said:

If we get that type of "pattern change," it's often preceeded by a decent sized storm. Plus, if that Hudson Bay blocking fails to completely decay, a -PNA won't be the death knell for east coasts snow threats.

People have a recency bias with respepct to -PNA...while I agree that its not as easy for a - PNA pattern to bare fruit for the east coast as it was 20-30+ year ago, its also not likely to be as anomalous or hostile as it was in 2023.

[PhiEaglesfan712]

30 minutes ago, mitchnick said:

If we get that type of "pattern change," it's often preceeded by a decent sized storm. Plus, if that Hudson Bay blocking fails to completely decay, a -PNA won't be the death knell for east coasts snow threats.

Yeah, February 2006 and February 2021 are classical examples of cold/snow happening with a -PNA. This was following long periods of warm and virtually snowless weather during +PNA.

[LakePaste25]

31 minutes ago, PhiEaglesfan712 said:

Yeah, February 2006 and February 2021 are classical examples of cold/snow happening with a -PNA. This was following long periods of warm and virtually snowless weather during +PNA.

I believe late January 2021 had an SSW, which lead to less of a traditional Nina signal and likely saved Feb. 

[LakePaste25]

Same theme as January 2011. The GOA ridge plus the blocking is good enough to do the job. It is when the pacific blocking is back towards the Aleutians, the atlantic and AO blocking might not save the pattern (bootleg SE ridge). 

[LibertyBell]

2 hours ago, 40/70 Benchmark said:

Well, I mean...we don't live in Barrow....the best seasons have shitty periods. Feb 1996 low-key sucked.

You didn't do well in either the January 1996 blizzard or the big February 1996 snowstorm either, I take it?

It was one of our few wall to wall extremely cold and snowy winters.

[LibertyBell]

1 hour ago, PhiEaglesfan712 said:

The pattern came back again for the last week of March. Turned a +4 temperature departure for the first 3 weeks to near normal. Of course, it was too late for snow here at PHL, but places more north got snow in late March 2011.

PHL:

2011-03-23	43	38	40.5	-5.2	24	0	0.23	0.0	0
2011-03-24	44	33	38.5	-7.5	26	0	0.02	T	0
2011-03-25	45	28	36.5	-9.9	28	0	0.00	0.0	0
2011-03-26	43	27	35.0	-11.8	30	0	0.00	0.0	0
2011-03-27	46	30	38.0	-9.1	27	0	0.00	0.0	0
2011-03-28	47	28	37.5	-10.0	27	0	0.00	0.0	0
2011-03-29	52	31	41.5	-6.4	23	0	0.00	0.0	0
2011-03-30	51	33	42.0	-6.2	23	0	T	0.0	0
2011-03-31	44	39	41.5	-7.1	23	0	0.05	0.0	0

 

NYC:

2011-03-23	40	32	36.0	-8.8	29	0	0.87	T	0
2011-03-24	44	30	37.0	-8.2	28	0	0.09	1.0	1
2011-03-25	42	28	35.0	-10.5	30	0	0.00	0.0	0
2011-03-26	40	26	33.0	-12.9	32	0	0.00	0.0	0
2011-03-27	45	28	36.5	-9.7	28	0	0.00	0.0	0
2011-03-28	45	26	35.5	-11.1	29	0	0.00	0.0	0
2011-03-29	49	31	40.0	-6.9	25	0	0.00	0.0	0
2011-03-30	53	36	44.5	-2.8	20	0	0.01	0.0	0
2011-03-31	43	37	40.0	-7.7	25	0	0.13	T	0

 

BOS:

2011-03-20	40	30	35.0	-4.2	30	0	0.00	0.0
2011-03-21	41	34	37.5	-2.0	27	0	0.16	0.3
2011-03-22	44	35	39.5	-0.3	25	0	0.00	0.0
2011-03-23	40	32	36.0	-4.1	29	0	0.00	0.0
2011-03-24	39	31	35.0	-5.4	30	0	0.01	0.2
2011-03-25	45	30	37.5	-3.2	27	0	0.00	0.0
2011-03-26	41	26	33.5	-7.5	31	0	0.00	0.0
2011-03-27	45	27	36.0	-5.4	29	0	0.00	0.0
2011-03-28	48	28	38.0	-3.7	27	0	0.00	0.0
2011-03-29	49	32	40.5	-1.5	24	0	0.00	0.0
2011-03-30	55	34	44.5	2.1	20	0	0.00	0.0
2011-03-31	44	33	38.5	-4.2	26	0	0.35	0.6

Yep, I remember March 2011 as moderately snowy

 

[jm1220]

1 minute ago, LibertyBell said:

You didn't do well in either the January 1996 blizzard or the big February 1996 snowstorm either, I take it?

It was one of our few wall to wall extremely cold and snowy winters.

We never have a wall to wall cold snowy winter at our latitude-we had the later Jan thaw in 1996 for example and in 2011 we shut completely off after 2/1. The key is maximizing the snow output when it’s cold enough and the pattern’s favorable. Hopefully this upcoming Jan pattern has the pieces in place and we can have a good outcome. Our chances are better if we don’t have to rely on a fast northern stream to spawn something in time for our longitude, or be stuck with lousy SWFEs and we get help from the Gulf.