donsutherland1

It has been a long and increasingly demoralizing march across the calendar through December into early January in wait for measurable snow in New York City and Philadelphia. Social Media has periodically lit up whenever a stray operational run popped a big snowstorm into existence (when subsequent runs popped it back out of existence, there was silence). That the event was depicted well beyond 7 days seemed to have no impact whatsoever in a seeming scramble to be "first" not "right." Reality is sobering. Model skill scores show that the extended range remains shrouded in the fog of uncertainty despite advances in the modeling. Objective conclusions respect uncertainty. They are not beholden to preconceived beliefs about future outcomes, much less desires for future outcomes. Where do we stand now? Without measurable snowfall today, Winter 2022-2023 will be among just 11 winters that saw no measurable snowfall through January 5th at Central Park. The wait will go on. Is there potential? The January 13-15 timeframe suggests some potential exists to break the measurable snow drought. 1. Guidance has shifted toward a brief period of colder weather leading up to mid-month. A larger share of time with readings near or below freezing offers a window for accumulating snow. If, of course, there is a system to bring precipitation. 2. Discrete systems cannot be identified much less pinned down with any degree of reliability at long timeframes. But ensembles can provide insight. Just over one-third (14/51 or 35%) of members on the 1/5 0z cycle of the EPS ensembles had 1" or more snowfall in New York City during the broad timeframe mentioned above. 1" or above is useful proxy for measurable snowfall at this range, because that amount rises above the general "noise" of variability in scenarios with lesser amounts. 3. Adjusting key teleconnections for potential error (widening ranges) and then looking at the 1950-2022 period can also provide some insight (not enough for firm predictions given sample size issues and the importance of synoptic features). At long ranges, scenarios must suffice. Looking at January cases where the AO ranged from -1 to +1 and the PNA ranged from -0.5 to +0.5, there were three storms that delivered 10" or more snow to at least one of the following cities: Boston, New York City, Philadelphia, or Washington, DC. The biggest was the January 1978 snowstorm. The others occurred in January 1954 and January 1987. The number of 10"+ cases for that teleconnection range during January 1950-2022 were as follows: Boston: 1; New York City: 1; Philadelphia: 2; Washington, DC: 1. The number of 4"+ cases were: Boston: 12; New York City: 8; Philadelphia: 7; Washington, DC: 5. This would imply low potential for a 10" or greater snowfall and very low potential for a widespread 10" or above snowfall on coastal plain. However, all of the 10" cases occurred when El Niño conditions were present. Currently, La Niña prevails. The biggest snowfalls during La Niñas for the above constraints on time and teleconnections were: Boston: 6.5"; New York City: 6.3"; Philadelphia: 6.6"; and Washington, DC: 4.1". Potential spoiler alert: None of the 500 mb patterns preceding the above storms were a close match to what is currently forecast (EPS) 192-240 hours out. January 1987 is almost a complete opposite with its ridge-trough positions. 4. History is an imperfect guide to the future. A historical approach has limitations. It says nothing about synoptic systems. What do the ensembles say? Just 3/51 (6%) members showed 10" or more snowfall in New York City. All three were widespread big snowfalls, though. History + Ensembles can provide value when agreement exists. From the above, one can cautiously conclude that January 13-15 offers a window of opportunity to break the measurable snow drought. If things go really well, there might be a small chance of a big snowfall. Much can still change given the timeframe involved. There remain no guarantees. Chatter about big amounts on Twitter or Instagram or Facebook (with or without the posting of long-range snow maps) is pure speculation, as it goes far beyond the bounds of objectivity, regardless of the author.

Yes. That’s JFK’s only such case on record.

Only 1977 (-1) and 1985 (-2) had subzero lows at JFK. 1980 had a low of 3. 1983 holds the record for 12/25 at JFK with a low of 2.

Morning thoughts… Today will be partly to mostly cloudy and mild. High temperatures will reach the middle and upper 50s in most other areas. Likely high temperatures around the region include: New York City (Central Park): 54° Newark: 57° Philadelphia: 61° Some showers or light rain is possible tonight into tomorrow. Normals: New York City: 30-Year: 40.0°; 15-Year: 40.9° Newark: 30-Year: 40.5°; 15-Year: 41.7° Philadelphia: 30-Year: 41.8°; 15-Year: 42.8°

18 consecutive days with lows above freezing (January 13-30, 1932).

Temperatures soared to near record and record warmth in many parts of the region. Daily records included: Atlantic City: 70° (old record: 68°, 1950) Islip: 65° (old record: 64°, 1998) New Haven: 61° (old record: 55°, 2015) New York City-Central Park: 66° (tied record set in 1950) White Plains: 65° (old record: 61°, 1993) Following today's exceptional warmth, it will turn cooler tomorrow. Nevertheless. daily temperatures will continue to run warmer than normal through the first 10 days of January. Overall, readings will average about 15° above normal during the first week of the month. The second week of January will see some cooling from the first week's exceptional warmth, but a cold outcome is unlikely. Some guidance suggests that there could be a sharper but brief cold shot just before mid-month. 2022 became the 14th year during which New York City received no measurable snowfall through December 31st. During the 13 prior years, mean seasonal snowfall was 16.0" (median seasonal snowfall: 16.3"). Just 8% of those winters rallied to see 30" or more seasonal snowfall. 31% of those winters wound up with less than 10" of seasonal snowfall. Just under half (46%) had 20" or more seasonal snowfall. The lowest seasonal snowfall for those cases of 2.8" was recorded in 1972-1973. The highest seasonal snowfall for those cases was 32.8", which occurred during 2015-2016. The ENSO Region 1+2 anomaly was -0.3°C and the Region 3.4 anomaly was -0.7°C for the week centered around December 28. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.48°C and the ENSO Region 3.4 anomaly has averaged -0.87°C. La Niña conditions will likely persist through mid-winter before fading to neutral conditions. The SOI was +17.91 today. The preliminary Arctic Oscillation (AO) was -0.765 today.

Some photos ahead of today's near record and record warmth.

Another day, still no measurable snow for NYC. There are some hints in the extended range, but no consensus exists and the timeframe is a low-skill one.

It reached a daily record 65 there.

The most common ranges 10"-20" seasonal snowfall might be feasible. I suspect the worst case scenario would be one where the City receives less than 1" snowfall (1997-98 came close only to be bailed out by a 5" snowfall in March).

It will be interesting to see how warm it gets. Clouds could limit today’s warming.

Temperatures across the area are soaring to near record and record highs. Yet another day is passing where snow-starved New York City and Philadelphia won't see any measurable snowfall. The larger Boston, New York City, and Philadelphia corridor is currently passing through a fairly novel situation. Beginning in the 1990s, winters with very low snowfall in Boston, New York City, and Philadelphia through the end of December began to appear. Winter 2022-2023 became just the 5th winter beginning with 1893-1894 where Boston saw less than 2" of snow and both New York City and Philadelphia had no measurable snowfall through January 4th. The sample size is very small, but most of those winters went on to see below normal seasonal snowfall. Could things be worse? Perhaps. Since 1950, Winter 2022-2023 became only the second winter to see no measurable snowfall in both New York City and Philadelphia when the Arctic Oscillation (AO) was negative for all 35 days. The other winter: 2001-2002. During Winter 2001-2002, the MJO passed through Phase 8 during January 4-9 and Phases 8-1-2 during January 4-18. Temperatures remained generally mild. Phase 8 passage: Boston: 39.3°; New York City: 39.7°; Philadelphia: 39.5° Phases 8-1-2 passage: Boston: 39.8°; New York City: 42.4°; Philadelphia: 43.4° During the passage through phases 8-1-2, New York City picked up 3.5" of snow and Philadelphia saw 4.0". And that concluded the snow season for both cities. Boston limped to a seasonal total of 15.1". For now, even as the odds are increasingly tilting toward below normal snowfall, a disastrously low outcome isn't the most likely scenario. Indeed, some guidance supports at least the potential for some snow by mid-month. But that's guidance. Things can change. Finally, even as it isn't the most likely outcome, a disastrously low outcome cannot be dismissed outright.

At 11 pm, Atlantic City (69°), New Haven (57°), and White Plains (63°) have all set new record highs. More are likely.

Morning thoughts… Today will be variably cloudy and unseasonably warm. High temperatures will reach the lower 60s along the coastline and middle and upper 60s in most other areas. A shower is possible in some areas. Likely high temperatures around the region include: New York City (Central Park): 64° Newark: 66° Philadelphia: 68° It will turn somewhat cooler starting tomorrow. Normals: New York City: 30-Year: 40.1°; 15-Year: 41.1° Newark: 30-Year: 40.6°; 15-Year: 41.8° Philadelphia: 30-Year: 41.9°; 15-Year: 42.9°

Graph showing winters without measurable snowfall through December 31s through January 3:

Exceptionally warm air began pushing into the region today. Parts of the Middle Atlantic region saw record warmth today. Records included: Baltimore: 69° (old record: 68°, 2000) Sterling, VA: 69° (old record: 68°, 2000) Washington, DC: 69° (old record: 68°, 2000 and 2004) Wilmington, DE: 64° (tied record set in 2000) Wilmington, NC: 77° (tied record set in 2000 and tied in 2020) Tomorrow will be mainly cloudy and very warm. The temperature will likely soar into the 60s as far north as southern New England. Some parts of the Middle Atlantic region could see the thermometer reach or exceed 70°. Overall, readings will average 10°-15° above normal during the first week of the month. The second week of January could see some cooling from the first week's exceptional warmth, but a cold outcome is unlikely. 2022 became the 14th year during which New York City received no measurable snowfall through December 31st. During the 13 prior years, mean seasonal snowfall was 16.0" (median seasonal snowfall: 16.3"). Just 8% of those winters rallied to see 30" or more seasonal snowfall. 31% of those winters wound up with less than 10" of seasonal snowfall. Just under half (46%) had 20" or more seasonal snowfall. The lowest seasonal snowfall for those cases of 2.8" was recorded in 1972-1973. The highest seasonal snowfall for those cases was 32.8", which occurred during 2015-2016. The ENSO Region 1+2 anomaly was -0.3°C and the Region 3.4 anomaly was -0.7°C for the week centered around December 28. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.48°C and the ENSO Region 3.4 anomaly has averaged -0.87°C. La Niña conditions will likely persist through mid-winter before fading to neutral conditions. The SOI was +19.23 today. The preliminary Arctic Oscillation (AO) was -0.318 today.

With respect to fantasy range (> 240 hours out) storminess suggested by some ensemble members, below are the 500 mb clusters. The first set (23 members) would favor a storm that moves off the coast too far to the south and east to pose much of a winter weather threat for the northern Middle Atlantic Region (confirmed by the 1000 mb cluster). The second set (16 members) might hold the most promise. In short, it is premature to have a great deal of confidence in what looks like a potential snowstorm on some of the ensemble members through the mists of fantasy range. For a fresh reminder of the importance of waiting for more data--particularly in the higher skill range of the guidance--the operational ECMWF had a significant to major snowstorm at the end of its 1/3 0z run. 12 hours later, the 1/3 12z cycle had no such event.

Almost certainly, the RRWT map will be wrong. It frequently dumps the Northern Hemisphere's cold into North America. Its current 6-10 day outlook provides a good illustration of that tendency. The 6-10 day period will likely be cooler than the first week of January, but there remains little support for a cold outcome. The EPS and GEFS are in very strong agreement that temperatures will descend closer to normal but the overall 6-10 day period will be warmer than normal. I suspect that the problem with the RRWT tool is that it treats all Rossby Waves alike. Instead, origin and duration matter. From a recent paper: Higher than normal medium-range skill scores are often associated with the presence of long-lasting RWPs (about 8 days) in the initial conditions, very often triggered far away in the west Pacific (RWP_pac_eu). Bad medium-range skill scores are instead associated with shorter RWPs coming from central US or the west Atlantic. The analysis of probabilistic skill scores also supports an increase in predictive skill associated with long RWPs coming from the west Pacific, even at longer ranges, with better skill up to week 3, suggesting a possible link with MJO events.

Morning thoughts… Today will be mostly cloudy and mild. Showers are possible. High temperatures will reach the middle and upper 50s in most areas. Some areas could reach the lower 60s. Likely high temperatures around the region include: New York City (Central Park): 57° Newark: 60° Philadelphia: 62° It will turn somewhat cooler starting Thursday. Normals: New York City: 30-Year: 40.3°; 15-Year: 41.2° Newark: 30-Year: 40.7°; 15-Year: 41.9° Philadelphia: 30-Year: 42.1°; 15-Year: 43.1°

Congratulations Rodney S. Well done.

Through week 2, above normal temperatures are forecast to continue in the U.S. on the EPS weekly guidance. Beyond 2 weeks, skill scores are low.

Tomorrow will be variably cloudy and unseasonably mild. The warmth will peak on Wednesday with temperatures rising into the 60s as far north as southern New England. Overall, readings will average 10°-15° above normal during the first week of the month. The second week of January could see some cooling from the first week's exceptional warmth, but a cold outcome is not assured. Although some of the guidance suggests that the MJO could move into Phase 8 at an amplitude at or above 1.000 within two weeks, Phase 8 is not always cold. During January 3-6, 1997, much of the CONUS was much warmer than normal despite the MJO's being in Phase 8 coupled with a negative Arctic Oscillation. While 1997-style warmth is not yet the most likely outcome, a scenario where temperatures generally reach the 40s across the region during the daytime hours through mid-month seems more likely than one with much below normal readings. 2022 became the 14th year during which New York City received no measurable snowfall through December 31st. During the 13 prior years, mean seasonal snowfall was 16.0" (median seasonal snowfall: 16.3"). Just 8% of those winters rallied to see 30" or more seasonal snowfall. 31% of those winters wound up with less than 10" of seasonal snowfall. Just under half (46%) had 20" or more seasonal snowfall. The lowest seasonal snowfall for those cases of 2.8" was recorded in 1972-1973. The highest seasonal snowfall for those cases was 32.8", which occurred during 2015-2016. The ENSO Region 1+2 anomaly was -0.3°C and the Region 3.4 anomaly was -0.7°C for the week centered around December 28. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.48°C and the ENSO Region 3.4 anomaly has averaged -0.87°C. La Niña conditions will likely persist through mid-winter before fading to neutral conditions. The SOI was +30.81 today. The preliminary Arctic Oscillation (AO) was -0.117 today. On December 31 the MJO was not available. The December 30-adjusted amplitude was 1.635 (RMM).

There is some discussion that the latest GEFS forecast of widespread 5-day average warm anomalies would be wrong should the MJO forecast be accurate. However, the January 3-6, 1997 exception argues for waiting for more data before reaching conclusions.

IMO, it is premature to print the obituary for Winter 2022-2023 in the New York City area, even as some might be drafting, even revising, their obituaries. However, a strong signal about the overall character of Winter 2022-2023 could become evident by the end of January. If the January 16-31 mean temperature exceeds 32° in New York City following a 40° or above January 1-10 mean temperature, that could provide strong evidence that Winter 2022-2023 will see much below normal snowfall. Caveats apply from the sample size (n=21) and the impact of climate change on precipitation outcomes and hemispheric patterns. For those keen on writing Winter 2022-2023's obituary but facing "writers' block," some boilerplate language follows: This winter had great promise for snowfall. With deep Atlantic blocking throughout December, the rise of the PNA to positive levels, and a 3-sigma Arctic blast, the pattern became especially favorable for snowfall. Numerous significant snowstorms heralding snowy winters had occurred in the midst of similar patterns and sufficient cold air. Yet, despite the anticipation and excitement, December saw no measurable snowfall. For snow lovers, it was as joyless a Hanukkah and Christmas as one could have imagined. The biting Arctic winds added to the sting of the sight of barren frozen ground. Overall, Winter 2022-2023 proved to be remarkably mild and its lack of snowfall was noteworthy. Winter 2022-2023 is will be remembered only in the nightmares of snowless winters. Back to January 2, a great deal of patience is required while much of the New York City-Newark-Philadelphia areas await their first measurable snowfall of the winter.

Morning thoughts… Today will be partly sunny and mild. High temperatures will reach the lower and middle 50s in most areas. Likely high temperatures around the region include: New York City (Central Park): 54° Newark: 57° Philadelphia: 59° Temperatures will be above to much above average into at least the middle of next week. Normals: New York City: 30-Year: 40.4°; 15-Year: 41.4° Newark: 30-Year: 40.9°; 15-Year: 42.1° Philadelphia: 30-Year: 42.2°; 15-Year: 43.3°