donsutherland1

-2 at JFK.

Yes, but that winter’s patterns were generally very good for snowfall. The 12 days of a horrible pattern didn’t have much impact. The lack of snow during those 12 days during a snowy winter illustrates just what a bad pattern it is.

Such patterns are not common. For the January-February 1950-2023 period, there were 4,606 days with 344 (7.5%) meeting the criteria (AO: +1.000 or above /EPO +1.000 or above). There were three winters where January-February saw 10 or more such days. 1963-64: 14 days; Total snowfall during those days: 0.2" 1988-89: 22 days; Total snowfall during those days: None 2019-20: 12 days; Total snowfall during those days: 0.2"

Week ahead numbers: Mild with perhaps a strong shot of warmth and wet.

I agree. That’s why I termed it a pause.

It’s a much weaker signal than for December and January. So far, the Washington, DC area has had some snowfall. Hopefully, after the upcoming pause, there will be some bigger storms.

A genuine "kiss of death" for snowfall pattern for January and February would be the combination of an AO of +1.000 or above and EPO of +1.000 or above. Such a pattern yields much below climatological frequency of measurable snowfall in New York City. The largest snowfall among the 344 dates that met those criteria was just 2.0". So far, the guidance does not show more than a few such days. Therefore, even as the forecast pattern for the closing 7-10 days of January is not a good one, it could be worse.

Following another night in the teens in New York City and some single-digits outside of New York City and Newark, tomorrow will be fair and cold. Readings will approach or reach freezing in parts of the region. Afterward, the development of an EPO+/AO+ pattern will lead to a noticeable warming trend that could send temperatures well into the 40s across the region and even into the 50s in parts of the region. This warm period will assure that January will wind up as a warmer than normal month and Winter 2023-24 will become yet another warmer than normal winter in the New York City and Philadelphia areas. The expected monthly warm anomaly has increased in recent days as the development of this pattern has grown increasingly likely. The generally mild conditions could continue into the first week of February with only brief interruptions. The ENSO Region 1+2 anomaly was +0.9°C and the Region 3.4 anomaly was +1.9°C for the week centered around January 10. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +1.18°C and the ENSO Region 3.4 anomaly has averaged +1.95°C. A basinwide El Niño event is ongoing. The ongoing El Niño event has recently peaked. The SOI was +15.13 today. The preliminary Arctic Oscillation (AO) was +0.568 today. That is the first positive reading this month. Should the AO remain positive for the remainder of this month as is indicated on the guidance, it will have been negative on 58% of days during December and January. That is consistent with historic experience. Strong blocking in the final week of November, as occurred this year, has often been followed by frequent blocking in December and January. On January 18 the MJO was in Phase 5 at an amplitude of 2.993 (RMM). The January 17-adjusted amplitude was 2.729 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 93% probability that New York City will have a warmer than normal January (1991-2020 normal). January will likely finish with a mean temperature near 36.2° (2.5° above normal).

Lighter events with the EPO+/AO+ combination being forecast. The biggest was 3”. 8”+ shown on the 6z GFS wasn’t realistic. It’s worth tracking things while having an idea of what’s plausible and what’s unlikely.

With temperatures remaining below freezing, water is beginning to freeze over in the New York City suburbs. The cold will be shortlived.

I agree. The forecast pattern for the end of January is hostile. Solutions such as the 6z GFS for significant snowstorms should be discounted.

We've had measurable snow. The percentage of days with measurable snow with an AO+/NAO+ is lower than it is when the AO and NAO are negative. The chart I posted had specific ranges of teleconnections (AO: +1.000 or above; EPO: 0.000 to +2.000) as forecast on the EPS and GEFS. NYC has not seen a greater than 3" snowstorm during the second half of January with that pattern. It had measurable snowfall on almost 12% of such days (little lower than climatology).

Some snow is certainly plausible. The kind of snowfall shown on the 6z GFS (and retracted on the following 12z run) is not. Unfortunately, no measurable snowfall is also a possible outcome (above climatological probability). The PNA+ should blunt the magnitude of warmth, but overall, the remainder of the January should be warmer than normal. As for the AO-/NAO-, all of NYC's measurable snowfall has occurred with the AO- and almost all of its measurable snowfall has occurred with the NAO-. The PNA- limited opportunities for a big snowfall. The kind of AO+/EPO+ pattern that is forecast is not a snowy one, even when the PNA is positive.

Today, the Arctic Oscillation rose to positive levels for the first time this month. That is the first piece of what is forecast to become an AO+/EPO+ pattern. Such patterns consistent with the forecast (AO: +1.000 or above/EPO: 0.000 to +2.000) support below normal frequency of measurable snow events during the second half of January. Based on the guidance (temperature anomalies and forecast pattern), New York City will likely see little or no snowfall for the remainder of this month.

The closing 7-10 days of January will feature an EPO+/AO+ pattern. The latest EPS shows 500 mb height anomalies and surface temperature anomalies that are as close to a textbook case of what one has historically seen from such a pattern: The ECMWF Weeklies: January 22-29: This is a high confidence idea that the closing week to 10 days of January will be warmer than normal across most of North America except for Alaska, parts of the Southwest, and parts of Mexico.

Bias can be an issue regardless of one's position on climate change. However, objectivity requires that one consider the climate context when assessing, for example, potential analogs. All things being equal, identical 500 mb patterns will be warmer than those in the past. Thus, one can't conclude that every pattern similar to past one that brought extreme cold will bring similar magnitude cold today. Bitter cold outbreaks can still occur, but they have decreased in frequency and expanse. Patterns can also get "stuck" more often than in the past. That means warmth can persist for longer periods of time and the more limited areas of cold can persist for longer periods of time. December 2023's exceptional warmth in North America and notable cold in Scandinavia are examples of what can happen when the pattern largely becomes "stuck." Globally, of course, December 2023 was the warmest December on record on all the major datasets.

Dover, DE: 7.0"

Unfortunately, I wasn't there. However, it's possible that the amount was fairly reasonable. I was in Rye at lunchtime and took a few photos. The actual snowfall there was around 0.5" when I stopped by (additional light snow fell afterward for about two hours probably bringing the actual figure to around an inch or so). Behind the mansion (out of view), there are some wooden steps that are not sheltered and provide a reasonable basis for measurement. A lot of the preceding snowfall encased in ice had not melted, so the ground looked more like an inch or two.

Bastardi's claims still influence opinions and posts, including here. So do claims of some others e.g., the wild map drawn by the forecaster showing 12"-18" of snow at Allentown in early January when nothing remotely close to that was on the table. Bastardi and some of the others draw upon the wishes and hopes of those who like cold/snow, leading them to believe ideas that, quite frankly, are often absurd from the onset. Afterward, when the extreme forecasts fail, there is unnecessary disappointment, along with inaccurate perceptions that meteorologists can't forecast. It's worth examining some of these claims periodically. Perceptions that February will start very cold are based on nothing but a single cycle operational run (ensembles, weekly guidance, other operational guidance, and expected teleconnections all argue against such a scenario). Invoking the mid-February 2016 Arctic outbreak absent strong evidence for such an extraordinary outcome is reckless. So far, all of January's storms have behaved relatively in line with what had realistically been expected. There were no huge surprises so far this month.

That came out a short time ago. The 0.1” was the 1 pm figure.

Following the upcoming warmup after this weekend, we'll need to wait until after the first or second weeks of February for more opportunities for cold and snow. Following the jet extension, if the North Pacific Jet shifts Equatorward, that would favor a return to cold. If, however, the North Pacific Jet remains or shifts further Poleward, that would potentially delay the return of cold. Most of the guidance suggests that the first week of February will at least start mild. ENSO climatology associated with strong El Niño event favors cooler weather especially in the days leading up to and going beyond mid-month. Given ENSO climatology, I suspect that there will be some additional opportunities for snow in February, even if there is no extreme cold.

Through 1 pm, snowfall amounts included: Atlantic City: 1.3" Baltimore: 4.1" New York City: 0.1" Newark: 0.6" Philadelphia: 2.9" Washington, DC: 3.3" There were some 6.0" amounts. Areas receiving 6.0" of snow included Clayton, Dover, and Middletown in Delaware. Following the storm, the temperature will fall into the teens in New York City tonight and again tomorrow night. Outlying areas could experience some single-digit cold. Tomorrow will be fair but very cold with the mercury struggling to reach the lower and middle 20s across the northern Mid-Atlantic region. Overall, this coming weekend will see this winter's coldest readings so far. Beyond that, the development of an EPO+/AO+ pattern will lead to a noticeable warming trend that could send temperatures well into the 40s across the region and even into the 50s in parts of the region. This warm period will very likely assure that January will wind up as a warmer than normal month and Winter 2023-24 will become yet another warmer than normal winter in the New York City and Philadelphia areas. The generally mild conditions could continue into the first week of February with only brief interruptions. The ENSO Region 1+2 anomaly was +0.9°C and the Region 3.4 anomaly was +1.9°C for the week centered around January 10. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +1.18°C and the ENSO Region 3.4 anomaly has averaged +1.95°C. A basinwide El Niño event is ongoing. The ongoing El Niño event has recently peaked. The SOI was +20.45 today. The preliminary Arctic Oscillation (AO) was -0.535 today. Strong blocking in the final week of November, as occurred this year, has often been followed by frequent blocking in December and January. On January 17 the MJO was in Phase 4 at an amplitude of 2.729 (RMM). The January 16-adjusted amplitude was 2.667 (RMM). Based on sensitivity analysis applied to the latest guidance, there is an implied 87% probability that New York City will have a warmer than normal January (1991-2020 normal). January will likely finish with a mean temperature near 35.8° (2.1° above normal).

What happens when one posts maps for extreme cold from late November through December and the period winds up among the warmest on record? What happens when one posts maps of near historic cold in the Northeast to end December and start January but temperatures again average above normal? What happens when one posts a GGEM run showing 10”+ snow for NYC on January 19th with a PNA- pattern and it becomes clear that there will be no major snowstorm? Some punt ahead to hype another cold or snowy event. And how does the GFS look the following day for the same point in time? Although such maps remain well outside the skillful range, the dramatic change underscores the futility of latching onto unskillful guidance. Serious forecasters respect the limitations of models. They don’t exploit the models’ limitations to confirm biases and pursue clicks. Yet, that’s the kind of hype one finds on X/Twitter and other social media from several accounts on a frequent basis. Such hype damages the credibility of professional private and public sector meteorologists who consistently provide good forecasts, but who often are drowned out by the hype of those who seek clicks/views but then tarnished by the fallout resulting from the failed extreme forecasts made by those who hype extreme events. And even as some of the accounts frequently punt ahead with repeated calls for cold/snow, it’s important to remember that in the larger context, the periodic convergence of cold/snow with such calls is far more a matter of coincidence than skill.

Rye, NY:

That’s the way it seems right now. It could still be close.