donsutherland1

The record is 56 consecutive days (December 24, 1947 through February 17, 1948). The 2010-11 streak was the third longest.

BWI finished at 11.3".

As noted earlier, IMO writing the event off completely goes beyond what can reasonably be supported by the models and their ensembles. Indeed, there has been some improvement during the 18z cycle.

A number of those were high-impact storms i.e., 12/20/2009, 12/27/2010, 2/9/2013, 1/24/2016, 1/29/2022, etc.

That was the area I was most uncertain about. I overdid the impact of the warm air aloft. Hopefully, I'll do better next time.

Unfortunately, I don't have the 6z figures.

Looking back, my errors for the 1/24-26 snowstorm:

At 12z, 8 GEFS members and 1 EPS member had 6" or more snow for NYC. The EPS member in question had 16".

Yes, I'm aware that it's time lagged. Nevertheless, its 18z data was probably reflecting the 12z suite or perhaps slightly later. At this timeframe, the details don't matter too much. I just wanted to illustrate that there are alternatives to a clean miss. I suspect that a solution that grazes the coast might currently be the most likely scenario. That would allow for a light snowfall from Philadelphia to NYC and moderate maybe larger amounts across parts of eastern Long Island into southeastern New England. The Cape could do quite well. Having said that, it's not uncommon for model tracks to vary by 50 to sometimes 150 miles over a four-day lead time. I suspect that by late tomorrow or Thursday, we should start to be able to pin down the details with some degree of confidence.

Arctic air now covers the region. Highs will be mainly in the lower 20s through Friday. One or more days could see highs in the teens. The last winter with more than one high in the teens was Winter 2018-19 when there were two such days. Moreover, New York City has the potential to see the temperature dip into the single digits for lows on one or more days during this period. Some snow flurries or snow showers are possible Thursday night into Friday morning. Additional snow is possible on Sunday. However, there remains significant uncertainty about the location of the storm's development and its track. A large storm would be historic. For reference, New York City has seen just one 10" or above snowstorm one week or less following a 10" or above snowstorm: February 3-4, 1926 (10.4") and February 9-10, 1926 (12.4"). The shortest interval between 10" or above daily snowfalls is 14 days: March 2, 1896 (10.0") and March 16, 1896 (12.0"). Records go back to 1869. Overall, January 20th-February 3rd will likely be the coldest and perhaps snowiest two-week period this winter. The forecast WPO-/EPO-/AO-/PNA+ pattern is typically the coldest pattern in January and among the coldest during the first half of February. A persistently positive PNA will have above climatological risk of moderate or significant snowfalls. For perspective, the coldest two-week period this winter prior to January 20th was January 3-16, 2026 and January 4-17, 2026 with a mean temperature of 30.3°. The snowiest two-week period was December 14-27, 2025 when 7.2" of snow fell. Already, snowfall since January 20th has surpassed that figure. 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 January 14. 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 -0.68°C. La Niña conditions will likely continue into at least late winter. The SOI was -2.82 today. The preliminary Arctic Oscillation (AO) was -4.601 today. That is the lowest AO value since February 16, 2025 when the AO was -4.772. Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a cooler than normal January (1991-2020 normal). January will likely finish with a mean temperature near 30.2° (3.5° below normal). Supplemental Information: The projected mean would be 2.4° below the 1981-2010 normal monthly value.

There remains potential for snowfall on Sunday in the New York City area with an even higher probability of snowfall across eastern Long Island. What's fairly certain is that a storm will develop somewhere along the Southeast coast and possibly become quite deep. What's uncertain and subject to synoptic details (the placement of vorticity maxima, 500 mb low, etc.) that the guidance can't reliably resolve at the current lead time is the exact location where the storm will develop and its ultimate track. By Thursday, the guidance should be moving into a more skillful lead time. As a result, there are varying solutions. Several models now take the storm out to sea with no impact on the New York City area. Others graze the region, possibly with several inches of snow. The 18z NBM even brings close to 0.50" QPF to New York City. This large spread reflects the degree of uncertainty that still exists. Although it looks less likely that this will be a blockbuster storm, writing the event off completely goes beyond what can reasonably be supported by the models and their ensembles. Here's the latest WPC probabilistic assessment of a moderate impact:

Let's see where the synoptic details are tomorrow. At 500 mb, there remain some important differences among the guidance.

Common theme on the 12z cycle: The GFS and GGEM have brought the precipitation farther north and west. It's too soon to write off the storm for the NYC area and especially Long Island. Details still can't be resolved reliably this far out.

Cape Hatteras has only received two 12" or above snowstorms: December 29-30, 1917 12.0" (NYC: 2.0") December 23-24, 1989 13.3" (NYC: None)

For an illustration: 0z: 6z: