donsutherland1

Philadelphia's December-January mean temperature of 33.3° was the coldest such period since Winter 2010-2011 (31.0°). It was tied for the 48th coldest such period on record. New York City's December-January mean temperature of 32.1° was also the coldest such period since 2010-2011 (31.2°). It was also tied for the 48th coldest such period on record.

Uncertainty about the February 15-28 period has increased. What is fairly certain are the following: 1) Substantial warmup in the Plains States 2) Brief cool shot to the Southwest and then a return of warmer conditions. The cool shot likely won't be sufficient to preclude Phoenix from experiencing its warmest winter on record. Moderation is likely to occur across the Great Lakes Region, Northeast, Mid-Atlantic, and Southeast during and after February 10th. What happens beyond 7-10 days is where things become increasingly uncertain. The CFSv2 favors a continuation of above normal temperatures through the end of February. The ECMWF weeklies bring colder conditions for the February 23-28 period. CFSv2: ECMWF Weeklies: Even as wave lengths are shortening, the Arctic Oscillation (AO) could hold the key. The EPS and GEFS agree on the development of a WPO-, EPO+, PNA- pattern. During such patterns, conditions in the East tend to be much colder when the AO is negative than when it is positive. New York City provides a good example. Since 1980, WPO-, EPO+, PNA-, AO- patterns have seen a mean February 15-28 temperature of 33.9°. In contrast, WPO-, EPO+, PNA-, AO+ patterns have seen a mean temperature of 44.5°. So, if the AO goes positive, the warmth from the Plains will likely come eastward. WPO-, EPO+, PNA-, AO- Patterns: WPO-, EPO+, PNA-, AO+ Patterns: The latest AO forecast is below. A near neutral AO would favor near seasonable to somewhat above seasonable temperatures in the East. Historic experience following the breakdown of long-duration (25-day or longer) AO- regimes that began in February favors AO variability following the breakdown of such regimes. Only 1986 saw a prolonged and strong AO+ regime develop. As noted previously, due to shortening wave lengths, the consensus outcome of a resumption of above normal temperatures in the Southwest to close out February is the base case.

Yes. That's correct. The ECMWF is actually using a potentially somewhat warmer period than 1991-2020 for calculating its subseasonal anomalies. The site mentions: The mean anomalies are derived from the ECMWF Sub-seasonal range ensemble consisting of 100 ensemble members plus a control member and averaged over a seven day period. Anomalies are calculated with respect to the Model Climate, which is derived from re-running an 11-member ensemble over the last 20 years, giving 220 realisations in total. See bottom of: https://charts.ecmwf.int/products/opencharts_extended_meteogram?base_time=202602050000&lat=51.4333&lon=-1.0&station_name=Reading A fuller discussion, which also notes 20 years of values, is here: https://confluence.ecmwf.int/display/FUG/Section+5.3.2+SUBS-M-climate%2C+the+sub-seasonal+model+climatehttps://confluence.ecmwf.int/display/FUG/Section+5.3.2+SUBS-M-climate%2C+the+sub-seasonal+model+climate Below is a quick comparison of the 1991-2020 period with the last 20 years for 10 select cities to provide an idea of how things have changed.

Tomorrow will be another cold day with highs in the upper 20s and lows in the teens. A strong surge of Arctic air will arrive for the weekend, possibly accompanied by some snow flurries or snow showers. Some areas could pick up a heavier snow squall. Much of the region could see a coating to an inch of snow early Saturday morning. The temperature will rise no higher than the lower 20s in New York City Sunday will be even colder. Temperatures on Sunday will likely top out in the teens in New York City with a low in the single digits. The persistent and often severely cold pattern will likely break near February 10th. However, exceptional warmth appears unlikely through at least mid-February. The ENSO Region 1+2 anomaly was +0.1°C and the Region 3.4 anomaly was -0.4°C for the week centered around January 28. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.38°C and the ENSO Region 3.4 anomaly has averaged -0.57°C. La Niña conditions will likely continue into at least late winter. The SOI was +28.05 today. The preliminary Arctic Oscillation (AO) was -2.852 today.

I'd like to see the EPO go negative toward the end of February. At that point, due to shortening wave lengths, there would be a stronger shot at a return to cold. Overall, that seems to be a reasonable idea, but there could be other variables that shape the outcome that can't be well-forecast at this point in time.

With shortening wave lengths, it actually becomes better for snowfall in the East than a PNA+.

There's no question that the PNA+ regime is ending. The ECMWF weeklies keep the PNA negative through the duration of their forecast period.

Colder air will move back into the region tonight. As a result, tomorrow and Friday will see highs in the upper 20s and lows in the teens. An even stronger surge of Arctic air will likely arrive for the weekend, possibly accompanied by some snow flurries or snow showers. Some areas could pick up a heavier snow squall. Highs on Sunday could be in the teens in New York City with lows in the single digits. The persistent and often severely cold pattern could break near February 10th. However, exceptional warmth appears unlikely through at least mid-February. So far, January 20-February 2 has been the coldest two-week period this winter with a mean temperature of 21.0° in New York city. January 17-30 with 13.4" of snow has been the snowiest two-week stretch. The ENSO Region 1+2 anomaly was +0.1°C and the Region 3.4 anomaly was -0.4°C for the week centered around January 28. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.38°C and the ENSO Region 3.4 anomaly has averaged -0.57°C. La Niña conditions will likely continue into at least late winter. The SOI was +31.22 today. The preliminary Arctic Oscillation (AO) was -3.454 today.

I've done the Coney Island polar plunge a few times.

Ray, Don't let the unnecessary jab affect you. Your work, effort to continually learn and improve, and you are highly respected here. People who are insecure often try to shield themselves from their own shortcomings by seizing on and exaggerating the real or perceived flaws, mistakes, and missteps of others. It is a deeply counterproductive approach, especially when it comes to people skills. Success in almost any environment depends on strong interpersonal abilities. Leaders and entrepreneurs succeed, because they can effectively appeal to people in promoting their vision, ideas, products, and services. Without good interpersonal skills, even considerable talent (and he certainly has it) is unlikely to be fully realized or effectively leveraged.

MAX 17F ... MIN 6F ... SNOW 0.2"

Yes. That's due to shortening wave lengths. EPO becomes relatively more important.

Tomorrow will be another relatively mild day. Highs will likely top out in the lower to perhaps middle 30s. A few flurries are possible as a weak system drags a cold front across the region. Colder air will then return on Thursday. An even stronger surge of Arctic air could arrive for the weekend, possibly accompanied by some snow flurries or snow showers. Highs both Saturday and Sunday could be in the teens in New York City. The last time there were two or more consecutive such highs was during January 5-7, 2018. The persistent and often severely cold pattern could break near February 10th. 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 +0.1°C and the Region 3.4 anomaly was -0.4°C for the week centered around January 28. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.38°C and the ENSO Region 3.4 anomaly has averaged -0.57°C. La Niña conditions will likely continue into at least late winter. The SOI was +24.06 today. The preliminary Arctic Oscillation (AO) was -3.750 today.

2015 is prominently featured in the coldest 30-day periods in terms of minimum temperatures:

Through today, cumulative snow depth is 83” in NYC. That’s the highest since 2015-16.

Newark had a high of -1 on January 10, 1859.

For NYC, only 2002 and 2020 had no measurable snowfall for February 1-March 31.

1887-88 is ahead mainly because it was several degrees colder through January even as it had slightly less snowfall than the current winter.

Ray has done an awesome job so far. Statistically, a cold March seems less likely, but it's still in play. I think March's outcome depends on whether the modeled SSWE can occur and, if so, whether it can propagate in a favorable fashion. If not, even if March starts cool, things could quickly break to the warm side. New England would probably hold onto the cold longer than the Mid-Atlantic. A strong EPO-/AO- pattern would probably be needed to deliver a 2018-style outcome. At this stage, the WPO becomes less important due to the shorter wave lengths.

Temperatures have begun to moderate. In New York City, the temperature broke above freezing for the first time since January 23. That was the longest such stretch since Winter 2017-2018. Tomorrow and Wednesday will likely see highs in the lower to perhaps middle 30s. A few flurries are possible on Wednesday as a weak system drags a cold front across the region. Colder air will then return on Thursday. An even stronger surge of Arctic air could arrive for the weekend, possibly accompanied by some snow flurries or snow showers. The persistent and often severely cold pattern could break near February 10th. 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 +0.1°C and the Region 3.4 anomaly was -0.4°C for the week centered around January 28. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.38°C and the ENSO Region 3.4 anomaly has averaged -0.57°C. La Niña conditions will likely continue into at least late winter. The SOI was +24.02 today. The preliminary Arctic Oscillation (AO) was -3.066 today.

The longest stretch of subfreezing days since 2017-18 ended today. The ECMWF weeklies show a distinct milder period of 1-2 weeks duration. Social media is suddenly abuzz about the warmth it has noticed. Still, there's no need to despair. Winter 2025-2026 has already delivered some genuinely great moments. Although those moments might be in the past, they cannot be erased by the forecast moderation that lies ahead beginning around February 10th. Some highlights: New York City experienced its coldest December-January period since 2014-2015. New York City saw an 11.4" snowfall with many areas outside the City picking up 12"-18". New York City has seen two highs in the teens and two lows in the single digits. Outside the City, numerous locations have experienced subzero lows. Ice and ice floes have reappeared in the Hudson River for the first time in years. In a wider perspective, parts of the Great Lakes Region saw a record November daily snowfall, Toronto experienced its biggest snowstorm on record, and parts of Georgia, South Carolina, and North Carolina enjoyed a generational snowstorm. Nothing is cast in stone. Model skill beyond two weeks is low. Forecast patterns can change. Sometimes abruptly. IMO, rather than riding an emotional roller-coaster with each turn of the models or allowing the most negative outcomes to drive winter's wonderful moments from memory, it's better to appreciate what we've already experienced and stay patient about what lies ahead. Spring will come. It always does. But Winter 2025-2026 may still bring additional cold and snowfall, even if the models cannot currently see the cold and snow at the long lead times involved.

I was referring to the ECMWF weekly maps in general. I prefer the ECMWF chart to vendors.

I went to Cape May for the storm. There were near whiteout conditions.

Yes, they're definitely a step back (continuing the trend from recent days). I actually prefer the daily data, as one can better evaluate what's happening than if one had to make guesses over 3- and 4-day intervals.

February 2015 had exceptional warmth in the western third of the CONUS.