bluewave

No recent years going into January had anything close to that 500 mb pattern. The only January with such a prominent -EPO/-PNA/-NAO was 1969. FWIW, NYC finished at 31.8°, 1.10” of precipitation, and only 1.0” of snow. It was a very dry month. The caveats are that the extended EPS is only just a snapshot of what it’s showing from the end of December into early January. Skill falls off beyond the 2nd week.

The extended EPS is -NAO/-EPO/-PNA from late December into January. Dec 20-27 Dec 27 to Jan 3 Jan 3 to Jan 10

No doubt. We will need to weaken the -PNA enough in late December into early January for the -EPO and -NAO to work for us.

It’s easier to get pattern improvements after January 20th in El Niño years since they are back-loaded like 15-16. But we want to start putting snow points on the board by the end of December in La Ninas to reach normal snowfall. That’s why the December the 3” rule for NYC has worked out every La Niña since the 1990s. La Niña years that we have to wait until after January 20th for a decent snow like 99-00 usually underperform in the snowfall department.

There really is not set time limit on how long a pattern can last. While some patterns only last weeks, other can extend to a year or even longer. Plus you can have sub patterns existing within even larger patterns. The larger over the top warm pattern ran from last December until this November with only short breaks. This month is something new with the warmest departures to our south. So any cool down to the pattern will begin to press from the north rather than the Southeast cooling off first.

In very warm winter patterns like we have now, it usually takes a series of steps to shift the pattern to something more favorable. Some models try to rush things. So it’s often better to look at the more conservative outcomes before the pattern flips. New England usually cashes in before our area does. So that is the place to look at first if you want to start seeing more wintery outcomes. The good news is that the longer range guidance continues to indicate that the pattern right after Christmas is showing improvements.

That’s fine. I guess the tone you are seeing is a result of the pattern through the 20th. Hopefully, we get a window of opportunity late month into early January. Kind of looks like the CFS is trying to show something like this. But the question then becomes how long can it last? The CFS retrogrades the pattern to something less favorable by mid-January . It may take a SSW to get a longer lasting boost from from this MJO progression and +AAM spike. Maybe the next few runs of weeklies will provide some clues.

I just mean that I wouldn’t consider a pattern critique trolling. I have no problem with anyone criticizing a pattern or a weather model. It would be nice if the GEPS is right about the SE Ridge flattening out during the last week of the month. It kind of looks like what we would hope for with a MJO 8 and +AAM.

People making posts discussing the current actual pattern is not trolling.

You have to realize that the discussion we are having is about the pattern leading up to Christmas. Not sure what you mean by changing goalposts.The post Christmas pattern potential has been discussed here at length. The hope has always been that the Pacific can relax enough to flatten out the SE Ridge. Getting a MJO closer to phase 8 with a +AAM could be helpful. So try going back and reading more before you leave a snarky quick post telling us how we are all gloom and doom.

Anything too amped will cut in this pattern leading up to Christmas. A system that is too weak will get sheared out and suppressed by the fast Pacific flow. Thread the needle will be a challenge for us but easier in New England. But any snow here at all is a big win in such a hostile Pacific pattern.

We just saw how poorly the GFS did with the fast Pacific flow last week.

Getting a favorable Pacific is more important for our area. New England can get by with a -EPO/-PNA/-NAO. But a -PNA trough over the West will push the gradient into New England. We will need to eventually flatten out that SE Ridge near the end of the month.

That’s what made it so easy to remember the individual storms. We had the surprise 15” on 1-20-78 that was forecast to be a rainstorm. The Feb 78 blizzard followed a few weeks later. The next season featured the PD1 storm. April 82 had our greatest very late season blizzard on record. It was followed up by the Feb 83 snowstorm. Next memorable event was the surprise 1-23-87 snow that was also supposed to be rain. Central Long Island got a surprise narrowly focused norlun band that left areas just east and west with nothing in Dec 88.

The 3” snowfall marker for December in NYC has only worked with La Niña winters since they are supposed to be front-loaded. It’s not something we can us use in El Niño’s since they usually are back-loaded. But since this year we are getting a February strong -PNA pattern in December, it may or may not be valid. If we can’t make it to 3” before the end of December, that would put us in the below normal category for what we have since the 1990s.

Snowfall for our area really comes down to getting intervals of -NAO and -AO blocking. But this must be accompanied by a relaxation of the hostile Pacific patterns. While all our winters since the 15-16 Super El Niño have been warmer than average, the snowfall has been up and down. Even though December warmth has been a winning bet for the last 9 out of 10 years, it’s tough to forecast seasonal snowfall correctly from October or November.

While ENSO is a part of the pattern, we have been getting irregular expressions of those various ENSO states in recent years. The background warming pattern in December is independent of any ENSO state. 9 out of the last 10 Decembers have been warmer than average. Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Dec Click column heading to sort ascending, click again to sort descending. Year Mean Avg Temperature Temperature Departure 2020 39.2 +1.7 2019 38.3 +0.8 2018 40.1 +2.5 2017 35.0 -2.5 2016 38.3 +0.8 2015 50.8 +13.3 2014 40.5 +3.0 2013 38.5 +1.0 2012 41.5 +4.0 2011 43.3 +5.8

Newark had a high of 69° which was the 6th highest December monthly maximum temperature on record. RECORD EVENT REPORT NATIONAL WEATHER SERVICE NEW YORK, NY 121 AM EST SUN DEC 12 2021 ...RECORD HIGH TEMPERATURE SET AT NEWARK NJ... A RECORD HIGH TEMPERATURE OF 69 WAS SET AT NEWARK NJ YESTERDAY. THIS BREAKS THE OLD RECORD OF 65 SET IN 1966. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Dec Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 1998 76 0 2 2001 74 0 3 2006 72 0 - 1982 72 0 - 1946 72 0 4 2015 71 0 - 2013 71 0 - 1984 71 0 5 1978 70 0 6 2021 69 20 - 1964 69 0 - 1956 69 0

The other problem is that there are forecasts using analogs from a much colder era than we have now. Cold analogs from the 70s to even the mid 90s have not worked out. But we still see forecasts trying to use those colder analogs without success in recent years. 76-77 was the last top 10 coldest winter in our area and nothing has come close since then.

But none of the actual weather models were forecasting anything remotely close to some of those Twitter forecasts. While the models always had a slightly colder than normal November, at no point did they have a heavy November snowstorm signal like we got in 2012 or 2018. The first week of December was forecast to be warm in the West and a little cooler than normal in the Northeast. But the ridge expanded further east and our area was warmer. The much above average warmth for Mid-December forecast is right on track.

That’s what is was like in the 70s and 80s. Even some of our best snowstorms weren’t forecast the day before. NWP has come a long way since then. I give the NWS plenty of credit for doing their best with the early technology that they had at the time. The Alden Difax model charts were really crude compared to what we have now. I can still remember the familiar NWS voices on NOAA Weather Radio. Took a trip I to to the NWS at 30 Rock back in the 1980s. The weather radar room looked like something out of a 50s sci-fi movie. Outside the room was a big wall full of weather maps. There was a telephone booth-like spot to make the weather radio recordings. Those were the days when the Central Park observations were very high quality. There were no trees blocking the sensors. I believe the NWS staff would walk directly over to the Park for the snowfall measurements. But that all charged when they moved the office out to OKX in the 1990s.

Record high of 67° so far at Newark. RECORD EVENT REPORT NATIONAL WEATHER SERVICE NEW YORK, NY 0437 PM EST SAT DEC 11 2021 ...RECORD HIGH TEMPERATURE SET AT NEWARK NJ... A RECORD HIGH TEMPERATURE OF 67 WAS SET AT NEWARK NJ TODAY. THIS BREAKS THE OLD RECORD OF 65 SET IN 1966 AND 1971.

Record tie for NYC and new record at EWR. RECORD EVENT REPORT NATIONAL WEATHER SERVICE NEW YORK, NY 319 PM EST SAT DEC 11 2021 ...RECORD HIGH TEMPERATURE TIED AT CENTRAL PARK NY... A RECORD HIGH TEMPERATURE OF 64 WAS TIED AT CENTRAL PARK NY TODAY. THIS TIES THE OLD RECORD OF 64 SET IN 1879. AN UPDATE WILL BE SENT IF A HIGHER TEMPERATURE IS REACHED. RECORD EVENT REPORT NATIONAL WEATHER SERVICE NEW YORK, NY 313 PM EST SAT DEC 11 2021 ...RECORD HIGH TEMPERATURE SET AT NEWARK NJ... A RECORD HIGH TEMPERATURE OF 66 WAS SET AT NEWARK NJ TODAY. THIS BREAKS THE OLD RECORD OF 65 SET IN 1971. AN UPDATE WILL BE SENT IF A HIGHER TEMPERATURE IS REACHED.

Newark just tied the record high. RECORD EVENT REPORT NATIONAL WEATHER SERVICE NEW YORK, NY 241 PM EST SAT DEC 11 2021 ...RECORD HIGH TEMPERATURE TIED AT NEWARK NJ... A RECORD HIGH TEMPERATURE OF 65 WAS TIED AT NEWARK NJ TODAY. THIS TIES THE OLD RECORD OF 65 SET IN 1971. AN UPDATE WILL BE SENT IF A HIGHER TEMPERATURE IS REACHED.

This December has already experienced record warmth across a wide expanse of the US and it’s only the 11th. So I am not sure what you are talking about. Your 60s argument for a few hours makes as much sense saying that last December wasn’t snowy since it only really snowed hard for a day or two.The record warmth this month is a big part of why the tornado devastation occurred. We had a wintertime Jet stream clashing with out of season warmth.