bluewave

I completely understand the motivation. I don’t think most posters that leave weenies are being malicious. But it’s important to weigh the potential strengths and weaknesses of any long range projected patterns. I post some of those tweets and maps in the interest of sharing weather information. The tweets that I post contain model charts that some people don’t have access to. There are some +AAM and hi res VP anomalies charts only available with commercial subscription packages.

I wouldn’t call it that. But their have been a number of posts getting weenied over the last month for just posting model data. Now I can understand if the charts were long range GFS OP snowfall maps. But most of the posts were just 500 mb height anomaly maps discussing teleconnections. We need to take emotions out of long range model discussions.

That’s not what we were talking about.

The tweet from Matt that you weenied is still there.

The posts that you were referencing are still there. So I am not sure what you are talking about. You even posted yesterday that we may only have a short window to make something work. So if this is the case, wouldn’t you want to maximize our potential like I mentioned?

Why do you keep arguing against points that were never made? You were called out in the December thread for the same issues. Nobody has mentioned specific snowfall amounts in a forecast period beyond one week. We have been discussing which pattern combinations maximize our snowfall potential. So it’s great if we finally get some cooperation from the Pacific side. But it would be nice if it occurred while we still have some Atlantic blocking for a bigger potential. So nobody has said that all the stars need to align to get snow in NYC.

With the way this winter has been going, we would want both the AO and PNA in our favor at the same time. Getting both would maximize any potential window of opportunity while it lasts. But if things can tilt in our favor for a time, a relaxed Pacific could work for us.

The long range EPS has been showing this for a while. While the mid -January -PNA tries to relax for a time, we lose the +AO. and +NAO. So the change in the Pacific is making the Atlantic less favorable.

Yeah, the Euro is like most of the other guidance placing the emphasis on the first wave.

The GFS is overamped on that second wave compared to the Euro, CMC, and UKMET.

We can add one of the highest recorded 250mb jet stream winds above Green Bay to the list of extremes this month.

Some of the warmest December minimum temperatures on record around the region this month. POU recorded the 3rd warmest minimum. Only the 5th time that HPN didn’t drop below 20°. It was also the 5th time that NYC didn’t drop below 25°. Many of the top 5 warmest were in recent years. Time Series Summary for Poughkeepsie Area, NY (ThreadEx) - Month of Dec Click column heading to sort ascending, click again to sort descending. Rank Year Lowest Min Temperature Missing Count 1 2015 24 0 2 1996 18 0 3 2021 16 4 - 2014 16 0 - 2006 16 0 4 2011 14 0 - 1974 14 0 - 1957 14 0 5 2018 13 0 - 1984 13 0 - 1972 13 0 Time Series Summary for WESTCHESTER CO AP, NY - Month of Dec Click column heading to sort ascending, click again to sort descending. Rank Year Lowest Min Temperature Missing Count 1 2015 28 0 2 2012 24 0 3 2021 20 5 - 2014 20 1 - 1984 20 0 4 2018 19 1 - 1997 19 8 - 1996 19 8 - 1974 19 0 5 2011 18 0 - 2001 18 0 Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Dec Click column heading to sort ascending, click again to sort descending. Rank Year Lowest Min Temperature Missing Count 1 2015 34 0 2 2012 28 0 3 1974 26 0 4 2021 25 4 - 1984 25 0 5 2018 24 0 - 2014 24 0 - 1908 24 0

At least the Sierras are getting some much needed snowpack.

Almost like a cold season version of what happened with the extreme heat in the PACNW last summer.

Not that much cold this year as Newark is near the warmest year on record with 5 days to go. Islip is in 4th place. You can see how many top 10 warmest years there were just since 2010. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2021 58.0 5 2 2012 57.8 0 3 1990 57.5 0 4 2020 57.3 0 - 2011 57.3 0 5 2016 57.2 0 - 1998 57.2 0 6 2010 57.0 0 - 2006 57.0 0 - 1973 57.0 0 7 1991 56.9 0 8 2002 56.5 0 - 1993 56.5 0 9 2017 56.4 0 10 1999 56.3 0 Time Series Summary for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2012 55.2 0 2 1998 55.0 0 3 2020 54.9 0 4 2021 54.7 5 - 2016 54.7 0 5 1999 54.3 0 6 2017 54.2 0 - 2011 54.2 0 - 1991 54.2 0 - 1990 54.2 0 7 2010 54.0 0 8 2006 53.9 0 9 2018 53.7 0 10 2002 53.6 0

More ridiculous December heat for the next 5 days will give DFW the warmest December on record by a wide margin. Time Series Summary for Dallas-Fort Worth Area, TX (ThreadEx) - Month of Dec Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2021 60.2 6 2 1933 54.0 0 3 2015 53.6 0 4 1970 53.5 0 5 1965 52.8 0 - 1939 52.8 0

Really extreme sounding warmth under the record Aleutians Ridge.

Still some trees with leaves for the first snowfall in NYC.

Yeah, it’s a big challenge trying to figure out the week 3-4 forecast based on week 1-2. Analog roll forwards beyond week 2 can be very low skill. Older analogs from colder eras haven’t been working very well in our post 2010 warmer climate. There is also a small sample size issue since many patterns have unique features that don’t repeat in the same ways. Plus we have random events like wave breaks which analogs won’t work for. Maybe machine learning will be the next big leap forward in long range forecasting. I think that’s what the ECWMF is researching for improvement to the weeklies and seasonal forecasts.

It seems like the EPS weeklies only have skill beyond 15 days when a pattern change happens during week 1. This works well when the new pattern lasts at least 4 weeks. But many pattern changes first show up on the EPS radar between days 8-15. So in those cases, the old week 3 forecast can be way off. I am not sure how many times the weeklies have correctly predicted a pattern change that happened beyond week 2.

More records with the extreme December Aleutians Ridge.

This was the 5th Christmas at Newark to reach 55° since 2008. Data for December 25 - NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature Precipitation Snowfall Snow Depth 1964-12-25 69 44 0.01 0.0 0 1982-12-25 68 40 0.02 0.0 0 2014-12-25 64 41 0.10 0.0 0 2015-12-25 63 54 0.03 0.0 0 2020-12-25 62 28 0.66 0.0 0 1940-12-25 61 32 0.00 0.0 0 1994-12-25 60 41 T 0.0 0 1979-12-25 59 47 0.37 0.0 0 1965-12-25 59 40 0.85 0.0 0 1936-12-25 57 36 0.00 0.0 0 2021-12-25 55 38 0.16 0.0 0 2008-12-25 55 33 0.11 0.0 0

NYC Metro has been the only region in the I-95 corridor that hasn’t been able to surpass the 95-96 snowfall totals since 2010. We could have done it in 10-11 if the snows didn’t shut off at the end of January. The best snows missed to our NE in 14-15 and to our S in 09-10. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Snowfall Oct 1 to Apr 30 Missing Count 1 1996-04-30 75.6 0 2 1948-04-30 63.9 0 3 2011-04-30 61.9 0 Time Series Summary for Boston Area, MA (ThreadEx) Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Snowfall Oct 1 to Apr 30 Missing Count 1 2015-04-30 110.6 0 2 1996-04-30 107.6 0 3 1994-04-30 96.3 0 Time Series Summary for Philadelphia Area, PA (ThreadEx) Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Snowfall Oct 1 to Apr 30 Missing Count 1 2010-04-30 78.7 0 2 2014-04-30 68.0 0 3 1996-04-30 65.5 0 Time Series Summary for Baltimore Area, MD (ThreadEx) Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Snowfall Oct 1 to Apr 30 Missing Count 1 2010-04-30 77.0 0 2 1996-04-30 62.5 1 3 2003-04-30 58.1 0 Time Series Summary for Washington Area, DC (ThreadEx) Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Snowfall Oct 1 to Apr 30 Missing Count 1 2010-04-30 56.1 0 2 1899-04-30 54.4 0 3 1996-04-30 46.0 0

December is our fastest warming winter month. That’s why the new climate 1991-2020 climate normals have the greatest winter temperature increase in December. The only colder than average December in the last decade was 2017. New 1991-2020 climate normals compared to 1981-2010 EWR Dec….38.0….36.5….+1.5 Jan….32.8….31.6…..+1.2 Feb….35.1….34.6…..+0.5 Avg…..35.3….34.2….+1.1 NYC Dec….39.1…..37.5….+1.6 Jan….33.7…..32.6...+1.1 Feb….35.9….35.3….+0.6 Avg…..36.2…35.1….+1.2 LGA Dec…40.0….38.2….+1.8 Jan….34.4….32.9….+1.5 Feb….36.3….35.3….+1.0 Avg….36.9….35.5…..+1.4 JFK Dec….38.3….37.7….+0.6 Jan…..32.8….32.7….+0.1 Feb….34.5….34.9…..+0.4 Avg….35.2….35.1…..+0.1 ISP Dec….37.1…..35.6…..+1.5 Jan….31.9….30.6…..+1.3 Feb...33.3….32.8…..+0.5 Avg….34.1….33.0…..+1.1 BDR Dec…37.0….35.4….+1.6 Jan….31.4….30.1….+1.3 Feb….33.1….32.4….+0.7 Avg…..33.8…32.6….+1.2 HPN Dec…35.1….33.6….+1.5 Jan….29.8….28.3…+1.5 Feb….31.9….30.9….+1.0 Avg…..32.6….30.9…+1.4