bluewave

Don’t be so hard on yourself as you are one of the best forecasters on here. When I saw how extreme the December2015 forcing for an El Niño in the WPAC was leading to the +13.3 in NYC, it caused me to gain a ton of respect for what has been occurring in the WPAC. https://phys.org/news/2021-04-distinctive-mjo-super-el-nino.html A research group, led by Dr. Wenjun Zhang from the Nanjing University of Information Science and Technology analyzed MJO activity of the super El Niño event during the Northern Hemisphere winter of 2015/16. Observations show that the western Pacific MJO activity was strongly suppressed during the peak phase of the 1982/83 and 1997/98 super El Niño events. However, during the crest of the 2015/16 super El Niño event, western Pacific MJO-related convection was enhanced. "It is apparent that the enhanced western Pacific MJO is mainly related to its sea surface temperature (SST) anomaly distribution and the associated background thermodynamic conditions." said Dr. Zhang. His team's complete research and data are published in Advances in Atmospheric Sciences. When compared to the previous super El Niño events, the warm SST anomaly, or change from average, of the 2015/16 El Niño was located more westward than during the other two extreme seasons. Additionally, no significant cold SST anomaly was detected in the western Pacific. Accordingly, the moisture and air temperature tended to increase in the central-western Pacific during the winter of 2015/16 unlike the previous super El Niño events. This research highlights that climatologists should consider the SST anomaly distribution of super El Niño events for future MJO activity studies.

Our annual warm up over 55° between 12-17 and 12-25 was right on schedule. This pattern has become more pronounced over the years. While the general pattern did exist prior to 2011, this is the first 15 year run with no interruption. The last time we didn’t see this warm up was back in 2009 and 2010. Data for December 19, 2025 through December 19, 2025 Click column heading to sort ascending, click again to sort descending. CT DANBURY MUNICIPAL AP WBAN 60 NJ NEWARK LIBERTY INTL AP WBAN 59 NJ TETERBORO AIRPORT WBAN 59 NJ CALDWELL ESSEX COUNTY AP WBAN 59 NY ISLIP-LI MACARTHUR AP WBAN 59 NY RIVERHEAD RESEARCH FARM COOP 59 NY LAGUARDIA AIRPORT WBAN 58 NY NY CITY CENTRAL PARK WBAN 58 NY MONTGOMERY ORANGE COUNTY AP WBAN 58 CT NEW HAVEN TWEED AP WBAN 58 CT MERIDEN MARKHAM MUNICIPAL AP WBAN 58 NY FARMINGDALE REPUBLIC AP WBAN 57 NY JFK INTERNATIONAL AIRPORT WBAN 57 CT IGOR I SIKORSKY MEMORIAL AIRPORT WBAN 57 NY WESTCHESTER CO AP WBAN 57 NY SHIRLEY BROOKHAVEN AIRPORT WBAN 57 NY BAITING HOLLOW COOP 57 NY UPTON COOP - NWSFO NEW YORK COOP 57 CT NORWICH PUBLIC UTILITY PLANT COOP 57 NJ HARRISON COOP 56 NJ TETERBORO AIRPORT COOP 56 NY ST. JAMES COOP 56 CT GROTON NEW LONDON AP WBAN 56 NY CENTERPORT COOP 55

This will be a good test for the AIFS EPS coming up since it matches the composite more than the EPS with the further east ridge axis.

Very nice job. Can’t say I remember seeing this accumulation pattern before from a clipper. I didn’t notice any available models showing the NW heavy snow band from Sussex into Orange and surrounding areas.

Yeah, we would want the ridge in a similar position to what we got with the recent clipper to make things interesting. I am just not sure yet whether the Pacific Jet can relax enough to allow for sufficient retrogression. The time to watch would probably be early in January.

This is going to be one of the strongest -WPO blocks that we have seen for the month of December. But it’s a different configuration of other factors that we have previously seen with December -WPOs in the past. This one has a much more amplified Pacific Jet into the PACNW and BC than we have seen before with the historic flooding in those areas. Plus we have an out of phase +EPO and very strong ridge onto the Western US. The ridge that was out West is shifting further east leading to the moderation in temperatures across the CONUS. Unique December 2025 500 mb and Pacific Jet stream pattern compared to previous very strong -WPO patterns

This is the first 20 day below normal streak for the new 1991-2020 climate normals era. xmACIS2 reset all the prior period departures to the 1991-2020 climate normals. So we don’t have the earlier departures based on 1981-2010, 1971-2000, 1961-1990, 1951-1980..etc.

2010-2011 was some of the biggest snow piles my whole time in Long Beach where the old amusement park used to be.

One of the more impressive December shifts from colder to warmer across the CONUS since 2000.

December 1917 was the inverse of December 2015. Climatological Data for NEWARK LIBERTY INTL AP, NJ - December 1917 Click column heading to sort ascending, click again to sort descending. Sum 728 526 - - 933 0 3.52 23.5 Average 31.7 17.0 24.1 -13.9 - - - - Normal 44.8 31.2 38.0 - 837 0 4.14 5.4 1917-12-01 45 39 42.0 0.0 23 0 0.73 0.0 1917-12-02 44 26 35.0 -6.7 30 0 0.00 0.0 1917-12-03 41 19 30.0 -11.4 35 0 0.00 0.0 1917-12-04 M 29 M M M M 0.00 0.0 1917-12-05 43 29 36.0 -4.9 29 0 0.00 0.0 1917-12-06 M 29 M M M M 0.00 0.0 1917-12-07 M 21 M M M M 0.00 0.0 1917-12-08 43 17 30.0 -10.0 35 0 0.78 4.5 1917-12-09 43 14 28.5 -11.2 36 0 0.00 0.0 1917-12-10 16 7 11.5 -28.0 53 0 0.02 0.2 1917-12-11 22 9 15.5 -23.7 49 0 0.00 0.0 1917-12-12 20 15 17.5 -21.4 47 0 0.03 0.3 1917-12-13 32 14 23.0 -15.6 42 0 0.80 8.0 1917-12-14 30 22 26.0 -12.4 39 0 0.80 8.0 1917-12-15 M 11 M M M M 0.00 0.0 1917-12-16 19 8 13.5 -24.4 51 0 T T 1917-12-17 30 15 22.5 -15.1 42 0 0.05 0.5 1917-12-18 33 20 26.5 -10.9 38 0 0.00 0.0 1917-12-19 34 25 29.5 -7.6 35 0 0.00 0.0 1917-12-20 39 32 35.5 -1.4 29 0 0.00 0.0 1917-12-21 43 26 34.5 -2.1 30 0 0.00 0.0 1917-12-22 39 20 29.5 -6.9 35 0 0.00 0.0 1917-12-23 32 12 22.0 -14.2 43 0 0.00 0.0 1917-12-24 41 25 33.0 -2.9 32 0 0.00 0.0 1917-12-25 M 28 M M M M 0.11 T 1917-12-26 M 18 M M M M 0.00 0.0 1917-12-27 M 10 M M M M 0.00 0.0 1917-12-28 31 10 20.5 -14.6 44 0 0.00 0.0 1917-12-29 M -2 M M M M 0.20 2.0 1917-12-30 4 -13 -4.5 -39.2 69 0 0.00 0.0 1917-12-31 4 -9 -2.5 -37.0 67 0 0.00 0.0 Climatological Data for NEWARK LIBERTY INTL AP, NJ - December 2015 Click column heading to sort ascending, click again to sort descending. Sum 1755 1331 - - 465 0 4.40 0.3 - Average 56.6 42.9 49.8 11.8 - - - - 0.0 Normal 44.8 31.2 38.0 - 837 0 4.14 5.4 2015-12-01 52 42 47.0 5.0 18 0 0.36 0.0 0 2015-12-02 56 45 50.5 8.8 14 0 0.16 0.0 0 2015-12-03 55 44 49.5 8.1 15 0 T 0.0 0 2015-12-04 53 39 46.0 4.8 19 0 0.00 0.0 0 2015-12-05 54 35 44.5 3.6 20 0 0.00 0.0 0 2015-12-06 55 33 44.0 3.4 21 0 0.00 0.0 0 2015-12-07 58 34 46.0 5.7 19 0 0.00 0.0 0 2015-12-08 49 38 43.5 3.5 21 0 0.00 0.0 0 2015-12-09 53 33 43.0 3.3 22 0 0.00 0.0 0 2015-12-10 62 48 55.0 15.5 10 0 T 0.0 0 2015-12-11 60 46 53.0 13.8 12 0 0.00 0.0 0 2015-12-12 65 48 56.5 17.6 8 0 0.00 0.0 0 2015-12-13 68 54 61.0 22.4 4 0 0.00 0.0 0 2015-12-14 67 52 59.5 21.1 5 0 0.24 0.0 0 2015-12-15 68 52 60.0 21.9 5 0 0.05 0.0 0 2015-12-16 53 43 48.0 10.1 17 0 T 0.0 0 2015-12-17 59 50 54.5 16.9 10 0 1.02 0.0 0 2015-12-18 56 37 46.5 9.1 18 0 T 0.0 0 2015-12-19 41 34 37.5 0.4 27 0 0.00 0.0 0 2015-12-20 45 33 39.0 2.1 26 0 0.00 0.0 0 2015-12-21 54 34 44.0 7.4 21 0 0.00 0.0 0 2015-12-22 61 52 56.5 20.1 8 0 0.06 0.0 0 2015-12-23 66 50 58.0 21.8 7 0 1.44 0.0 0 2015-12-24 71 59 65.0 29.1 0 0 0.03 0.0 0 2015-12-25 63 54 58.5 22.8 6 0 0.03 0.0 0 2015-12-26 60 48 54.0 18.5 11 0 0.02 0.0 0 2015-12-27 62 46 54.0 18.7 11 0 0.08 0.0 0 2015-12-28 46 34 40.0 4.9 25 0 0.05 0.1 0 2015-12-29 45 34 39.5 4.6 25 0 0.60 0.2 0 2015-12-30 49 38 43.5 8.8 21 0 0.24 0.0 0 2015-12-31 49 42 45.5 11.0 19 0 0.02 0.0 0

We have been getting the windshield wiper effect from run to run. Some runs a little over and other runs a little under. So with the warm up coming the next several days, my guess for December 17 to 31 will be near 0 to +1.

Just updating for the newer data on 12-17 vs 12-10. The EPS is around a 0 to +1 the rest of the month. So that would yield a 7 station average of around -3 to -4 from the current -7.7. Long Island is running a little warmer and is only -5.5 at ISP through the 16th.

This is going to be one of the strongest -WPO blocks that we have seen for the month of December. But it’s a different configuration of other factors that we have previously seen with December -WPOs in the past. This one has a much more amplified Pacific Jet into the PACNW and BC than we have seen before with the historic flooding in those areas. Plus we have an out of phase +EPO and very strong ridge onto the Western US. Unique December 2025 500 mb and Pacific Jet stream pattern compared to previous very strong -WPO patterns

All we can say is that the first 16 days of December have been one of our coldest 16 day periods relative to the means of the 2020s so far. The clipper was a nice contribution to this period feeling very wintry around the area. This was actually the coldest first half of December in 20 years. The new Newark records for December now go back to 1850. So this was ranked 26th coldest which is very respectable in our warmer 2020s climate. The current 7 station departure across the area is -7.7. With the moderation coming up next few weeks, the final number this month may finish in the -3 to -4 range. Models have been fluctuating from run to so we won’t know the exact number for a weeks. EWR…..-8.1 NYC……-8.7 LGA……-8.7 JFK…….-7.8 HPN……-7.6 BDR…...-7.9 ISP……..-5.4 AVG…….-7.7 Time Series Summary for NEWARK LIBERTY INTL AP, NJ Coldest 12-01 to 12-16 periods Click column heading to sort ascending, click again to sort descending. 1 1867-12-16 24.1 5 2 1904-12-16 24.6 0 3 1910-12-16 25.5 0 4 1917-12-16 25.7 4 5 1876-12-16 27.0 5 6 1868-12-16 27.3 3 7 1958-12-16 27.9 0 - 1871-12-16 27.9 1 8 1902-12-16 28.6 0 9 1989-12-16 28.8 0 - 1869-12-16 28.8 4 10 1860-12-16 28.9 2 11 1880-12-16 29.0 3 12 1895-12-16 29.1 2 13 1859-12-16 29.4 4 14 1886-12-16 29.5 4 15 1882-12-16 29.7 2 16 1915-12-16 29.8 1 17 1903-12-16 30.0 0 - 1872-12-16 30.0 2 18 2005-12-16 30.4 0 19 1976-12-16 30.6 0 20 1854-12-16 30.8 3 21 1898-12-16 31.0 0 22 1937-12-16 31.1 0 23 1942-12-16 31.2 0 24 1875-12-16 31.4 0 25 1851-12-16 31.7 4 26 2025-12-16 31.8 0 - 1945-12-16 31.8 0

Interesting new study confirming other recent studies that the cold pool in the North Atlantic is more a sign of the atmospheric patterns rather than an AMOC decline. Anthony Masiello ‪@antmasiello.bsky.social‬ Follow Natural variability, in low frequency states of atmospheric circulation, is becoming increasingly likely as the main explanation for the North Atlantic warming hole. ‪Sang-Ki Lee‬ ‪@sklee621.bsky.social‬ · 1mo The Atlantic's warming hole is not a sign of the AMOC weakening, a new study suggests ocean2climate.org/2025/11/12/t... The Atlantic’s ‘Warming Hole’ Isn’t What You Think: 5 Surprising Truths From New Climate Research This blog post and the “Deep Drive” podcast on a new paper “Atmosphere-driven processes in shaping long-term climate variability in Greenland and the broader subpolar North Atlant… ocean2climate.org 11:10 AM · Nov 12,