bluewave

Here in SW Suffolk about 75% of the trees have lost their leaves. But there are still a few trees that are still fully leafed out in brilliant colors. This may be some of the best color that we have seen in early December. The current photos coming in from NYC are just gorgeous.

It doesn’t look like the current MJO phase 6 is having much influence on the pattern. A MJO phase 6 during a La Niña is a strong +PNA. Currently getting the opposite now with a strong -PNA. We can only hope that if it goes into 7 that we get something resembling an actual phase 7 later in December.

We will need a SSW in January. There were only 3 La Niña Decembers with a strong -PNA and +AO. while 08-09 and 84-85 had SSWs in January, 71-72 didn’t. That being said, 3 years is a very small sample size and our climate has warmed quite a bit since then. But we would be happy to get some blocking to push back against the Pacific Jet for snow chances. https://csl.noaa.gov/groups/csl8/sswcompendium/majorevents.html

It seems like the pattern forcing this near record -PDO is having a greater influence than just the La Niña alone. The -PDO is being driven by the extreme vortex in the Northeast Pacific. This caused a record +EPO in the fall. The vortex is next forecast to move to a very strong -PNA position. Unfortunately, this is combining with a very +AO pattern. The main question is what is forcing the -PDO instead of recent years with a more +PDO La Niña ? All the guidance has -PNA +AO until further notice

They have a site called confluence that reviews how the Euro did with some individual East Coast storms. The case below was for the January 2016 blizzard. It had too much storm suppression keeping the heaviest snows south of NYC. That was the one of the biggest NAM wins that we ever saw. https://confluence.ecmwf.int/display/FCST/201601+-+Snowstorm+-+US+east+coast 5. Good and bad aspects of the forecasts for the event Early signal (from Sunday 17 Jan 00z) and very consistent forecasts Too low accumulation over NYC Question about snow density for the case

This will be the first test of the newly upgraded Euro with a coastal storm in the winter. It had been having suppression issues with coastal storms in recent years. So if the models like the GFS and CMC are right about a track closer to our area, then they weren’t able to address this issue on the upgrade. But if the CMC and GFS go south then we’ll know the issue was fixed. While the Euro has been the top scoring global model in recent years, I have never seen any official statistics for East Coast storm track performance. Maybe the model is tuned for performance in Europe? Even though the Euro has struggled with East Coast storm tracks in recent years, it still does good with the EPS 500 mb teleconnection patterns. My only critique is that it can be too weak with ridges along the East Coast and show too much ridging near Alaska. This was the case recently with it having too weak a +EPO and too slow a Pacific Jet. It also seems like the GFS was a little faster to show the Pacific Jet flattening the Western Ridge and big -PNA drop.

The warmer pattern has actually moved up in time vs what the models were showing at the end of November. Both the 6-10 day forecasts and 11-15 were too cold. The warmer start to December so far and the warm up ahead of the cutter on Monday wasn’t even forecast. New 1-5 vs old 6-10 New 6-10 vs old 11-15

Another day with the high temperatures warmer than guidance. EWR….51 NYC….48 LGA….50 ISP…..49 JFK....49

While I don’t really know the inside details from the ECMWF, maybe the record warm Atlantic is causing it to underestimate the SE ridge and WAR? 168 hr Euro forecast for Monday 168 hr GFS closer to reality New Euro closer to original GFS stronger WAR Record SST warmth to our east

The Euro missed the warmup for Monday while the GFS will be closer to reality. Old runs GFS is closer New run Euro caves to GFS

Yeah, the amplitude of the December AO has gone way up since 2000. We seem to be getting more total December AO days above +3 and below -3. So some very impressive swings from year to year. https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.ao.index.b500101.current.ascii Total December AO days +3 or above and -3 or below 2000….-3….11 days 2001….-3…..2 days 2004….+3….2 days 2005....-3…..3 days 2006….-3…..8 days 2009….-3….21 days 2010….-3….11 days 2011….+3…..9 days 2012….-3…..4 days 2013….+3….5 days 2015…..+3….3 days 2016….+3…..4 days 2019….+3…..1 day 2020….-3……1 day 2021……+3….1 day so far

Those RMM charts probably won’t be a reliable indicator of the pattern in situations like this. https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjoupdate.pdf A Pacific MJO event is likely to destructively interfere with La Niña, and there remains uncertainty as to whether the MJO will maintain an organized structure, as evidenced by large ensemble spread in the RMM forecasts through mid-December. Any coherence of the intraseasonal signal is more likely to be south of the equator.

Current pattern looks more like a La Niña January phase 5.

Our weather patterns have become much more amplified in recent years. We were talking about the record high heights over Alaska during the fall of 2018. These extreme reversals have also been occurring with AO and NAO in the Atlantic.

You know something much more extreme than the typical La Niña is going on when Alaska records the deepest fall +EPO vortex on record.

Winter 60s have become more common over the years. LGA reached 60° yesterday and most stations were close. Our next chance for 60s will be on Monday. December is starting warmer than forecast. KEWR GFSX MOS GUIDANCE 12/03/2021 0000 UTC FHR 24| 36 48| 60 72| 84 96|108 120|132 144|156 168|180 192 FRI 03| SAT 04| SUN 05| MON 06| TUE 07| WED 08| THU 09| FRI 10 CLIMO X/N 49| 32 49| 35 49| 45 66| 43 44| 34 47| 40 49| 44 58 31 46

That was the last time we had a top 10 coldest fall and winter. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 1871 51.7 0 2 1887 51.8 0 3 1875 52.0 0 4 1888 52.2 0 5 1869 52.4 0 6 1883 52.5 0 7 1917 52.7 0 - 1873 52.7 2 8 1889 53.2 0 - 1880 53.2 0 9 1876 53.4 2 10 1976 53.7 0 - 1872 53.7 0 Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Season Mean Avg Temperature Missing Count 1 1917-1918 25.7 0 2 1880-1881 26.5 0 3 1903-1904 27.3 0 4 1919-1920 27.4 0 5 1874-1875 27.7 4 - 1872-1873 27.7 0 6 1904-1905 28.1 0 7 1935-1936 28.3 0 8 1976-1977 28.4 0 - 1884-1885 28.4 0 - 1882-1883 28.4 0 9 1892-1893 28.6 0 - 1887-1888 28.6 0 10 1878-1879 29.0 2

Same here. I continue to love snowstorms as much as I did when I was young. So the lack of cold doesn’t really bother me that much. I can still remember going to the bus stop for school in the brutally cold 76-77 winter. That was probably our only winter that could resemble something during the little ice age.

We definitely seem to be in the minority as an online community. Most people that I talk to like the fact that our winters have become so much warmer. While many of them would be happier living in Florida, their jobs and family are here. Winters have become warm and snowy or warm and snowless. Hard to believe our last cold and snowy winters were 13-14 and 14-15. Maybe we can eventually get another colder El Niño modoki winter.

All the long range guidance continues to advertise a very warm pattern this month. The only other highly amplified Aleutians Ridge, -PNA, +AO, and SE Ridge La Niña December was 1984. But that doesn’t mean the rest of the winter will resemble 84-85 since we are in such a warmer climate now. A weaker match may mean that this winter tries to mount some sort of a comeback after December. Still way too early to speculate on the rest of the winter. EPS Dec 6 to 13 Dec 13-20 Dec 20-27

Central Park getting back closer to reality now the leaves blocking the sensor are falling. Regional Weather Roundup National Weather Service New York NY 200 PM EST THU DEC 02 2021 Note: "FAIR" indicates few or no clouds below 12,000 feet with no significant weather and/or obstructions to visibility. NYZ071-072-176-178-NJZ106-104-022000- New York City Metro Area CITY SKY/WX TMP DP RH WIND PRES REMARKS Central Park PTSUNNY 57 43 59 VRB6 29.67F World Trd Ctr NOT AVBL Bronx Lehman C N/A 55 43 62 SW8 N/A LaGuardia Arpt CLOUDY 58 42 55 SW10 29.65F Queens College N/A 57 43 58 SW12 N/A Kennedy Intl CLOUDY 55 45 68 S6 29.67F Breezy Point N/A 55 N/A N/A S3 N/A Brooklyn Coll N/A 57 43 58 S7 N/A Staten Island N/A 57 43 58 SW8 N/A Newark/Liberty CLOUDY 59 44 57 SW13 29.64F Teterboro PTSUNNY 54 44 69 SW8 29.63F $$ NYZ177-179-078>081-022000- Long Island New York CITY SKY/WX TMP DP RH WIND PRES REMARKS Jones Beach N/A 54 N/A N/A S9 N/A Wantagh N/A 54 48 82 S8 N/A Hempstead NOT AVBL Matinecock Pt N/A 55 N/A N/A SW9 N/A Farmingdale CLOUDY 54 45 71 SW10 29.67F MacArthur/ISP CLOUDY 53 46 77 SW10 29.67F Stony Brook N/A 55 45 67 S5 N/A Shirley CLOUDY 54 45 71 S8 29.67F Mt Sinai Harb N/A 55 N/A N/A S5 N/A Westhampton CLOUDY 53 47 79 SW10 29.68F East Hampton PTSUNNY 53 46 77 SW8 29.67F Southold N/A 54 45 71 S9 N/A Montauk N/A 54 48 80 SW9G17 29.68F

19-20 gave new meaning to the term backloaded winter. https://gothamist.com/news/videos-nyc-reacts-freaky-may-snowfall

Yeah, just goes to show how much warmer the models have corrected in recent days. The long range forecasts were about 30° colder. Somebody in NJ can make a run on 70° with enough sun. New run Old run

We don’t even need to look that far out to see how ridiculously warm this month is starting in the US and Southern Canada.

The monthly temperature increases from 81-10 to 91-20 have been more pronounced during certain months. Newark and Islip are compared below. The +1.0 or warmer months for either station were bolded. ……….EWR…..ISP Dec…+1.5….+1.5 Jan….+1.2…+1.3 Feb….+0.5….+0.5 Mar….+0.4….+0.6 Apr….+0.5…..+0.6 May...+0.6….+0.9 Jun….+0.3….+0.6 Jul…..+1.4…..+1.1 Aug...+0.6….+0.9 Sep….+1.0….+1.3 Oct…..+0.9..+1.4 Nov….+0.2..+0.5