bluewave

Yeah, we were all waiting on the MJO back in December. But it got stuck in the warm phases longer than forecast due to the record warm pool north of Australia. The magnitude of the shift in January matches some recent years like 14-15 and 15-16. But those were El Niño years which we came to expect dramatic changes after a warm start. This is really the first time a La Niña shifted so much from December record warmth and lack of snow to record snow and colder in January. Now we have an example of this NE PAC blocking pattern during ENSO neutral 14-15, El Niño 14-15, and La Niña in 21-22. So it can occur in varying ENSO states. This makes seasonal forecasting more challenging since this mode can replace or enhance ENSO expectations.

Recent studies have found that the persistent ridge near the West Coast and Hudson Bay TPV pattern is a result of rising WPAC SSTs. https://www.mdpi.com/2073-4433/10/12/793/htm 4. Conclusions The diagnostics undertaken here suggest that the leading mode of the wintertime atmospheric stationary waves in the Northern Hemisphere has undergone a notable change. Since the 1980s, the first leading mode of anomalous winter stationary eddies in the subseasonal timescale has alternated from the PNA to a comparably strong NAWD. Given that EOF describes the variance of individual patterns, the observed increase in the amplitude of NAWD suggests that it may have overtaken the PNA as the more common type of winter variability, with increased influence from western North Pacific SSTs. The CESM large-ensemble simulations forced with increasing greenhouse gas indicate that the NAWD variance will gradually amplify alongside its low-frequency natural variability. This result implies that the subseasonal variation of the atmospheric circulations over North America could continue to be dominated by the NAWD mode, with the potential to sharpen the east–west temperature and precipitation division across North America. Further comparison of EOF1/EOF2 with PNA/NAWD using spatial correlation reveals a pattern change that is consistent among different reanalysis datasets. Analysis of the paleoclimate simulations suggests that NAWD does co-vary with the global temperature variation at centennial timescales: the NAWD variance was weak in the cooler Pleistocene and gradually increased and stabilized in the warmer Holocene. We further examined large-scale forcing of both atmospheric and oceanic origins for the amplified NAWD and found that most of the documented climate indices, which showed a connection to the 2013–2014 extreme winter of North America, are insignificantly correlated with NAWD with the exception of certain oceanic features like the WNP and Niño 4 (Y + 1); these imply that regional SST anomalies in the subtropical West Pacific may provoke teleconnections that affect NAWD. Future examination of the dynamic processes leading to the NAWD amplification should consider the stationary waves maintenance, namely the jet–terrain interactions, tropical and extratropical diabatic heating, and the effect of Arctic amplification.

Yeah, it leads to these dramatic pattern changes over a short period of time like we saw from December to January. Now it looks like the January pattern is repeating in February. So a combination of big weather swings and stuck weather patterns.

Yeah, competing marine heatwaves are becoming the key to understanding these extreme winter patterns. It adds a new level of complexity to seasonal forecasting. So the old La Niña or El Nino based forecasts are becoming less reliable.

There also seems to be some connection to what we had with the Ridiculously Resilient Ridge back in the 2015 El Niño. Notice how close the forcing was this January to 2015. Both years had convection from the CP to WPAC. This was the coldest January since 2015. We also had a blizzard track not far from Juno with the heaviest snows from LI to SE New England. The +PNA and -EPO this January was just a little weaker than January 2015. So it’s possible the models showing more of a +PNA in February may be the pattern lingering from January. Comparison of January 2022 to 2015 with Nino-like forcing from CP to WPAC

The first 30° month in NYC since 15-16. Monthly Mean Avg Temperature for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Dec Jan Feb Season 2021-2022 43.8 30.3 M 37.1 2020-2021 39.2 34.8 34.2 36.1 2019-2020 38.3 39.1 40.1 39.2 2018-2019 40.1 32.5 36.2 36.3 2017-2018 35.0 31.7 42.0 36.2 2016-2017 38.3 38.0 41.6 39.3 2015-2016 50.8 34.5 37.7 41.0

We are already seeing a model disagreement between the GEFS and the other guidance near the end of the ensemble runs on February 16th. The EPS and GEPS keep the +PNA pattern going. It could be related to the split forcing in the tropics. The convection south of India would normally produce a -PNA in February. But we see the lingering forcing near the Central Pacific which is more Nino-like as was the case in January. Forcing in that area favors a more +PNA in February. So that may be what the EPS and GEPS is picking up on.

There is no set interval between the date of the SSW and local effects for our area. We had a snowstorm on the same day as the one on 1-23-87. But some years it can take up to 3 weeks. So there is no way of trying to game out how long it will take for the influences to reach the troposphere as each event is unique. Plus we don’t know it the super long range EPS is even correct. It’s very difficult to predict these beyond 2 weeks. So if the weeklies turn out to be correct, then it would be quite an accomplishment. https://csl.noaa.gov/groups/csl8/sswcompendium/majorevents.html

Parts of Long Island already have as much snow at the beginning of February as all of last year. Most years since 02-03 were over 30”. This is a first for a 20 year period. The few years that were below average were under 15”. So no years in the middle between more extreme highs and lows. Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr May Season Mean 0.0 0.5 5.5 13.2 12.1 6.8 0.3 T 37.3 2021-2022 0.0 T 0.3 31.8 M M M M 32.1 2020-2021 T 0.0 7.5 1.1 24.9 T T 0.0 33.5 2019-2020 0.0 0.1 4.2 2.5 0.0 T T T 6.8 2018-2019 0.0 4.3 T 0.9 3.5 4.1 T 0.0 12.8 2017-2018 0.0 T 6.0 22.0 1.4 31.9 4.6 0.0 65.9 2016-2017 T T 3.2 14.0 14.7 7.4 T 0.0 39.3 2015-2016 0.0 0.0 T 24.8 13.2 3.2 0.2 0.0 41.4 2014-2015 0.0 T 0.4 30.2 13.4 19.7 0.0 0.0 63.7 2013-2014 0.0 0.3 8.1 25.2 24.5 5.4 0.2 0.0 63.7 2012-2013 0.0 4.2 0.6 3.3 31.4 7.4 0.0 0.0 46.9 2011-2012 0.3 0.0 T 3.8 0.6 T 0.0 0.0 4.7 2010-2011 0.0 T 14.9 34.4 3.9 2.1 T 0.0 55.3 2009-2010 0.0 0.0 25.3 6.4 21.7 0.4 0.0 0.0 53.8 2008-2009 0.0 T 10.4 8.9 3.3 13.6 T 0.0 36.2 2007-2008 0.0 0.0 2.6 0.8 7.3 T 0.0 0.0 10.7 2006-2007 0.0 T 0.0 1.0 4.2 3.8 T 0.0 9.0 2005-2006 0.0 0.5 7.6 4.7 19.9 3.2 0.1 0.0 36.0 2004-2005 0.0 T 7.0 21.5 17.0 13.3 0.0 0.0 58.8

The remarkable thing is that even our least snowy winters since 09-10 still had record snows. The 11-12 winter had the record snowiest October in NYC. 19-20 tied for the snowiest May with the trace of snow. So every year since 09-10 had a top 10 snowiest month at one of the sites in the OKX forecast zones.

The historic +13.3 departure in December 2015 marked the shift to much warmer winters. This January is only the 5th winter month out of the last 20 with below normal temperatures. The coldest departure month was this January at -3.2 NYC Jan 22….-3.2 Dec 21….+4.7 Feb 21….-1.1 Jan 21….+2.2 Dec 20…+1.7 Feb 20…+4.8 Jan 20….+6.5 Dec 19….+0.8 Feb 19….+0.9 Jan 19….-0.1 Dec 18…+2.6 Feb 18…+6.7 Jan 18….-0.9 Dec 17…..-2.5 Feb 17…..+6.3 Jan 17….+5.4 Dec 16….+0.8 Feb 16….+2.4 Jan 16….+1.9 Dec 15….+13.3

Updated for January. ISP….#2….31.8 LGA…#4…20.4 JFK….#5…17.5 BDR…#5…20.8

You can see how tough it is for the ASOS to get an accurate liquid equivalent from the blizzard. The local Cocorahs look much closer to reality. That ASOS precip of 0.51 at ISP is much lower than the 1.75 at a nearby station which also reached 20”+ like ISP ISLIP NY Jan 29 Climate: High: 29 Low: 14 Precip: 0.51 Snow: 23.2 Daily Precipitation Report Station Number: NY-SF-77 Station Name: Nesconset 1.4 SSW Observation Date 1/30/2022 8:18 AM Submitted 1/30/2022 9:19 AM Gauge Catch 0.80 in. Notes Blizzard Snow Information 24-hr Snowfall 9.0 in. 24-hr Snowfall SWE (Snow Water Equivalent) 0.80 in. 24-hr Snowfall SLR (Snow to Liquid Ratio) 11.2 : 1 Snowpack Depth 20.0 in. Snowpack SWE (Snow Water Equivalent) 1.75 in. Snowpack Density 9 % Duration Information Precipitation Began -- Precipitation Ended -- Heavy Precip Began -- Heavy Precip Lasted -- Duration Time Accuracy -- Additional Information Flooding None Additional Data Recorded No

Another extreme weather reversal from December to January. We went from one of the warmest Decembers on record to one of the snowiest Januaries. These sharp reversals from month to month have become more common in recent years. The last December to January one to make big headlines was the 15-16 winter. Also notice how many of the top 10 snowiest Januaries there have been since 2010. ACY takes the most extreme snowfall record for January beating the previous record holder by 12.9”. 2nd snowiest January at ISP Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Jan Click column heading to sort ascending, click again to sort descending. Rank Year Total Snowfall Missing Count 1 2011 34.4 0 2 2022 31.8 2 3 2015 30.2 0 4 1978 27.7 0 5 2014 25.2 0 6 2016 24.8 0 7 1965 24.6 0 8 2018 22.0 0 9 2005 21.5 0 10 1996 20.2 0 4th snowiest January at LGA Time Series Summary for LAGUARDIA AIRPORT, NY - Month of Jan Click column heading to sort ascending, click again to sort descending. Rank Year Total Snowfall Missing Count 1 2011 32.6 0 2 2016 28.8 0 3 1996 27.6 0 4 2022 20.4 2 5 1982 20.3 0 6 2015 19.7 0 7 1948 18.3 0 8 2004 17.8 0 9 2014 16.7 0 10 1978 16.6 0 5th snowiest January at JFK Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Month of Jan Click column heading to sort ascending, click again to sort descending. Rank Year Total Snowfall Missing Count 1 2016 31.3 0 2 1996 23.0 0 3 2011 22.1 0 4 1978 20.1 0 5 2022 17.5 2 6 1965 17.4 0 7 2015 17.1 0 8 2014 17.0 0 9 1961 16.7 0 10 1988 15.7 0 ACY new snowiest January by a wide margin Time Series Summary for Atlantic City Area, NJ (ThreadEx) - Month of Jan Click column heading to sort ascending, click again to sort descending. Rank Year Total Snowfall Missing Count 1 2022 33.2 2 2 1987 20.3 0 3 2014 18.8 0 4 2016 16.7 0 5 1961 15.9 0

My guess is that the wave break caused by the blizzard shifted the pattern across the Northern Hemisphere in early February. Older runs before the models caught on to how strong the storm would be had a -PNA pattern. Now this has flipped to more of a +PNA with Arctic high pressure becoming a player.

This is the 12th storm since the 09-10 winter to produce a 20” or greater snowfall in our area. SPOTTER ...SUFFOLK COUNTY... ISLIP AIRPORT 24.7 IN 0700 PM 01/29 OFFICIAL NWS OBS BAY SHORE 24.2 IN 0800 PM 01/29 NWS EMPLOYEE MEDFORD 23.5 IN 0345 PM 01/29 TRAINED SPOTTER SMITHTOWN 23.0 IN 0955 PM 01/29 TRAINED SPOTTER BELLPORT 22.0 IN 0610 PM 01/29 PUBLIC SAINT JAMES 21.6 IN 0855 PM 01/29 TRAINED SPOTTER 1 W BLUE POINT 21.4 IN 0735 PM 01/29 NWS EMPLOYEE CENTEREACH 21.4 IN 0448 PM 01/29 PUBLIC NORTH PATCHOGUE 21.4 IN 0425 PM 01/29 PUBLIC 2 S DEER PARK 21.0 IN 0530 PM 01/29 PUBLIC SAYVILLE 20.8 IN 0404 PM 01/29 NWS EMPLOYEE SMITHTOWN 20.0 IN 0230 PM 01/29 TRAINED SPOTTER

Recent model runs correcting much stronger with the Arctic high pressure for next week. New run Old run

It’s easy to lose track of all these high end snow events in recent years. Maximum 2-Day Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Rank Value Ending Date Missing Days 1 27.8 2013-02-09 0 2 25.9 1978-02-07 0 3 24.9 2015-01-27 0 4 23.9 2009-12-20 0 5 23.7 2016-01-24 0 6 23.4 2016-01-23 0 7 20.1 1983-02-12 0 8 19.9 2006-02-12 0 9 18.4 2018-03-22 0 10 17.8 1978-01-20 0 11 17.4 2015-01-28 0 12 17.0 1996-01-08 0 - 17.0 1969-02-10 0 - 17.0 1967-03-22 0 15 16.7 2013-02-08 0 - 16.7 2006-02-13 0 17 16.5 1978-02-06 0 18 16.0 2018-01-05 0 - 16.0 2018-01-04 0 - 16.0 1982-04-07 0 - 16.0 1982-04-06 0 22 15.6 1978-01-21 0 23 15.2 2011-01-12 0 24 15.1 2005-01-23 0 25 15.0 1969-02-09 0 - 15.0 1967-03-23 0

This band in SW Suffolk is currently the heaviest of the day so far with near whiteout conditions at times.

ISP approaching their snowiest day on record with many of the top 10 during the recent record snowfall era. Maximum 1-Day Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Rank Value Ending Date 1 23.4 2016-01-23 2 17.4 2015-01-27 3 16.7 2013-02-08 - 16.7 2006-02-12 4 16.5 1978-02-06 5 16.0 2018-01-04 - 16.0 1982-04-06 6 15.6 1978-01-20 7 15.0 1969-02-09 - 15.0 1967-03-22 8 14.9 2018-03-21 9 14.3 2017-02-09 - 14.3 2009-12-20 10 14.0 2011-01-12

It’s been a while since NYC has snowed at 15°. Central Park SNOW 15 11 83 N12G25 29.72F VSB 1/2

We see this when broad troughs take too long to close off. So it produces a double barrel low before the eastern one takes over. It’s easier for the upper low to close of faster when there is a -AO and -NAO. This gives us a 50/50 low with more of a ridge over SE Canada and helps the northern stream close off earlier to our SW.

The low to the east is stronger than the one to the west.

Best banding from the Jersey Shore NNE to Long Island.

Suffolk approaching a foot of snow.