bluewave

This tweet gives another answer to your good question.

The March -2.35 -PDO was the lowest in March since 1956 when the reading was -2.93. March 2009 was the last time below -2 in March at -2.06. Near record trough along the West Coast driving the SST pattern. So these are the warmest SSTs anomalies near the coast of South America in March for such a cold PDO. https://www.ncei.noaa.gov/pub/data/cmb/ersst/v5/index/ersst.v5.pdo.dat

It’s a good observation. -PNA and +AO patterns of the 1950s and 1960s didn’t have the SE Ridge. So those patterns were colder and snowier than what we have been getting recently. The Gulf Stream is much warmer and pumps the SE Ridge.

This was the deepest trough from December to March over California since the 1970s. A bit of a departure from recent years with the record ridge that was in place. The years with the lowest heights are below. Got a stronger SE Ridge this year than composite. So the record warm pool over the the Gulf Stream helped boost the SE Ridge and displace the 50/50 low even with strong blocking intervals. 2023 5591 1998 5597 1979 5598 1975 5595 1973 5586 1969 5564 1949 5558

The 95-96 measurements were close to the surrounding areas. Data for October 1, 1995 through April 30, 1996 Click column heading to sort ascending, click again to sort descending. State Name Station Type Total Snowfall CT DANBURY COOP 118.4 NY YORKTOWN HEIGHTS 1W COOP 103.7 NY PORT JERVIS COOP 97.3 NJ CHARLOTTEBURG RESERVOIR COOP 96.0 NY WALDEN 1 ESE COOP 95.2 NY GARDNERVILLE COOP 92.3 NY PATCHOGUE 2 N COOP 92.0 NY WEST POINT COOP 90.7 CT JEWETT CITY COOP 90.0 NY WEST NYACK COOP 88.4 CT MIDDLETOWN 4 W COOP 85.0 NY BRIDGEHAMPTON COOP 84.0 NY DOBBS FERRY-ARDSLEY COOP 83.1 CT STAMFORD 5 N COOP 82.2 NY WESTCHESTER CO AP WBAN 80.7 NY GREENPORT POWER HOUSE COOP 80.0 NY RIVERHEAD RESEARCH FARM COOP 78.8 NJ NEWARK LIBERTY INTL AP WBAN 78.4 NY LAGUARDIA AIRPORT WBAN 77.9 NY MINEOLA 1 NE COOP 77.8 NY ISLIP-LI MACARTHUR AP WBAN 77.1 CT COCKAPONSET RANGER STA COOP 76.0 CT IGOR I SIKORSKY MEMORIAL AIRPORT WBAN 75.7 NY NY CITY CENTRAL PARK WBAN 75.6 CT NORWICH PUBLIC UTILITY PLANT COOP 74.3 NY SUFFERN COOP 73.9 NJ GREENWOOD LAKE COOP 73.1 NJ PLAINFIELD COOP 71.4 CT GROTON COOP 71.4 NY NEW YORK AVE V BROOKLYN COOP 69.9 NJ TETERBORO AIRPORT WBAN 69.5 NY OCEANSIDE COOP 69.0 NY JFK INTERNATIONAL AIRPORT WBAN 69.0 NJ WANAQUE RAYMOND DAM COOP 66.6 NJ MIDLAND PARK COOP 66.3 NJ CANOE BROOK COOP 65.5

Very volatile snowfall seasons since the 1990s. There were 6 top 10 snowiest and 8 least snowiest years. So doing seasonal snowfall forecasting has been nearly impossible. Very big swings between years. Much less variation in the 60s, 70s, and 80s. Time Series Summary for JFK INTERNATIONAL AIRPORT, 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 69.0 0 2 1961-04-30 58.5 0 3 2003-04-30 56.2 0 4 1978-04-30 48.5 0 5 2010-04-30 47.2 0 6 1967-04-30 47.0 0 7 2014-04-30 45.6 0 8 1994-04-30 45.2 0 9 2015-04-30 44.2 0 10 2011-04-30 42.0 0 Time Series Summary for JFK INTERNATIONAL AIRPORT, 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 1973-04-30 1.6 0 2 2023-04-30 2.1 29 3 1998-04-30 3.6 0 4 2012-04-30 3.7 0 5 2020-04-30 3.8 0 6 2002-04-30 4.5 0 7 1995-04-30 7.9 0 8 1989-04-30 8.2 0 9 2007-04-30 8.5 0 10 1990-04-30 9.6 0

Would be only the 7th April tornado in NJ. https://climate.rutgers.edu/stateclim/climatologies/njtornado.html We don’t know enough about this one yet for any analogs.

Yeah, we haven’t had 2 consecutive years under 5” before. Getting 0 is a challenge since even Philly, DC ,and Richmond haven’t been able to avoid a trace. Time Series Summary for NY CITY CENTRAL PARK, NY - Oct through Sep Click column heading to sort ascending, click again to sort descending. Rank Season Total Snowfall Missing Count 1 2022-2023 2.3 182 2 1972-1973 2.8 0 3 2001-2002 3.5 0 4 1918-1919 3.8 1 5 2019-2020 4.8 0 6 1900-1901 5.1 2 7 1931-1932 5.3 0 8 1997-1998 5.5 0 9 2011-2012 7.4 0 10 1988-1989 8.1 0 - 1877-1878 8.1 0 11 1950-1951 9.3 0 12 1996-1997 10.0 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 1973-04-30 T 0 2 2023-04-30 0.3 29 - 2020-04-30 0.3 0 3 1998-04-30 0.8 0 4 1950-04-30 2.0 0 5 2012-04-30 4.0 0 - 2002-04-30 4.0 0 6 1931-04-30 4.1 0 7 1951-04-30 4.6 0 8 1992-04-30 4.7 0 9 1959-04-30 5.1 0 - 1942-04-30 5.1 0 10 1919-04-30 5.5 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 1998-04-30 0.1 0 - 1973-04-30 0.1 0 3 2023-04-30 0.4 29 4 2020-04-30 0.6 0 5 2012-04-30 2.0 0 6 1976-04-30 2.2 0 7 1931-04-30 2.5 0 8 2013-04-30 3.1 0 9 2002-04-30 3.2 0 10 1919-04-30 3.3 0 Time Series Summary for Richmond Area, VA (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 2023-04-30 T 29 - 1919-04-30 T 0 2 1945-04-30 0.5 0 3 1951-04-30 0.7 0 4 2008-04-30 0.8 0 5 1992-04-30 0.9 0 6 1981-04-30 1.0 0 - 1921-04-30 1.0 1 7 1956-04-30 1.1 0 8 1998-04-30 1.2 88 - 1976-04-30 1.2 0 9 2007-04-30 1.3 0 10 2020-04-30 1.5 0

Warmth could be a factor again if this is another strong to super basin-wide event as outlined in the paper below. They theorize the expanding WPAC warm pool has lead to stronger El Niño’s since the 1970s. We only had 3 notably colder Modoki El Niño’s with 50”+ around NYC since the 1980s in 02-03, 09-10, and 14-15. Most other El Niño’s were near average to above normal warmth in 82-83, 86-87, 87-88, 91-92, 94-95, 97-98, 04-05, 06-07 and 15-16. So 3 out of 12 notably colder with 50”+ snow. So that was the rarest group. Snowfall was much more variable among the remaining 9 years. 2 super El Niño years had memorable snowstorms in 82-83 and 15-16 in warm winters. The 97-98 super was a disappointment with all warmth an little snow. 86-87 and 04-05 El Niño’s had decent snows around the region with near normal temperatures. Odd years like 06-07 and 94-95 were milder without much snow. https://www.pnas.org/doi/10.1073/pnas.1911130116 Historical change of El Niño properties sheds light on future changes of extreme El Niño 49,207114 Significance How the magnitude of El Niño will change is of great societal concern, yet it remains largely unknown. Here we show analysis of how changing El Niño properties, due to 20th century climate change, can shed light on changes to the intensity of El Niño in the future. Since the 1970s, El Niño has changed its origination from the eastern Pacific to the western Pacific, along with increased strong El Niño events due to a background warming in the western Pacific warm pool. This suggests the controlling factors that may lead to increased extreme El Niño events in the future. If the observed background changes continue under future anthropogenic forcing, more frequent extreme El Niño events will induce profound socioeconomic consequences. Abstract El Niño’s intensity change under anthropogenic warming is of great importance to society, yet current climate models’ projections remain largely uncertain. The current classification of El Niño does not distinguish the strong from the moderate El Niño events, making it difficult to project future change of El Niño’s intensity. Here we classify 33 El Niño events from 1901 to 2017 by cluster analysis of the onset and amplification processes, and the resultant 4 types of El Niño distinguish the strong from the moderate events and the onset from successive events. The 3 categories of El Niño onset exhibit distinct development mechanisms. We find El Niño onset regime has changed from eastern Pacific origin to western Pacific origin with more frequent occurrence of extreme events since the 1970s. This regime change is hypothesized to arise from a background warming in the western Pacific and the associated increased zonal and vertical sea-surface temperature (SST) gradients in the equatorial central Pacific, which reveals a controlling factor that could lead to increased extreme El Niño events in the future. The Coupled Model Intercomparison Project phase 5 (CMIP5) models’ projections demonstrate that both the frequency and intensity of the strong El Niño events will increase significantly if the projected central Pacific zonal SST gradients become enhanced. If the currently observed background changes continue under future anthropogenic forcing, more frequent strong El Niño events are anticipated. The models’ uncertainty in the projected equatorial zonal SST gradients, however, remains a major roadblock for faithful prediction of El Niño’s future changes.

The developing El Niño will become more basin wide instead of east based with the further west WWB than the more EPAC one in a March which warmed 1+2.

71 mph gust in Central NJ which has been an active area for severe in recent years.

That’s for sure.

Yeah, this SST profile keeps pumping the SE Ridge.

80 mph gust from Lake Erie buoy.

Peak gust of 71 mph so far with numerous 60s gusts.

I believe they are approaching 90” this morning which would be 3rd highest. Around 3” more after this chart was compiled through yesterday Time Series Summary for Minneapolis-St Paul Area, MN (ThreadEx) - Oct through Sep Click column heading to sort ascending, click again to sort descending. Rank Season Total Snowfall Missing Count 1 1983-1984 98.6 0 2 1981-1982 95.0 0 3 1950-1951 88.9 0 4 2010-2011 86.6 0 5 2022-2023 86.5 183 6 1916-1917 84.9 0 7 1991-1992 84.1 0 8 1961-1962 81.2 0 9 1951-1952 79.0 0 10 1966-1967 78.4 0

Severe storms can overperform on Saturday even to the coast with steep mid-level lapse rates, strong shear, an helicity. Morning warm front with possible multiple rounds convection in afternoon into evening. The key may be getting enough spacing between all the storms. But there can be squall segments and supercells. The models are all over the place on convection timing and placement. The Euro has morning, midday and evening convection.

I think 9° on a radiational cooling night between JFK-LGA-NYC is near the upper limit. But have no idea what the max difference is for those sites for radiational cooling.

NYC has had a strong UHI effect for the low temperatures since the late 1800s. Warmer lows than Newark but the highs were similar before the tree growth over the sensor. Data for August 11, 1896 through August 11, 1896 Click column heading to sort ascending, click again to sort descending. State Name Station Type Lowest Min Temperature NY NY CITY CENTRAL PARK WBAN 81 NJ NEWARK COOP 78 NY BRONX COOP 78 NY WORLD TRADE CENTER WBAN 76 CT NEW LONDON COOP 75 NJ PATERSON COOP 74 NJ PLAINFIELD COOP 73 NJ ELIZABETH COOP 73 CT BRIDGEPORT COOP 73 NY SETAUKET STRONG COOP 73 Data for August 11, 1896 through August 11, 1896 Click column heading to sort ascending, click again to sort descending. State Name Station Type Highest Max Temperature NJ ELIZABETH COOP 97 NJ NEWARK COOP 97 NY WEST POINT COOP 96 NJ PLAINFIELD COOP 96 NY NY CITY CENTRAL PARK WBAN 96 CT MIDDLETOWN 4 W COOP 96 NJ PATERSON COOP 95 NY BRONX COOP 94 Data for August 14, 1908 through August 14, 1908 Click column heading to sort ascending, click again to sort descending. State Name Station Type Lowest Min Temperature NY NY CITY CENTRAL PARK WBAN 84 NJ JERSEY CITY COOP 75 NJ NEWARK COOP 75 NY BEDFORD HILLS COOP 75 NJ ELIZABETH COOP 74 NY CARMEL COOP 74 NY SALISBURY MILLS COOP 73 NY CUTCHOGUE COOP 73 NJ PATERSON COOP 72 Data for August 14, 1908 through August 14, 1908 Click column heading to sort ascending, click again to sort descending. State Name Station Type Highest Max Temperature NJ ELIZABETH COOP 95 NY WEST POINT COOP 94 NY MOUNT HOPE COOP 93 NJ PLAINFIELD COOP 93 NY NY CITY CENTRAL PARK WBAN 93 CT WATERBURY ANACONDA COOP 92 NJ JERSEY CITY COOP 92 Data for July 2, 1901 through July 2, 1901 Click column heading to sort ascending, click again to sort descending. State Name Station Type Lowest Min Temperature NY NY CITY CENTRAL PARK WBAN 82 NJ ELIZABETH COOP 80 NJ PATERSON COOP 80 NY MIDDLETOWN 2 NW COOP 79 NY PORT JERVIS COOP 79 NJ NEWARK COOP 78 Data for July 2, 1901 through July 2, 1901 Click column heading to sort ascending, click again to sort descending. State Name Station Type Highest Max Temperature NJ ELIZABETH COOP 105 NY MOUNT HOPE COOP 104 NJ PLAINFIELD COOP 104 NY PORT JERVIS COOP 103 NJ NEWARK COOP 103 NY BEDFORD HILLS COOP 102 CT WATERBURY ANACONDA COOP 102 NJ PATERSON COOP 102 NY SALISBURY MILLS COOP 100 CT NORWALK COOP 100 CT BRIDGEPORT COOP 100 CT MIDDLETOWN 4 W COOP 100 NY NY CITY CENTRAL PARK WBAN 100 Data for July 1, 1901 through July 1, 1901 Click column heading to sort ascending, click again to sort descending. State Name Station Type Lowest Min Temperature NJ ELIZABETH COOP 79 NY NY CITY CENTRAL PARK WBAN 78 NJ NEWARK COOP 76 NY MIDDLETOWN 2 NW COOP 74 NY BEDFORD HILLS COOP 74 NJ PATERSON COOP 73 NY CARMEL COOP 73 NY SETAUKET STRONG COOP 73 Data for July 1, 1901 through July 1, 1901 Click column heading to sort ascending, click again to sort descending. State Name Station Type Highest Max Temperature NJ ELIZABETH COOP 104 NY PORT JERVIS COOP 102 NJ PLAINFIELD COOP 102 NJ NEWARK COOP 102 NJ PATERSON COOP 102 NY MOUNT HOPE COOP 102 NY NY CITY CENTRAL PARK WBAN 100

The BNL tower thermometers show how shallow the radiational cooling inversion is. A low of 21 at the surface and 35 at around 160 feet. So just above the surface of the Pine Barrens is similar in temperature to NYC.

Lows with good radiational cooling outside urban areas. EWR and JFK were able to radiate when winds went calm. NYC…38 LGA…38 JFK…29 EWR..33 FRG…28 ISP….26 HWV…24 FOK…15 HPN…28 DXR…23

Sharp gradient that month. Lower totals further NW. Higher totals across Eastern Suffolk. But ISP did better in 17-18. So banding can make a dramatic effect across 25 miles. You can see an even another big spread in 95-96. Lower years like this one can be more uniform. ISP was way above Upton in 13-14. So it’s all a matter of where the best banding sets up. Data for October 1, 1966 through April 30, 1967 Click column heading to sort ascending, click again to sort descending. Name Station Type Total Snowfall BNL COOP 74.9 SETAUKET STRONG COOP 42.6 ISLIP-LI MACARTHUR AP WBAN 50.8 RIVERHEAD RESEARCH FARM COOP 56.9 PATCHOGUE 2 N COOP 62.8 WESTHAMPTON GABRESKI AP WBAN 66.1 BRIDGEHAMPTON COOP 68.9 Data for October 1, 2017 through April 30, 2018 Click column heading to sort ascending, click again to sort descending. Name Station Type Total Snowfall BRIGHTWATERS 0.7 NNW CoCoRaHS 72.0 NESCONSET 1.4 SSW CoCoRaHS 71.8 ISLIP-LI MACARTHUR AP WBAN 65.9 PORT JEFFERSON STATION 0.3 SSW CoCoRaHS 59.2 CENTERPORT COOP 58.5 UPTON COOP - NWSFO NEW YORK COOP 55.2 Data for October 1, 1995 through April 30, 1996 Click column heading to sort ascending, click again to sort descending. Name Station Type Total Snowfall BRIDGEHAMPTON COOP 84.0 GREENPORT POWER HOUSE COOP 80.0 ISLIP-LI MACARTHUR AP WBAN 77.1 PATCHOGUE 2 N COOP 92.0 RIVERHEAD RESEARCH FARM COOP 78.8 BNL COOP 90.8 Data for October 1, 2022 through April 30, 2023 Click column heading to sort ascending, click again to sort descending. Name Station Type Total Snowfall ORIENT POINT STATE PARK COOP 7.4 NESCONSET 1.4 SSW CoCoRaHS 7.4 RIDGE 1.8 SE CoCoRaHS 6.6 UPTON COOP - NWSFO NEW YORK COOP 6.5 PORT JEFFERSON STATION 0.3 SSW CoCoRaHS 6.0 CENTER MORICHES 0.5 N CoCoRaHS 5.5 CENTERPORT COOP 5.4 BRIDGEHAMPTON COOP 5.1 CENTEREACH 1.3 NE CoCoRaHS 5.1 ISLIP-LI MACARTHUR AP WBAN 5.0 Data for October 1, 2013 through April 30, 2014 Click column heading to sort ascending, click again to sort descending. Name Station Type Total Snowfall ISLIP-LI MACARTHUR AP WBAN 63.7 BAITING HOLLOW COOP 62.7 CENTERPORT COOP 60.8 RIVERHEAD RESEARCH FARM COOP 57.3 MOUNT SINAI COOP 55.8 ROCKY POINT 2.0 N CoCoRaHS 51.4 UPTON COOP - NWSFO NEW YORK COOP 47.3

Yeah, it was very active for record tracking. But was rough for outdoor workers and activities. Traffic jams were common in Long Beach. Plus the beach and boardwalk were overcrowded.

California getting close to surpassing the all -time snowpack record set during the 82-83 super El Niño.