bluewave

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.

The blizzard is occurring around the heaviest snowfall dates of the season since the 09-10. ISP snowiest dates since 09-10 12-14…6.3 12-16…5.8 12-19…9.6 12-20…14.3 12-26….11.3 1-2……..7.8 1-3……..8.6 1-4…….16.0 1-7…….16.8 1-12…..14.0 1-21…..18.6 1-23….23.4 1-26….11.6 1-27…..27.0 1-30….5.9 2-1……11.1 2-2….5.9 2-3….11.6 2-5….12.9 2.7…..6.5 2-8….19.6 2-9….26.8 2-10….9.2 2-13….8.3 2-18….6.0 2-21…5.8 2-26…9.5 3-1…..9.6 3-2….11.5 3-5….6.4 3-7…..8.5 3-13….6.4 3-20….5.9 3-21….18.5

This is our next one coming right at the peak period for heavy snow events since the 09-10 winter.

The -PNA warm up next week matches La Niña climo for February. But the quick +PNA return goes off script. This winter continues to do its own thing. A +PNA La Niña February is very rare. But so was such an extreme record -PNA December. So who knows anymore with this more extreme climate.

The next several runs will be decisive. But even the runs 24hrs before the January 2000 event were way off. Tiny initialization errors throw the models off. https://journals.ametsoc.org/view/journals/mwre/130/4/1520-0493_2002_130_0957_icsaeg_2.0.co_2.xml Short- and medium-range (24–96-h) forecasts of the January 2000 U.S. east coast cyclone and associated snowstorm are examined using the U.S. Navy global forecast model and adjoint system. Attention is given to errors on the synoptic scale, including forecast position and central pressure of the cyclone at the verification time of 1200 UTC 25 January 2000. There is a substantial loss of predictive skill in the 72- and 96-h forecasts, while the 24- and 48-h forecasts capture the synoptic-scale features of the cyclone development with moderate errors. Sensitivity information from the adjoint model suggests that the initial conditions for the 72-h forecast starting at 1200 UTC 22 January 2000 contained relatively small, but critical, errors in upper-air wind and temperature over a large upstream area, including part of the eastern Pacific and “well observed” areas of western and central North America. The rapid growth of these initial errors in a highly unstable flow regime (large singular-vector growth factors) is the most likely cause of the large errors that developed in operational short- and medium-range forecasts of the snowstorm. The large extent of the upstream sensitive area in this case would appear to make “targeting” a small set of new observations an impractical method to improve forecast skill. A diagnostic correction (derived from adjoint sensitivity information) of a part of the initial condition error in the 72-h forecast reduces the forecast error norm by 75% and improves a 1860-km error in cyclone position to a 105-km error. This demonstrates that the model is capable of making a skillful forecast starting from an initial state that is plausible and not far from the original initial conditions. It is also shown that forecast errors in this case propagate at speeds that are greater than those of the synoptic-scale trough and ridge features of the cyclone.

Better data assimilation closer to storm time.

This is why models struggle so much with East Coast storm tracks beyond 24-48 hrs. As as been said here by many, it results in the back and forth between runs and models. Small changes make a big difference.

Imagine if we get the Euro track further west with GEM lower pressure and higher winds.

Anything is possible with these record SSTs in the Western Atlantic. We saw our first 950mb low of the modern era just 4 years ago near the benchmark. Each of the models have been taking turns showing such low pressures. https://www.weather.gov/okx/Blizzard_Jan42018 The development of the blizzard began along the southeast coast on Wednesday, January 3rd. An ampflying upper level trough spawned low pressure off the coast of Florida. The low underwent rapid intenisifcation from Wednesday night through the Thursday morning as it moved north-northeast along the coast. The low passed just east of the 40°N 70°W benchmark Thursday afternoon. The central pressure when the storm developed was around 1004 millibars at 1 pm Wednesday. 24 hours later, the central pressure fell to 950 mb which is a 54 millibar drop. The rapid intensification of the storm led to the heavy snow and blizzard conditions across portions of the region.

The record SSTs result in deeper low pressure, heavier precipitation, and stronger winds when storms can track close enough to our area.

A dusting here in SW Suffolk as the steady light snow is picking up in this band across LI.

You can bet if one of these long range SSW forecasts actually verifies, then it will be just in time for March.