bluewave

It will be interesting to see if we can make it over to MJO phase 7 in mid-March. The GEFS has a strong WWB pattern developing as the MJO propagates east. It may be strong enough to shift us out of this multiyear La Niña event to our next El Niño.

While the EPS weeklies update will be out later, the GEFS is taking the MJO warm tour into March. Strong MJO 4-6 right into early March with a warm SE Ridge pattern and +AO. But signs of MJO 7 by mid-March allowing more blocking. This is when the GEFS tries to weaken the very intense SPV. Feb 23 to Feb 28 Mar 1-7 Mar 16 weaker SPV and MJO 7

The usual warm spots in the region could see 3 days in a row reaching 50° to boost the monthly departures.

The current MJO forecast progression would have March starting out warmer than average. This would probably last through phases 5 and 6. If we can make it over to 7 eventually, that’s where it could get colder again with maybe a final snow event for someone in the region.

I think the wild card for the very long range is whether this MJO is able to shift us into an El Niño. The long range GFS VP anomalies take us from from MJO 5 to 6-7 in March. This eventually produces a WWB which could lead to an El Niño formation by the summer. Several El Niño’s have occurred following strong March MJO 6-7 events. Tail end of La Niña near the surface GEFS MJO driven WWB in March

My two favorite snowstorms since 2010 were Boxing Day and Jan 2016. Boxing Day for my best drifts since Feb 78 in Long Beach. Jan 2016 for overall totals, duration, and best monthly comeback on record from Dec 15. But the Nemo snowband in February 2013 surpassed both those events for intensity. They even wrote a paper on it. That storm could have produced a 50” jackpot if it had stalled. https://journals.ametsoc.org/view/journals/wefo/29/6/waf-d-14-00056_1.xml 4. Summary and conclusions The 8–9 February 2013 Northeast blizzard was a unique event, exhibiting several intriguing dual-polarization radar signatures. This study investigates the evolution and nature of these signatures, and the thermodynamic conditions within which they developed, to obtain a better understanding of the fundamental microphysical processes within this system. Polarimetric data (from the S-band KOKX radar) were analyzed alongside RAP model wet-bulb temperature analyses, as well as surface precipitation type observations from both mPING and the NWS Forecast Office in Upton, New York, for interpretation of polarimetric signatures. Values of ZH during this event were extraordinary for a winter storm, exceeding 50 dBZ and reaching as high as 60 dBZ within a shallow layer just above the surface. Also, as the incoming snowbands proceeded northward, the polarimetric data exhibited an exceptionally distinct transition from frozen to unfrozen precipitation, providing detail that was often unmatched by the numerical model output. During this event, the polarimetric observations were critical for accurately assigning the transition from liquid to frozen precipitation, illustrating how dual-polarization radar data could be a potentially valuable tool for forecasters when nowcasting transitional winter precipitation. Another prominent feature of the event was the remarkable differential attenuation, resulting from the radar beam propagating through regions of heavy wet snow and mixed-phase precipitation. These differential attenuation observations reached magnitudes that exceed anything previously documented for S-band radar observations in snow. This study also documents a downward excursion of the MLBB to the surface, characterized by reduced ρhv and locally maximized ZH and ZDR; this feature was correlated with an abrupt transition line of precipitation types at the surface. Some of the most distinctive signatures observed during the event were elevated horizontal layers of enhanced ZDR and KDP, and reduced ρhv, located above the environmental freezing layer and within the comma-head region of the cyclone. The enhanced ZDR values likely signified the presence of large, horizontally oriented ice crystals at the subfreezing temperatures aloft, near the model-predicted −15°C TWisotherm, where the conditions for rapid depositional growth are most favorable. These depositional growth layers appeared to be correlated with the increase in heavy snowfall; ice crystals were generated aloft, aggregated, descended, and then contributed to the large ZH values near the surface. The layers appeared increasingly more evident as the period of greatest ZH values neared, with the initial layer observations preceding the greatest surface ZH by several hours, demonstrating the potential utility of this signature for nowcasting increases in precipitation at the surface. Several polarimetric artifacts were also observed and provided valuable information about the system’s microphysical processes. Distinct depolarization streaks occurred with frequency during the 2300 UTC hour, when ZH exceeded 55 dBZ near the surface. These radial streaks of positive and negative ZDR indicated regions of atmospheric electrification (and possible regions of supercooled water), and they originated at uncharacteristically low heights, atop weak convective updrafts in regions of heavy wet snow. The effects of nonuniform beamfilling were also observed during the event, indicating large gradients of ΦDP within the radar resolution volume, due to a nonuniform mixture of precipitation types and sizes within the radar beam cross sections. Finally, a “snow flare” of reduced ρhv, enhanced ZDR, moderate KDP, and low ZH flared outward from the radar and appeared similar to a three-body scattering signature commonly reported in hailstorms; this signature could also be due to sidelobe contamination. This feature was associated with very large snowflakes and ice hydrometeors at the surface, including anomalous ice hydrometeors (Ganetis et al. 2013), which had the appearance of small, irregular hailstones. This study provides a next step toward understanding the fundamental microphysical processes within winter precipitation and how polarimetric signatures relate to larger-scale storm structure and evolution. The radar signatures investigated herein convey the value of polarimetry in identifying features undetectable in conventional radar data. These signatures are associated with hazardous winter weather conditions that cause havoc on the public and transportation sectors, both at the surface and in the air. Therefore, polarimetry provides a valuable tool for short-term detection and prediction of winter weather precipitation types, especially transitional events.

With the record KU pattern since 09-10, the bar has been raised relative to what past expectations used to be. Everyone wants to be closer to the big jackpot zone. With the lateJanuary blizzard, the place to be was around ISP. My only real disappointment in this new snowfall era was missing the NEMO 50 DBZ 6”+ per hour band and the near 40” max. https://www.washingtonpost.com/weather/2022/02/01/northeast-snow-storm-climate/ Single-day records are not the only objective way to quantify the incredible winter weather activity of recent years. A metric known as the Northeast Snow Impact Scale (NESIS), which calculates the population-weighted snowfall footprints of winter storms, can be used to compare the social strain induced by Northeast winters. Analysis of NESIS data shows the 2008-2018 period saw more than three times as many winter storms as any other decade since at least 1958-1968.

The current SPV is very strong and beginning to couple with the +AO. That’s why this month is turning out warmer than January was. So it’s the opposite of what a SSW is.

It’s a French site. The ENSO specific composites come in handy. But since the MJO can be just one part of the forcing equation, there can be variations when interference patterns exist. They seem to work best when there is a strong MJO without other competing forcing influences. https://www.frenchscotpilotweather.com/mjo

Phases 5-6 in March are warm during a La Niña. So it looks like March could come in mild. But if the MJO can make it over to phase 7, then we could get a cool down in mid to late March. Hard to tell from this far out in time.

Looks like all the models finally weaken the +PNA after Presidents Day as the split forcing consolidates near the Maritime Continent.

The multiyear ice for 2021 finished at the 2nd lowest behind 2012. So just looking at the extent rebound from 2020 can be a bit deceptive. The amount of MYI is one of the key indicators as to how much the Arctic has warmed. https://arctic.noaa.gov/Report-Card/Report-Card-2021/ArtMID/8022/ArticleID/945/Sea-Ice Sea ice age Sea ice drifts around the Arctic Ocean, forced by winds and ocean currents, growing and melting thermodynamically. Ice convergence can also lead to dynamic thickening (i.e., ridging and rafting) while ice divergence during winter exposes open water within which new ice can form. Age is a proxy for thickness as multiyear ice (ice that survives at least one summer melt season) grows thicker over successive winter periods. Age is here presented over the Arctic Ocean domain (Fig. 3, inset) for the period 1985-2021. In the week before the 2021 annual minimum extent, when the age values of the remaining sea ice are incremented by one year, the amount of multiyear ice remaining in the Arctic Ocean was the second lowest on record (above only 2012). The September multiyear sea ice extent declined from 4.40 million km2 in 1985 to 1.29 million km2 in 2021 (Fig. 3). Over the same period, the oldest ice (>4 years old) declined from 2.36 million km2 to 0.14 million km2. In the 37 years since records began in 1985, the Arctic Ocean has changed from a domain dominated by multiyear ice to one where first-year ice prevails. A younger ice cover implies a thinner, less voluminous ice pack.

We are back to the high temperatures beating guidance as the TPV retreats further NW with the more +AO pattern. February pattern so far January pattern

The TPV shifting closer to Greenland from Hudson Bay in January is allowing milder temperatures this month near the East Coast with the more +AO pattern.

A recent study found that the extreme drop in MYI coverage with the 2007 season has slowed the rate of new extent record minimums in September. The last record minimum extent in September occurred back in 2012. But we came close to that record a few years ago. The thinner ice makes it easier for the winds to push around the extents quite a bit from year to year. So we can have large differences between years like 2012 and 2013 and 2020 and 2021. The big story is that even the most favorable seasons since 2007 have never been able to approach early 2000s extents and volume levels. So it appears that the fundamental shift in the Arctic has already occurred back in 2007. While we’ll eventually surpass 2012 and head toward an ice free season in the future as the planet warms, 2007 may be more significant than the first technically ice free season below 1 million sq km. https://iopscience.iop.org/article/10.1088/1748-9326/aae3ec From the peak MYI coverage in 2002 to the end of our record in 2017, the Arctic has lost more than 2 × 106 km2, a decrease of 50%; MYI now covers less than one-third of the Arctic Ocean. As with ice volume, the largest decline in MYI coverage followed the record-setting end-of-summer ice extent in 2007. In addition to annual ice export, recent losses of MYI are due to melt of MYI advected into the southern Beaufort Sea from the north coast of Greenland and the CAA, the source region of the thickest and most deformed ice in the Arctic Ocean. https://climate.nasa.gov/news/2817/with-thick-ice-gone-arctic-sea-ice-changes-more-slowly/ The Arctic Ocean's blanket of sea ice has changed since 1958 from predominantly older, thicker ice to mostly younger, thinner ice, according to new research published by NASA scientist Ron Kwok of the Jet Propulsion Laboratory, Pasadena, California. With so little thick, old ice left, the rate of decrease in ice thickness has slowed. New ice grows faster but is more vulnerable to weather and wind, so ice thickness is now more variable, rather than dominated by the effect of global warming. Working from a combination of satellite records and declassified submarine sonar data, NASA scientists have constructed a 60-year record of Arctic sea ice thickness. Right now, Arctic sea ice is the youngest and thinnest its been since we started keeping records. More than 70 percent of Arctic sea ice is now seasonal, which means it grows in the winter and melts in the summer, but doesn't last from year to year. This seasonal ice melts faster and breaks up easier, making it much more susceptible to wind and atmospheric conditions. Kwok's research, published today in the journal Environmental Research Letters, combined decades of declassified U.S. Navy submarine measurements with more recent data from four satellites to create the 60-year record of changes in Arctic sea ice thickness. He found that since 1958, Arctic ice cover has lost about two-thirds of its thickness, as averaged across the Arctic at the end of summer. Older ice has shrunk in area by almost 800,000 square miles (more than 2 million square kilometers). Today, 70 percent of the ice cover consists of ice that forms and melts within a single year, which scientists call seasonal ice. Sea ice of any age is frozen ocean water. However, as sea ice survives through several melt seasons, its characteristics change. Multiyear ice is thicker, stronger and rougher than seasonal ice. It is much less salty than seasonal ice; Arctic explorers used it as drinking water. Satellite sensors observe enough of these differences that scientists can use spaceborne data to distinguish between the two types of ice. Thinner, weaker seasonal ice is innately more vulnerable to weather than thick, multiyear ice. It can be pushed around more easily by wind, as happened in the summer of 2013. During that time, prevailing winds piled up the ice cover against coastlines, which made the ice cover thicker for months. The ice's vulnerability may also be demonstrated by the increased variation in Arctic sea ice thickness and extent from year to year over the last decade. In the past, sea ice rarely melted in the Arctic Ocean. Each year, some multiyear ice flowed out of the ocean into the East Greenland Sea and melted there, and some ice grew thick enough to survive the melt season and become multiyear ice. As air temperatures in the polar regions have warmed in recent decades, however, large amounts of multiyear ice now melt within the Arctic Ocean itself. Far less seasonal ice now thickens enough over the winter to survive the summer. As a result, not only is there less ice overall, but the proportions of multiyear ice to seasonal ice have also changed in favor of the young ice. Seasonal ice now grows to a depth of about six feet (two meters) in winter, and most of it melts in summer. That basic pattern is likely to continue, Kwok said. "The thickness and coverage in the Arctic are now dominated by the growth, melting and deformation of seasonal ice." The increase in seasonal ice also means record-breaking changes in ice cover such as those of the 1990s and 2000s are likely to be less common, Kwok noted. In fact, there has not been a new record sea ice minimum since 2012, despite years of warm weather in the Arctic. "We've lost so much of the thick ice that changes in thickness are going to be slower due to the different behavior of this ice type," Kwok said. Kwok used data from U.S. Navy submarine sonars from 1958 to 2000; satellite altimeters on NASA's ICESat and the European CryoSat-2, which span from 2003 to 2018; and scatterometer measurements from NASA's QuikSCAT and the European ASCAT from 1999 to 2017.

All the models have been too fast with the forcing changes going back to December. The convection has been stalling in place acting more like a standing wave. So the pattern change they were forecasting near the solstice got pushed back to January. Then they were too fast to weaken the January +PNA which is now continuing into February. The other thing is that the MJO has been competing with forcing in other locations. This month we have split forcing in the IO and WPAC at the same time. So we aren’t getting the typical MJO forcing response. That being said, the late February forecast will probably come down to whether we keep the split forcing or it consolidates more near the Maritime Continent. Split forcing pattern in IO and WPAC

The EPS is identical to the GEPS at day 15. The GEFS is on its own. The main difference between the GEPS and GEFS is the tropical convection. The GEFS is slower moving the forcing east from the IO than the GEPS. So the GEPS and EPS have more of a -PNA in late February with the convection closer to the Maritime Continent.

The time to watch for snow potential here will be next week following the record 582 DM West Coast heat dome in California. Then we get another big amplification and the trough begins to pull back to the Plains. But as usual, the storm details will come down to the short term forecasts.

The Ridiculously Resilient Ridge continues to make headlines.

This was the first time that we ever had a +PNA January with a PDO value lower than -2.00. https://www.ncei.noaa.gov/pub/data/cmb/ersst/v5/index/ersst.v5.pdo.dat https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.pna.monthly.b5001.current.ascii.table Jan 2022 PDO….-2.42 PNA…..+1.01 Jan 2000 PDO…-2.20 PNA….-0.82 Jan 1972 PDO…-2.12 PNA…-1.41 Jan 1956 PDO….-2.26 PNA….-1.32 Jan 1952 PDO…-2.19 PNA…-1.98

Hard to know any details for the day 8-10 period. But the EPS and GEPS have an impressive +300 to +400 meter 500 mb height anomaly just off the West Coast. So a general storm signal exists in mid-February.

We didn’t have the big gap between snowstorms this year that we had last year. Our January snowstorms were only 3 weeks apart. Last year we had a big intermission between the mid-December and early February events. So another period to watch for snow in mid-February would only be a little over 2 weeks later than our last snow on the 29th.

Yeah, ISP has averaged around 40” since 2010. Newark is running closer to 35”. It’s been the best era for snowstorms tracking near the benchmark which favors Long Island. 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 Season Mean 0.0 0.7 5.4 15.4 11.8 6.8 0.4 40.0 2021-2022 0.0 T 0.3 31.8 0.2 M M 32.3 2020-2021 T 0.0 7.5 1.1 24.9 T T 33.5 2019-2020 0.0 0.1 4.2 2.5 0.0 T T 6.8 2018-2019 0.0 4.3 T 0.9 3.5 4.1 T 12.8 2017-2018 0.0 T 6.0 22.0 1.4 31.9 4.6 65.9 2016-2017 T T 3.2 14.0 14.7 7.4 T 39.3 2015-2016 0.0 0.0 T 24.8 13.2 3.2 0.2 41.4 2014-2015 0.0 T 0.4 30.2 13.4 19.7 0.0 63.7 2013-2014 0.0 0.3 8.1 25.2 24.5 5.4 0.2 63.7 2012-2013 0.0 4.2 0.6 3.3 31.4 7.4 0.0 46.9 2011-2012 0.3 0.0 T 3.8 0.6 T 0.0 4.7 2010-2011 0.0 T 14.9 34.4 3.9 2.1 T 55.3 2009-2010 0.0 0.0 25.3 6.4 21.7 0.4 0.0 53.8 Monthly Total Snowfall for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season Mean 0.4 1.1 5.9 11.2 11.1 5.1 0.5 34.9 2021-2022 0.0 0.1 0.1 14.6 0.1 M M 14.9 2020-2021 T 0.0 11.9 3.2 30.6 T 0.0 45.7 2019-2020 0.0 T 4.2 2.7 T T T 6.9 2018-2019 0.0 6.4 T 0.9 4.8 9.9 0.0 22.0 2017-2018 0.0 T 7.7 10.1 3.4 13.2 5.0 39.4 2016-2017 0.0 T 3.4 9.3 7.9 9.4 0.0 30.0 2015-2016 0.0 0.0 0.3 25.7 5.2 1.6 T 32.8 2014-2015 T 1.4 0.3 14.9 13.5 16.3 T 46.4 2013-2014 0.0 T 9.4 20.8 30.3 0.2 0.4 61.1 2012-2013 0.0 6.6 1.9 1.4 10.8 8.8 0.0 29.5 2011-2012 5.2 0.0 0.0 3.3 0.3 0.0 0.0 8.8 2010-2011 0.0 T 24.5 37.4 4.1 2.2 T 68.2 2009-2010 0.0 0.0 13.3 1.7 32.9 T 0.0 47.9

This year the heaviest snows have shifted back to the east. Last several seasons it was more west. So a continuation of the multi-year windshield wiper effect between ISP and EWR. Time Series Summary for ISLIP-NEWARK Click column heading to sort ascending, click again to sort descending. Ending Date Total Snowfall ISP Total snowfall EWR 2022-04-30 32.3 14.9 2021-04-30 33.5 45.7 2020-04-30 6.8 6.9 2019-04-30 12.8 22.0 2018-04-30 65.9 39.0 2017-04-30 39.3 39.0 2016-04-30 41.4 32.8 2015-04-30 63.7 46.4 2014-04-30 63.7 61.1 2013-04-30 46.9 29.5 2012-04-30 4.7 8.8 2011-04-30 55.3 68.2 2010-04-30 53.8 47.9

I guess we are lucky that there hasn’t been a further south version of Jan 98 closer to our northern zones. https://www.weather.gov/media/btv/events/IceStorm1998.pdf This storm had historic impacts across northern New York, northern New England and southeast Canada due to the prolonged duration of the event (both meteorological and recovery period) and the magnitude of ice accretion and precipitation amounts. The most famous meteorological aspect of this storm was the devastating and destructive ice accumulation of more than 3 inches (75mm) in portions of northern New York and southeast Canada, with heavy ice accumulation across northern New England as well. Another major aspect of this storm was the extremely heavy precipitation across the region, including over 5 inches of rain that caused major flooding in portions of western New York.