bluewave

Light accumulation and snow here in SW Suffolk. The temperature is 31°. But it was 60° yesterday so the snow is only sticking on the colder surfaces.

Yeah, more spring in the Rockies with 60s to snow tomorrow. Then our next warm up later in the week. Models have near record February high pressure to our east. So we could get some impressive winds and low topped convection ahead of the storm system.

Continuation of our long term winter rising 60° day count with the 7th 60° day this winter.

The current record high of 61° at ISP beat the old daily record of 55° by a wide margin. https://www.wrh.noaa.gov/mesowest/getobext.php?sid=KISP&table=1&num=168&banner=off Islip Area, NYVersion: 16.3 (created 2022-01-24)Period of record: 1963 through 2020 2/12 55 in 1984 54 in 2018 54 in 2009+

Good model agreement on the MJO consolidating near the Maritime Continent into early March with warmer than average temperatures for us and a near record SPV +AO pattern.

This extreme AO volatility from winter to winter is making seasonal forecasting even more challenging.

Models in late January really missed the SPV coupling with the stronger +AO. So we keep beating daily high temperature guidance. New forecast Old forecast

Phase 5 and 6 are both warm in March during a La Niña. Those CPC composites aren’t ENSO specific. The French site has the different MJO phases for ENSO.

This is a great example of how big a difference the AO can make for snowfall distribution across the region. Last winter was +PNA and -AO allowing storms to tuck in closer to the coast. This year is more progressive with the +AO and +PNA since January. The more +AO allows lows to close off and go negative tilt too late. So the storms track further east and ISP does much better than areas further west. This is why it’s easier for jackpots with KU events like last winter to end up closer to NYC and nearby NNJ with - AO.

This MJO wave may be important as to what type of weather patterns we get next winter. El Niño events usually need the MJO to make a strong push into phase 7 in March. That phase in the WPAC usually brings a WWB pattern which warms the Pacific. Both the EPS and GEFS have the MJO going into phases 4-5 for the rest of February and early March. If the MJO stalls out again near phase 6 in early March, then any return to cooler in March will get pushed back. The MJO not making a strong enough push into 7 could also mean the ENSO gets struck in neutral with a La Niña background state possibly remaining entrenched again for next winter.

Record warmth and record snowfall have become the new winter normals on Long Island. RECORD EVENT REPORT NATIONAL WEATHER SERVICE NEW YORK, NY 0421 PM EDT THU FEB 10 2022 ...RECORD HIGH TEMPERATURE SET AT ISLIP MACARTHUR AIRPORT... A RECORD HIGH TEMPERATURE OF 56 WAS SET AT ISLIP MACARTHUR AIRPORT TODAY. THIS BREAKS THE OLD RECORD OF 54 SET IN 2001. RECORDS GO BACK TO THE YEAR 1963 AT THIS CLIMATE STATION. RECORD EVENT REPORT...CORRECTED NATIONAL WEATHER SERVICE NEW YORK, NY 616 PM EST SUN JAN 30 2022 ...RECORD DAILY MAXIMUM SNOWFALL SET AT ISLIP NY FOR JANUARY 29TH... ...RECORD DAILY MAXIMUM SNOWFALL SET AT ISLIP NY FOR ANY CALENDAR DAY... A RECORD SNOWFALL OF 23.5 INCHES WAS SET AT ISLIP NY FOR JANUARY 29TH. THIS BREAKS THE OLD RECORD FOR THIS DATE OF 1.5 INCHES SET IN 2014. THIS SNOWFALL OF 23.5 INCHES ON JANUARY 29TH 2022 ALSO BREAKS THE PREVIOUS CALENDAR DAY MAXIMUM SNOWFALL RECORD OF 23.4 INCHES OF SNOWFALL RECORDED ON JANUARY 23RD 2016. RECORDS GO BACK TO THE YEAR 1963 AT THIS CLIMATE STATION. RECORD EVENT REPORT NATIONAL WEATHER SERVICE NEW YORK, NY 0206 PM EDT SUN JAN 02 2022 ...RECORD HIGH TEMPERATURE SET AT ISLIP MACARTHUR AIRPORT... A RECORD HIGH TEMPERATURE OF 58 WAS SET AT ISLIP MACARTHUR AIRPORT TODAY. THIS BREAKS THE OLD RECORD OF 57 SET IN 2000. RECORDS GO BACK TO THE YEAR 1963 AT THIS CLIMATE STATION. RECORD EVENT REPORT NATIONAL WEATHER SERVICE NEW YORK, NY 137 AM EST FRI DEC 17 2021 ...RECORD HIGH MINIMUM TEMPERATURE SET AT ISLIP NY... A RECORD HIGH MINIMUM TEMPERATURE OF 52 WAS SET AT ISLIP NY YESTERDAY. THIS BREAK THE OLD RECORD OF 49 SET IN 1971. RECORDS GO BACK TO THE YEAR 1963 AT THIS CLIMATE STATION.

Sometimes you just have to laugh.

We are on track for another winter with 20 days or more reaching 50°+.

The winter warmth since the 15-16 winter has been unprecedented in our area. This will be our 7th warmer than average winter in a row. The one month of cold in January was a real outlier. You have to wonder what type of pattern it will take to have a colder than average winter again.

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.