bluewave

The forecast wave break caused by the near record 930s mb low north of Japan changed the entire pattern going into March from several days ago. We saw a similar event in early December lead to the record Aleutians ridge. This time the very strong block will be further east producing the colder -EPO +PNA pattern for us in early March. New run Old run

The winters warming at a faster rate than the springs gives us the feeling of a delayed start to spring. ISP has had more March snowfall than December snowfall since 11-12. Plus the coldest temperature departures relative to the mean in NYC have been occurring later. The winter typically has the coldest daily temperature departure of the year. But 7 years between 1991 and 2021 featured the coldest daily annual temperature in the spring. There were only 2 years between 1960 and 1990 that this was the case. The last 2 years had the coldest annual departure in May. Record late trace of snow and cold in May 2020 and the record cold for the Memorial Day weekend last year. We went from record 80° temperatures in late February 2018 to record snow in March 2018. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=32&network=NYCLIMATE&station=NY5801&year=2021&var=avg&gddbase=50&gddceil=86&how=diff&cmap=jet&_r=t&dpi=100&_fmt=png 1991-2021 coldest temperature of year in spring Mar 1993 Mar 1998 Mar 2002 Mar 2007 May 2010 May 2020 May 2021 1960 to 1990 Mar 1967 Mar 1978 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 0.8 2.8 14.5 11.9 7.9 0.5 37.6 2021-2022 0.0 T 0.3 31.8 3.3 M M 35.4 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

The top end winter 70-80° days have been increasing also. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Dec through Feb Click column heading to sort ascending, click again to sort descending. Rank Season Highest Max Temperature Missing Count 1 2017-2018 80 0 2 1998-1999 76 0 - 1948-1949 76 0 3 2016-2017 74 0 - 2001-2002 74 0 - 1996-1997 74 0 - 1953-1954 74 0 - 1949-1950 74 0 4 1984-1985 73 0 5 2006-2007 72 0 - 1982-1983 72 0 - 1946-1947 72 0 6 2015-2016 71 0 - 2013-2014 71 0 - 2010-2011 71 0 7 2019-2020 70 0 - 1997-1998 70 0 - 1978-1979 70 0 - 1938-1939 70 0 - 1931-1932 70 0

This many 60 degree days used to be rare during the winter. Now we are approaching 10 days this winter. So we are able to get the odd juxtaposition of winter 60s and snow close together which was typically the domain of March and April snows in the old days.

Unusually high pressure for our area this morning. It may have allowed some slight radiational cooling at LGA when the winds went calm. One of the rare times that LGA is cooler than NYC and JFK and close to Staten Island. 600 AM EST WED FEB 16 2022 CITY SKY/WX TMP DP RH WIND PRES REMARKS Central Park PTCLDY 31 16 54 S3 30.73S LaGuardia Arpt MOCLDY 28 13 53 CALM 30.72R Kennedy Intl PTCLDY 31 20 63 S12 30.74R WCI 22 Newark Liberty PTCLDY 24 12 60 W5 30.72S WCI 18 Teterboro Arpt PTCLDY 21 13 71 N3 30.72R Bronx Lehman C N/A 32 16 51 S2 N/A Queens College N/A 32 19 59 S2 N/A Breezy Point NOT AVBL Brooklyn Coll N/A 32 21 64 S7 N/A WCI 26 Staten Island N/A 27 16 63 W2 N/A

I ran the numbers for our area between the 81-10 and the new 91-20 climate normals. December is the fastest warming month of winter and the entire year. So the record warmth this December fit the pattern. While spring and March has been warming, the rate is lower than the other seasons of the year. The monthly temperature increases from 81-10 to 91-20 have been more pronounced during certain months. Newark and Islip are compared below. The +1.0 or warmer months for either station were bolded. ……….EWR…..ISP Dec…+1.5….+1.5 Jan….+1.2…+1.3 Feb….+0.5….+0.5 Mar….+0.4….+0.6 Apr….+0.5…..+0.6 May...+0.6….+0.9 Jun….+0.3….+0.6 Jul…..+1.4…..+1.1 Aug...+0.6….+0.9 Sep….+1.0….+1.3 Oct…..+0.9..+1.4 Nov….+0.2..+0.5

The warm spots could make a run on 10 days reaching 60° for the DJF winter period. First surge of 60°+ will be from later Thursday into Friday with the 60 mph gust potential. Then another warm up next week with more 60° potential. It used to be rare to get this many 60° days during the winter. But the winter 60° days have been steadily increasing.

The common denominator to this winter pattern has been the record North Pacific blocking. The ridge has been shifting back and forth each month since December. So we get this extreme volatility from month to month and day to day. The tropical forcing and wave breaks seem to be acting as catalysts for the changes. Standard MJO relationships and composites haven’t matched the canonical expectations this winter. So we have been getting a mash up of competing influences. Maybe the return of the West Coast Ridge near the start of March also has mixed causes and any specific MJO composites won’t really capture the totality of the pattern.

Another wave breaker pattern change near the beginning of March. All the models have a deep low pressure in the 930s next week to the north of Japan. This combines with the MJO to eventually push the ridge back to the West Coast and eventually flatten out the SE Ridge near the start of March. It’s interesting that a similar process lead to the early December pattern change. But this time the MJO has different teleconnections for later in the season allowing a shift from late February warmth to early March cold. The big story this year is the reliable pattern changes near the start of every month. Cold in November…record warmth in December…coldest January since 2015 with record snows….shift to warmer in February with less snow….shifting back colder as we start March.

Thursday night into Friday will be our next cutter with 60°+ temperatures and wind gust potential near 60 mph in the usual windier spots. Then we cool down again with more 60° potential ahead of another storm next week. So a continuation of the big weather swings pattern with the warmer days more impressive than the cold. This allows the temperatures to average out warmer than normal.

It was the first time that NYC dropped below 0° since 1994. But POU still hasn’t reached -20 or colder since 1994. Looks like -14 has been the best POU has been able to do since 2010. Time Series Summary for Poughkeepsie Area, NY (ThreadEx) Click column heading to sort ascending, click again to sort descending. Rank Ending Date Lowest Min Temperature Oct 1 to Apr 30 Missing Count 1 1961-04-30 -30 0 2 1967-04-30 -23 0 - 1951-04-30 -23 0 3 1954-04-30 -22 0 4 1994-04-30 -20 9 - 1981-04-30 -20 0 - 1968-04-30 -20 0 Time Series Summary for Poughkeepsie Area, NY (ThreadEx) Click column heading to sort ascending, click again to sort descending. Ending Date Lowest Min Temperature Oct 1 to Apr 30 Missing Count 2022-04-30 -3 76 2021-04-30 -3 0 2020-04-30 5 0 2019-04-30 -4 0 2018-04-30 -14 0 2017-04-30 -1 0 2016-04-30 -6 0 2015-04-30 -14 0 2014-04-30 -9 0 2013-04-30 -5 0 2012-04-30 1 1 2011-04-30 -14 1 2010-04-30 -1 3

Today is the 6th anniversary of the first NYC below 0° day since 1994. Only in our post 2010 climate could NYC drop below 0° in February following a +13.3° December. Then we had one of our recent temperature swings to 54° two days later followed 60s on February 20th.

It feels even colder today since it was 62° on Saturday. These big temperature swings are becoming more common. The 46° drop at ISP is the 2nd greatest on record for a 2 day period in February. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=169&network=NY_ASOS&zstation=ISP&hours=42&month=feb&dir=cool&_r=t&dpi=100&_fmt=png

Yeah, March has been warmer and snowier than December over the last 10 years. Monthly Mean Avg Temperature for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Year Dec Jan Feb Mar Season Mean 38.9 32.6 33.9 40.3 36.4 2020-2021 37.2 32.9 32.2 42.4 36.2 2019-2020 36.8 37.3 38.2 44.8 39.3 2018-2019 38.1 31.1 34.4 38.7 35.6 2017-2018 33.8 30.1 39.1 38.0 35.3 2016-2017 36.6 36.2 37.8 37.1 36.9 2015-2016 48.4 33.3 35.7 45.5 40.7 2014-2015 39.6 28.7 21.6 35.2 31.3 2013-2014 37.1 27.7 29.7 35.8 32.6 2012-2013 40.5 33.1 32.1 38.3 36.0 2011-2012 40.5 36.2 38.1 47.3 40.5 Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Year Dec Jan Feb Mar Season Mean 3.0 12.8 12.8 7.9 36.5 2020-2021 7.5 1.1 24.9 T 33.5 2019-2020 4.2 2.5 0.0 T 6.7 2018-2019 T 0.9 3.5 4.1 8.5 2017-2018 6.0 22.0 1.4 31.9 61.3 2016-2017 3.2 14.0 14.7 7.4 39.3 2015-2016 T 24.8 13.2 3.2 41.2 2014-2015 0.4 30.2 13.4 19.7 63.7 2013-2014 8.1 25.2 24.5 5.4 63.2 2012-2013 0.6 3.3 31.4 7.4 42.7 2011-2012 T 3.8 0.6 T 4.4

The March volatility has moved up in time to DJF. Now we regularly get 60s and snow close together in the winter. It used to mostly be the domain of March in the old days.

Getting larger flakes now in SW Suffolk as the temperature has risen to 33°.

2” here in SW Suffolk on the cars and grass with the paved surfaces just wet and 32°.

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.