bluewave

Pretty impressive how the 50/50 low remains stuck in place even with the record AO swings. March 1-8, 2021 EPS forecast

Big temperature swing coming up. Temperatures will rise to near 70° on Thursday. Then another Arctic front will move through later in the weekend and drop the temperatures back into the 20s.

The warmth around the solstice since 2011 has been unprecedented. Data for December 18 - NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature Precipitation Snowfall Snow Depth 1937-12-18 64 39 0.10 0.0 0 2006-12-18 61 44 0.00 0.0 0 1984-12-18 61 41 0.00 0.0 0 2016-12-18 59 31 0.07 0.0 1 1966-12-18 59 41 0.00 0.0 0 2001-12-18 58 43 0.31 0.0 0 2015-12-18 56 37 T 0.0 0 2012-12-18 56 44 0.52 0.0 0 Data for December 19 - NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature Precipitation Snowfall Snow Depth 1931-12-19 60 36 0.00 0.0 M 1967-12-19 58 40 0.00 0.0 0 2017-12-19 57 43 0.00 0.0 0 Data for December 21 - NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature Precipitation Snowfall Snow Depth 2013-12-21 64 42 T 0.0 0 2011-12-21 62 41 0.13 0.0 0 2018-12-21 61 50 1.37 0.0 0 1957-12-21 61 44 0.07 0.0 0 1990-12-21 59 46 0.25 0.0 0 2012-12-21 57 36 0.91 0.0 0 1973-12-21 57 26 2.00 T T Data for December 22 - NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature Precipitation Snowfall Snow Depth 2013-12-22 71 57 0.03 0.0 0 1998-12-22 65 23 0.07 0.0 0 1949-12-22 64 46 T 0.0 0 1967-12-22 63 39 0.28 0.0 0 1990-12-22 62 57 0.01 0.0 0 2015-12-22 61 52 0.06 0.0 0 2011-12-22 61 47 0.08 0.0 0 Data for December 23 - NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature Precipitation Snowfall Snow Depth 1990-12-23 67 58 0.31 0.0 0 2015-12-23 66 50 1.44 0.0 0 1949-12-23 63 33 0.16 T 0 1931-12-23 63 49 T 0.0 M 2013-12-23 62 42 0.53 0.0 0 2007-12-23 62 39 0.69 0.0 0 2006-12-23 60 46 0.64 0.0 0 2004-12-23 59 39 0.62 0.0 0 2019-12-23 57 31 0.00 0.0 0 Data for December 24 - NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature Precipitation Snowfall Snow Depth 2015-12-24 71 59 0.03 0.0 0 1990-12-24 64 30 0.45 0.0 0 1996-12-24 63 38 0.37 0.0 0 2020-12-24 60 37 0.43 0.0 0 1941-12-24 60 47 0.46 0.0 0 Data for December 25 - NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature Precipitation Snowfall Snow Depth 1964-12-25 69 44 0.01 0.0 0 1982-12-25 68 40 0.02 0.0 0 2014-12-25 64 41 0.10 0.0 0 2015-12-25 63 54 0.03 0.0 0 2020-12-25 62 28 0.66 0.0 0

Day 10 cutters have been turning into day 7 Miller Bs. New run Old run

The 50/50 lows have been beating model expectations over that record warm pool. Started out with the near record 935 mb 50/50 low ahead of the Dec 17-18 storm. Then we saw the -5SD TPV dive into Eastern New England last week.

Yeah, the big 50/50 low and east based block snuck up on the models. The individual storm details will probably have to wait a while. But the volatility in the North Atlantic sector over the last month has been very impressive. New run Old run

The big AO and NAO volatility continues on the 12z guidance. Models have the +5 AO rise and warm up this week. But now they introduce a -4.5 SD 50/50 low over the weekend. This wave break may result in a return to a more east based -NAO in mid to late March. So I think that’s why the models are struggling so much with the storm details past 120 hrs. The main takeaway may be this week will be the warmest for a while as lows may cutoff behind the intense 50/50 vortex.

So far JFK is the big warm and dry downslope flow winner at 65°. 000 SXUS51 KOKX 091757 OSOOKX New York City Metropolitan Area Weather Roundup National Weather Service New York NY 100 PM EST TUE MAR 09 2021 CITY SKY/WX TMP DP RH WIND PRES REMARKS Central Park SUNNY 63 27 25 W9G17 30.29F LaGuardia Arpt MOSUNNY 60 28 29 NW13 30.26F Kennedy Intl MOSUNNY 65 29 25 W15G24 30.27F Newark Liberty MOSUNNY 64 27 24 NW15 30.27F Teterboro Arpt SUNNY 61 32 33 NW16G22 30.26F

This officially ends the 8th longest under 55° day streak at Newark. It was also the 25th longest under 60° day streak. Number of Consecutive Days Max Temperature < 55 for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Run Length Ending Date Period of record: 1931-01-01 to 2021-03-08 1 111 1963-03-23 2 87 1941-03-22 3 84 2003-03-14 4 83 1956-02-24 5 78 1969-03-16 6 77 1977-02-22 7 76 1968-03-07 - 76 1948-02-17 8 73 2021-03-08 9 69 1971-02-11 10 65 2015-03-10

My only regret over this period is that I missed out on the Nemo 6” per hour 50 DBZ band. But maybe we can see something like that in the 2020s closer to our area. Be interesting to see if we can get a 40” event like BGM did in December.

Remarkable snowfall run since 02-03. Even winters with above normal temperatures have been able to produce above normal snowfall. Below normal snowfall years like 06-07, 07-08, 11-12, 18-19, and 19-20 have been the exception rather than the rule.

Our first 60° day since Christmas.

Yeah, long term SST warming is boosting the expectations for what is considered a normal Atlantic hurricane season.

Yeah, a new study indicates that the active phase that began in 1995 may be more of a new normal. With warming Atlantic SSTs, we may not be able to count on a less active phase happening again like the 1970s and 1980s. Another study just out reinforces the idea of the warm pool remaining in place to our east. We saw how the warmer SSTs and higher pressures there last summer lead to an active close in storm track.

This will be only the 6th time since 1991 that NYC had to wait until March for the first 60°+ day of the year. But it’s the first time following a warmer than average winter. So you can see how rare the winter south based blocking pattern was. First/Last Summary for NY CITY CENTRAL PARK, NY Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year First Value DJF AVG Temp 2015 03-26 (2015) 62 31.4 2003 03-16 (2003) 68 31.2 2014 03-11 (2014) 66 32.9 2010 03-08 (2010) 61 33.8 2004 03-01 (2004) 63 32.4 2021................................................36.1

GFS continuing with the first -5 to +5 AO rise in such a short period of time. 2021 2 10 -5.285 2021 2 11 -5.254

The bigger AO swings since 2010 have made seasonal AO forecasting even more challenging. https://climexp.knmi.nl/getindices.cgi?WMO=NCEPData/cpc_ao&STATION=AO_CPC&TYPE=i&id=someone@somewhere

If that +5 verifies, then I believe it would be the first time that the AO rose from under -5 to +5 in just 30 days.

I guess we had to know that the MJO would eventually make it to phases 8-1.

March and November are the few months of the year that bucked the big warming trend since 2010.

This was the 2nd most backloaded DJF period on Long Island since 2010. Only Nemo in 2013 featured a more lopsided February snowfall total relative to December and January. 09-10 was more a bookend winter on Long Island. Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Year Dec Jan Feb Season 2012-2013 0.6 3.3 31.4 35.3 2020-2021 7.5 1.1 24.9 33.5 2013-2014 8.1 25.2 24.5 57.8 2009-2010 25.3 6.4 21.7 53.4 2016-2017 3.2 14.0 14.7 31.9 2014-2015 0.4 30.2 13.4 44.0 2015-2016 T 24.8 13.2 38.0 2010-2011 14.9 34.4 3.9 53.2 2018-2019 T 0.9 3.5 4.4 2017-2018 6.0 22.0 1.4 29.4 2011-2012 T 3.8 0.6 4.4 2019-2020 4.2 2.5 0.0 6.7

We were as backloaded as Glasgow was frontloaded.

More confirmation of the GFS cold bias fix.

The AO reversal in February continues to set records. This is the first February with a daily -5 reading and only a monthly -1 average. The previous -5 drops in 2010, 1978, and 1969 all had -3 and lower monthly averages. https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.ao.index.b500101.current.ascii https://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/monthly.ao.index.b50.current.ascii.table 2021 -2.484 -1.191 2010 -2.587 -4.266 1978 -0.347 -3.014 1969 -2.967 -3.114