bluewave

I think the inability of the El Niño to couple last winter really threw them off. https://www.climate.gov/news-features/blogs/enso/csi-enso-case-missing-central-pacific-rainfall

The Met Office seasonal model did a nice job picking up on the winter pattern back in the fall.

This was the warmest 12-22 to 2-24 period on record at 40.1 degrees in NYC. It was also the 5th lowest snowfall total at 2.3”. Last year over this period was 10th lowest at 3.6”. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Dec 22 to Feb 24 Missing Count 1 2020-02-24 40.1 0 2 1932-02-24 39.8 0 3 2006-02-24 39.6 0 4 2017-02-24 39.5 0 5 2012-02-24 39.3 0 - 1998-02-24 39.3 0 6 2002-02-24 39.2 0 7 1990-02-24 38.8 0 8 1937-02-24 38.7 0 9 1933-02-24 38.6 0 10 1950-02-24 38.5 0 Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Snowfall Dec 22 to Feb 24 Missing Count 1 1998-02-24 0.5 0 2 1919-02-24 0.8 0 3 1890-02-24 1.0 0 4 1959-02-24 1.9 0 5 2020-02-24 2.3 0 6 1990-02-24 2.4 0 7 1992-02-24 2.5 0 8 1973-02-24 2.6 0 - 1932-02-24 2.6 0 9 2002-02-24 3.5 0 10 2019-02-24 3.6 0

Philly narrowly avoided the trace of snow they got in 72-73.

This has to be one the biggest PDO reversals from December to February. The record ridge north of Hawaii and strong +EPO resulted in the big SST departure shift. One of the strongest La Niña-like patterns without out an official La Niña. This is what can happen with record SST’s from the date line to the Indian Ocean.

After the top 2 warmest Februaries on record in 2017 and 2018, we are on track for another top 10 warmest finish. There have been 7 out of 11 warmer than normal Februaries since 2010. .............EWR....NYC....LGA 2020.....+5.5...+5.0....+4.4...so far 2019....+1.4.....+0.9...+0.5 2018....+6.8....+6.7.....+7.1 2017....+7.0....+6.3.....+7.5 2016....+2.5....+2.4.....+3.1 2015....-12.0...-11.4....-11.1 2014....-4.7.....-3.7.....-4.0 2013....-0.5.....-1.4.....-0.8 2012....+5.9....+5.6....+6.1 2011....+1.8.....+0.7.....+1.2 2010....-1.4......-2.2......-1.5

Thickest frost of the season here in SW Suffolk. Temperature at 33 degrees but the there is a thick layer of frost on cars and the roofs. Almost feels like freezing rain on the cars with the dense fog until a few minutes ago.

Black ice is possible across Suffolk with dense frog and temperatures below freezing. MacArthur/ISP FOG 31 31 100 CALM 30.06F VSB 1/4 Stony Brook N/A 36 36 100 S5 N/A WCI 32 Shirley FAIR 32 30 92 CALM 30.08S FOG Mt Sinai Harb N/A N/A N/A N/A S8 N/A Westhampton CLOUDY 21 20 96 CALM 30.09S East Hampton CLOUDY 25 24 96 CALM 30.08S FOG Special Weather Statement National Weather Service New York NY 516 AM EST Mon Feb 24 2020 NYZ078>081-241300- Northwestern Suffolk-Northeastern Suffolk-Southwestern Suffolk- Southeastern Suffolk- 516 AM EST Mon Feb 24 2020 Patchy dense fog has developed across portions of Suffolk County early this morning. In addition to reduced visibilities, with temperatures near or below freezing, black ice is also possible this morning, especially on bridges and overpasses. Use caution on the roads early this morning and leave plenty of distance between cars, keeping in mind that any pavement that appears damp may be icy. Fog should lift shortly after sunrise.

We are a little early this year. Our lowest annual readings just above or below 10% are usually in March or April.

The 13% relative humidity at Newark is the lowest of the year. Newark Liberty FAIR 57 7 13% https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=157&network=NJ_ASOS&station=EWR&year=2020&var=min_rh&dir=above&thres=95&dpi=100&_fmt=png

Like an early spring afternoon in the desert with deep blue skies and low humidity. Newark Liberty FAIR 57 9 14%

The SE Ridge has kept the heaviest rains to our west since late December.

The temperatures are off to the races. Newark has jumped 14 degrees in a few hours. The warm spots probably go 55-60 degrees today.

This has been the driest start to the year since 2012 for NYC and surrounding stations. My last rain event with over 1.00” was back on January 25th. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Ending Date Total Precipitation Jan 1 to Feb 23 Missing Count 2020-02-23 3.93 1 2019-02-23 6.11 0 2018-02-23 7.20 0 2017-02-23 6.77 0 2016-02-23 7.52 0 2015-02-23 7.27 0 2014-02-23 8.24 0 2013-02-23 5.30 0 2012-02-23 3.63 0 2011-02-23 6.59 0 2010-02-23 5.17 0

Mild and dry February day with a 17% relative humidity at Newark. Newark Liberty FAIR 48 5 17 SW15

Preliminary AO data suggests that we may have a new 2nd highest reading following the record on February 10th. The first month with two +6 or higher values. https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/daily.index.ascii 01Feb2020 0.20221E+01 -0.52677E-01 0.29204E+00 -0.64548E+00 02Feb2020 0.18573E+01 0.21773E+00 0.20699E+00 -0.55492E+00 03Feb2020 0.12789E+01 0.15999E-01 0.71990E-01 0.41582E+00 04Feb2020 0.11909E+01 -0.10099E+00 0.56737E-01 0.79638E+00 05Feb2020 0.11668E+01 -0.29145E+00 0.34918E+00 0.96277E+00 06Feb2020 0.21146E+01 -0.21840E+00 0.56460E+00 0.11092E+01 07Feb2020 0.22717E+01 0.24262E+00 0.94827E+00 0.37856E+00 08Feb2020 0.31727E+01 0.82119E+00 0.87266E+00 -0.29577E+00 09Feb2020 0.51799E+01 0.14128E+01 0.44704E+00 -0.61452E+00 10Feb2020 0.63415E+01 0.15626E+01 -0.16199E+00 -0.78893E+00 11Feb2020 0.52334E+01 0.12471E+01 -0.42390E+00 -0.63371E+00 12Feb2020 0.32855E+01 0.10390E+01 -0.15466E+00 0.42111E+00 13Feb2020 0.18597E+01 0.79792E+00 0.64890E-01 0.11103E+01 14Feb2020 0.16864E+01 0.83402E+00 0.19030E+00 0.59934E+00 15Feb2020 0.27003E+01 0.11294E+01 0.25389E+00 -0.32445E+00 16Feb2020 0.41686E+01 0.12515E+01 0.12688E+00 -0.45273E+00 17Feb2020 0.47429E+01 0.12109E+01 0.62894E-01 0.58521E-01 18Feb2020 0.46598E+01 0.10510E+01 0.97554E-01 0.70548E-01 19Feb2020 0.43469E+01 0.10294E+01 0.21451E-01 -0.29174E+00 20Feb2020 0.43393E+01 0.10597E+01 0.13981E+00 -0.19496E+00 21Feb2020 0.58365E+01 0.12835E+01 0.22726E+00 0.24356E+00 22Feb2020 0.61873E+01 0.15184E+01 0.26919E+00 0.85533E+00 Date AO NAO PNA AAO

The GEFS cold bias strikes again. https://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/

First time that several of our stations don’t even have a trace of snow for February.

Could be another year with close in powerful hurricane activity.

Yeah, this has easily been our warmest 5 winter period on record. Average winter temperatures near 40 degrees are typical for Richmond, Virginia. https://www.weather.gov/media/akq/climateRECORDS/RIC_AVE_T.pdf Time Series Summary for NY CITY CENTRAL PARK, NY - Dec through Feb Click column heading to sort ascending, click again to sort descending. Season Mean Avg Temperature Departure 2019-2020 39.0 +3.9 2018-2019 36.3 +1.2 2017-2018 36.1 +1.0 2016-2017 39.3 +4.2 2015-2016 41.0 +5.9

Today will be one of our rare cold departure days before we warm back up to around 50 degrees over the weekend. NYC is currently in 8th place for warmest winter. The 39.0 degree average is close to +4 for the winter. Time Series Summary for NY CITY CENTRAL PARK, NY - Dec through Feb Click column heading to sort ascending, click again to sort descending. Rank Season Mean Avg Temperature Missing Count 1 2001-2002 41.6 0 2 2015-2016 41.0 0 3 2011-2012 40.5 0 4 1931-1932 40.2 0 5 1997-1998 39.6 0 6 2016-2017 39.3 0 7 1990-1991 39.1 0 8 2019-2020 39.0 9 9 1998-1999 38.6 0 10 1948-1949 38.5 0

I agree. Certain signals must just be easier for models to detect in the fall. We often see different models exhibit better skill with one element of the forecast than another. This winter some models did better with the AO and NAO than last year. But while they indicated another year with the ridge north of Hawaii, the strength of the +EPO wasn’t we’ll forecast in advance. Last winter may have come down to the models missing the the fact that the El Niño never was able to couple. Several of us were discussing in the fall of 2018 how the SST configuration wasn’t aligned with the typical El Niño pattern. The SOI fall reversal was also a red flag that seasonal forecasts would struggle. So it’s always a challenge to know exactly what if any forecast elements the seasonal models will have success with. ENSO blog write up on last winter https://www.climate.gov/news-features/blogs/enso/csi-enso-case-missing-central-pacific-rainfall

We will find out next fall and winter whether this was another two year stuck pattern like 2009-2011, 2013-2015 and 2016-2018. Two year stuck winter patterns have been the maximum since 2010. Hopefully, this isn’t a throwback to the longer snow droughts of the late 1990’s and early 2000’s.

Most of the seasonal models had a strong +NAO +AO for the winter from the fall forecasts. Some research points to the record +IOD late in the fall into early winter. While several seasonal models had the strong ridge north of Hawaii, they all underestimated the strength of the +EPO.