New York's Winter Snow Totals Revised Upward for 2015 & 2016

If the winter of 2015 wasn't tough enough, on March 24 the New York office of the National Weather Service issued a statement announcing that the season's snowfall in Central Park had been revised upward by 3.3".  This is the only time I can recall weather records being changed so significantly weeks after the fact.  The official announcement can be found here.  I would have loved to have been privy to the discussions that led to this decision.  I'm especially curious how NWS pinpointed the three snow events that were under-reported (Jan. 6, Jan. 24, and Feb. 2). 

 

For quite a few years weather hobbyists, myself included, questioned the measurements from Central Park since it consistently reported lower accumulations than Newark Airport, LGA and JFK (yet it often had higher rainfall); therefore, it was gratifying to see the issue addressed.  Perhaps it had something to do with the fact that the other reporting locations are at airports (perhaps tree branches in the park were blocking snowflakes?).  A post from New York Metro Weather addressed the subject and its implications for confidence in future snow totals.

 

 

A number of other revisions have resulted from the NWS announcement:

1. With 50.3" the new total, the winter of 2015 moves from 22nd to 18th snowiest.
2. Feb. 2's snowfall of 5.0" (revised from 3.3") ties it with 1874 as the snowiest Feb. 2.  This new amount also increased the winter's number of snowfalls of four inches or more to six, tying it with last winter.
3. With Jan. 6's total snow revised from 0.5" to 1.0", the number of snowfalls of an inch or more this winter increased to 13, which is one more than last winter (which had seven inches more total snowfall) and the most since the winter of 1994.
4. Winter 2015 is now the fourth of the past six to see 50" or more of snow.  By comparison, the average is one such snowy winter every ten years.

   

Then the following winter there was revision made to that season's snowfall - and this one had more of an implication.  On Jan. 23 a blizzard dumped 26.8" of snow, putting it just 0.1" behind the biggest accumulation of all time from ten years earlier.  Then three months later the National Weather Service announced that snow from a final band, which amounted to 0.7", had been omitted.  This additional accumulation upped the storm's total to 27.5" and made it New York's biggest snowstorm.

      

These revisions brought to mind 1983 when it was announced at the end of that year that Central Park's rain gauge had been broken since May.  This was an especially crucial matter since 1983 reported the most rain on record, but was it valid?  This put the NWS in a sticky spot, but rather than address it they let it linger for years.  The issue resurfaced in 2011 when that year received the second greatest annual rainfall.  However, some thought it could lay claim as rainiest because of 1983's shaky measurement.  Pressed, the NWS finally decided that the 1983 record would stand - although previous NOAA climate reports left monthly rainfall totals for 1983 blank and noted the equipment malfunction.  I wasn't convinced by their argument.

 

 

The Freakish Snow & Cold of March 1956, 1958, and 1967

 

 

Although many winters have a significant snowfall and a cold snap in March, it often happens in the first two weeks of the month, and is usually limited to one snow event and a few days of cold weather.  This post, however, looks at three years that fell within a twelve-year period in the middle of the 20th century that experienced freakish snow and cold in the second half of the month. 

 

1956 (March 12 - April 8)

During this four-week period 25" of snow fell and temperatures were 6.5 degrees below average.  There were snowfalls of 6.7" and 11.6" that occurred two days apart, on March 16-17 and March 18-19, and then a 4.2" snowfall occurred on April 8 (as well as two smaller snowfalls under two inches).  Up until these four wintry weeks just eight inches of snow had fallen for the entire winter.

 

 

1958 (March 14-21)

On March 14 there was a snowfall of 4.1" followed a week later (March 20-21) by a nor'easter that dumped 11.8" of wet snow.  (This storm paralyzed an area from Maryland, eastern Pennsylvania and much of New Jersey with 20-40 inches.)  And while temperatures in NYC were colder than average during both snowfalls, temperatures much of the time were above freezing.  This ended up being the snowiest month of the winter.

 

 

 

1967 (March 15-23)

During this nine-day period 15.4" of snow fell from three storms, and temperatures were 15 degrees below average.  On the 18th, the high/low was only 20°/10°, which was 27 degrees below average.  Then, on the morning of the 19th the low fell to 8° above zero, the latest date on record for a single-digit reading.  From late afternoon on the 15th until noon on the 20th the temperature was 32° or colder.  This brutal cold was followed by a 10" snowfall on March 22.

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Persistent Cold Characterized Winter 2015, With No January OR February Thaw

 

 

Even the coldest winters occasionally see temperatures rise into the 50s for a few days in a row in January and February.  (The mildest reading during these months is typically in the upper 50s.)  The winter of 2015, however, was marked by persistent cold.  Between Jan. 6 and March 7, a period of nearly nine weeks, the temperature never rose above 45° - an unprecedented stretch.  This streak beat the old record, set in the winter of 1948, by four days.  Temperatures during these days were eight degrees below average, with a high/low of 34°/19°; and temperatures were 13 below average between Feb. 13 and March 7.  Additionally, 44.7" of snow fell, 70% more than what falls in a typical winter in its entirety.

 

LONGEST STREAKS W/HIGHS OF 45° OR COLDER
(Since 1910)
	# of		Average
Winter	Days	Date Range	High	Low	Below	Snow
2015	61	Jan 6-Mar 7	33.8	19.3	-8.0	44.7"
1948	57	Dec 19-Feb 13	31.6	20.0	-6.4	56.6"
1977	52	Dec 21-Feb 10	29.4	17.8	-8.7	22.0"
1981	43	Dec 14-Jan 25	31.5	18.9	-7.3	10.8"
1978	43	Jan 27-Mar 10	31.8	18.5	-7.3	28.0"
1969	43	Feb 1-Mar 15	38.5	23.3	-1.8	22.2"
1925	43	Dec 20-Jan 31	34.4	21.1	-3.7	28.2"
1996	42	Dec 7-Jan 17	33.7	23.1	-5.5	36.7"
2011	41	Jan 3-Feb 12	34.6	24.3	-2.8	33.6"
1985	40	Jan 3-Feb 11	33.0	22.0	-4.1	18.4"
1936	40	Jan 16-Feb 24	29.1	15.7	-8.6	20.3"
1923	39	Jan 22-Mar 1	32.8	20.2	-5.0	25.4"
1945	38	Jan 2-Feb 8	32.2	18.3	-5.7	16.6"
2004	36	Jan 5-Feb 9	30.4	18.0	-7.6	18.0"
1970	35	Dec 13-Jan 16	30.2	21.1	-6.9	11.7"
Source: NOAA Local Climatological Data

 

We Are Living In Extraordinarily Snowy Times

 

 

40 inches of snow is considered a hefty amount for a New York winter, a total that's about 50% above average.  Over the years, winters with this much snow have occurred once every four years.  This average, however, masks extended periods with and without snowy winters.  For example, winters between 1873 and 1923 averaged snowfall of 40 inches or more once every three years, but then the 24-year period that followed (between 1924 and 1947) had just one snowy winter.  More recently there was a 26-year period between 1968 and 1993 that also had just one.  

 

Most recently, New York found itself in the midst of an abundance of snowy winters, the most recent being the winter of 2017-18.  Specifically, nine of the sixteen winters between 2003-2018 had 40 inches or more of snow, an unprecedented concentration (including four winters in a row).  Of the five winters that didn't see this much, three were well below average (under 13") and the other two picked up an average amount of snow.  (The three winters after 2018 have each had less than 40", but winter 2020-21 came close, with 38.6" measured.)

 

 

PEAKS & VALLEYS OF WINTERS WITH 40 INCHES+ SNOWFALL
	# of	# of Winters	% with
Time Period	Winters	40"+ Snow	40"+ Snow
All Winters	152	36	24%
1870-1872	3	0	0%
1873-1923	51	17	33%
1924-1947	24	1	4%
1948-1967	20	6	30%
1968-1993	26	1	4%
1994-2002	9	2	22%
2003-2018	16	9	56%
Source: NWS New York Office

Winter 2015 Recap - Global Warming Takes a Holiday

 

 

The winter of 2015 started off  mild, but then cold weather established itself in the second week of January and didn't loosen its grip.  (This analysis is based on meteorological winter, which begins on Dec. 1 and ends on Feb. 28.)  Despite the relatively mild temperatures of December (three degrees above average), this was the coldest winter since 2003, as January was 2.7 degrees below average and February 11.4 below average.  This frigid January and February combo was the coldest since the winter of 1920 - and the tenth coldest overall (eight of the top 10 occurred more than 100 years ago).  February was the coldest since 1934, and the tenth coldest of any month.

 

The winter had no sub-zero days but there were nine days with lows in the single digits, the most since 1994 (which was also the last winter to have a sub-zero reading).  Of course, there were a number of days in which with wind chills were in the -5° to -15° range.  

 

Last winter, also a harsh one, was characterized by a record amount of snow in a 30-day period (42 inches).  This winter was characterized by persistent cold, which resulted in a new record for most consecutive days in which the temperature never rose above 43°.  The streak began on Jan. 6 and continued for the rest of the winter, a period of nearly eight weeks (and it continued into the first week of March).  During these days the mean temperature was nearly eight degrees colder than average.

 

 

In January and February, a series of snowstorms were forecast that didn't live up to their potential, or ended up bypassing us (burying Boston instead).  However, even with these fizzled snowstorms Jan/Feb picked up a healthy 30.5" of snow, which was well above the average of 16.2".  There was a snow cover of two inches or more for the last five weeks of the winter. 

 

 

In total, there were nine snowfalls of an inch or more (and one other that amounted to 0.9").  The largest accumulation came from the snowstorm of Jan. 26-27, which brought 9.8".  This storm had originally been forecast to dump 24"-36" on the City.  In February there were three with accumulations of between three and four inches.  

 

Twice this winter I appeared on PIX-11's 5 o'clock newscast to comment on the frigid conditions.

 

COLDEST JAN/FEB
	Mean Temperature
Winter	Jan	Feb	Jan/Feb
1875	23.8	25.2	24.5
1904	25.3	25.4	25.3
1918	21.7	30.4	25.8
1920	23.4	28.5	25.9
1888	23.0	29.3	26.0
1912	23.7	28.8	26.2
1885	29.4	22.7	26.2
1893	23.7	29.4	26.4
1881	24.7	28.7	26.6
2015	29.9	23.9	27.1
Source: NWS New York, NY