Tags: Barrow Street, Capital Grille, East 42nd Street, Fiorello LaGuardia, Jefferson Market library, Lexington Avenue, New York Public Library, Patience and Fortitude, photos of snow in New York City, Seventh Avenue South, Sheridan Square, slush in New York, snow covered steps, snow drifts in New York City, Snow in New York during the winter of 2017, Walk Sign in the snow
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The first month of 2017 was no different from the 18 preceding months, i.e., it was warmer than average. And it was well above average, by 5.4 degrees, with only seven days colder than average (and eleven were 10 degrees or more above average). It ranks as the 13th mildest January on record. The period between 1/11-1/29 was especially mild, with temperatures ten degrees above average. During this period there were thirteen days in a row in which the temperature stayed above 32° and sixteen days in a row with above average mean temperatures. The warmest reading occurred on 1/12, when the high reached a record-setting 66° - the warmest reading in January in ten years. Other highlights:
The month had 7.9" of snow, which came from four snowfalls; much of it fell on 1/7 when 5.1" piled up. The monthly total was an inch above average, but what's noteworthy is the fact that this was the snowiest January of any of the 25 mildest (which average 2.3" of snow). Additionally, four of New York's coldest Januarys had less snowfall than January 2017 (and three had a similar amount).
SMALL VARIATION BETWEEN HIGHS AND LOWS
Also noteworthy was the month's diurnal variation in temperature, which, at 9.4 degrees was the smallest of any January (the 50-year average is 12.3 degrees). It's also the only January to have a diurnal variation less than 10 degrees (January 1960 and 2011 had DVs of 10.1 degrees). Seven days had variations of of five degrees or less; however, one outlier was 1/13, which had a 30-degree difference between its high and low (high/low of 62/32).
NOR'EASTER PRODUCES NEARLY HALF OF MONTH's PRECIPITATION
A nor'easter on 1/23-24 brought winds that gusted to 47 mph and 2.34" of rain. This storm arrived on the one-year anniversary of New York's biggest snowfall (27.5"). And that storm's liquid precipitation was practically the same as this year's amount (2.32").
OLD MAN WINTER'S BRIEF APPEARANCE
A few days before the record high of 66° there was a 3-day period with temperatures that were quite cold, with every day having highs only in the mid-20s. (In a span of three days the high temperature went from being fifteen degrees below average to twenty-eight degrees above average.) Average high/low during this cold snap was 25/17, eleven degrees below average. This included the coldest reading of the month, 14° on 1/9. The 5.1" snowfall fell during this cameo appearance of Old Man Winter.
Snow seems to captivate us more than rain, perhaps because it's limited mostly to four months of the year. Or maybe it's because of its ability to transform the landscape into a magical wonderland. What never ceases to amaze me is that snowflakes are able to pile up on Manhattan's busy streets. And although New York may be the "City that never sleeps", at times it can be brought to a standstill and its cacophony hushed by a blanket of snow. Below are some interesting facts about New York's snowfall patterns and extremes ...
In the past 100 years only 1920 had a January thru March that was colder than 2015's. What placed 2015 this high was February's extraordinarily cold conditions (11.4 degrees below average). However, when all winters going back to 1870 are considered 2015 falls to thirteenth coldest (but this still among the top 10%). Where 2015 stands out is in its snowfall. Among the twelve colder years 2015 was the snowiest, with snowfalls in Jan-Feb-March amounting to 49.1", which was nearly ten inches more than the second highest total.
|COLDEST FIRST 3 MONTHS OF YEAR|
|Source: NOAA, Local Climate Data|
|*Weighted to reflect Feb's 28/29 days|
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:
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.
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 wintry four 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.
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.
Presently New York finds itself in the midst of an abundance of snowy winters, including this winter. Eight of the thirteen winters between 2003-2015 have 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.
|PEAKS & VALLEYS OF WINTERS WITH 40 INCHES+ SNOWFALL|
|# of||# of Winters||% with|
|Time Period||Winters||40"+ Snow||40"+ Snow|
|Source: NWS New York Office|
Before it turns to slush, new-fallen snow in New York brings a blanket of serenity even to the great metropolis. And wintertime covers of The New Yorker perfectly capture the ineffable beauty of the season. Here are my favorites (captions are mine) ...
I've written a similar post about my favorite summertime covers. Large reproductions of these covers, as well as every New Yorker cover (nearly 5,000), are available for purchase on Conde Nast's website. (And small versions are sold by street vendors throughout midtown Manhattan.)
Measurable snow has fallen in November in New York, on average, once every three years. And Novembers with an inch or more of snow have occurred once every five years. However, over the years the likelihood of having snow in November has decreased. Between 1869 and 1912 an inch of snow fell in November once every three years, and in between 1913 and 1955 it fell once every four years, but since 1956 an inch or more of snow has fallen just once every ten years. Here are some more findings:
|LAST 10 NOVEMBERS WITH SNOW|
|Snow (in Inches)|
Meteorological winter falls between Dec. 1 and Feb. 28 and is largely a creation of convenience to make the calculation of winter snowfall and average temperatures easier. On average, 78% of a year's snow piles up during these three months, or about twenty inches (based on New York winters going back to 1870). However, the portion of snow that has fallen outside of meteorological winter in this century has been considerably less, down to 12% (about three inches).
Seventeen winters have had more than half of their snow fall outside of meteorological winter. The most recent was in 1998. The winter of 1896 had the most snow fall before and after meteorological winter - 33.5" of its 46.3" total. Seven winters have had more than 20" fall outside of meteorological winter. The last time it happened was back in 1956.
Twelve winters have had all of their snow fall during meteorological winter. The last time it happened was in the winter of 2010 when there was 51.4" of snow. The winter of 2014 is one of three winters to have all but 0.1" fall during the three months of MW.
Looking at New York's snowiest winters, there have been 35 with 40 inches of snow or more (going back to the winter of 1870.) Seven of them had less than two inches of snow fall outside of meteorological winter - four of those were in the past ten years, including this recent winter, which had just 0.1" of its 55.4" fall beyond Dec., Jan. and Feb.
|% OF WINTER SNOW|
|DURING & BEYOND METEOROLOGICAL WINTER|
|(Winters w/40"+ Snowfall)|
|Total||% During||% Beyond|
|(Analysis of NOAA Climate Data for NYC)|