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.
On occasion I've been asked to give my viewpoint about weather events on New York TV station WPIX. PIX-11 news reporter James Ford came across my blog and has contacted me at least eight times to provide my historical perspective. Five of those times I had the time to meet with him. (It helps that PIX's office is down the street from my office on 42nd St.) Here are the appearances I've made (so far) including links to each:
This post was inspired by this winter, when the high reached 61° on Feb. 20, six days after a frigid low of -1° (the only sub-zero reading so far this century). In researching other big rebounds following a sub-zero reading I uncovered one that was even more dramatic. It occurred in February 1943 when the temperature soared to 63° just five days after a low of -8° (the first of five days in a row in the 60s). However, winter 2016 can lay claim to a tie for the quickest rise to 50° after a sub-zero - two days later (it also happened in the winters of 1934 and 1918). The chart below looks at the shortest and longest rebounds to temperatures in the 50s since 1900.
This winter (2015-16) the first day to have a high of 32° or colder wasn't until Jan. 5, which is about three weeks behind schedule. It was the tenth winter of the past 100 years to have the first such day occur in January (and last winter's first freezing high was on Dec. 31). At the other end of the spectrum, the earliest date for the first 32° high temperature occurred in 1942 on Nov. 14. The last time New York City had a high this cold in November was just two winters ago, on Nov. 24, 2013. The chart below lists the ten winters that had their first 32° high in January:
It should be noted that a late start to the winter doesn't necessarily translate into a continued mild season. Although the winters of 1919, 1975, 1998, 2008 and 2012 were mild (2012 was the second mildest and 1998 was fourth mildest), four of the winters on the chart above had periods of frigid temperatures and snow (the jury is still out on what the rest of this winter will bring):
Winter of 1987 - Two days after the winter's first high of 32° or colder (on 1/20) a snowstorm dumped 8.1" of snow, which was then followed by five days with highs below freezing. In the four weeks following the first high of 32° temperatures were 2.5 degrees below average and 14.4" of snow fell.
Winter of 1985 - In the four weeks that followed the first 32° high (on 1/9), temperatures were five degrees below average. A major Arctic outbreak produced one of New York's coldest days in recent memory, with a high/low of +9/-2 on Jan. 21. And in the three-week period between Jan. 17 and Feb. 6 there were three snowfalls between four and six inches.
Winter of 1972 - A few days after the first high of 32° (on 1/6) there was a streak of five days in which temperatures were 16 degrees above average. Then an Arctic outbreak moved in mid-January that dropped the temperature to +5° on Jan. 16. February was cold and snowy, with eighteen inches of snowfall. Between Feb. 5 and 23 temperatures were four degrees below average and, similar to the winter of 1985, there were three snowfalls between four and six inches.
Winter of 1924 - Although January had average temperatures, there were four mornings with lows in the single digits (two lows of 5° and two of 7°). February was cold (five degrees below average) and on April 1 8.5" of snow fell.
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.
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|
|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|
Winter 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. 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 degrees. 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.
|Source: NWS New York, NY|
Compared to last January, January 2015 wasn't as cold or snowy, but it was still colder and snowier than average, with a mean temperature 2.7 degrees below average and snowfall more than double the month's average (16.9" vs. 7.0"). It was also the wettest January since 1999. What follows are the four key stories of the month:
|JANUARY 2015 v JANUARY 2014|
|Average High (+/-)||36.1 (-2.2)||35.4 (-2.9)||38.3|
|Average Low (+/-)||23.6 (-3.3)||21.8 (-5.1)||26.9|
|Mean Temp (+/-)||29.9 (-2.7)||28.6 (-4.0)||32.6|
|Highs of 32 or Colder||9||13||9|
Not only was the 2.10" deluge on Jan. 18, 2015 a record for the date, it was New York's biggest January rainstorm in sixteen years (since Jan. 3, 1999, when 2.42" fell). This makes it the biggest January rainstorm of the 21st century. And in the years between 1999 and 2015 there were four January's that had about this amount of rain for the entire month. Since 1970 this was the eighth biggest January rainstorm (ranked ninth if snowstorms are added to the mix). Other findings:
|JANUARY STORMS THAT PRODUCED MORE THAN TWO INCHES OF PRECIPITATION (SINCE 1970)
|Jan 20-21, 1979||3.98"||19||54/27||Began as 0.5" of snow|
|Jan 26-28, 1976||2.89"||28||56/35|
|Jan 4, 1982||2.73"||15||58/36|
|Jan 23-24, 1998||2.65"||20||47/34|
|Jan 3, 1999||2.42"||12||51/35|
|Jan 24-25, 1979||2.32"||16||53/35|
|Jan 25-26, 1978||2.25"||18||58/35|
|Jan 7-8, 1996||2.16"||25||23/16||All snow 20.2")|
|Jan 18, 2014||2.10"||13||42/34|
|Jan 25-26, 1986||2.07"||23||51/38|
|Jan 26-27, 2011||2.06"||21||32/29||All snow (19.0")|
|Source: NOAA, Local Climatological Data|