NYC Monthly Summary: February 2015

February was frigid in New York City this year! With an average monthly temperature of 23.9°F, it was the city’s 3rd coldest February on record.

We experienced several arctic outbreaks that caused fountains to freeze and ice to form on both the Hudson and East Rivers. Overall, we had 15 out of 28 days where our high temperature did not get above freezing. We also had 7 days where our low temperature dropped into the single digits, including February 20th when the mercury plummeted to 2°F in Central Park, marking a new record low for the date. Our normal high for the month is 42°F and our normal low is 29°F.

These relentlessly cold conditions were produced by an almost continuous deep dip in the jet stream that allowed arctic air to dive south into our region. Some scientists suggest there may be a connection between these extended periods of extreme cold and climate change. They say as the Arctic warms, the jet stream slows down creating a wavier configuration that allows weather systems to stay in place longer.

In terms of precipitation, February is usually a snowy month in the Big Apple and this year was no exception. The city had 11.9 inches accumulate in Central Park, which is 2.7 inches above average. The month did not bring us a single blockbuster snow event, but rather a string of small storms. Rainfall, on the other hand, was lacking.  The city only received 2.04 inches, which is 1.05 inches below normal for the month.

Credit: The Weather Gamut

Credit: The Weather Gamut

Climate Change Projections for NYC

Climate Change is a global problem with impacts that vary from place to place. In New York City, they include hotter temperatures, heavier precipitation events, rising sea levels, and increased flooding. Each one of these local challenges was spelled out in detail by the latest report from the New York City Panel on Climate Change (NPCC).

According to the report, temperatures are expected to increase between 4.1°F and 5.7°F by the 2050s and between 5.3°F and 8.8°F by the 2080s. The frequency of heat waves is forecast to jump from the current average of 2 per year to 6 by the end of century.

Annual precipitation is projected to increase 4% to 11% by the 2050s and 5% to 13% by the 2080s. The report also calls for the number of days with extreme precipitation – heavy rain and snow – to increase 1.5 times by the 2080s.

Local sea levels are expected to rise between 11 inches and 21 inches by the 2050s, 18 inches to 39 inches by the 2080s, and up to six feet by 2100. As an archipelago, NYC is especially vulnerable to sea level rise. Higher sea levels give storm surges a higher starting point, allowing floodwaters to reach further inland. That means Sandy-like flooding will become more probable in the future even with a less powerful storm. In fact, if the high end projections of sea level rise come to fruition, the current 1-in-100 year flood event could happen roughly every 8 years.  The city’s flood zone is expected to double in size by 2100.

These changes are not only significant for their quantities, but also for the rate at which they are forecast to occur.  To put them into perspective, compare them to the recent past. Between 1900 and 2013, the city’s annual temperature increased 3.4°F, mean annual precipitation increased 8 inches, and local sea levels rose by 1.1 feet.

Taking steps to both adapt to and mitigate climate change, NYC has started building flood protection systems and has pledged to reduce its greenhouse gas emissions 80% from 2005 levels by 2050.

Formed in 2008, the NPCC assesses the latest climate science and analyzes the specific impacts facing NYC.  It issues a report every 3 years.

Credit: NPCC 2015 Report

NYC faces an increasing risk of floods due to sea level rise and climate change.                          Credit: NPCC 2015 Report

Record-Breaking Cold in NYC

After getting off to a relatively slow start, winter has kicked into high gear. For the second time in less than a week, a massive arctic outbreak has sent most of the eastern U.S. into a deep freeze.  From Michigan to Florida, many communities are dealing with record cold conditions.

Here in New York City, the temperature dropped to 2°F in Central Park early Friday morning – a new record low for the date.  The previous record of 7°F was set in 1950. Factoring in the wind-chill, it felt like -15°F. Our normal low temperature for this time of year is 30°F.

As cold as it was on Friday, it was not the coldest day the Big Apple has ever experienced. That dubious honor, according to the NWS, belongs to February 9, 1934, when the air temperature reached a brutal low of -15°F.

This current arctic invasion is being dubbed “The Siberian Express”, as its bitterly cold air originated in Siberia in northern Russia. As it retreats later this weekend, temperatures are expected to moderate a bit before another cold shot heads our way. Remember, these types of frigid conditions can be life-threatening. Stay warm!

Arctic Blast Sends NYC into a Deep Freeze

Another arctic outbreak has sent a large part of the US into a deep freeze. Across the East, temperatures tumbled this weekend with some places experiencing the coldest conditions they have seen in decades.

Here in New York City, the mercury fell to just 3°F in Central Park early Monday morning. That is the coldest temperature the city has seen in 11 years, but not quite a record. According to the NWS, the record low for the date was set in 1888 when the temperature was only 1°F. Our normal low for this time of year is 29°F.

Produced by a deep dip in the jet stream, our current frigid conditions will be staying in place for a while. In fact, a reinforcing shot of bitterly cold arctic air is expected to arrive in the region later this week. These types of temperatures can be life threatening, so remember to bundle up!

Frozen Fountain in NYC's Bryant Park.  Credit: FOX

Frozen Fountain in NYC’s Bryant Park. Credit: FOX

Groundhog Day 2015

Today is Groundhog Day, the midpoint of the winter season.

On this day, according to legend, the weather conditions for the second half of winter can be predicted by the behavior of a prognosticating groundhog.  If the groundhog sees its shadow after emerging from its burrow, there will be six more weeks of winter.  If it does not see its shadow, then spring will arrive early.

The practice of using animal behavior to predict future weather conditions goes back to ancient times.  The particular custom that we are familiar with in the United States grew out of the old world tradition of Candlemas brought by German settlers to Pennsylvania in the 1880s. Today, many communities across the U.S. and Canada continue this age-old ritual with their own special groundhogs.

The most famous of these furry forecasters is Punxsutawney Phil from Pennsylvania – he was portrayed in the 1993 film, “Groundhog Day”. This year, despite an overcast sky, Phil saw his shadow and is calling for six more weeks of wintry conditions.

In New York City, our local weather-groundhog is Charles G. Hogg – more popularly known as “Staten Island Chuck”.  Coming out of his burrow this morning, he did not see his shadow and is predicting an early spring for the Big Apple.

Long-range forecasts are a tricky business, so a difference of opinion is not that uncommon. Either way, the spring equinox is 46 days away.

NYC Monthly Summary: January 2015

January is typically the coldest month on the calendar for New York City and this year was no exception. We had nine days where the high temperature did not get above freezing and two overnight lows in the single digits. While there were also a few unseasonably warm days, the multiple bouts of extreme cold brought the city’s average monthly temperature down to 29.9°F.  That is 3.1°F below normal.

On the precipitation side of things, the city had 11 days with measurable rainfall.  In all, we received a remarkable 5.23 inches of rain, which is 1.58 inches above normal. Of this impressive total, 2.1 inches fell in a single day, January 18th, setting a new daily rainfall record for the date. Snow was also plentiful with 15.3 inches measured in Central Park. Most of this fell during a single storm – a clipper system that transitioned to a nor’easter – at the end of the month. On average, January usually brings the city a total of 7 inches of snow.

Credit: The Weather Gamut

Credit: The Weather Gamut

Credit: The Weather Gamut

Credit: The Weather Gamut

First Major Winter Storm of 2015 in NYC

A major winter storm blasted a large area of the eastern U.S. on Monday and Tuesday. Heavy snow and high winds impacted states from the Mid-Atlantic to New England.

Here in New York City, the storm dumped 9.8 inches of snow in Central Park. While that is a substantial amount, it is a far cry from the record-breaking numbers and blizzard conditions that were forecast. In response to this forecast bust, the NWS said, “The science of forecasting storms, while continually improving, still can be subject to error, especially if we’re on the edge of the heavy precipitation shield. Efforts, including research, are already underway to more easily communicate that forecast uncertainty.”

Starting out as a weak area of low pressure, this storm quickly intensified when it interacted with the jet stream and transformed into a massive nor’easter. It tracked further east than expected and that change in distance to the coast made a big difference in where the heaviest snow fell. On Long Island, only a few miles east of NYC, communities dealt with blizzard conditions and over 20 inches of snow.

While not one for the record books in the Big Apple, this storm ended the so-called snow drought in the northeast and brought enough snow for a fun day of sledding in parks across the city.

Weather and Art: Vortex

The word vortex – popularized last winter by extended arctic outbreaks related to a wobbly polar vortex – can sound rather ominous. A vortex, however, is simply a whirling mass of air or water.  Its spiral pattern is found throughout nature.

In the weather world, vortices form for a variety and combination of reasons, including differences in atmospheric pressure, wind shear, and centrifugal force. Tornadoes, waterspouts, and hurricanes, are all examples. They, unlike the polar vortex, are visible because of the water vapor and debris that gets sucked into them.

The spiral shape of a vortex is also represented in art in various sizes and materials. One of the largest is Richard Serra’s massive (67’x21’x20’) cor-ten steel sculpture, “Vortex” (2002), at the Modern Art Museum of Fort Worth in Texas. One of my more recent sightings, however, was on a much smaller scale. Also simply titled “Vortex” (1932), this was a small (11×14”) gelatin silver photographic print by Edward W. Quigley at the Museum of Modern Art in NYC. As someone who is fascinated by the intersection of art and science, this image really stood out to me at MOMA’s current photography exhibition, “Modern Photographs: The Thomas Walther Collection, 1909-1949”. It is on view through April 19, 2015.

Credit: Edward W. Quigley and MOMA

“Vortex”, 1932.  Credit: Edward W. Quigley and MOMA

Credit: Richard Serra and

“Vortex”, 2002.  Credit: Richard Serra and Modern Art Museum of Fort Worth