Tag Archives: winter

Weather Lingo: Nor’easter

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The winter season can produce a number of different types of storms. One of these is a nor’easter.

These intense systems generally affect the east coast of the United States from the mid-Atlantic to New England. They traditionally develop when a strong area of low pressure to the south moves up the coast and meets cold air pushing down from Canada. With a plentiful supply of moisture from the Atlantic, these storms are notorious for producing copious amount of precipitation. The exact type – rain or snow – depends on the temperature at the time of the storm. They are also known for their strong onshore winds that can cause coastal flooding and beach erosion.

Spinning counterclockwise, these storms take their name from the steady northeasterly wind they produce. 

Credit: NOAA

Spring Preview Brings NYC Warmest February Day Ever Recorded

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The calendar says February, but it felt more like May in New York City on Wednesday. The temperature in Central Park soared to 78°F, setting not only a new record high for the date but marked the warmest February day ever recorded in the Big Apple.

Records are usually broken by fractions of a degree, but these were shattered. According to the NWS, the previous daily record, which was set in 1930, was 68°F and the former record monthly high that had been in place since February 24, 1985, was of 75°F. The city’s normal high this time of year is 43°F.

The primary driver of these unusually balmy conditions is a strong Bermuda High off the east coast of the US. Spinning clockwise, it is funneling warm southern air into the region.

Venturing out without coats and enjoying lunch alfresco, many New Yorkers took full advantage of this early spring preview. Personally, however, it felt a little surreal. February is typically the snowiest month of the year in NYC – a time when sledding and ice-skating are more common than ice-cream trucks and frisbees.

That said, these spring-like conditions will be short-lived. Temperatures are expected to return to more seasonable levels tomorrow. Get ready for weather whiplash!

Temperatures soared to record levels in NYC on Feb 21. Credit: The Weather Gamut

January 2018: Earth’s Fifth Warmest on Record

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Our global temperature continued its upward trend last month with January 2018 marking the fifth warmest January ever recorded on this planet. The last four Januarys now rank among the five warmest on record.

According to a report by NOAA’s National Centers for Environmental Information, Earth’s combined average temperature for the month – over both land and sea surfaces – was 54.88°F. That is 1.28°F above the 20th-century average. January was also the 397th consecutive month with a global temperature above its long-term norm. That means the last time any month posted a below average reading was December 1984.

While heat dominated most of the planet this January, some places were particularly warm, including the western half of the United States and most of Europe. For the contiguous US as a whole, January ranked among warmest third of the nation’s 124-year period of record.

Coming on the heels of 2017 – Earth’s third warmest year on record and warmest year without an El Niño – these soaring temperatures are largely attributed to the long-term trend of human-caused climate change. In fact, La Niña conditions – the cool counterpart of El Niño – were present in the Pacific during January.

Global temperature records date back to 1880.

January 2018 was the planet’s 5th warmest January on record. Credit: NOAA

The Outlook for the Winter Olympics in a Warming World

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Millions of American are tuning in to watch the Winter Olympics in Pyeongchang, South Korea and one of the ads they are seeing features a strong message on sustainability from Toyota. Showing ice sculptures of athletes melting, the company is promoting their hybrid vehicles and says it wants “to help keep our winters, winter”. It is a poignant and timely message as our global temperature warms and the viability of many previous Winter Olympic host sites is declining.

Since the first winter games were held in 1924, the month of February – the traditional time of year for this global event – has increased an average of 1.82°F worldwide. If this current rate of warming continues, according to Climate Matters, only 6 of the 19 past host sites will be reliable future venues by the end of the century. Under a business as usual scenario, previous host cities, on average, are expected to see a temperature increase of 7.9°F by the 2080s. Significant cuts to greenhouse gas emissions would reduce that warming to 4.86°F

Warming winters also affect athletes’ ability to train. In the US, NOAA says winter temperatures have increased almost twice the rate of summer temperatures. If this trend continues, some areas are likely to see the ski season cut in half by 2050. This truncated season correspondingly means an economic hit for the winter sports and recreation industry. These businesses, according to Protect Our Winters, contribute $72 billion to the national economy annually and support more than 600,000 jobs.

The 2014 Olympics in Sochi, Russia were the warmest winter games on record.

Credit: Climate Central

Weather and Art: “Love of Winter”

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Today is Valentine’s Day, a holiday when chocolate treats and images hearts abound. But for me, it is George Bellows’ Love of Winter that always comes to mind as we mark the mid-point of what is usually New York City’s snowiest month of the year.

A longtime personal favorite, this 1914 painting captures the spirit of those who embrace the season. Filled with the blurred movement of skaters on a frozen pond and accented with spots of bright color that pop against the snow, it conveys the joy of being out in nature on a cold winter day.

While Bellows is better known for depicting scenes of boxing matches and urban life, art historians say he enjoyed the challenge of painting the varied lighting conditions produced by a snow-covered landscape. In fact, he wrote a letter to a friend in January 1914 complaining about the lack of snow in the New York City area that winter. He said, “There has been none of my favorite snow. I must paint the snow at least once a year.” Then, about a month later, his wish for snow was granted and this painting was created.

Love of Winter is part of the Friends of American Art Collection at the Art Institute of Chicago.

“Love of Winter”, 1914 by George Bellows. Collection of the Art Institute of Chicago

From Snow to Ice, Winter Precipitation Can Take Several Forms

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The winter season can produce various types of precipitation – rain, freezing rain, sleet, or snow. It depends on the temperature profile of the lower atmosphere.

All precipitation starts out as snow up in the clouds.  But, as it falls toward the Earth, it can pass through one or more layers of air with different temperatures.  When the snow passes through a thick layer of warm air – above 32°F – it melts into rain.  If the warm air layer extends all the way to the ground, rain will fall at the surface.  However, if there is a thin layer of cold air – below 32°F – near the ground, the rain becomes super-cooled and freezes upon impact with anything that has a temperature at or below 32°F.  This is known as freezing rain.  It is one of the most dangerous types of winter precipitation, as it forms a glaze of ice on almost everything it encounters, including roads, tree branches, and power lines.

Sleet is a frozen type precipitation that takes the form of ice-pellets. Passing through a thick layer of sub-freezing air near the surface, liquid raindrops are given enough time to re-freeze before reaching the ground. Sleet often bounces when it hits a surface, but does not stick to anything.  It can, however, accumulate.

Snow is another type of frozen precipitation.  It takes the shape of six-sided ice crystals, often called flakes.  Snow will fall at the surface when the air temperature is below freezing all the way from the cloud-level down to the ground.  In order for the snow to stick and accumulate, surface temperatures must also be at or below freezing.

When two or more of these precipitation types fall during a single storm, it is called a wintry mix.

Precipitation type depends on the temperature profile of the atmosphere. Credit: NOAA

Groundhog Shadow or Not, Spring has Been Trending Earlier

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

On this day, according to folklore, 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 that German settlers brought 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”. Here in New York City, our local weather-groundhog is Charles G. Hogg. A resident of the Staten Island Zoo, he is more popularly known as “Staten Island Chuck”. This year, the two groundhogs had a difference of opinion. Phil predicts six more weeks of winter and Chuck is calling for an early spring.

But, shadow or no shadow, as the planet warms spring is trending earlier. Below is a look at the temperature trend during the six weeks following Groundhog Day since 1950 in New York City.

Spring is trending earlier as the planet warms. Credit: Climate Central

NYC Monthly Summary: January 2018

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January was another month of wild temperature swings in New York City. It produced part of the city’s third longest sub-freezing cold streak on record and a significant January Thaw. Overall, highs ranged from a frigid 13°F to an unseasonably balmy 61°F. In the end, however, these extremes just about balanced each other out. The city’s mean temperature for the month was 31.7°F, which is only 0.9°F below normal.

 

In terms of precipitation, January was unusually dry. In all, the city received 2.18 inches of rain, which is 1.47 inches below average. Snowfall, on the other hand, was abundant with 11.2 inches measured in Central Park. Of this total, 9.8 inches fell during a single storm on January 4 and set a new daily snowfall record for the date. The city, on average, gets 7 inches of snow for the entire month of January. Nonetheless, NYC is listed as “abnormally dry” in the latest report (Feb 1) from the US Drought Monitor.

Credit: The Weather Gamut

Auroras: What Causes the Northern and Southern Lights

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Auroras occur throughout the year, but the long nights of winter at high latitudes provide an optimal environment in which to see this amazing natural phenomenon.

These colorful patterns of light that dance across the night sky are the result of charged particles from the sun interacting with the Earth’s atmosphere. Originating in a massive explosion on the sun known as a coronal mass ejection, the protons and electrons travel nearly 93 million miles before some of them reach the Earth. When they encounter the planet’s magnetic field, they are pulled toward the poles, where the magnetic force is strongest. There, they interact with atmospheric gases and produce the variety of colors we see. The main factor in which colors are displayed, however, is altitude. Different gases, such as nitrogen and oxygen, vary in concentration at different levels of the atmosphere.

Oxygen molecules can generate green auroras up to 150 miles above sea level and red auroras further up. Nitrogen molecules produce blue lights up to 60 miles above the ground and violet colored lights at higher levels. Auroras, in general, extend from 50 miles to as high as 400 miles above the Earth’s surface.

The word aurora is Latin for dawn. Therefore, the “aurora borealis”, the northern lights, means “dawn of the north”. At the South Pole, the lights are known as the “aurora australis”, which means “dawn of the south”.

Aurora Borealis over Alaska. Credit SmithsonianMag

A January Thaw in NYC

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The calendar says January, but it felt more like spring in New York City on Tuesday. The temperature soared to 60°F in Central Park, a staggering 22°F above average for this time of year and 2°F shy of the record high for the date.

This unseasonable warmth is part of the “January Thaw” currently taking place in a large part of the eastern United States. After an extended cold blast, this is a period when winter’s grip relaxes a bit and temperatures rise at least 10°F above normal for a few days. It does not necessarily occur every year, but when it does, it is usually in mid to late January, hence the name.

With temperatures in the 50s since Saturday, many New Yorkers have been out in the parks enjoying the break from the cold. It is, however, still January. So, keep your winter gear handy.

Melting ice on The Lake in Central Park, NYC. Credit: Melissa Fleming