First Snowfall of the Season in NYC

New York City saw its first measurable snowfall of the 2017-2018 season on Saturday. According to the NWS, 4.6 inches of snow was measured in Central Park.

While not a blockbuster event, it was enough to leave the city looking like a winter wonderland. With all the holiday lights and decorations on display, the softly falling flakes added to the festive atmosphere.

The timing of this first snowfall was about normal for the Big Apple. On average, the first flakes of the season are seen by December 14. Our earliest first snow event on record was on October 21, 1952, and our latest was January 29,1973. New York City typically gets 25.3 inches of snow for the entire winter season.

First flakes of the season fly in NYC. Credit: Melissa Fleming

How the Santa Ana Winds Help Wildfires Spread

The Santa Ana winds are notorious for exacerbating wildfires in southern California.

These strong winds blow warm, dry air across the region at different times of the year, but mainly occur in the late autumn. They form when a large pressure difference builds up between the Great Basin – a desert that covers most of Nevada and parts of Utah – and the coastal region around LA. This pressure gradient funnels air downhill and through the passes of the San Gabriel and San Bernardino mountains toward the Pacific. According to the NWS, the Santa Ana winds can easily exceed 40 mph.

Originating in the high desert, the air starts off cool and dry. But as it travels downslope, the air compresses and warms. In fact, it warms about 5°F for every 1000 feet it descends. This dries out the region’s vegetation, leaving it susceptible to any type of spark. The fast-moving winds then fan the flames of any wildfires that ignite.

The Santa Ana winds are named for Santa Ana Canyon in Orange County, CA.

Credit: NWS

The Supermoon and Other Moon Names

The first and only supermoon of 2017 will rise on Sunday.

Supermoons are the result of the moon’s elliptical orbit around the Earth. They occur when the moon reaches perigee – its closest point to our planet (less than 223,694 miles). As it is so close, a supermoon looks 7% larger and 16% brighter than an average full moon. When seen near the horizon – where buildings or mountains provide a foreground – an illusion is created that makes the super moon look even bigger. They happen about every thirteen months or so.

When the moon is furthest from Earth – at apogee – it is called a micro-moon.

Full moons occur every 29.5 days when the moon is on the side of the Earth directly opposite the Sun. It reflects the sun’s rays and appears as a beautiful silver disk in the sky.

Ancient civilizations used full moons as a guide to schedule important activities, such as hunting and farming. They gave them each a name based on the dominant weather pattern or typical animal and plant activity during a particular month. In North America, according to National Geographic, native tribes used the moon names listed below. Many are still in use today.

  • January: Wolf Moon or Ice Moon
  • February: Snow Moon
  • March: Worm Moon or Sap Moon
  • April: Sprouting Grass Moon
  • May: Flower Moon
  • June: Strawberry Moon
  • July: Buck Moon
  • August: Sturgeon Moon or Grain Moon
  • September: Harvest Moon
  • October: Hunter’s Moon
  • November: Beaver Moon
  • December: Cold Moon or Long Night Moon

A blue moon is when a second full moon occurs in a single month. Given the uneven nature of our calendar system, these happen roughly every 2.5 years.

The apparent size of the moon as seen from Earth. Credit: KQED

Autumn 2017: Fourth Warmest in NYC

The winter solstice is still a few weeks away, but meteorological Fall (September, October, and November) has officially ended and it was the fourth warmest on record in New York City.

The season, a transitional period between summer and winter, can often feel like a temperature roller coaster. This year, highs ranged from 91°F to 38°F. In the end, though, the warmth came out on top. The city’s average temperature for the three months was 60.4°F, which is 2.9°F above normal.

In all, fifty-nine days posted above-average readings and two of the season’s three months were warmer than their long-term norms. In fact, October 2017 was the city’s warmest October on record.  

This autumn was dominated by a pattern of warm spells separated by a few short-lived blasts of cold air. It was largely driven by the jet stream staying well to the north for most of the season with just a few dips southward.

The city’s warmest autumn on record, according to the NWS, occurred in 2015, which tied 1931 with an average temperature 61.8°F.  The coldest was 1871 when the three-month average was only  51.7°F.  Central Park weather records date back to 1869.

Credit: The Weather Gamut

NYC Monthly Summary: November 2017

November 2017 felt like a temperature roller coaster in New York City. Highs ranged from an unseasonably balmy 74°F to a chilly 38°F. But with fourteen out of thirty days posting below average readings, including two record lows, the cold won out in the end. The city’s mean temperature for the month was 46.6°F, which 1.1°F below average.

In terms of precipitation, the month was mostly dry. Only 1.58 inches of rain was measured in Central Park, marking the fifth month in a row to deliver below average rainfall. The city usually gets 4.02 inches of rain in November.

Credit: The Weather Gamut

Extremely Active 2017 Atlantic Hurricane Season Comes to a Close

The 2017 Atlantic Hurricane Season officially ends today.  Not only was it above average, as predicted, it was the basin’s fifth most active season on record.

According to NOAA, there were seventeen named storms this season. Of these, ten developed into hurricanes and six were major hurricanes with ratings of category 3 or higher on the Saffir-Simpson Scale. An average season produces twelve named storms, six hurricanes, and three major hurricanes. It is also interesting to note that this year’s ten hurricanes developed consecutively over the course of ten weeks, marking the largest number of hurricanes to form in a row in the satellite era.

This season’s Accumulated Cyclone Energy (ACE), which measures the intensity and duration of storms, was also exceptionally high. On average, a season will post an ACE of 104 in the Atlantic. This year, according to researchers at Colorado State University, it was 226 – the seventh highest in the historical record.

Officially running from June 1 to November 30, the season got off to an early start this year. Tropical Storm Arlene was a rare pre-season storm that developed in April. Another interesting outlier was Hurricane Ophelia in October. It was the easternmost major hurricane ever observed in the Atlantic Basin and the strongest storm on record to hit the Republic of Ireland. The biggest names of the season, however, were Harvey, Irma, and Maria.

In August, Harvey made landfall in Texas as category-4 hurricane. It was the first major hurricane to hit the United States since Wilma in 2005. It was also the wettest storm on record, dumping more than 50 inches of rain in southeastern Texas. This extreme precipitation caused catastrophic flooding in the Houston area.

Hurricane Irma maintained category-5 strength winds for 37 hours before making landfall as a category-4 storm in the Florida Keys. Measuring about 425 miles in diameter, Irma was wider than the Florida peninsula and its effects were felt across the entire Sunshine state in early September.

Just two weeks later, Hurricane Maria devastated Puerto Rico. It was the third category-four hurricane to hit the US, or one of its territories, in less than a month. In 166 years of record keeping, that never happened before.

Causing so much destruction, Harvey, Irma, and Maria will likely be retired from the World Meteorological Organization’s list of storm names.

This active hurricane season was largely the result of above-average sea surface temperatures in the Atlantic and ENSO neutral to cool La Niña conditions in the Pacific. With warm water to fuel storms coupled with reduced wind shear across the Gulf of Mexico, tropical development in the Atlantic basin was essentially unhindered.

In terms of economic impact, ENKI Operations, a private research firm, estimates the property damage, clean up costs, and lost business productivity from this year’s storms to be $206 billion. That would make 2017 the costliest hurricane season on record for the US. The official tally from NOAA will not be available until early 2018.

Data: NOAA

Energy Flow: A Wind Powered Public Art Installation in Pittsburgh

On a recent visit to Pittsburgh, PA I had the opportunity to see “Energy Flow”, a wind-powered art installation on Rachel Carson Bridge. It was created in 2016 through a collaboration between environmental artist, Andrea Polli, and WindStax, a Pittsburgh-based wind turbine manufacturer.

Using sixteen small vertical axis wind turbines to power 27,000 LED lights, the piece produces a rainbow of colors up and down the bridge’s vertical supports. The light show visualizes the local wind speed and direction in real time as detected by an onsite weather station. The project also has battery storage to power the lights for up to twelve hours when the wind is not blowing. In essence, this artwork turned the bridge into a micro-grid – a single location where power is produced, stored and consumed.

As a site-specific art installation, it honors the environmental legacy of Rachel Carson (1907-1964). She was a native of the Pittsburgh area who went on to become a marine biologist and famous environmental writer. Her books, such as “Silent Spring”, are widely credited with inspiring the environmental movement of the 1960s that eventually brought about federal laws like the Clean Air Act.

The project also highlights Pittsburgh’s new focus on technological innovation and sustainability. Once known as the “Smokey City”, because of all the pollution that billowed from its plethora of mills and factories, Pittsburgh has refocused its economy and remade its image. Situated at the confluence of three rivers – the Allegheny, Monongahela, and Ohio – it is home to an astounding 446 bridges and is now often referred to as the “City of Bridges”. The Rachel Carson Bridge was originally, and rather simply, called the Ninth Street Bridge after it opened in 1926. It was renamed on Earth Day 2006.

“Energy Flow” was only expected to be up for a few months to celebrate Pittsburgh’s Bicentennial. But due to popular demand, its run has been extended through the end of 2018.

“Energy Flow” Wind/Light Installation on Rachel Carson Bridge, Pittsburgh, PA. Credit: Covestro LLC

Weather and the NYC Macy’s Thanksgiving Day Parade

The Macy’s Thanksgiving Day Parade is a long-standing holiday tradition in New York City.  For 91 years, it has marched rain or shine. Nevertheless, the weather has been a factor in the event several times over the years.

Famous for its giant character balloons, high winds are the main weather challenge for the parade. According to city guidelines, the multi-story balloons cannot fly if there are sustained winds in excess of 23 mph or gusts higher than 34 mph. These regulations were put in place following a 1997 incident where gusty winds sent the “Cat in the Hat” balloon careening into a light post, which caused debris to fall on spectators.

The only time the balloons were grounded for the entire parade was in 1971 when torrential rain swept across the city. In 1989, a snowstorm brought the Big Apple a white Thanksgiving with 4.7 inches of snow measured in Central Park. The parade marched on that year but without the “Snoopy” and “Bugs Bunny” balloons as they were damaged by high winds earlier that morning.

This year, the wind is not expected to be a problem. Temperatures, however, are forecast to be a bit chilly – mostly in the 30s during the parade hours. So, bundle up if you are planning to be outside along the route.

Marching from West 77th Street to West 34th Street in Manhattan, the 91st Annual Macy’s Thanksgiving Day Parade is scheduled to begin at 9 AM on Thursday morning.

Happy Thanksgiving!

Paddington Bear Balloon floats down 6th Ave in Macy’s Thanksgiving Day Parade. Credit: Macy’s

Outcomes of the UN Climate Change Conference in Bonn

The UN Climate Change Conference in Bonn, Germany, known as COP 23, concluded on Saturday. Its goal was to draft the rules and processes needed to translate the spirit of the historic Paris Agreement into action.

Years in the making, the 2015 Paris Agreement set the target of holding global warming to 2°C (3.6°F) above pre-industrial levels. To achieve this goal, nearly 200 countries submitted individual voluntary emissions reduction plans known as nationally determined contributions (NDCs). But when added up, the current collection of NDCs, which vary widely in ambition, will miss the 2°C goal.  In fact, they would allow for a 3.2°C (5.76°F) rise in the global temperature. This is why the agreement requires countries to reassess their plans every five years once it goes into effect in 2020.

One of the main goals of the Bonn meeting was to create a standardized rulebook for the monitoring and reporting of these independent undertakings. While some progress was made, the negotiators agreed to wait until the end of 2018 to finalize these vital rules. However, they did agree to begin discussing the NDC shortfall and the need to increase ambitions before 2020 at the next COP. This process was labeled the “Talanoa Dialogue”, which is a tradition of inclusive and transparent conversation used to resolve differences without blame in Fiji – the official host of this year’s conference.

The issue of financing climate adaptation – the touchy subject having wealthy nations pay to help poor nations adapt to climate change – was also pushed down the road. However, the delegates did establish an expert group to discuss the issue of “loss and damages”.

Although ratified in record time, the Paris Agreement is a fragile accord. All commitments are voluntary and vulnerable to the political will of individual governments – both now and in the future. Moreover, there are no penalties for those who do not live up to their promises.

That said, on the second day of this two-week conference, war-torn Syria announced that it would sign the Paris pact. This move now leaves the US as the only country not part of the global agreement. The Trump administration announced its intention to withdraw the US from the accord in June.

Outside of the formal COP meetings, the positive spirit of the Paris Agreement pushed forward. Nineteen countries and several sub-national actors (states and cities) created the “Powering Past Coal Alliance”. Its aim is to phase out the use of coal, the most carbon-intensive fossil fuel, by 2030. According to the International Energy Agency, coal still powers 40% of the world’s electricity.

The Bonn meeting was the 23rd session of the Conference of the Parties (COP) to the U.N. Framework Convention on Climate Change (UNFCCC). It was lead by Fiji but held in Germany because of logistical concerns on the small island nation.The next conference (COP 24) will take place in December 2018 in Katowice, Poland.

Credit: UN

October 2017: Earth’s Fourth Warmest on Record

Our global temperature continued its upward trend last month with October 2017 tying October 2003 as the fourth warmest October ever recorded on this planet. Only October 2014, 2015, and 2016 were warmer.

According to the State of the Climate Report by NOAA’s National Centers for Environmental Information, Earth’s combined average temperature for the month – over both land and sea surfaces – was 58.41°F. That is 1.31°F above the 20th-century average. October was also the 394th 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.

It is also interesting to note that the ten warmest Octobers on record have all occurred in the 21st century.

While heat dominated most of the planet last month, some places were particularly warm, including much of Europe, northern Russia, and the northeastern United States. For the contiguous US as a whole, the month ranked among the warmest third of the historical record.

These soaring temperatures are largely attributed to the long-term trend of human-caused climate change. In fact, a weak La Niña – the cool counterpart of El Niño – developed in the tropical Pacific during October.

Year to date, the first ten months of 2017 were the third warmest such period of any year on record. With only two months left, 2017 is expected to end up among the top three warmest years ever recorded on this planet. Global temperature records date back to 1880.

October 2017 was the planet’s 4th warmest October on record. Credit: NOAA