Monthly Archives: July 2016

Climatic Visions: An Art Exhibition on Climate Change

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Art and science have joined forces at the New York Hall of Science in an effort to expand public understanding of climate change. In a group exhibition called Climatic Visions II, photographs and collages explore some of the challenges of this pressing issue.

On display in the Le Croy Gallery, the exhibit features artwork by Cristina Biaggi, Melissa Fleming, Isabella Jacob, and Doris Shepherd Wiese. Co-curated by Audrey Leeds and Marcia Rudy, the exhibit runs from July 30 to October 30, 2016 and is free with general museum admission

The New York Hall of Science is located at 47-01 111th Street, Queens, NY 11368.

"Exit Glacier, Alaska" from the series "American Glaciers" by Melissa Fleming. Image credit: Melissa Fleming.

“Exit Glacier, Alaska” from the series “American Glaciers” by Melissa Fleming. Image credit: Melissa Fleming.

Weather Gamut Writer Talks about NYC Heat Wave on WUTV

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It was a great thrill to be asked back to The Weather Channel’s WUTV show tonight!  As a personal weather station owner based in New York City, we discussed the heat wave that has been baking the Big Apple.

The show, which dives into the science behind different weather events, airs weeknights from 6 to 8 PM EST on The Weather Channel.

Melissa Fleming appears on WUTV, July 26, 2016.

Weather Gamut writer, Melissa Fleming, talks with Mike Bettes on WUTV. July 26, 2016.

What is a Heat Dome?

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Summer is the season for warm weather. So, when temperatures reach 5°F to 10°F above average, it can be excessively hot. When this type of weather lasts for multiple days, it is usually the result of a phenomenon known as a “heat dome”.

Although not an official meteorological term, it does help paint a picture of what is happening. To start, an area of high pressure develops under a ridge in the jet stream. Acting like a lid in the upper atmosphere, it forces warm air that would normally rise to sink back toward the surface. As it sinks, it compresses and warms even further. Unable to escape, the hot air is remains in place until the ridge breaks down or moves.

Heat domes are not rare events, but when they produce extended heat waves and poor air quality, they can pose serious dangers to human health.

A Heat Dome forms in the upper atmosphere. Credit: NOAA

A Heat Dome forms in the upper atmosphere. Credit: NOAA

First Heat Wave of 2016 for NYC

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The heat is on in NYC! With temperatures reaching into the 90s for three consecutive days, the Big Apple is officially in the midst of its first heat wave of the summer.

In Central Park, the temperature reached 90°F on Thursday, 94°F on Friday, and on Saturday it climbed to 96°F – our hottest day so far this year. Looking ahead, the 90-degree weather is forecast to continue through at least the middle of the week.

Humidity levels are also expected to remain high, making it feel even hotter. Heat index values, which combine air temperature and relative humidity, are projected to be in the mid to upper 90s and even enter the triple digits on some days.

While these conditions can be oppressive, they are also very dangerous. Extended exposure can cause a number of serious health hazards. Both a heat advisory and air quality alert have been issued for the city.

As hot as the past few days have been, they were not record breakers. The dubious honor of producing the city’s hottest day ever recorded belongs to July 9, 1936 when the temperature reached a sizzling 106°F.

How Dangerous is Lightning?

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Big summer thunderstorms are impressive to watch. However, they are also extremely dangerous.

According to NOAA, lightning is the second deadliest type of weather in the US after floods. On average, it claims the lives of 49 people every year in this county and seriously injures even more. This year, to date, lightning has killed 16 people across nine states. Two were struck just this week.  Sadly, this number will likely go up before the summer is over.

Lightning comes in variety of forms, but the cloud to ground variety is the most threatening to us at the surface. A typical bolt carries a current of about 300 million volts and can heat the air around it to 50,000°F. That is five times hotter than the surface of the sun.

Around the globe, lightning hits the Earth about 100 times per second. In the US, the odds of a person being struck by lightning in any given year are 1 in 960,000 or 1 in 12,000 during an average lifetime of 80 years.

So, to avoid becoming a statistic, follow the advice of the NWS – “When thunder roars, go indoors.”

Credit: NOAA

Credit: NOAA

thunderroars_goindoors

Credit: NOAA/NWS

June 2016: Warmest June on Record for Planet Earth

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Our global temperature continued its upward trend last month with June 2016 marking the warmest June ever recorded on this planet.

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 61.52°F. That is a staggering 1.62°F above the 20th century average and 0.04°F above the former record that was set just last year.

June 2016 also marked the 14th month in a row to break a monthly global temperature record – the longest such streak on NOAA’s books. Moreover, it was the 378th consecutive month with a temperature above the 20th century average. That means the last time any month posted a below average reading was December 1984.

While heat dominated most of the planet this June, some places were particularly warm, including North America. Here in the contiguous US, with a monthly temperature of 71.8°F, which is 3.3°F above average, it was our warmest June on record. The previous record of 71.6°F was set in 1933. Arizona and Utah were each record warm.

These soaring temperatures, scientists say, were driven by the long-term trend of human-caused climate change. While El Niño gave global temperatures a boost earlier in the year, it has since dissipated.

Year to date, the first six months of 2016 were the warmest such period on record. This increases the likelihood that 2016 will surpass 2015 as the Earth’s warmest year ever recorded. Global temperature records date back to 1880.

June 2016 was the hottest June ever recorded. Credit: NOAA

June 2016 was the hottest June ever recorded. Credit: NOAA

2016 is heads and shoulders above the previous record warm years. Credit: NOAA

YTD, 2016 is heads and shoulders above previous record warm years. Credit: NOAA

Weather Observations Date back to 1700s at Chatsworth House

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Traveling in the Peak District of England recently, I had the opportunity to visit Chatsworth House – the seat of the Dukes of Devonshire. (For a pop culture reference, check out the 2008 film “The Duchess”.) While I went mainly to see the historic home and beautiful gardens, I was pleasantly surprised to spot a meteorological instrument shelter and Campbell-Stokes sunshine recorder on the lawn behind the palatial house.

Weather observations have been made on the estate since the 1700s. Even with updates to the instruments over the years, that makes it – as far as I know – one of the oldest, continuously operated personal weather stations around. Some of the highlights from its long history include:

  • Coldest temperature was -19°C (-2.2°F) on February 24, 1947
  • Wettest month was December 1914, with 23cm (9 inches) of rain
  • Driest year was 1780 with 49cm (19.3 inches) of rain
  • Darkest month was December 1930, with barely 7 hours of sunshine
  • Sunniest month was July 1989, with 255 hours of sunshine
  • The Great Storm of 1962 destroyed hundreds of trees on the estate

Given their substantial stake in agriculture, landowners of the 18th and 19th centuries wanted a better understanding of weather and climate.  Their extensive records helped build a foundation for what would later become the science of meteorology.  Today, they provide detailed local climate histories. At Chatsworth, observations are still taken every morning at 9AM.

PWS at Chatsworth House, Derbyshire, England. Credit: Melissa Fleming

PWS at Chatsworth House, Derbyshire, England. Credit: Melissa Fleming.

The Thames Barrier Protects London from Flooding

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The Thames Barrier protects millions of people and billions of dollars worth of property in greater London from flooding. As a New Yorker who experienced Superstorm Sandy and its record storm surge first hand, I made a point to visit this crucial piece of engineering during a recent trip to the UK.

Completed in 1982 at the cost of £535 million (about £1.6 billion today), the barrier was built in response to the catastrophic North Sea Flood of 1953. Often called the worst natural disaster to hit the UK, the floodwaters claimed the lives of 307 people and caused widespread damage estimated at £50 million (£1.2 billion today).

According to the UK Met Office, the deadly flood was caused by the combination of a high spring tide and an intense extra-tropical storm in the North Sea. Together, they generated a storm surge of 18.4 feet above average sea level. Moving upstream during the overnight hours of January 31, 1953, the high water overwhelmed the existing floodwalls and inundated communities along the Thames Estuary with little or no warning.

Situated downstream of central London, the barrier consists of ten individual steel gates that span a section of the river that is 1700 feet wide. It is the second largest movable flood barrier in the world, after the Oosterscheldekering barrier in the Netherlands. The Netherlands were also hard hit by the 1953 storm, with over 1800 lives lost to floodwaters.

When a storm surge or an exceptionally high tide is expected, all of the individual gates of the Thames Barrier are closed creating a solid steel wall, approximately five stories high, across the river. While this protects London from flooding from the sea, the barrier can also be used to help reduce fluvial flooding caused by heavy rainfall. When a high amount of water is forecast to flow downriver, the barrier is closed just after low tide. This creates a volume of space behind the barrier – sort of like a temporary reservoir – for the extra water coming downstream to fill. Without the barrier, the incoming tide would take up this space and cause the river water to rise even higher and spill out of its banks.

To date, according to the UK Environment Agency, the Barrier has been closed 176 times since it became operational 34 years ago. Of these closings, 89 were to protect against tidal flooding and 87 were to help alleviate fluvial flooding.  At the time it was built, it was only expected to be used 2 to 3 times per year.

Looking ahead, as the climate warms, heavy precipitation events in the UK are expected to increase and sea levels will continue to rise. This means the barrier will most likely be called into action even more often.

While there was debate about the feasibility and cost of building the barrier, as there is with any large government project,  it has repeatedly proven itself to have been a worthwhile investment. It is expected to remain a viable flood defense tool through the 2060’s.

The Thames Barrier protects London from flooding. Credit: Melissa Fleming.

The Thames Barrier protects London from flooding. Credit: Melissa Fleming.

The Flood Forecasting Lions of London

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The River Thames is as much a part of London as the buildings and palaces that sit along its banks. During a recent visit to the UK’s capital city, I learned more about this storied river and its long history of flooding.

London is situated along the tideway – the part of the Thames that is subject to tides. As such, it faces a flood threat from exceptionally high tides and powerful storm surges sent up river from the North Sea. Heavy rains that fall west of the city can also send torrents downstream.

Today, the mighty Thames Barrier protects the city against massive deluges, but an older flood warming system is still visible along parts of the river.

These are the bronze lion heads that line both sides of the Thames at Victoria Embankment in central London. Installed in the late 1860’s as part of the Great London Sewage Works project, they are often overlooked today as decorative moorings.

While they do not offer any protection from floods, the lions serve as visual markers for rising water. Basically, if the water level reaches their mouths, the city is at risk of a flood. Or, as the locals like to say, “When the lions drink, London will sink.”

Bronze lion heads line the wall of the River Thames, London.

Bronze lion heads line the wall of the River Thames, London.

Earth’s Aphelion 2016

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The Earth will reach its farthest point from the Sun today – an event known as the aphelion.  It will officially take place at 16:24 UTC, which is 12:24 PM Eastern Daylight Time.

This annual event is a result of the elliptical shape of the Earth’s orbit and the off-centered position of the Sun inside that path. The exact date of the Aphelion differs from year to year, but it’s usually in early July – summer in the northern hemisphere.

While the planet’s distance from the Sun is not responsible for the seasons, it does influence their length. As a function of gravity, the closer the planet is to the Sun, the faster it moves. Today, Earth is about 152 million kilometers (94 million miles) away from the Sun. That is approximately 5 million kilometers (3 million miles) further than during the perihelion in early January. That means the planet will move more slowly along its orbital path than at any other time of the year. As a result, summer is elongated by a few days in the northern hemisphere.

The word, aphelion, is Greek for “away from sun”.

Image Credit: mydarksky.org

Earth is farthest from the Sun during summer in the northern hemisphere. Image Credit: mydarksky.org