Monthly Archives: August 2018

Third Heat Wave of the Summer Bakes the Big Apple

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The third heat wave of the summer baked the Big Apple this week.

The threshold for what constitutes a heat wave varies by region, but here in the New York City area it is defined as three consecutive days with temperatures reaching 90°F or higher. This week, the mercury in Central Park reached 94°F on Tuesday, 92°F on Wednesday, and 90°F on Thursday. With the dew point temperature in the 70s, it felt even hotter.

There was also little relief from the heat at night. All three dates tied or set new record warm low readings. The temperature only dropped to 79°F on Tuesday, 81°F on Wednesday, and 78°F on Thursday. The previous record high minimum temperature for all three dates was 78°F.

The main driver of this dramatic heat and humidity was a dominant Bermuda High, a large area of high pressure situated off the east coast. Spinning clockwise, it steered hot, humid air from the Gulf of Mexico toward the northeast.

The normal high and low for this time of year in New York City is 81°F and 66°F, respectively.

Credit: The Weather Gamut

Hurricane Lane: The Wettest Tropical System Ever Recorded in Hawaii and the Second Wettest for US

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Hurricane Lane, the twelfth named storm of eastern Pacific hurricane season, slammed the state of Hawaii with strong winds and flooding rains over the weekend. It was the wettest tropical cyclone on record in the Aloha state.

The storm, according to the NWS, peaked at category-5 strength, but weakened as it approached Hawaii. While it did not make landfall, its outer rain bands still packed a punch that was felt across the island chain. The Big Island, however, was one of the hardest hit. In the town of Mountain View, about 15 miles southwest of Hilo, 52.02 inches of rain was reported. That is the second highest rainfall total ever recorded from a tropical cyclone in the entire United States. The highest total, 60.58 inches, fell in Nederland, Texas during Hurricane Harvey in 2017.

The slow moving nature of Lane and the orographic lift provide by the mountainous terrain of Hawaii helped push the rainfall total into the record books. Falling in a relatively short period of time, the relentless precipitation caused widespread flooding, mudslides, and road closures. It also forced mass evacuations as well as a number of water rescues.

While the eastern and central Pacific basins produce about 15 named storms a year, they rarely hit Hawaii. This is largely because of the state’s location in the vast Pacific Ocean. Sitting at about 20°N latitude, most storms pass south of the archipelago or dissipate in the relatively cooler waters to its north and east.

The last hurricane to make landfall in Hawaii was Iniki, a category-4 storm, in 1992.

Source: NWS

Hurricanes, Typhoons, and Cyclones: What’s the Difference?

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As Hurricane Lane makes its way toward Hawaii, many people have been asking me why the storm is not being called a typhoon given that it is taking place in the Pacific. The answer is all about location.

Hurricanes, typhoons, and cyclones are all the same type of storm – tropical cyclones. They are just called different things in different parts of the world. It’s like the way people in certain parts of the US say “soda” when referring to a cold fizzy drink, while people in other parts of the country use the word “pop”.

The term hurricane is used for tropical cyclones in the northern hemisphere from the Greenwich Meridian (0°) westward to the International Date Line (the 180° line of longitude). That includes the Atlantic basin as well as the eastern and central Pacific. The eastern Pacific is defined as everything north of the equator from the west coast of the North American continent to 140°W. The central Pacific, where Hawaii is located, extends from 140°W to 180°W.

Typhoon is the word used for storms west of that line, any area known as the western Pacific. If a hurricane crosses the International Date Line and maintains its strength, it will be renamed as a typhoon. In 2014, for example, Hurricane Genevieve became Typhoon Genevieve when it crossed into the western Pacific.

Across the southern hemisphere, all tropical cyclones are simply called cyclones.

These powerful storms, regardless of what we call them, can pose a threat to life and property. All warnings should be taken seriously.

Credit: American Red Cross

July 2018: Earth’s Fourth Warmest July on Record

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Our global temperature continued its upward trend last month with July 2018 marking the fourth warmest July ever recorded on this planet. Only July 2015, 2016, and 2017 were warmer, with July 2016 holding the top spot.

According to the State of the Climate report by NOAA’s National Centers for Environmental Information, Earth’s combined average temperature for July – over both land and sea surfaces – was 61.75°F, which is 1.35°F above the 20th-century average. July also marked the 403rd 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 July, some places were particularly warm, including much of Europe, Scandinavia, the western United States, and parts of southern Asia. For the contiguous US as a whole, July 2018 tied with 1998 as the eleventh warmest July on record.

These soaring temperatures are largely attributed to the long-term trend of human-caused climate change. ENSO-neutral conditions prevailed in July, which means there was neither a warm El Niño nor a cool La Niña in the Pacific to influence global weather patterns.

Year to date, the first seven months of 2018 were the fourth warmest such period of any year on record. Global temperature records date back to 1880.

July 2018 was the planet’s 4th warmest July on record. Credit: NOAA

The Deadly Danger of Lightning

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Thunderstorms are impressive displays of the power of nature. However, they are also extremely dangerous.

On average, according to NOAA, lightning claims the lives of 47 people every year in the US and seriously injures hundreds more. To date in 2018, lightning has killed 16 people across eight states. The most recent victim was struck this Saturday at Sunken Meadows State Park on Long Island, NY. Local officials say the man was sheltering under a tree during an early evening storm.

Lightning comes in variety of forms, but the cloud to ground variety is the most threatening to people. 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.

This type of lightning, NOAA says, strikes the US about 25 million times a year. However, 70% of lightning fatalities occur during the summer months. The season marks not only the peak of thunderstorm activity in the US, but also the time of year when people spend more time outdoors.

Top ten activities that contributed the most to lightning deaths in the US, 2006-2017. Credit: NWS

According to a NWS report on lightning deaths in the US from 2006 to 2017, the vast majority of victims were men engaged in an outdoor leisure activity. Listing a variety of different pastimes at the time they were struck, fishing topped the list as the most deadly. It accounted for nearly 10% of the lightning fatalities during that period.

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

Credit: NWS/NOAA

Weather and Health: Hot Car Deaths

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Summer weather can pose a number of health and safety concerns, from poor air quality to being hit by lightning. One of the more deadly risks for children, however, is heatstroke when they are left in a hot car.

Since 1998, according to kidsandcars.org, there has been an average of 37 hot car deaths in the US every year. That is one every nine days. This year, there have already been 34 deaths reported.

Credit: USA Today

On a sunny day, the interior temperature of a parked car can increase 19°F in just ten minutes. That means if the outside air temperature is a seemingly comfortable 70°F, the inside of the car can heat up to near 90°F in a very short period. The situation is even worse when the outside temperature is higher and the car sits in the sun longer.

According to the Mayo Clinic, if the human body reaches 104°F, organ damage and death become a real risk. Children are even more vulnerable because their smaller bodies can heat up between three to five times faster than that of an adult. Most hot car victims are under the age of three.

These dangerous situations develop in a number of different ways. Children can sometimes find their own way into a car while playing outside or a guardian leaves them alone in a vehicle for what seems like a quick errand. However, the majority of hot car deaths occur when a parent or caregiver gets distracted or has a change in their daily routine and simply forgets that a child is in the back seat when they park their car.

To avoid a heartbreaking tragedy, remember to Look Before You Lock!

NoHeatstroke.org

Lightning: The Five Second Rule

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As a thunderstorm moves into an area, lightning  illuminates the sky followed by rumbles of thunder. Using this sequence of events and applying some simple math, you can estimate how far away the storm is.

Since lightning travels at approximately the speed of light – 186,000 miles per second – you see it almost instantly.  Thunder, on the other hand, travels at the speed of sound – about one mile in five seconds. These different rates of travel allow you to estimate the distance between yourself and the lightning.

To do this, count the seconds between seeing the flash of lightning and hearing the clap of thunder. Divide that number by five and you will know how far away the  lightning is. For example, if you count fifteen seconds between seeing lightning and hearing thunder, the lightning is about three miles away.

But, remember, if you can hear thunder, lightning is close enough to strike. So, as NOAA recommends, “When thunder roars, go indoors.”

Cloud to ground lightning strike. Credit: NWS

Storm Breaks Daily Rainfall Record in NYC

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August has only just begun and it is already New York City’s wettest August in seven years. This is largely due to the strong thunderstorms that swept through the city on Saturday and unleashed more than half a month’s worth of rain in just a few hours.

According to the NWS, 2.9 inches of rain was measured in Central Park, setting a new record for the date. The previous record of 2.39 inches had been in place since 1983. On average, the Big Apple gets 4.44 inches of rain for the entire month of August.

The torrential rain, which came on the heels of NYC’s wettest July in fourteen years, flooded roadways and caused power outages across the city. Significant delays and cancellations were also reported at the area’s airports.

This type of heavy rain event, according to NOAA, is expected to become more common in the northeast as global temperatures continue to rise and precipitation patterns change.

Record rain floods the streets on the upper east side of Manhattan. Credit: ScooterCaster/NY1

Second Heat Wave of the Summer Bakes the Big Apple

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New York City is sweltering through its second heat wave of the summer.

The threshold for what constitutes a heat wave varies by region, but here in the NYC area it is defined as three consecutive days with temperatures reaching 90°F or higher. Wednesday marked the city’s fourth day of scorching conditions.

With the dew point temperature in the 70s, it felt even hotter. The heat index – the so-called real feel temperature – reached into the triple digits.

The main driver of this dramatic heat and humidity is a dominant Bermuda High, a large area of high pressure situated off the east coast. Spinning clockwise, it has been steering hot, humid air from the Gulf of Mexico toward the northeast.

While these conditions are oppressive, they can also be dangerous. The NWS issued both heat advisories and air quality alerts for the city over the past few days.

The normal high for this time of year in the Big Apple is 84°F.

Credit: The Weather Gamut

Weather and Health: Air Quality

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The air we breathe is not always good for us. It often contains pollution, which can cause or aggravate a number of health issues including respiratory and cardiovascular diseases.

Under the Clean Air Act, the EPA is responsible for monitoring air pollution across the United States. Calculated on the Air Quality Index (AQI), a standardized indicator, the agency’s daily reports focus on the health effects people may suffer as a result of breathing polluted air. The scale runs from 0-500 with increasing AQI values correlating to higher levels of pollution and an escalating risk to public health. Values above 100 are considered unhealthy.

Unlike some other environmental challenges, air pollution is nearly impossible to avoid, as we all need to breathe. Caused mainly by vehicle exhaust, power generation, and industrial emissions, its sources are ubiquitous. The five major air pollutants measured on the AQI are, ground level ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide.

Pollutants often build to unsafe concentrations on days with very high temperatures and/or a lack of wind.  Ground level ozone, for example, forms when nitrogen oxides react with heat and U.V. light near the surface. Air quality alerts, therefore, are often issued in conjunction with heat advisories.