August 2018: Earth’s Fifth Warmest August on Record

Our global temperature continued its upward trend last month. August 2018 marked not only the fifth warmest August on record, but also closed out the planet’s fifth warmest June to August season – a period known as meteorological summer in the northern hemisphere.

According to the State of the Climate report by NOAA’s National Centers for Environmental Information, Earth’s combined average temperature for August – over both land and sea surfaces – was 61.43°F, which is 1.33°F above the 20th-century average. This August also marked the 404th 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.

Globally, the collective period of June, July, and August was also unusually warm. NOAA reports that Earth’s average temperature for the season was 1.33°F above the 20th century average of 60.1°F. That makes it the fifth warmest such period on record.

While heat dominated most of the planet during this three-month stretch, some places were particularly warm, including much of Europe, central Asia, and the southwestern United States. For the contiguous US as a whole, the season tied with 1934 as the fourth warmest summer on record.

These soaring temperatures are largely attributed to the long-term trend of human-caused climate change. ENSO-neutral conditions prevailed in August, 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 eight months of 2018 were the fourth warmest such period of any year on record. Global temperature records date back to 1880.

Credit: NOAA

August 2018: Ninth Warmest August on Record for NYC

August 2018 was a hot month in New York City. It produced two separate heat waves and a total of seven days with readings in the 90s. Overnight lows were also mostly warmer than normal. In the end, the city’s mean temperature for the month was 78.1°F, which is 2.9°F above average. That means August 2018 is now tied with August 1955 as the city’s ninth  warmest August on record.

August was also an over-achiever in terms of precipitation. In all, a whopping 8.59 inches of rain was measured in Central Park. That marks the city’s wettest August in seven years. Of this impressive total, 2.90 inches fell on a single day (August 11), setting a new daily rainfall record for the date. The city, on average, gets 4.44 inches of rain for the entire month.

Credit: The Weather Gamut

Third Heat Wave of the Summer Bakes the Big Apple

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

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

Storm Breaks Daily Rainfall Record in NYC

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

May 2018: Earth’s Fourth Warmest May on Record

Our global temperature continued its upward trend last month. May 2018 marked not only the fourth warmest May on record, but also closed out the planet’s fourth warmest March to May season, known as meteorological spring in the northern hemisphere.

According to the State of the Climate report by NOAA’s National Centers for Environmental Information, Earth’s combined average temperature for May – over both land and sea surfaces – was 60.04°F, which is 1.44°F above the 20th-century average. The years 2014-2018 now rank among the five warmest Mays on record.

This May also marked the 401st 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 May, some places were particularly warm, including much of Europe and North America. Here in the contiguous US, it was our warmest May ever recorded. The previous record had been in place since 1934.

Globally, the three-month period of March, April, and May was also unusually warm. NOAA reports that Earth’s average temperature for the season was 1.48°F above the 20th century average of 56.7°F. That makes it the fourth warmest such period on record.

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

Year to date, the first five months of 2018 tied 2010 as the fourth warmest such period of any year on record. Global temperature records date back to 1880.

May 2018 was the fourth warmest May ever recorded on Earth. Credit: NOAA

How Hail Forms

The thunderstorms of spring and summer are notorious for their powerful winds and heavy rain. However, when strong enough, they can also produce hail.

Hailstones start off as water vapor that is lifted high into the atmosphere by the updraft of a thunderstorm. Rising into cooler air, it condenses and forms water droplets. Once these liquid droplets reach a level where the temperature is below freezing, they turn into tiny ice crystals. Overtime, they get larger as other water droplets freeze to them on contact, forming layers like an onion.  Once a hailstone gets too heavy for the updraft, it falls to the ground.

The stronger the updraft of a storm, the longer a hailstone remains suspended, and the larger it can grow. For a ball of ice to be considered a hailstone, according to the AMS, it has to measure at least 5mm in diameter.

The largest hailstone ever recorded in the US was found in Vivian, South Dakota on June 23, 2010. It measured 7.9 inches in diameter and weighed 1.94 pounds. The updraft supporting it would have had to exceed 150 mph.

Needless to say, hail can cause serious damage to people and property.

May 2018: Fifth Warmest on Record in NYC

May felt like a weather roller-coaster in New York City this year. Highs ranged from a cool 54°F to a record warm 92°F. However, with 20 out of 31 days posting above average readings, the warmth won out in the end. The city’s mean temperature for the month was 66.9°F, which is 4.5°F above average. That makes May 2018 the fifth warmest May on record in NYC.

On the precipitation side of things, May was below normal despite producing 13 days with measurable rainfall.  In all, 3.53 inches of rain was measured in Central Park. Of that total, 0.58 inches fell during a severe thunderstorm that swept through the city on May 15. The month, on average, brings the New York City 4.19 inches of rain.

Credit: The Weather Gamut

 

Suddenly Summer: Record Breaking Spring Heat in NYC

After a long cold winter and a chilly start to spring, it suddenly felt like summer in New York City this week.

According to the NWS, the temperature in Central Park hit 90°F on Wednesday. That marked the city’s first 90°F reading of the year and tied the daily record set in 2001. The sultry conditions continued on Thursday as the temperature climbed to 92°F, setting a new record high for the date. The previous record of 90°F had been in place since 2001.

Thursday’s low of 70°F was another record breaker, surpassing the old record of 68°F from 2001. In fact, this low reading was warmer than the date’s normal high. The city’s average high and low temperatures for this time of year are 67°F and 50°F, respectively.

These dramatic temperatures are the result of a Bermuda High, a large area of high pressure situated off the mid-Atlantic coast. Spinning clockwise, it has created a warm southwesterly flow of air into the northeast.

This summer-like weather brought many New Yorkers out of hibernation and into the city’s numerous parks and outdoor cafes. However, for some, the heat comes with a cost. It can lead to the formation of ground-level ozone, which is why an air quality advisory was issued for the area. Anyone with respiratory concerns, like asthma, has been advised to stay indoors.

While these temperatures are unseasonable, the city has seen 90° readings arrive even earlier. The earliest, according to NWS records, was April 7, 2010, when the mercury climbed to 92°F.

If you are not quite ready for summer, fear not. Conditions more typical of May are expected to return this weekend.

A week of weather whiplash for NYC. Credit: The Weather Gamut

Spring Storm Sets New Daily Snowfall Record in NYC

A spring snowstorm slammed the northeastern United States on Monday. Coming on the heels of a mild Easter weekend, it felt like weather whiplash across the region.

Here in New York City, the storm dumped 5.5 inches of snow in Central Park, setting a new daily snowfall record for the date. The previous record of 2 inches had been in place since 1871. The storm also marked the snowiest April day the city has seen in 36 years.

Despite the ground being relatively warm, the heavy, wet snow was able to accumulate because it came down very quickly. La Guardia Airport reported a snowfall rate of 2 inches per hour.

The city, on average, gets 0.6 inches of snow for the entire month of April.

Source: NWS