A powerful thunderstorm moved through New York City on Tuesday night. Generating strong winds and heavy rain across area, it also brought hail to Staten Island, one of the city’s outer boroughs.
According to reports, hailstones measuring 1.8 inches in diameter came down in the Bull’s Head neighborhood. Roughly the size of golf balls, it was the largest hail reported in the city since 2011.
The storm was strong enough to warrant a tornado warning for the area, but luckily no twisters touched down in the five boroughs. Nonetheless, the large hail is a testament to the storm’s intensity. Simply put, the stronger the updraft of a storm, the longer hailstones remain suspended, allowing them to grow larger.
Tropical cyclones, known as hurricanes in the United States, develop around the globe at different times of the year. In this country, we are most impacted by the Atlantic hurricane season, which affects the North Atlantic Ocean, Caribbean Sea, and the Gulf of Mexico. It runs from June 1 through November 30.
Overall, NOAA predicts a 70% likelihood of nine to fifteen named storms forming this season, of which four to eight could become hurricanes, including two to four major hurricanes. An average season produces twelve named storms, including six hurricanes and three that become major hurricanes.
This year’s outlook, according to NOAA, reflects several competing factors. On one side, there are above average sea surface temperatures in the tropical Atlantic to fuel any storms that develop. Additionally, there is an enhanced west African monsoon in place that can initiate disturbances that turn into storms over the Atlantic. On the other hand, there is an ongoingEl Niño event. El Niño conditions in the Pacific tend to cause increased wind shear in the Atlantic, which suppresses tropical development in that basin.
Subtropical Storm Andrea, the first named storm of 2019, has kicked off the Atlantic Hurricane Season early. Its arrival marks the fifth year in a row to produce a pre-season storm.
Forming south of Bermuda on Monday, it generated winds measured up to 40mph. However, did not last long. It dissipated quickly as it moved north into cooler conditions.
Classified as subtropical, Andrea was a hybrid between a tropical storm and a regular low-pressure system usually found at higher latitudes. A tropical system is fueled by the latent heat released by the evaporation of ocean water while a regular storm is powered by the temperature contrast between air masses. Hybrids are able to access both energy sources.
Hurricane season in the Atlantic is officially designated as June 1 to November 30, but there is nothing inherently magical about those dates. While conditions for storm development are traditionally more likely during that time, storms can form anytime when given the right environment.
Other recent out-of-season storms include: Alberto and Beryl in 2012, Ana in 2015, Alex and Bonnie is 2016, Arlene in 2017, and Alberto in 2018. It is worth nothing that Alex formed in January 2016, but was really more of a late remnant of the 2015 hurricane season.
Subtropical Storm Andrea becomes first named storm of the 2019 Atlantic hurricane season. Credit: NOAA
Our global temperature continued its upward trend last month with April 2019 marking the second warmest April ever recorded on this planet. Only April 2016 was warmer.
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 58.37°F. That is 1.67°F above the 20th-century average. April was also the 412th 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 in April, some places were particularly warm, including parts of Greenland, Scandinavia, and Asia. These soaring temperatures are largely attributed to the long-term trend of human-caused climate change.
For many people in thecontiguous US, especially in the northern and central parts of the country, this April was relatively cool. To put this disparity into context, consider that the United States constitutes less than 2% of the total surface of the Earth. This detail also highlights the fact that climate change is a complex global phenomenonthat involves much more than the short-term weather conditions that are happening in any one part of the world.
Year to date, the first four months of 2019 were the third warmest such period of any year on record. Global temperature records date back to 1880.
April 2019 was Earth’s second warmest April on record. Credit: NOAA
Art and science are coming together in Provincetown, MA this weekend at the BrotoEco Conference. Now in its second year, the event focuses on brainstorming ideas and fostering collaborations across these seemingly divergent fields of study.
A late season nor’eastersoaked the northeastern United States on Monday. Heavy rain triggered flood alerts and advisories from Virginia to Connecticut, and areas further north reported snow.
Here in New York City, 0.70 inches of rain fell in Central Park. This came on the heels of the 1.32 inches that fell the day before when a separate storm system moved through the area. To date this May, the city has received 3.70 inches of rain and it is only the middle of the month. May, on average, brings the city a total of 4.19 inches of rain.
The storm also ushered in unseasonably cool temperatures, making it feel more like March than May. The high in NYC only made it to 48°F on Monday, setting a new record for the coldest high temperature for the date. The old record of 49°F was set in 1914. The normal high for this time of year is 70°F.
This storm was the result of a deep dip in the jet stream that moved over the region, which, in turn, helped generate an area of low pressure off the coast. Producing gusty northeasterly winds, it was categorized as a nor’easter. While this type of storm is more common during the fall and winter months, they can develop any time of the year.
A late spring nor’easter soaked the northeastern US. Credit: weather.com
Across the contiguous United States, spring temperatures have increased an average of more than 2°F over the past fifty years, according to Climate Central. The southwest part of the country has seen the fastest seasonal increase, with Las Vegas, NV and Tucson, AZ warming more than 6°F since 1970.
Warming temperatures mean more frost-free days. While this may lengthen the growing season for some crops, it also extends the allergy season and allows pests like mosquitos and ticks to live and thrive longer.
Looking ahead, if greenhouse gas emissions continue to rise, scientists say spring could arrive at least two weeks earlier by 2050 compared to recent years.
Our planet’s atmospheric concentration of carbon dioxide (CO2) has broken yet another record. April’s average reading of 413.52 parts per million (ppm) set a new record high, according to Scripps’ Mauna Loa Observatory in Hawaii. This marks yet another high point on the definitively upward trend of the Keeling Curve, a well-known climate change indicator.
To put this rapidly increasing number into perspective, consider that when the observatory was first established in 1958, the CO2 level was 315 ppm, slightly higher than the pre-industrial level of 280 ppm. Going back even further, ice-core research shows that today’s level of atmospheric CO2 is unprecedented in the last 800,000 years.
CO2 is one of the most prevalent greenhouse gases in the atmosphere due to human activities such as the burning of fossil fuels and deforestation. While it is a vital part of our atmosphere’s mix of gases and helps keep the planet from freezing, too much of it causes problems. Simply put, more greenhouse gases in the atmosphere trap more heat and increase the planet’s average temperature.
Since the pre-industrial era, according to the IPCC, Earth’s mean temperature has increased 1°C (1.8°F). As temperatures rise, long established weather patterns are shifting. Some areas are getting wetter, while others are getting dryer, and coastal communities are feeling the impacts of rising sea levels.
This new CO2 milestone, therefore, is not good news. The IPCC’sSpecial Report on Global Warming of 1.5°C released this past autumn clearly states that the impacts of climate change will be greater at a lower degree of warming than previously thought. To avoid the worst of these various impacts, the report says greenhouse gas pollution must be reduced by 45% from 2010 levels by 2030, and slashed to net zero by 2050.
This type of reduction will require massive action and enormous political will.
This April was also above average in terms of precipitation, with 18 out of 30 days producing measurable rainfall. In all, 4.55 inches of rain was measured in Central Park. Of that total, 1.03 inches fell on a single day. The city, on average, gets 4.50 inches of rain for the entire month.
April 2019 was NYC’s 8th warmest April on record. Credit: The Weather Gamut