Active 2019 Atlantic Hurricane Season Comes to a Close

The 2019 Atlantic Hurricane Season officially ended on Saturday.  It marked the fourth year in a row with above-average activity.

According to NOAA, there were eighteen named storms this season. Of these, six developed into hurricanes and three were major hurricanes with ratings of category 3 or higher on the Saffir-Simpson Scale. It also posted an Accumulated Cyclone Energy (ACE) index of 129.8 An average season produces twelve named storms, six hurricanes, three major hurricanes, and an ACE of 106.

Officially running from June 1 to November 30, the season got off to an early start with Subtropical Storm Andrea forming in May. This was the fifth consecutive year to see a pre-season storm develop. The biggest names of the season, however, were Dorian and Lorenzo.

In September, Hurricane Dorian made landfall in the Bahamas as a category-5 storm with winds measured up to 185mph and a minimum pressure of 910 millibars.  It was the strongest storm on record to hit the island nation, claiming the lives of at least 60 people and leaving several billion dollars worth of damage in its wake.

Dorian also marked 2019 as the fourth year in a row to see a category-5 storm develop in the Atlantic basin, a new record.

Out at sea, Hurricane Lorenzo became the second category-5 storm of the season. It was also the easternmost Category-5 storm in the Atlantic on record. As for a possible connection to climate change, it is interesting to note that twenty-eight category-5 storms have developed in the Atlantic since 1950 with fourteen of them occurring since 2003.

For the contiguous United States this season, Tropical Storm Imelda caused the most damage. Moving slowly across Texas and Louisiana, it dumped between 30 and 44 inches of rain on the area over the course of three days. It unleashed catastrophic flooding throughout the region and became the fifth wettest tropical cyclone on record in the continental US.

This active hurricane season, according to NOAA, was largely the result of above-average sea surface temperatures in the Atlantic, a stronger than normal West African monsoon, and ENSO neutral conditions in the Pacific. In other words, the combination of warm water to fuel storms and reduced wind shear across the Gulf of Mexico allowed for unhindered tropical development in the Atlantic basin.

Credit: NOAA

Fall Nor’easter Transitions to Sub-Tropical Storm Melissa

The nor’easter that has been battering the northeast coast of the US for several days transitioned to Sub-Tropical Storm Melissa on Friday. It is now the 13th named storm of the Atlantic hurricane season.

Lingering offshore since Wednesday, states from the mid-Atlantic to New England have been feeling its impacts in the form of strong winds, heavy rain, and coastal flooding. On Friday, its sustained winds were measured up to 60 mph.

Classified as subtropical, Melissa is a hybrid between a tropical storm and a regular low-pressure system. 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.

The National Hurricane Center expects Melissa to become post-tropical and move further out to sea over the weekend.

Subtropical Storm Melissa swirling off the coast of New England. Credit: NOAA

What Causes the Smell of Rain?

Rain is often associated with particular smells. But, rain itself is odorless. So, where do these aromas come from?

The distinctive scent that lingers in the air after a rainstorm is known as petrichor. It is the product of two reactions that occur when rainwater hits the ground. Its main driver is a soil-dwelling bacteria called actinomycetes. These microorganisms thrive in moist conditions, but as the soil dries out, they produce spores. These are then released into the air by the moisture and force with which the rain hits the ground. This happens at the same time the rainwater is mixing with oils that were secreted by plants onto nearby rocks and soil during times of dryness. Together these reactions produce the musky petrichor smell, which is particularly strong after a long dry spell. The term was coined in 1964 by two Australian scientists, Isabel Joy Bear and RG Thomson. They derived it from the Greek words, “petra” meaning stone and “ichor”, the term used to describe the blood of the gods in ancient mythology.

A different, and often more pungent, rain smell is associated with thunderstorms. After the powerful electric charge of a lightning bolt splits the oxygen and nitrogen molecules in the atmosphere, they often recombine as nitric oxide. This, in turn, interacts with other atmospheric chemicals to form ozone (O3). When people say they can “smell the rain coming”, this is the scent they detect as it often arrives in the wind ahead of an approaching storm.

Credit: freepik

May 2019: A Soggy Month for NYC

May was another month of wild temperature swings in New York City. Producing several cases of weather whiplash, highs ranged from a chilly 48°F to an unseasonably balmy 86°F. In the end, however, these extremes balanced each other out. The city’s mean temperature for the month was 62.2°F, which is only 0.2°F below average.

On the precipitation side of things, May was unusually wet. The month brought the city a relatively rare spring nor’easter and several impressive thunderstorms. One of which produced golf ball sized hail on Staten Island, one the city’s five boroughs. Overall, 19 out 31 days posted measureable rainfall that added up to 6.82 inches for the month. While that is a soggy statistic, it was not the wettest May the city has seen. That dubious honor belongs to May 1989 when 10.24 inches of rain was measured in Central Park. The city, on average, gets 4.19 inches for the month.

Credit: The Weather Gamut

Names for the 2019 Atlantic Hurricane Season

Today is the first day of the 2019 Atlantic Hurricane Season. Although one named storm, Andrea, already formed, the season officially runs from June 1 to November 30.

Since 1950, each tropical storm or hurricane to form in the Atlantic has been given a unique name. They come from a set of six rotating lists produced by the World Meteorological Organization. A name is retired only when a storm was particularly noteworthy – causing a large number of fatalities or an extraordinary amount of damage.

Some notable retired names include:  Harvey, Irma, Katrina, Maria, Michael, and Sandy. The names for this year’s storms are listed below.

Credit: NOAA

Strong Storm Pelts NYC Borough with Large Hail

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.

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.

Large hail fell from an intense thunderstorm over Staten Island, NYC on May 28, 2019. Image Credit: Staten Island Advance/ J Yates

The 2019 Atlantic Hurricane Season Outlook

The number of hurricanes that develop in the Atlantic basin varies from year to year. For 2019, NOAA’s Climate Prediction Center is forecasting a near average season.

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.

A major hurricane is one that is rated category 3 or higher on the Saffir-Simpson scale.

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 ongoing El Niño event. El Niño conditions in the Pacific tend to cause increased wind shear in the Atlantic, which suppresses tropical development in that basin.

Last year, 2018, saw a very destructive hurricane season in the Atlantic. It produced fifteen named storms, including, Florence and Michael.

Regardless of the number of storms that actually form this year, it is important to remember that it only takes one land-falling system to make it an impactful season.

Subtropical Storm Andrea Kicks Off the 2019 Atlantic Hurricane Season Early

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

Spring Nor’easter Brings Unseasonably Cold, Wet Weather to NYC

A late season nor’easter soaked 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

Hurricane Names Florence and Michael Retired by WMO

There will never be another hurricane by the name of Florence or Michael. The World Meteorological Organization (WMO) has announced that it is officially retiring these names from its list of Atlantic cyclones.

The WMO is responsible for naming tropical storms and hurricanes around the world.  It maintains a set of six rotating lists for each hurricane-prone region. After a six-year cycle, names are re-used.  Names are only retired when a storm was particularly noteworthy – causing a large number of fatalities or an extraordinary amount of damage.

Hurricane Florence. Credit: NOAA

The 2018 Atlantic Hurricane Season was active, but two storms were particularly destructive. Hurricane Florence made landfall in North Carolina in September as a cat-1 storm and dumped a massive amount of rain on the area. Traveling inland, it caused catastrophic flooding in parts of both North and South Carolina. In Elizabethtown, NC, 35.93 inches of rain was reported, making it the wettest tropical cyclone on record for the state. For the contiguous US, it ranked as the eighth wettest.

Hurricane Michael. Credit: NOAA

In October, Hurricane Michael hit the Florida panhandle as a cat-4 storm. With winds measured up to 155mph, it was the strongest storm on record to strike the region and the third strongest storm to make landfall in the continental US. Its powerful winds and storm surge flooding decimated the Panama City area.

To date, according to the National Hurricane Center, 89 storm names have been retired since the current naming system began in 1953. The 2005 hurricane season holds the record for the most retired names – five – in one season.

Starting in 2024, when last year’s list is recycled, the names Florence and Michael will be replaced by Francine and Milton.

The 2019 Atlantic hurricane season officially begins on June 1.