Tag Archives: national

Hurricane Florence Swamps the Carolinas

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Hurricane Florence, the 6th named storm of the Atlantic Hurricane season, slammed North and South Carolina this weekend.

Steered across the Atlantic by a strong area of high pressure, Florence made landfall near Wrightsville Beach, NC on Friday morning as a category-1 storm.  It peaked at category-4 strength while still over the ocean, but weakened as it moved closer to the US coast.

Despite this downgrade, Florence still packed a powerful punch. Its strong winds, flooding rains, and storm surge forced people to evacuate their homes and caused significant property damage as well as widespread power outages across the region. In the hard hit city of New Bern, NC, at the mouth of the Neuse River, a storm surge of more than ten feet was reported. Local officials there say upward of 4000 homes and businesses were damaged or destroyed.

Moving as slowly as 2 mph at one point, Florence essentially stalled out over the region, allowing it to unleash massive amounts of precipitation. Preliminary reports show that the storm set new state records for rainfall from a single tropical cyclone in both North and South Carolina. In Elizabethtown, NC, 35.93 inches was reported, crushing the previous record of 24.06 inches set by Hurricane Floyd in 1999. In South Carolina, the town of Loris, about 25 miles north of Myrtle Beach, reported 23.63 inches of rain, eclipsing the old record of 17.45 inches set by Tropical Storm Beryl in 1994.

If these numbers are confirmed by the NWS, that would mean four state tropical cyclone rainfall records were broken in the last thirteen months. The other two being Texas with 60.58 inches of rain from Hurricane Harvey in August 2017 and Hawaii with 52.02 inches from Hurricane Lane just last month.

Measuring 400 miles wide, Florence’s successive bands of heavy rain also caused catastrophic inland flooding as several rivers in the region overflowed their banks and inundated communities. In Fayetteville, NC – nearly 100 miles from the coast – more than 15 inches of rain was reported as of Monday. The Cape Fear River, which runs through the city, is forecast to crest at 61.8 feet on Tuesday, which is more than 25 feet above flood stage.

The death toll from this storm currently stands at 20, with most fatalities being water related. Sadly, as the rivers across the area continue to rise, that number is expected to increase in the coming days.

Hurricane Florence off the coast of the Carolinas. Credit: NOAA

Wind Cave National Park and the Science Behind What Makes the Wind Blow

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I recently visited Wind Cave National Park in South Dakota, which protects a beautiful expanse of the Northern Great Plains as well as one of the largest and most complex cave systems in the world. While well known for its geology, the park’s namesake feature is also an excellent example of the science behind a basic weather phenomenon – wind.

Wind, which is air in motion, is the result of differences in atmospheric pressure. These pressure differences are caused by the temperature differences created by the uneven heating of the Earth’s surface by the Sun.  Several factors contribute to this unbalanced process, including cloud cover, large bodies of water, topography, and vegetation.

As the surface warms, air heats and rises, creating an area of low pressure. To fill that void, air from an area of relatively higher-pressure rushes in, creating a flow of air that we recognize as wind. The greater the pressure differences between these two areas, the stronger the breeze.

Atmospheric pressure conditions at the cave entrance during my visit. Credit: Melissa Fleming

At Wind Cave, given its vast size, the air pressure inside the cave is constantly working to equalize with that above ground. Therefore, when there is an area of high pressure at the surface, the wind will blow into the cave. If there is an area of low pressure on the surface, the wind will blow out of the cave. For this reason, the cave is described in the oral histories of the Lakota – a Native American tribe who consider it scared – as “the hole that breathes cool air”.

Park Ranger demonstrates the flow of air coming out of the small cave entrance with a ribbon. Credit:RVDreamLife

While other large cave systems can generate barometric winds, those at Wind Cave are more noticeable because of the small size of its entrance. As the Venturi Effect shows, when space is constricted, air will flow faster. Legend says that the first non-native settlers to discover the cave – two brother named Jesse and Tom Bingham – did so by accident when the wind from its entrance blew the hat off one of their heads in 1881.

According to the NPS, winds at the cave’s natural entrance have reached up to 25-mph.

Wind Cave National Park, SD. Credit: Melissa Fleming

The Continental Divide Determines Where Rain Goes After it Hits the Ground

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Most people are familiar with the various types of precipitation that falls from the sky. However, have you ever wondered where all that water goes after it falls or melts? The answer is largely dependent on what side of the continental divide it landed.

A continental divide is a natural boundary that separates the river systems of a continent. They are usually tall mountain ranges that direct the flow of rivers and streams to different oceans. Essentially, any precipitation that falls or melts on one side will flow into one ocean basin and anything that falls or melts on the other side of the divide will flow into another basin.

Sign in Rocky Mountain National Park marks the location of the Continental Divide in CO. Credit: Melissa Fleming

Every continent has at least one and some have multiple. In the United States, the main divide is the Rocky Mountains. It is part of the Great Continental Divide of the Americas, which runs from western Alaska through the Andes Mountains in South America. It separates water that runs into the Atlantic Ocean from water that flows into the Arctic or Pacific Oceans.

In some cases, water finds its way into an endorheic basin with no outlet to an ocean.  Utah’s Great Salt Lake and Oregon’s Crater Lake are well known examples.  Here, the water re-enters the water cycle via evaporation. A small percentage of precipitating water also seeps into the ground where it replenishes soil moisture and underground aquifers. That said, the vast majority of water returns to the world’s oceans where it will eventually be evaporated and fall as precipitation again somewhere on the planet.

North America has several drainage divides, but the Great Divide (red) is the largest. Credit: ContinentalDivide.net

 

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

Wildfires Are Scorching the American West

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Summer is wildfire season in the American West and it is off to a blazing start.

As of Monday, according to the National Interagency Fire Center, fifty-nine large wildfires – defined as greater than 100 acres – are currently burning in nearly a dozen states. These include Alaska, California, Colorado, Idaho, New Mexico, Nevada, Oregon, Texas, Utah, Washington, and Wyoming.

One of the newest conflagrations, the Ferguson Fire, is raging just outside of Yosemite National Park in California’s Sierra Nevada mountains. At the height of tourist season, the fire has closed down Highway 140, one of the main entrances to the Park. It has forced the evacuation of several communities along Yosemite’s western edge as well as some hotels inside the Park. Ignited on Friday, the fire has burned more than 9,000 acres and is only 2% contained. Sadly, it has also claimed the life of one firefighter who was battling the flames.

Another hard hit state is Colorado, where seven large fires are burning. The largest is the Spring Creek Fire, which stared at the end of June and has burned more than 108,000 acres in Costilla and Huerfano counties.

These huge fires are being fueled by extremely hot and dry conditions that have left the region’s vegetation susceptible to any type of spark. Just a few days ago, excessive heat advisories were in effect for a large swath of the west as temperatures soared well above average.

Year to date, 3.3 million acres in the US have been charred, which is above average for this point in the season. The country’s worst wildfire year on record was 2015 when more than ten million acres burned.

Ferguson Fire in the Sierra National Forest, outside of Yosemite National Park in California. Credit: InciWeb/BlakeScott

Thomas Jefferson: Founding Father of Weather Observers

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As the main author of the Declaration of Independence and the third President of the United States, Thomas Jefferson is regarded as one of this country’s Founding Fathers. He was also an astute and systematic weather observer.

Portrait of Thomas Jefferson by Rembrandt Peale, 1805. Credit: NYHS

In the summer of 1776, Jefferson was in Philadelphia, PA to sign the Declaration of Independence.  While there, he purchased a thermometer and a barometer – new and expensive weather equipment at that time. For the next 50 years, he kept a meticulous weather journal.  He recorded daily temperature data wherever he was – at home in Virginia or while traveling.

On July 4, 1776, Jefferson noted that the weather conditions in Philadelphia were cloudy with a high temperature of 76°F.

In an effort to understand the bigger picture of climate in America, Jefferson established a small network of fellow observers around Virginia as well as contacts in a few other states. According to records at Monticello, his estate in Virginia, he hoped to establish a national network for weather observations. While this plan did not come to fruition during his lifetime, today’s National Weather Service considers him the “father of weather observers.”

Happy Independence Day!

An excerpt from Thomas Jefferson’s Weather Journal, July 1776. Credit: NCDC

Names for the 2018 Atlantic Hurricane Season

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Today is the first day of the Atlantic Hurricane Season. Although one named storm, Alberto, already formed this year, 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 Atlantic Basin storm names include: Andrew, Harvey, Irma, Irene, Katrina, Maria, and Sandy. The names for this year’s storms are listed below.

Credit: NOAA

2018 Atlantic Hurricane Season Outlook: Average to Above Average

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The number of hurricanes that develop in the Atlantic basin varies from year to year. For 2018, NOAA’s Climate Prediction Center is forecasting an average to above 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 ten to sixteen named storms forming this season, of which five to nine could become hurricanes, including one 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 outlook, according to NOAA, is based on the possibility of the development of a weak El Niño and near-average sea surface temperatures in the tropical Atlantic. El Niño conditions in the Pacific tend to cause increased wind shear in the Atlantic, which suppresses tropical development in that basin.

Last year, 2017, was the most active Atlantic Hurricane season in more than a decade.  It produced seventeen named storms, including Harvey, Irma, and Maria. But regardless of the number of storms that actually form this year, it is important to remember that it only takes one land-falling system in your community to make it an impactful season.

Source: NOAA

 

The Eastern Pacific Hurricane Season Begins Today

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Hurricane season in the eastern Pacific begins today.

Tropical cyclones, known as hurricanes in the United States, develop around the globe at different times of the year. In the northeastern Pacific, they tend to form between May 15 and November 30. This early start, compared to the Atlantic, is due to the basin’s warm sea surface temperatures and relatively low wind shear.

While powerful, these Pacific storms are generally not as familiar to Americans as those that form in the Atlantic Ocean or Gulf of Mexico. This is because they rarely make landfall in this country. In fact, it has only happened twice. A hurricane slammed San Diego, CA in 1858 and a tropical storm battered Long Beach, CA in 1939. This low rate of occurrence is attributed to the cold water of the California Current that flows south along the west coast. Nonetheless, Pacific hurricanes can still impact the US.

Developing in the tropics, Pacific storms deteriorate as they travel north to cooler waters and in some cases over the mountains of Mexico. However, their remnants are still laden with moisture when they reach the southwestern US, where they often unleash flooding rains.

East Pacific storms can also cross into the Central Pacific and affect Hawaii. (The dividing line between the two basins is 140°W longitude). One such storm was 1992’s Hurricane Iniki, the worst hurricane in the state’s history. With wind speeds measured up to 145mph, it was rated category-4 on the Saffir-Simpson scale.

On average, the eastern Pacific produces 15 to 16 named storms in any given year. Of those, eight to nine develop into hurricanes with 4 to 5 becoming major hurricanes.

Source: NWS

Red, Blue, and Green: The Environment Was Not Always a Polarized Issue

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Earth Day is a time to focus on the environment. These days, however, it is hard to discuss the topic in the US without politics coming into play. While there have always been debates about land and resource uses, the issue today is more polarized then ever with the division almost always running down party lines. Those in favor of environmental protection and conservation are usually Democrats and those pushing for economic and commercial development tend to be Republicans. This type of tribal divide, however, was not always the case. There is a long history of Republicans taking action to protect the environment.

In 1864, President Abraham Lincoln, a Republican, signed the Yosemite Land Grant. This piece of legislation gave Yosemite Valley and the nearby Mariposa Big Tree Grove to the state of California. Championed by Senator John Conness (R-CA), it was first time in US history that land was designated for preservation and public use.

This historic legislation set the precedent for Yellowstone, which spreads across Wyoming, Montana, and Idaho to become this country’s first official National Park in 1872. Established by Congress, it was signed into law by President Ulysses S. Grant, a Republican.  Yosemite eventually also became a National Park in 1890 under President Benjamin Harrison, also a Republican.

Coming into office in 1901, Theodore Roosevelt, a Republican from NY, became known as the “Conservation President.” Using the power of the presidency, he protected approximately 230 million acres of public land. According to the NPS, this included the establishment of 150 national forests, 51 federal bird reserves, 4 national game preserves, 5 national parks, and 18 national monuments.

While also steadfast in his belief about utilizing the country’s natural resources, he understood the necessity of ensuring their sustainability. As such, he created the US Forest Service in 1905 as a division of the Department of Agriculture. He wanted to conserve forests for continued use.

By 1916, there were 35 National Parks and monuments across the US. To manage them all, President Woodrow Wilson – a Democrat – signed the Organics Act, creating the National Parks Service as a bureau within the Department of the Interior.

In the 1970’s, the environment returned to the national agenda, but with a new focus. After the 1969 Cuyahoga River fiire and the oil spill off Santa Barbara, CA, the rampant industrial pollution and deterioration of the nation’s natural environment became apparent. These human-caused disasters occurred around the same time as the publication of Earth Rise, a photograph taken by NASA astronaut William Anders as he looked back toward the planet. The image was a powerful reminder of how also fragile and unique the Earth really is. Together, these events led to the first Earth Day in 1970, where millions of people across the US came out to demand protection for the environment. As a result, President Richard Nixon – a Republican  – created the EPA. Soon afterwards, his administration passed the Clean Air Act, the Clean Water Act, and the Endangered Species Act.

By the 1980’s, the hole in the ozone became an international environmental concern because of the adverse effects it could have on human health and the environment. Under the UN’s Montreal Protocol, governments around the globe agreed to phase out the use of chlorofluorocarbons (CFCs) and halons. When released into the atmosphere, these gases, formerly found in aerosol spray cans and refrigerants, reduced the ozone’s capacity to absorb ultraviolet radiation. President Ronald Reagan, a Republican, signed the international agreement in 1988.

In the 1990s, climate change was beginning to be recognized as a serious environmental problem.  To address this issue, the UN organized the 1992 Earth Summit in Rio de Janeiro, Brazil. There, President George HW Bush – a Republican – signed the United Nations Framework Convention on Climate Change (UNFCCC). This international environmental treaty was the first step on the long and often bumpy road toward the Paris Climate Agreement of 2015.

The current Republican administration, however, has called climate change a “hoax”. It has announced plans to withdraw the US from the Paris Agreement and is rolling back the nation’s Clean Power Plan. So, it is safe to say that the Republican Party has been stepping back from its green legacy in recent years. In fact, we often hear Republican politicians and pundits say things like environmental regulation is detrimental to the economy.

History, however, has shown this argument to be largely false. In the past, some people saw National Parks as government land grabs that would hinder development. Today, they are among the most beloved landscapes in the country. They also generate millions of dollars every year from tourism for the local businesses that surround them. Regulations for clean air and water also had many positive outcomes. Not the least of which are the improved health of millions of Americans and the reclamation of polluted areas now open to new uses and clean sustainable development.

The lessons of history are clear. So, why is there such a polarized divide in this country over environmental issues? Who is benefiting from this rift? These are some important questions to consider not just on Earth Day, but everyday. After all, as the saying goes, everyday is Earth Day.

Earth Rise. Credit: William Anders/NASA