Slow-Moving Storms Like Florence Produce Big Floods — And Are Becoming The Norm

Hurricane Florence continued to ravage North Carolina on Sunday, prompting weather alerts for every county in the state. The storm moved sluggishly — it made landfall at about 6 mph Friday and had slowed to 2 mph on Saturday, dumping massive amounts of rain as it went. The deluge, called a 1,000-year rain event by the state’s governor, swelled rivers and drew comparisons to last years’ Hurricane Harvey. But Florence’s slow forward movement and dangerous torrent of heavy rain aren’t unique to hurricanes. These features are also present in big storms that strike around the country. And what’s more, extreme rainfall events are hitting more often, and big, slow-moving systems are becoming more common. As the climate changes, it’s not just that we can expect to see more hurricanes like Florence, it’s also that more storms of other types will look like this, too.

Even though hurricanes are formed differently from inland storms, the basic components of a record-breaking flood can be present in both, said Andreas Prein, a scientist at the National Center for Atmospheric Research. “It takes very high rainfall rates, high precipitation. It has to cover a big area. And it has to move slow. Those are the big ingredients that produce a big flood,” he said.

You can see the added dangers of a slow-moving storm by looking at the costliest hurricanes to hit the U.S. The forward speed of Atlantic hurricanes tends to vary by latitude, but the eastern and Gulf coasts mostly fall into an area where the average forward speeds are above 17 mph. The costliness of a storm depends in part on where it strikes — hitting a large urban area drives up costs much faster than hitting a more sparsely populated rural area — but all but three of the costliest storms moved at slower-than-average pace.

Florence was traveling at about a fraction of the average speed for its latitude when it made landfall and has made it obvious how a slow, wet storm can turn a hurricane from a coastal wind disaster to a far-reaching flood risk.

And one of the calling cards of climate change is the wet storms it produces. Scientists are still studying how the shifting environment is changing weather systems, but they’re more certain than usual that it’s causing an increase in extreme precipitation events. “Just look at the U.S. records for the last 100 years. Extreme daily rainfall rates went up in all regions,” Prein said.

There’s a clear causal explanation for that, said David Gochis, a hydrometeorologist at NCAR. Warmer air means more evaporation of surface water, resulting in more water vapor in the air that’s available to fall as rain.

The forward speed of storms is not as well-studied, experts said, but there’s some evidence that the same changing climate that’s leading to more extreme rainfall is also putting the brakes on big rainstorms, which means they dump more water in one place. “There’s research out there in the atmospheric community that’s found that in certain seasons — especially fall — large-scale, mid-latitude storms are slowing down,” Gochis said. And it’s not just hurricanes. What’s happening right now in North Carolina is, in this way, pretty similar to what happened in Colorado in 2013, when a storm parked over a single area for a week, causing flooding that collapsed bridges and homes and spurred massive evacuations.

Last year, Prein was involved in a paper that tried to model the impacts of climate change on large storm systems of all kinds, including, but not limited to, hurricanes. Prein said his paper didn’t find evidence that climate change was making storms move more slowly. But, he said, you could still end up with a higher likelihood of encountering a big, slow, wet storm. “It’s not that climate change is changing the speed of movement, but you get more big, high-intensity storms, which [tend to] move slowly,” he said.

The result is a shifting norm in flood risk across the country. If you live on the coast, you can probably expect more flooding caused by hurricanes like Florence. If you live in the Midwest, you can probably expect more thunderstorm-related flooding. And in both cases, the kind of big floods that were rare in the past are becoming more common now. How big can the storms (and the floods) get? We don’t know what the limits are, Gochis said. We know what’s been normal in the past. But if storms are getting slower and wetter, “Well, then you have to do the calculation again,” he said.

Storm Helene Alert For Strong Winds Widens Across Wales

A storm is set to hit Wales later but the strongest gusts are due to be weaker than first expected, the Met Office has said.

Storm Helene is due to arrive later on Monday with a yellow “be aware” warning from 21:00 BST. It is expected to last until 18:00 on Tuesday.

Winds are likely to reach 40mph to 50mph with top gusts of up to 60mph.

The Met Office has warned of delays to road, rail and air services while power loss and tree damage is “possible”.

The warning was originally for west Wales but it has since been extended to cover the whole country.

“The wind will pick up as the storm moves across us,” said Rhian Haf, BBC Wales weather presenter.

Strongest Storm Recorded This Year Leaves Path Of Destruction Across Asia

Although they are used to weathering several typhoons every year, Hong Kongers woke up shell-shocked on Monday after Super Typhoon Mangkhut, the strongest storm on the planet recorded this year, tore through the city on Sunday, injuring over 300 people but killing none. Even after such a devastating storm, most people went back to work on Monday, and the stock markets opened for trading.

Despite weakening after first hitting the Philippines and killing at least 65 people, the Hong Kong Observatory confirmed Mangkhut was the most powerful storm to hit the southern Chinese territory since records have been kept beginning in 1946.

Hong Kong avoided a direct hit and escaped without any fatalities, but Mangkhut’s ferocious winds and storm surge uprooted more than 1500 trees and broke hundreds of windows across the city.

Record-setting storm surges of more than 11 feet were measured in some parts of Hong Kong, while huge waves crashed into waterfront apartments. Low elevation and coastal neighborhoods like the beach town of Shek O and waterfront housing estate Heng Fa Chuen experienced flooding.

Windows across Hong Kong were blown out by wind gusts that were recorded at speeds of up to 120 mph. Most dramatically, dozens of windows of the One Harbourfront complex that juts out into Hong Kong’s famed Victoria Harbor were destroyed. Online video taken during the storm showed reams of paper being blown out from the building.

Hong Kong’s normally secure and bendable bamboo-scaffolding used in construction could not withstand the force of the winds, and many scaffolds were ripped off of buildings, crashing into the streets below.

The Hong Kong Government made the call to lower the storm signal early Monday morning to allow the stock market to open for trading, meaning that Hong Kongers were also expected to go to work.

Public transportation was not running at full capacity as numerous bus routes and light rail services were suspended due to debris, causing major crowding at transportation hubs across the city.

In a press conference Monday, trade union leader Lee Cheuk-yan criticized Hong Kong’s Chief Executive Carrie Lam for not giving workers a day off to recover from the typhoon.

Terence Chong, an Economics professor at Chinese University of Hong Kong told the South China Morning Post that if the entire city had not worked on Monday, the economic loss could amount to about $7.3 billion Hong Kong dollars, the equivalent of $930 million U.S. dollars.

What was left of Mangkhut went on to wreak havoc on neighboring Macau on Sunday, which suspended normal casino operations for the first time ever. The storm later made landfall in China’s Guangdong province, where it has killed at least four people.

JUST IN: Watch for Increased Geomagnetic Flux Approaching Autumn Equinox

Starting this week Earth’s magnetic field is vulnerable to enhanced charged particles making its way through Earth’s magnetic field as we approach Autumn Equinox. Since our seasons are caused by the tilt of Earth’s axis relative to its orbital plane, the equinox roughly marks the transition from longer periods of daylight to shorter ones or vice versa.

During this time an occurrence known as the Russell-McPherron effect; is a hypothesis identifying geomagnetic activity is more intense around fall equinox when the direction of the interplanetary magnetic field (IMF) is away the Sun.

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Outer Bands Begin Lashing North Carolina Coast With Winds, Rain

MYRTLE BEACH, S.C. — The big slosh has begun, and the consequences could be disastrous.

Hurricane Florence’s leading edge battered the Carolina coast Thursday, bending trees and shooting frothy sea water over streets on the Outer Banks, as the hulking storm closed in with 105 mph (165 kph) winds for a drenching siege that could last all weekend.

Forecasters said conditions will only get more lethal as the storm pushes ashore early Friday near the North Carolina-South Carolina line and makes its way slowly inland. Its surge of ocean water could cover all but a sliver of the Carolina coast under as much as 13 feet, and days of downpours could dump more than 3 feet of rain, touching off severe flooding.

Florence’s winds weakened as it drew closer to land, dropping from a peak of 140 mph (225 kph) earlier in the week, and the hurricane was downgraded from a terrifying Category 4 to a 2.

But North Carolina Gov. Roy Cooper warned: “Don’t relax, don’t get complacent. Stay on guard. This is a powerful storm that can kill. Today the threat becomes a reality.”

Forecasters said that given the storm’s size and sluggish track, it could cause epic damage akin to what the Houston area saw during Hurricane Harvey just over a year ago, with floodwaters swamping homes and businesses and washing over industrial and farm waste sites.

“It truly is really about the whole size of this storm,” National Hurricane Center Director Ken Graham said. “The larger and the slower the storm is, the greater the threat and the impact – and we have that.”

Schools and businesses closed as far south as Georgia, airlines canceled about 1,200 flights and counting, and coastal towns in the Carolinas were largely emptied out.

Around midday, Spanish moss blew sideways in the trees as the winds increased in Wilmington. Some of the few people still left in Nags Head on the Outer Banks took photos of angry waves topped with white froth. By early afternoon, utilities reported about 12,000 homes and businesses were already in the dark.

Wilmington resident Julie Terrell was plenty concerned after walking to breakfast past a row of shops fortified with boards, sandbags and hurricane shutters.

“On a scale of 1 to 10, I’m probably a 7” in terms of worry, she said. “Because it’s Mother Nature. You can’t predict.”

More than 1.7 million people in the Carolinas and Virginia were warned to evacuate over the past few days, and the homes of about 10 million were under watches or warnings for the hurricane or tropical storm conditions.

Duke Energy Co. said Florence could knock out electricity to three-quarters of its 4 million customers in the Carolinas, and outages could last for weeks. Workers are being brought in from the Midwest and Florida to help in the storm’s aftermath, it said.

As of 2 p.m., Florence was centered about 110 miles (180 kilometers) southeast of Wilmington, its forward movement slowed to 10 mph (17 kph). Hurricane-force winds extended 80 miles (130 kilometers) from its center, and tropical-storm-force winds up to 195 miles (315 kilometers).

Scientists said it is too soon to say what role, if any, global warming played in the storm. But previous research has shown that the strongest hurricanes are getting wetter, more intense and intensifying faster because of human-caused climate change.

Florence’s weakening as it neared the coast created tension between some who left home and authorities who worried that the storm could still be deadly.

Frustrated after evacuating his beach home for a storm that was later downgraded, retired nurse Frederick Fisher grumbled in the lobby of a Wilmington hotel several miles inland.

“Against my better judgment, due to emotionalism, I evacuated,” said Fisher, 74. “I’ve got four cats inside the house. If I can’t get back in a week, after a while they might turn on each other or trash the place.”

Authorities pushed back against any suggestion the storm’s threat was exaggerated.

The police chief of a barrier island in Florence’s bulls’-eye said he was asking for next-of-kin contact information from the few residents who refused to leave.

“I’m not going to put our personnel in harm’s way, especially for people that we’ve already told to evacuate,” Wrightsville Beach Police Chief Dan House said.

Some of those who are getting out of the way of Hurricane Florence and landing in Chicago.

Many passengers were relieved to make it into Chicago just before the airports in the southeast started shutting down Wednesday night. They were sending thoughts and prayers to their friends and family back home.

Many passengers flew to Chicago to be with relatives while they wait out the storm.

They described the panic back home to stock up on supplies, the long lines for gas… and their concerns that that they will be returning back home to damage and destruction.

“Me and my friends were out there shopping for groceries and water,” said Harshil Patel. “Everything running out from the stores.”

“I feel great being up here out of it, but I worry about all the family and friends back home,” said Teresa Moore, who lives in Raleigh.

And help is on the way from the Chicago-area at the request of FEMA. A group of paramedics and several ambulances from Elite Medical Transportation are in North and South Carolina to help with the evacuations.

JUST IN: ESA’s New Satellite ‘Aeolus’ Wows with First Wind Data

Just one week after ESA’s Aeolus satellite shone a light on our atmosphere and returned a taster of what’s in store, this ground-breaking mission has again exceeded all expectations by delivering its first data on wind – a truly remarkable feat so early in its life in space.

Named after Aeolus, who in Greek mythology was appointed ‘keeper of the winds’ by the Gods, this novel mission is the fifth in the family of ESA’s Earth Explorers, which address the most urgent Earth-science questions of our time.

Florence Rabier, Director General of the European Centre for Medium-Range Weather Forecasts (ECMWF), said, “We always knew that Aeolus would be an exceptional mission, but these first results have really impressed us.

“The essence of an Earth Explorer mission is to deliver data that advances our understanding of our home planet and that demonstrates cutting-edge space technology. With the first light measurements and now these amazing wind data; Aeolus has wowed us on both fronts.”

In particular, you can see strong winds, called the Stratospheric Polar Vortex, around the South Pole. These winds play an important role in the depletion of the ozone layer over the South Pole at this time of the year.

ESA’s Aeolus instrument manager, Denny Wernham, noted, “These first results are truly amazing. It took years to develop this remarkable mission and everyone’s hard work is really paying off.

“The satellite hasn’t even been in orbit a month yet, but the results so far look extremely promising, far better than anyone expected at this early stage.

“We are very proud to be part of the mission. Aeolus looks set to provide some of the most substantial improvements to our weather forecasts that we’ve seen over the past decade.”

ESA’s Aeolus mission scientist, Anne Grete Straume, explained, “These first wind data shown in the plot made by ECMWF are from one orbit. In the profile we can see large-scale easterly and westerly winds between Earth’s surface and the lower stratosphere, including jet streams.

It carries the first instrument of its kind and uses a completely new approach to measuring the wind from space.

ESA’s Earth Explorer Programme manager, Danilo Muzi, said, “Aeolus carries revolutionary laser technology to address one of the major deficits in the Global Observing System: the lack of direct global wind measurements.

“Aeolus’ Aladin instrument is extremely sensitive. When we switched it on we increased its energy levels step by step, checking it after every move.

“It is indeed wonderful to see that it is behaving superbly so soon after launch.”

Nicola Chamussy, Head of Airbus Space Systems, said, “These initial results look wonderful. Thanks to the meticulous preparatory work and testing, the mission is in really good shape. Our Aladin system engineer, Olivier Lecrenier, tells me that it has exceeded his best expectations.

New X-Ray Pulsar Found Near Center of Milky Way

Using NuSTAR spacecraft and NICER instrument, an international team of astronomers has found a new accreting millisecond X-ray pulsar. The newly discovered object, designated IGR J17591−2342, is the newest addition to a still short list of known accreting millisecond X-ray pulsars. The finding is reported in a paper published August 30 on the arXiv pre-print server.

Astronomers noted that IGR J17591−2342 is located near the center of our Milky Way galaxy, some 28,000 light years away from the Earth. The estimated accretion rate was found to be about 0.52 billionth of one solar mass per year. IGR J17591−2342 is so far the 22nd known AMXP. The authors of the paper underlined that their discovery enriches the census of these objects that are essential for the understanding of the late stages of stellar evolution.

X-ray pulsars exhibit strict periodic variations in X-ray intensity, which can be as short as a fraction of a second. Accreting millisecond X-ray pulsars (AMXPs) are a peculiar type of X-ray pulsars in which short spin periods are caused by long-lasting mass transfer from a low-mass companion star through an accretion disc onto a slow-rotating neutron star. Astronomers perceive AMXPs as astrophysical laboratories that could be crucial in advancing our knowledge about thermonuclear burst processes.

To date, only 21 AMXPs have been discovered, with spin periods ranging from 1.7 to 9.5 milliseconds. In order to expand the list of this peculiar objects, the scientific community is still actively searching for such sources using space observatories like NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) telescope.

Recently, a group of researchers led by Andrea Sanna of the University of Cagliari, Italy, has used NuSTAR to identify a new AMXP. The source, named IGR J17591−2342, was initially classified as an X-ray transient by European Space Agency’s INTernational Gamma-Ray Astrophysics Laboratory (INTEGRAL) during galactic center scanning on August 10, 2018. The team observed this source with NuSTAR, which revealed evidence about the nature of this object. Additional observations of the pulsar were conducted using the Neutron Star Interior Composition Explorer (NICER) onboard the International Space Station (ISS).

“In this letter, we describe a coherent timing analysis of the NuSTAR and NICER observations that provided the pulsar spin period and binary ephemeris,” the researchers wrote in the paper.

The team detected coherent X-ray pulsations around 527.4 Hz (1.9 milliseconds) in the NuSTAR and NICER observations performed almost 25 days from the beginning of the outburst, with a pulse fraction of 15 percent.

According to the paper, IGR J17591−2342 has an orbital period of about 8.8 hours. The mass of the neutron star was calculated to be approximately 1.4 solar masses, while the minimum mass of the companion is most likely 0.42 solar masses.