Tropical weather system developing near Florida
by Jeff Berardelli•The official start of hurricane season is still two weeks away, but the first named storm will likely form this weekend. With broadly this summer and fall, is this a signal those predictions are already materializing?The National Hurricane Center is monitoring an area of low pressure getting gradually better developed near South Florida and the Bahamas. They give the system an 80% chance of development through the weekend. If or when it develops sustained winds equal to or above 39 mph, the storm will be named Arthur.
For the 6th straight season in a row we may have an early season (before June 1st) tropical system form. This is the latest visible imagery of the hybrid system. It has an 80% chance of development this weekend as it moves NE. pic.twitter.com/6GBBUn0fZN
— Jeff Berardelli (@WeatherProf) May 15, 2020
If Arthur indeed forms in the coming days, this would be the sixth straight season with early tropical development occurring before the official start of Atlantic hurricane season on June 1st. The Atlantic basin has had named systems before June 1st every year since 2015.
The last 5 Atlantic hurricane seasons have produced an early season storm before June 1st. Will it occur again this year? pic.twitter.com/mnN8Rgj4QR
— Hurricane Tracker App (@hurrtrackerapp) May 8, 2020
Regardless, the system will produce heavy rain and wind gusts to tropical storm force — 39 mph or higher — in South Florida Friday and Friday night. Then the system will pull northeastward into the Bahamas Saturday.
Early next week the storm is forecast to move up the Eastern Seaboard, just offshore, into cooler waters with gradually weakening likely. While odds are it should remain offshore, it does bear watching as another storm in the eastern U.S. may try to pull it closer. Either way, breezy winds, rough surf and perhaps even some minor coastal flooding is in the cards for the Eastern seaboard.
It’s worth noting that the system may either be a tropical system, which is a purely tropical low, with what is called a „warm core,” meaning warm air makes up the whole system. Or it may be named a hybrid — subtropical system — which contains both warm and cold attributes. Hybrid systems usually take longer to development and typically do not get quite as strong.
This time of year subtropical systems are more common because they form with the help of cool pools of upper-level air left over from the winter and spring season. This helps destabilize the atmosphere, making it easier for systems to form when water temperatures are still not quite hot enough.
Typically, water temperatures above 80 degrees Fahrenheit are required for tropical formation. Right now, the general area where the system is forecast to form in the Bahamas is near or even slightly below that 80-degree threshold.
The early formation of tropical systems in recent years raises the question: Is climate change contributing?
Dr. Phil Klotzbach from Colorado State University, one of the nation’s leading hurricane forecasters, says warming water may factor in, but it’s more nuanced than that. „While several of the storms that have formed in the pre-season in recent years have formed over anomalously warm water, perhaps due to climate change, this system near south Florida is actually an exception,” he said.
Referring to the graphic below, Klotzbach said, „Here’s a plot showing current sea surface anomalies and the approximate forecast track of this disturbance. The waters near where the storm is currently located and where it is forecast to track are near their long-term average values.”
Water temperatures in the tropical Atlantic, and around the world, have increased over the past few decades, mostly due to human-caused climate change. That provides higher-octane fuel for tropical storm systems.
„There is very high confidence that the season length is linked to ocean temperatures,” says NOAA tropical cyclone expert Dr. Jim Kossin. „The earliest starts have become earlier and the latest ends have become later, but there’s a lot of uncertainty in the signal.”
Some of that uncertainty is linked to our increased ability to evaluate storms. Klotzbach says the increase in marginal early or late season systems is partly due to better observational ability. „These are the exact kind of storms that became much more commonplace with the development of microwave sensors that allow for better detection of weak warm cores,” he noted.
Kieran Bhatia, a hurricane and climate researcher and former postdoctoral fellow at Princeton University, cited the same general research and agrees with Klotzbach: „All this is evidence that it is very hard to produce meaningful trends that conclude earlier season storms are more likely due to climate change.” With that said, Bhatia says there is building consensus that a warming climate will lead to more intense storms in the future, as well as higher storm surge due to sea level rise and higher rainfall totals due to warmer air temperatures. „There is a growing body of evidence suggesting climate change is already increasing the magnitude of these hazards,” Bhatia said. With the increase in early-season storms, a debate has emerged in the meteorology community about whether to move the official start of the Atlantic hurricane season to an earlier date, perhaps in line with the East Pacific season which starts on May 15th. CBS News reached out to the National Hurricane Center to find out if there are any plans to do this. Dennis Feltgen, a communications and public affairs officer meteorologist for NHC, said, „There are no immediate plans to change anything, only to open a discussion of the pros and cons.” An argument against starting the season earlier is the fact that early-season systems are typically not very strong or impactful. Klotzbach says, „In the satellite era (since 1966), we’ve only had tw hurricanes form prior to June 1st and no hurricane on record (since 1851) has made continental U.S. landfall prior to June 1st.” As for whether or not an early start spells trouble for the season ahead, Klotzbach says not so much. „Historically, early season storm activity tells you very little about how active the upcoming season is likely to be,” he said. But there are many other reasons to believe that this hurricane season will likely be a busy one. As CBS News first in late April, all of the major seasonal forecasts are calling for a well-above-normal season with 14 to 20 named storms possible. The main reasons for these alarming forecasts are above-normal temperatures in the tropical development region of the Atlantic Ocean and cooling waters in the tropical Pacific, indicative of a possible La Niña forming by fall. La Niñas typically correspond with active Atlantic hurricane seasons. Klotzbach’s April forecast called for 16 named storms this season, above the average number of 12. At the time, Klotzbach felt there was some chance of La Niña developing, but since then he’s come to believe it more strongly. „I would say that I’m certainly more in favor of weak La Niña conditions now for the peak of the season than I would have been one month ago.” Klotzbach’s next seasonal forecast is due out in early June, and we will see if the increased risk of La Niña prompts him to increase his forecast numbers. Regardless, for those in potential hurricane zones, with the start of the season just two weeks away and the complications posed by the coronavirus pandemic, it would be a good idea to get an early start on preparing.Charity created by 2020 University of Vermont grad repurposes graduation gowns as PPE ; Inside a New York hospital for „Bravery & Hope: 7 Days on the Front Line” ; Great-grandmother gets to embrace family through „hug time” device
Photos taken 1 year apart show potentially troubling sign in volcano. by John Murphy•The Halema‘uma‘u crater on Kilauea, located in Hawaii, has been relatively quiet over the last year after a frenzy of activity in 2018, which all began with an explosive eruption of ash 30,000 feet into the air during May. But, since at least 2019, there has been a change that scientists believe could pose a potential danger to the Big Island. Water has started to collect in the caldera to form a lake.A caldera is a large crater left behind in a volcano after an eruption. From 2010 until 2018, a lava lake had filled the caldera rather than water. That changed in May 2018 when the eruption caused the lava lake to drain, collapsing the caldera floor and causing a hole nearly as deep as the 1,776-foot One World Trade Center. The eruption also created a 459-foot cliff (140 meters) north of the crater.About a year later, a helicopter pilot flying over the volcano noticed a mysterious green pool of water in the Halema‘uma‘u crater. A second report of the same findings from a helicopter passenger prompted USGS-Hawaiian Volcano Observatory researchers to survey the green pool of water.It was then discovered that water had indeed started to pool into the lowest part of the Halema’uma’u crater, and ever since the water was discovered in 2019, the depth of the lake has been steadily growing.
|The sequence of satellite images above shows Halema‘uma‘u crater before the lava lake drained (left), after the caldera floor had collapsed (middle) and after water pooled on the crater floor for nine months (right). (Joshua Stevens / Landsat data from the U.S. Geological Survey)|
„We know that the crater floor dropped a little more than 70 meters below the water table in 2018. Any time that you punch a hole below the level of the water table, water is eventually going to come in and fill that hole,” explained Don Swanson, a volcanologist at the U.S. Geological Survey’s Hawaiian Volcano Observatory.
|The pool of water in the Halemaʻumaʻu Crater on Aug. 7, 2019. (USGS / D. Swanson)|
Currently, the water has an area larger than five football fields combined and is approximately 100 feet (30 meters) deep, according to NASA‘s Earth Observatory.
The water has also changed color from the original chalky green to a rusty brown, due to chemical reactions happening in the water.
|The pool of water in the Halemaʻumaʻu Crater on April 21, 2020. Since its discovery in 2019, the pool has slowly been growing. (USGS / M. Patrick)|
As for how the water could affect a future eruption of the volcano, Swanson said it could contribute to an explosive eruption, since one of the main factors behind a big volcanic explosion is the amount of water and other gases that get caught up inside the magma.
„In one case, magma could rise quickly up the conduit and intersect with the lake,” said Swanson. „In the second, the crater floor could collapse and drop all of the water down to a zone where it would be quickly heated into steam.”
While an explosive eruption remains possible for Kilauea, Swanson said the next eruption could also happen slowly and all the water could evaporate.
„We do not want to be alarmist, but we also need to point out to the public that there is an increasing possibility of explosive eruptions at Kilauea,” said Swanson.
Only time will tell what is in store for Kilauea, but for now, the volcano is being closely researched and monitored by geologists.
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.
After dropping record rain in South Florida, a system remains on track to become the first named storm of the 2020 Atlantic hurricane season this weekend.
AccuWeather meteorologists expect conditions to become more conducive for the system to organize into a tropical depression or storm over the warm waters offshore of Florida and near the Bahamas.
„It is not out of the question this can happen late Friday, but more than likely, it will take until Friday night or Saturday for the first storm of the season to form,” Dan Kottlowski, AccuWeather’s top hurricane expert, said.
If the storm does not organize until later Saturday or Saturday night and it moves over slightly cooler water, it will likely be called a subtropical depression or storm – meaning it would be a hybrid of both a tropical and non-tropical storm.
Regardless, the first tropical or subtropical storm of the 2020 Atlantic hurricane season will be called Arthur.
After likely being named, the storm will track offshore of the southeastern United States and pass about 100 to 150 miles off the coast of North Carolina’s Outer Banks on Sunday night or Monday. Around that time, the storm should be at its peak intensity with sustained winds of around 50-60 mph, according to Kottlowski.
Worst impacts to Florida happening before storm develops
Residents of South Florida will continue to experience most of the impacts from this storm before it is classified as a depression or given the name Arthur.
Thursday was the second wettest May day on record for the city of Marathon in the Florida Keys. Heavy rain totaled 5.76 inches, stopping short of the city’s rainiest May day record of 6.60 inches set on May 27 in 1959.
Here’s a radar loop showing the disturbance over the Straits that has been producing the heavy rainfall across the Florida Keys. For a longer loop, please visit our Facebook page at https://www.facebook.com/NWSKeyWest/videos/905726396559115/ … #flwx #KeyWest #FloridaKeys
Downpours and thunderstorms will continue to stream over parts of southern Florida through Friday night as gusty winds blow. The heaviest downpours could trigger localized flash flooding in low-lying and poor drainage areas.
Even in the absence of flooding, heavy rain can still disrupt travel by reducing visibility and heightening the risk of vehicles hydroplaning when traveling at highway speeds.
„Meanwhile, the storm will bring gusty rain squalls, rough surf, strong rip currents and locally heavy rain to the Bahamas through Saturday,” AccuWeather Senior Meteorologist Rob Miller said.
„Localized flooding may occur with an AccuWeather Local StormMax™ of 6 inches (15 cm) anticipated, and sporadic power outages cannot be ruled out since winds may gust to an AccuWeather Local StormMax™ of 55 mph (88 km/h) as the storm strengthens.”
Storm to bring near miss to North Carolina’s Outer Banks
As it pushes away from the waters near Florida and the Bahamas, the storm and its heavy rain will remain well off the coast from northeastern Florida to southern North Carolina this weekend.
However, anyone planning to head to the beaches to seek relief from being pent up in recent months due to the COVID-19 pandemic should use caution. The risk of rough surf and strong rip currents will expand northward along the entire Southeast coast this weekend.
Along with the rough surf dangers, residents in the Outer Banks of North Carolina may also experience an uptick in gusty showers Sunday night into Monday.
„While it still appears that the worst of the storm will stay offshore, we are monitoring the potential for the storm to track closer to the coast and bring the Outer Banks more substantial rain and wind,” Miller said.
Beyond Monday, the storm is expected to lose its tropical characteristics as it tracks over the cool water well west and north of Bermuda Monday night through Wednesday.
At this time, the storm is expected to track away from the Northeast as a new storm from the Midwest takes up residence over the eastern U.S. for a lengthy time next week and leads to an extended stretch of wet and gloomy weather for some in the region.
It is not out of the question that this second storm pulls in the system that is expected to be called Arthur or its tropical moisture, causing even heavier rain to soak a swath of the East.
Even if the tropical system remains separate and heads out to sea, the second storm alone can still disrupt outdoor plans and even impact medical tents that are treating COVID-19 patients where its rain and gusty winds target the East.
Weekend storm to mark start of busy Atlantic hurricane season
The Atlantic hurricane season doesn’t start officially until June 1, but there has been a named storm before that day every year since 2015 – a trend that this weekend’s storm should continue.
An early start to hurricane season is not a true indicator of how active the season will be, but Kottlowski is concerned that the 2020 Atlantic hurricane season has the potential to be ‘very active.’
AccuWeather’s long-range forecasting team is predicting 14 to 20 tropical storms, of which seven to 11 will become hurricanes. Out of those hurricanes, the team anticipates four to six may strengthen further into major hurricanes (Category 3 or higher).
Kottlowski also warned that four to six named tropical systems could make direct impacts on the U.S. mainland, Puerto Rico and the Virgin Islands.
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.