NHC is updating its cone graphic for the 2025 hurricane season
Forecasters work to improve their forecasting and warning products every year. The updates for the 2025 hurricane season include a depiction of inland tropical storms and hurricane alerts in effect on its 'cone' graphic, the debut of a national rip current risk map for active tropical storms and earlier warnings for potential storms.
Here's a breakdown of the NHC's new changes for hurricane season.
The NHC says it will continue using its experimental cone graphic, which is frequently referred to as the cone of uncertainty. The graphic is meant to track the probable path of a tropical cyclone's center.
The cone is frequently misunderstood, which is one reason the NHC consistently updates the product. Here are this year's changes.
New symbols: The cone of uncertainty legend will now contain symbology for areas where a hurricane watch and tropical storm are in effect at the same time, marked by diagonal pink and blue lines.
Narrower cone of uncertainty: The size of the tropical cyclone track forecast error cone will be about 3-5% smaller compared to last year.
The cone graphic is meant to inform people about the center of a hurricane's probable track. It doesn't reflect the size of the storm, nor does it indicate the full area of its impact.
The cone's size is based on how accurate or inaccurate the NHC's forecasts have been over the past five years. The center of the storm tends to stay within the cone for roughly two out of every three forecasts, according to the NHC.
It shouldn't be used to determine your storm risk or whether you should evacuate. Instead, you should use it to determine where the center of the storm is likely to go and to see what watches and warnings are in effect.
Starting on May 15, the National Weather Service (NWS) will implement some significant changes to its Potential Tropical Cyclone advisory (PTC) system.
Extended forecast window: The National Hurricane Center will be able to issue PTC advisories up to 72 hours before anticipated impacts, which is up from the previous 48-hour window.
Relaxed warning criteria: The change eliminates the previous requirement that advisories could only be issued for PTCs that required land-based watches or warnings.
Due to an increase in surf and rip current fatalities in the United States, the NHC will provide current risk information from distant hurricanes and provide a national rip current risk map.
Rip current risk map: To highlight the risk of dangerous conditions, NHC will provide rip current risk information from local National Weather Service and Weather Force Cast Offices in the form of a map.
Current day, next day and a composite showing the highest risk over both days will be available for areas along the East and Gulf coasts of the U.S in one page.
This article originally appeared on Pensacola News Journal: National Hurricane Center is updating its 'cone' graphic
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Yahoo
3 hours ago
- Yahoo
Will Tropical Storm Erin impact Daytona, Flagler? See the latest on strengthening storm
All eyes in Florida remain on Tropical Storm Erin as it moves westward across the Atlantic, but it's still too soon to tell what impact the strengthening storm might have on Daytona Beach, Volusia and Flagler counties, according to the National Weather Service. Tropical Storm Erin is expected to begin strengthening soon and is likely to become a hurricane in the next 48 hours, according to the latest advisory from the National Hurricane Center. Erin is moving fast across the Atlantic, at 22 mph. It's forecast not only to become the Atlantic season's first hurricane, but also a major hurricane. A major hurricane is one that's a Category 3 or higher, with maximum sustained winds of at least 111 mph. Officials encourage residents to monitor Erin closely and to be prepared. 'It's still the same message, which is that it's too early to determine any sort of impacts to Central Florida, but it's a good opportunity to make sure that hurricane plans for yourself are in place, that you have your hurricane kit stocked and ready to go,' said Brendan Schaper, meteorologist with the National Weather Service in Melbourne. Those in Volusia and Flagler counties are urged to keep an eye on the forecast and be aware that peak hurricane season is now upon us, the NWS stated. Tropical Storm Erin expected to turn to the northwest, but when? At 5 a.m. Tuesday, Aug. 12, the center of Tropical Storm Erin was located near latitude 17.4 North, longitude 34.3 West. Erin is moving toward the west near 22 mph, and this motion is expected to continue for the next several days with a decrease in forward speed and a gradual turn toward the west-northwest. Daytona Beach, Flagler area forecast calls for hotter temperatures, rain Looking ahead to this week's forecast, temperatures are expected to trend hotter each day with heat index values approaching 102-107+ degrees, especially later in the week, according to the forecast discussion from the National Weather Service in Melbourne. Near normal rain and thunderstorm chances also are forecast, mainly along the path of the afternoon seabreeze, with higher coverage focused across the interior portions of Volusia and Flagler counties each day. 'It's going to trend hotter, especially later in the week,' Schaper said. 'Friday and Saturday are expected to be a couple of the hottest days, with temperatures to reach the mid-90s for most locations, with heat index values that could rise to potentially 109. 'It's kind of your typical summertime storm pattern.' A moderate risk of rip currents will continue at all area beaches through at least midweek. Those entering the ocean are advised to always swim in front of a staffed lifeguard station and never venture into the water alone. That risk could escalate depending on Erin's track, Schaper said. Daytona Beach weather radar Extended forecast for Daytona Beach Tuesday, Aug. 12: A 50% chance of showers and thunderstorms, mainly after 2 p.m. Mostly sunny, with a high near 90 and nighttime low around 77. Heat index values as high as 102. East southeast wind 5-10 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms. Wednesday, Aug. 13: A 50% chance of showers and thunderstorms. Mostly sunny, with a high near 91 and nighttime low around 77. Heat index values as high as 102. Light and variable wind becoming east southeast 5-10 mph in the afternoon. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms. Thursday, Aug. 14: A 40% chance of showers and thunderstorms. Sunny, with a high near 92 and nighttime low around 78. Calm wind becoming east southeast around 5 mph in the afternoon. Friday, Aug. 15: A 30% chance of showers and thunderstorms. Sunny, with a high near 92 and nighttime low around 78. Calm wind becoming east around 5 mph in the afternoon. Extended forecast for Palm Coast Tuesday, Aug. 12: A 40% chance of showers and thunderstorms after 1 p.m. Partly sunny, with a high near 91 and nighttime low around 76. Heat index values as high as 106. East wind 7-11 mph, with gusts as high as 17 mph. Wednesday, Aug. 13: A 60% chance of showers and thunderstorms after 2 p.m. Mostly sunny, with a high near 87 and nighttime low around 78. South wind 5-10 mph becoming east in the afternoon. Winds could gust as high as 16 mph. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms. Thursday, Aug. 14: A 40% chance of showers and thunderstorms. Mostly sunny, with a high near 88 and nighttime low around 78. Light and variable wind becoming southeast 5-7 mph in the morning. Friday, Aug. 15: A 40% chance of showers and thunderstorms. Sunny, with a high near 88 and nighttime low around 79. This article originally appeared on The Daytona Beach News-Journal: As Erin moves west in Atlantic what's the danger to Daytona, Flagler? Solve the daily Crossword
Yahoo
5 hours ago
- Yahoo
Tropical Storm Erin forecast to be hurricane by Friday
Aug. 13 (UPI) -- Tropical Storm Erin is slightly intensifying and forecast to become a hurricane on Friday morning over the central tropical Atlantic with a chance of ultimately affecting the U.S. East Coast, the Bahamas and Bermuda next week, the National Hurricane Center said Wednesday. For the first time since Erin became a tropical storm Monday morning, intensity increased, though just 5 mph, to maximum sustained winds of 45 mph, with gradual strengthening during the next two days forecast, the NHC said in its 5 p.m. EDT update. In the 11 p.m. update, Erin remained at 50 mph. Erin is forecast to reach hurricane status by 8 a.m. Friday with winds at least 74 mph, and a major hurricane, with winds of at least 111 mph, by 8 p.m. Sunday. It would be the first hurricane of the Atlantic season. Beryl was the first hurricane last year on June 24. The storm is about 1,095 miles east of the Northern Leeward Islands. Erin was moving westward at 16 mph and will shift to a north-westward track beginning Thursday night and into the weekend, the NHC said. On the forecast track, the storm's center will move over or near just north of the northern Leeward Islands. The NHC's "cone" doesn't track Erin past Monday night, and NHC forecasters remind that they have an average error of 150 to 214 miles at days four and five. In the latest discussion, NHC forecaster Jack Beven said there is a "greater than normal uncertainty about what impacts Erin may bring to portions of the Bahamas, the East Coast of the United States and Bermuda." But he said: "The risk of dangerous surf and rip currents across the western Atlantic basin next week is increasing." By this weekend, swells are forecast to cause life-threatening surf and rip current conditions, the NHC said. Alex Sosnowsky, an AccuWeather senior forecaster, said there is concern that residents, visitors, cruise lines, and shipping and fishing ventures "could pass paths with a powerful hurricane." With a track farther to the east, Bermuda could be directly in the path as a major hurricane. He said a farther west scenario would mean a greater risk of strong winds, rain and coastal flooding in the U.S., including eastern North Carolina, Long Island, New York and southeastern New England. "Families heading to U.S. Atlantic beaches for a late-summer vacation next week need to be extremely cautious when venturing into the surf," AccuWeather Lead Hurricane Expert Alex DaSilva said. "More than 50 people have lost their lives to rip currents and rough surf at beaches across the country so far this year, without any major hurricane nearby." There are no warnings or coastal watches in effect as tropical-force winds extend outward up to 60 miles. But those in the northern Leeward Islands, the Virgin Islands and Puerto Rico should monitor Erin's progress. The previous four named Atlantic storms this year were Andrea, Barry, Chantal and Dexter. None of them became hurricanes, and Chantal was the only one to make landfall in the United States, causing significant flooding in North Carolina. Helene struck that state last year as a tropical storm, causing an estimated $53 billion in damage, after hitting western Florida as a Category 4 hurricane. Four other hurricanes made landfall in the United States in 2024: Beryl, Debby, Francine and Milton.
CBS News
7 hours ago
- CBS News
Threat over after Alaska's capital sees record glacier-related flooding as river tops 16.6 feet
Waters have receded, ending the flood threat after Alaska's capital city faced record floodwaters Wednesday stemming from a basin dammed by the Mendenhall Glacier, which released an "outburst flood" that threatened parts of Juneau. "I think we were all very grateful to see the Hesko barriers work," Katie Koester, the Juneau city manager, said in an interview with CBS News Wednesday evening. "We can all breathe a sigh of relief. For the most part we had very minimal flooding and avoided a really catastrophic event." Water levels in the Mendenhall River, which flows through Juneau, reached unprecedented heights in the early morning hours and peaked at around 7:15 a.m. local time before beginning to fall, the National Weather Service said. At its peak, the river's flood stage rose to 16.65 feet, topping the previous record of 15.99 feet set last year, according to forecasters. "We could have easily had almost 1,000 structures — most of them residences, some multifamily — flooded," Koester said. "And for many of those homes it would have been the second year in a row of flooding. Really cold, icy waters, really difficult to mitigate against, does a lot of damage to your home because of that glacial silt." The Mendenhall Glacier is about 12 miles from downtown Juneau and is a popular tourist attraction due to its proximity to Alaska's capital city, home to 30,000 people, and easy access on walking trails. Homes on the city's outskirts are within miles of Mendenhall Lake, which sits below the glacier, and many front the Mendenhall River, into which the glacial outburst is flowing. Some Juneau residents in the flood zone evacuated Tuesday, heeding guidance from officials who warned the community: "Don't wait, Evacuate TONIGHT." Evacuated areas were reopened to residents only Wednesday afternoon, officials said. The city of Juneau said crews would be coming through to assess the flooding damage. It advised residents noto to drive through any standing water. "In addition to posing a safety hazard, driving generates waves that cause additional damage to nearby structures," the city said. On Tuesday morning, authorities confirmed water had started escaping the ice dam. Later Wednesday morning, U.S. Forest Service ranger Michael Downs told reporters at a news conference that the west side of the glacier's recreation area remained underwater, along with a number of trails in the national forest that surrounds it. The Forest Service has closed the entire Mendenhall Glacier Recreation Area until further notice, and Downs said at the briefing that it will likely be five or six days before rangers are able to fully assess the situation. The visitor's center in the recreation area, however, will reopen Thursday, he said. Public schools in Juneau will delay their return for the upcoming academic year by one day, resuming classes this Friday instead of Thursday, said Frank Hauser, the school district superintendent. Flooding from the basin has become an annual concern since 2011, and in recent years has swept away houses and swamped hundreds of homes. Government agencies installed temporary barriers this year in hopes of protecting several hundred homes in the inundation area from widespread damage. The flooding happens because a smaller glacier near Mendenhall Glacier retreated — a casualty of the warming climate — and left a basin, known as Suicide Basin, that fills with rainwater and snowmelt each spring and summer. When the water creates enough pressure, it forces its way under or around the ice dam created by the Mendenhall Glacier, enters Mendenhall Lake and eventually flows down the Mendenhall River, as it did Tuesday. Before the basin began overtopping, the water level was rising rapidly — as much as 4 feet per day, according to the National Weather Service. The city saw successive years of record flooding in 2023 and 2024 — with the river last August cresting at 15.99 feet, about a foot over the prior record set a year earlier — and flooding extending farther into the Mendenhall Valley. This year's flooding was predicted to crest at between 16.3 and 16.8 feet, the weather service said, but then said an even higher 16.75 feet was more likely. Last year, nearly 300 residences were damaged. Video posted on social media two years ago showed towering trees behind a home falling into the rushing Mendenhall River as the water ate away at the bank. Eventually, the home, teetering at the edge, also collapsed into the river. A large outburst can release some 15 billion gallons of water, according to the University of Alaska Southeast and Alaska Climate Adaptation Science Center. That's the equivalent of nearly 23,000 Olympic-size swimming pools. During last year's flood, the flow rate in the rushing Mendenhall River was about half that of Niagara Falls, the researchers say. City officials responded to concerns from property owners this year by working with state, federal and tribal entities to install a temporary levee along roughly 2.5 miles of riverbank in an attempt to guard against widespread flooding. The 10,000 "Hesco" barriers are essentially giant sandbags intended to protect more than 460 properties completely during an 18-foot flood event, said emergency manager Ryan O'Shaughnessy. The U.S. Army Corps of Engineers is at the start of what's expected to be a yearslong process of studying conditions in the region and examining options for a more permanent solution, such as a levee. The timeline has angered some residents, who say it's unreasonable. Outburst floods are expected to continue as long as the Mendenhall Glacier acts as an ice dam to seal off the basin, which could span another 25 to 60 years, according to the university and science center researchers.
