Latest news with #BulletinoftheAmericanMeteorologicalSociety
Yahoo
09-05-2025
- Science
- Yahoo
Hurricane Hunters fly into world's worst weather. See which storm was the bumpiest
MIAMI – New research is shedding light on just how bumpy Hurricane Hunter missions can be and which seat on the aircraft most closely resembles a roller coaster ride. To characterize these flights, meteorologists examined hurricane missions dating back to the 1980s and developed what they call the "bumpiness index." The index is based on a complex equation that factors in aircraft movements such as roll and pitch, which can vary significantly during a mission. "Since rotational motions are experienced differently depending on where someone is on a plane, the bumpiness index takes into account seat position," authors of the research published in the Bulletin of the American Meteorological Society stated. "We then rank the bumpiest flights in recent history by gathering flight-level data from every tropical cyclone mission on the P-3 since 2004 when data needed from missions for this analysis became readily available, as well as data from the infamous flights into Hurricanes Allen (1980) and Hugo (1989)." 2025 Atlantic Hurricane Season Guide Hurricane Ian in 2022 provided some of the most striking data for the one-of-a-kind study, with researchers documenting rapid accelerations and abrupt shifts in the aircraft. Despite the intense ride, Ian did not top the list as the bumpiest flight - that distinction went to Hurricane Hugo in 1989 - when the pilot's seat recorded a bumpiness value of 7.86 meters per second squared. The level of turbulence experienced during that flight would be classified as "severe" under NOAA's turbulence intensity scale. Despite such extreme conditions, missions largely proceeded as planned, including the deployment of the first uncrewed aerial system from a Lockheed WP-3D Orion aircraft during Hurricane Ian. Other notable tropical cyclones making the list include Hurricane Irma (2017), Hurricane Dorian (2019), and Hurricane Michael (2018). The study also evaluated bumpiness across the 19 seats on the aircraft and found that the right pilot seat was often the bumpiest, while the seat typically occupied by the lead scientist experienced the least amount of sway. During Hurricane Ian, the right pilot seat - referred to as "seat 2" - recorded the highest bumpiness value at 6.13 m/s², while "seat 10," typically assigned to the lead scientist, recorded the lowest at 4.40 m/s² - a difference of more than 36%. Something A Bit Unusual Is Happening In The Tropics The findings aligned with long-term theories and observations that those seated farther from the aircraft's center axis, either at the front or rear of the plane, tend to experience more intense movements than those seated near the wings. The same general rule applies to commercial aircraft, where passengers in the rear often endure bumpier rides, though nowhere near the levels encountered while flying through a hurricane. Aside from the flight crew, mission participants usually include meteorologists, weather reconnaissance officers and engineers, with flights often lasting several article source: Hurricane Hunters fly into world's worst weather. See which storm was the bumpiest
Yahoo
25-02-2025
- Climate
- Yahoo
Where Have All The EF5 Tornadoes Gone? The Surprising Reason Behind The 11-Year Drought
It may be hard to believe that with an average of 1,200 tornadoes each year in the United States, we haven't seen an EF5-rated twister in more than 11 years. But that doesn't mean the number of tornadoes is decreasing. In fact, it's quite the opposite. In 2024, the U.S. had more than 1,800 confirmed tornadoes – the second-most on record. And although the U.S. has not experienced an officially classified EF5 tornado in over a decade, this does not necessarily mean extreme tornadoes are becoming less frequent, either. The reality is that our standards for measuring them have simply changed. (For even more granular weather data tracking in your area, view your 15-minute details forecast in our Premium Pro experience.) A new study published in the Bulletin of the American Meteorological Society suggests that the decline in Earth's most violent twisters isn't because tornadoes are becoming weaker; rather, it's due to a change in how they're classified. Tornado classifications have evolved since the original Fujita (F scale) was developed in 1971. Under the original F scale, an F5 rating was given as follows: 'Whole frame houses tossed off foundations; steel-reinforced concrete structures badly damaged; automobile-sized missiles generated; incredible phenomena can occur.' However, scientists believed there were two major problems with the original F-scale: Wind speeds: Wind speeds were estimated at 261-318 mph for an F5 tornado. However, several engineering studies indicated that no evidence existed of tornado wind speeds above 250 mph. Structural Integrity: There were concerns about the lack of consideration for the integrity of structures with the original F-scale. Fujita even agreed that structural integrity should be taken into account when assigning an F-scale rating. So the Enhanced Fujita (EF) scale was established in 2006 and remains the standard for tornado classification today. This new scale lowers the maximum wind speeds to "over 200 mph." But the biggest difference, and what's believed to be the reason behind the decline in EF5 numbers, is that the EF scale accounts for structural engineering principles, incorporating different degrees of damage (DODs) for various types of buildings and structures. As a result, tornadoes that might have been classified as F5 under the old system could now be assigned an EF4 rating under the EF scale due to stricter criteria. (MORE: The Nation's Most Violent Tornadoes Of 2024) A key distinction between the F and EF scales is how they evaluate damage to single-family homes. Under the F-scale, a well-constructed home being swept away was automatically considered F5 damage. However, under the EF scale, the same level of destruction is typically classified as EF4 unless the home is explicitly proven to be built beyond standard construction codes. The study points out that building codes are ever-evolving, so even under these parameters, it will be difficult to maintain consistency with tornado classification in future years. This change in methodology significantly reduced the number of EF5 ratings. The study's authors argue that adjusting the EF5 wind speed threshold downward just 11 mph from 201 mph to 190 mph, or upgrading tornadoes with 190-200 mph estimated winds to EF5, would create a more consistent classification system that aligns with historical records dating back to 1880. This would reclassify 15 tornadoes over the last 14 years from EF4 to EF5, most recently the Rolling Fork, Mississippi, from March 2023. (MORE: America's F/EF5 Tornadoes Since 1950) The last official EF5 tornado to hit the U.S. was the infamous 2013 Moore, Oklahoma, tornado. This violent tornado was on the ground for more than 40 minutes, carving a path of devastation more than a mile wide at times. It was responsible for two dozen deaths, more than 200 injuries and upward of $2 billion in damage. To the untrained eye, most would immediately assume that it was an EF5 tornado. However, the EF scale is much more specific than what our mind can determine while emotionally invested in such a natural disaster. At the conclusion of the Moore tornado survey, it was determined that nine homes sustained EF5 damage. Not only were homes evaluated that were swept off their foundations, but field surveyors took into account "the foundation anchoring and estimation of how much force was applied to the foundation anchors before the house completely failed (i.e., how long did the walls remain attached prior to failure and removal from the foundation, as indicated by the degree of anchor bolt bending, bolt spacing, presence of proper washers and nuts on anchor bolts, and fraction of sill plates remaining)." In other words, this was a much more specific and detailed survey than one using the original F scale, which didn't take structural integrity into account at all. While there is no word on whether tornado ratings will be adjusted again, this shift in classification does raise important questions for meteorologists, engineers and policymakers on how top-tier tornado intensities are defined. These considerations could have profound implications for emergency preparedness, building codes and insurance assessments. Jennifer Gray is a weather and climate writer for She has been covering some of the world's biggest weather and climate stories for the last two decades.
Yahoo
23-02-2025
- Climate
- Yahoo
Absence of EF5 tornadoes maybe because of damage assessments, not changes in weather patterns
NORMAN, Okla. – Research recently published in the Bulletin of the American Meteorological Society suggests that the record-long drought of EF5 tornadoes is due to stricter use of damage ratings rather than any changes in the weather. According to a NOAA database, 59 EF5/F5 tornadoes have occurred since 1950, but it has been nearly 12 years since the last event, when an EF5 devastated Moore, Oklahoma in 2013. Researchers from the University of Oklahoma delved into the mystery surrounding the apparent disappearance of these powerful twisters and found that while such tornadoes still occur, what has changed is the way damage is surveyed after a tornado strikes. The original Fujita scale, developed in the 1970s, was used until 2007, when it was updated and replaced by what is now known as the Enhanced Fujita (EF) scale. The numerical ratings of tornadoes were not changed; they are still ranked from EF0 to EF5 on the scale, but damage indicators were added, which are used to identify the strength of tornadoes. The lack of damage indicators on the original Fujita scale was considered to be one of its many weaknesses, but the adjusted criteria may be too stringent to allow for the strength of tornadoes to accurately be depicted. For example, a well-built home that was swept off its foundation would have received an F5 rating on the Fujita scale pre-2007, but under the Enhanced Fujita scale, a similar home would likely fall under the EF4 category today. "Consequently, under the strictest application of the EF scale, to attain an EF5 rating from a single-family home being swept off its foundation, the home must technically be built above building code, which is a fundamental shift from the F scale and will inherently reduce the number of EF5 damage indicators (DIs) found in surveys," researchers stated. How Are Tornadoes Rated? The Enhanced Fujita Scale Explained Using data from 1880 to 2023, researchers calculated the probability of at least one F5/EF5 tornado occurring in any given year to be 41%, with the chance of 10 consecutive years passing without a tornado at just 0.3% - odds that suggest something is amiss with the recent lack of activity. Researchers noted that there have been many EF4 candidates, where, if the damage had been classified differently, the tornadoes would have been rated as EF5s. Examples include Rolling Fork, Mississippi, in 2023; Mayfield, Kentucky, in 2021; Shawnee, Oklahoma, in 2013; and Tuscaloosa, Alabama, in identified over a dozen events since 2011 where, if alternative damage indicators had been used, the tornadoes could have been classified as EF5s. "If all EF5-candidate tornadoes were instead rated EF5, the calendar-year probability of observing an F5/EF5 tornado from the 1880–2023 dataset would be 55.6%, nearly equivalent to the probability of an F5/EF5 tornado being observed in a calendar year as derived from the 1880–2013 dataset (56.0%) prior to the ongoing 10-year EF5 gap," the study stated. April Kicks Off America's Most Active Time Of Year For Tornadoes Researchers emphasized that it all comes down to what meteorologists want the EF5 category to represent. The group determined that lowering the current EF5 wind threshold from 201 mph to 190 mph would create more continuity based on previous climatology, without adjusting damage assessments. While changing the EF scale could lead to other issues, none appeared to outweigh the uncertainty surrounding the current rating products. The United States averages over 1,200 tornadoes every year with nearly 90% that are either determined to be an EF1, EF0 or an EFU, with not enough damage to determine a article source: Absence of EF5 tornadoes maybe because of damage assessments, not changes in weather patterns
