Tag Archives: Thunderstorms

National Weather Service Issues Warning: Radio Interruptions Expected as Thunderstorms Approach Alabama

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A significant storm is forecasted to impact Alabama this week, as the National Weather Service has halted radio services that deliver vital weather updates for the area.

The Birmingham NWS office announced it will conduct “mandatory scheduled updates” to the advanced weather interactive processing system, which is essential for displaying and integrating weather and water information and disseminating critical alerts like weather and water warnings to the public.

These updates are set to take place from May 19th to May 21st. During this period, the Birmingham office will manage the NOAA weather radio transmitter. The NWS states.

Despite the software updates, the NWS assures that weather forecasts, advisories, clocks, and warnings will still be available. However, radio outages are expected to affect transmitters in northern and central Alabama, including areas like Winfield, Wannta, Birmingham, Aniston, Tuscaloosa, Demopolis, Selma, Montgomery, Auburn, and Texasville.

The NWS did not provide immediate comments, but the agency stated online that the Birmingham forecast office will remain operational while the software updates proceed. Additionally, forecasting duties will also be carried out at the backup office in Peachtree City, Georgia.

NOAA Weather Radio forms a nationwide network of stations that relay official forecasts, weather alerts, and other information from the National Weather Service. This continuous service covers warnings about various threats, including earthquakes, avalanches, oil spills, and public safety announcements.

The National Oceanic and Atmospheric Administration, which supervises the National Weather Service, indicated that NOAA weather radio stations nationwide will undergo necessary updates on a rolling basis for two to three days leading up to June.

“The NWS Local Office intends to inform listeners both on-air and through the website when updates are scheduled,” agency officials noted. According to the NOAA Weather Radio website.

Alabama is among several states facing the threat of severe storms this week, with thunderstorms on Tuesday predicted to produce damaging hail and tornadoes, with wind gusts reaching 60 mph across northwest and central Alabama.

This week’s radio service disruption aligns with Alabama’s severe weather forecast, but it is not the only state bracing for harsh conditions.

An estimated 31 million people are susceptible to severe storms on Monday, stretching from northern Texas to Iowa. Potential hazards include strong winds, large hail, and tornadoes from Monday afternoon into the evening.

On Tuesday, the severe storm outlook will slightly shift, affecting areas from northern Louisiana to Indiana, with risks of large hail, winds, and strong tornadoes re-emerging.

In the meantime, a heat wave has driven temperatures into the late 90s in parts of Texas and Florida, reaching triple digits earlier this week.

These alerts follow a weekend of violent storms, leading to reports of tornadoes in at least 10 states, including Texas, Kansas, Missouri, and Kentucky, with a confirmed toll of at least 28 weather-related fatalities.

This deadly storm arrives as NOAA strives to fill critical forecasting positions nationwide following significant budget cuts to the National Weather Service during the Trump administration. Critics warn that the current staffing shortages in the NWS could pose a serious public safety risk, particularly with hurricane season on the horizon, increasing wildfire threats, and persisting extreme heat this summer.

Source: www.nbcnews.com

Unexpected forms of gamma-ray emissions observed in tropical thunderstorms

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Thunderclouds include more than just rain and lightning. In addition to visible light radiation, thunderclouds can produce powerful bursts of gamma rays that last one millionth of a second. Clouds can also glow steadily with gamma rays for seconds to minutes at a time. Using a battery of detectors onboard NASA’s ER-2 research aircraft, scientists have discovered a new type of gamma-ray radiation whose duration is shorter than steady light but longer than microsecond bursts. They call it a flickering gamma ray flash.

NASA’s high-flying ER-2 plane is equipped with the Fly’s Eye Stationary Lightning Mapper Simulator, which records gamma rays (purple in the illustration) from thunderclouds, and instruments in this artist’s impression of the Airborne Lightning Observatory for the Ground Gamma Ray Flash (ALOFT) mission. is installed. Image credit: NASA/ALOFT team.

Previous studies have reported two types of gamma-ray emissions from thunderclouds. One is a high-intensity burst known as a terrestrial gamma-ray flash, and the other is a moderate-intensity, long-duration gamma-ray glow.

However, the characteristics of these emissions and how they are produced are not completely understood.

Researchers used data collected by the aircraft during 10 flights in July 2023 to investigate gamma-ray emissions that occurred during marine and coastal thunderstorms in the Caribbean and Central America.

“The ER-2 aircraft will be the ultimate platform for observing gamma rays from thunderclouds,” said Professor Nikolai Ostgaard of the University of Bergen.

“Flying at 20 km (12.4 miles) allows us to fly directly above the clouds, as close as possible to the gamma-ray source.”

“There’s a lot more going on in thunderstorms than we imagined,” added Professor Steve Comer of Duke University.

“At the end of the day, basically all large thunderstorms produce gamma rays in different forms throughout the day.”

“Several aircraft operations have attempted to determine whether these phenomena are common, but results have been mixed, and some operations over the United States have not found gamma rays at all.”

“This project was designed to answer these questions once and for all.”

Professor Ostgaard, Professor Comer and their colleagues. identified Another type of gamma-ray radiation, called flicker gamma-ray flashes, consists of pulses of longer duration than terrestrial gamma-ray flashes.

A total of 24 flickering gamma-ray flashes were observed as the spacecraft passed over gamma-ray thunderclouds on five of its 10 flights. Seventeen of these flickering gamma-ray flashes resulted in lightning.

The researchers suggested that flickering gamma-ray flashes, which can begin as the emission of gamma rays and then suddenly increase in intensity into a series of pulses, may also be involved in the formation of lightning. are.

Because flickering gamma-ray flashes share similar characteristics with gamma-ray glows and terrestrial gamma-ray flashes, they propose that flickering gamma-ray flashes could provide evidence of a link between the two phenomena.

In another study, Dr. Martino Marisardi from the University of Bergen and colleagues investigated Characteristics of gamma ray glow detected by aircraft.

These included thundercloud systems covering an area of ​​more than 9,000 km.2 Luminescence was observed for at least 3 hours.

They found that the emission was general and not uniform across the emission region.

During nine of the 10 flights, more than 500 individual gamma-ray glows were observed across the study area, each lasting between 1 and 10 seconds.

These findings contradict the results of previous studies that reported that the gamma-ray glow can last up to several hundred seconds and is emitted uniformly over a range of up to 20 km.

Taken together, these findings improve our understanding of gamma-ray emissions from thunderclouds and suggest a causal relationship between glows and flashes and the possible role of these emissions in the subsequent development of lightning.

“These two new forms of gamma rays are what I find most interesting,” Professor Comer said.

“They don’t seem to be related to the occurrence of lightning. They somehow appear naturally.”

“There are hints in the data that they may actually be related to the process that causes lightning, but it’s still a mystery to scientists.”

The results are published in two papers: journal nature.

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N. Ostgard others. 2024. Gamma ray flashing, the missing link between gamma rays and TGF. nature 634, 53-56; doi: 10.1038/s41586-024-07893-0

M. Marisardi others. 2024. Highly dynamic gamma-ray emissions are common in tropical thunderclouds. nature 634, 57-60; doi: 10.1038/s41586-024-07936-6

Source: www.sci.news

Study finds air pollution may intensify summer thunderstorms

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Researchers from James Madison University conducted a comprehensive study of thunderstorm environments in two distinct geographic regions: Washington, DC, and the Kansas City metropolitan area.

Air pollution is increasing the intensity of summer thunderstorms. Image courtesy of ELG21.

Land cover and atmospheric boundary layer characteristics modify thunderstorms and their characteristic phenomenon: lightning.

The most intense thunderstorm contrasts on Earth occur along continental and oceanic boundaries.

Generally, lightning strikes land at an order of magnitude more than it strikes sea.

The thermodynamic properties of the atmosphere vary significantly with different land covers over the Earth’s surface.

“Pollutants act as cloud nuclei,” said Mace Bentley, a professor at James Madison University and lead author of the study.

“Updrafts carry them into the clouds, and the updrafts and downdrafts separate the polluting particles, dispersing the electrical charges in the clouds and encouraging lightning to form.”

For the study, the authors surveyed nearly 200,000 thunderstorm events in the Washington, DC, area and more than 300,000 in the Kansas City area.

Using 12 years of lightning data from the National Lightning Detection Network and data from hundreds of air pollution monitoring stations in two cities, they found that in highly volatile environments, increased pollution increases the frequency of anti-ground lightning strikes.

“Our analysis identified a total of 196,836 thunderstorm events in the Washington DC area, while 310,209 thunderstorms were identified from the Kansas City lightning database,” the researchers said.

“In Washington, DC and Kansas City, more than 37.7% and 39.2% of all thunderstorm events, respectively, consisted of 10 or more flashes.”

“Evidence suggests that thunderstorm environments during mild warm-season synoptic weather are substantially different in terms of thermodynamics, aerosol properties, and aerosol concentrations in the Washington, DC, and Kansas City regions,” the researchers added.

“However, thunderstorm intensity, as measured by flash counts, appears to be controlled by similar thermodynamic and aerosol relationships despite differences in the surrounding environments.”

“When we look at the environments in which thunderstorms occur, we find a statistically significant positive correlation between convective available potential energy and the number of lightning events.”

“Aerosol concentration also appears to be a more important quantity than particle size when it comes to lightning enhancement.”

Scientists are now conducting a similar study in Bangkok, Thailand, a megacity that is more polluted than Washington, DC, or Kansas City and sits in a hot, tropical climate.

The results so far are similar, but these storms are showing a higher incidence of lightning.

“It appears that urban pollution can enhance thunderstorms and lightning wherever you go in the world,” Prof Bentley said.

of study Published in a journal Atmospheric Research.

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Mace Bentley others2024. Towards elucidating the relationship between thunderstorms and aerosols: An observational study centered on Washington, DC and Kansas City, Missouri. Atmospheric Research 304: 107402; doi: 10.1016/j.atmosres.2024.107402

Source: www.sci.news