Severe Weather

With September historically being the busiest month for hurricanes in the tropical Atlantic, what lies ahead for the rest of this season? Dr. Ryan Truchelut of WeatherTiger explores the influence of El Niño and record-warm Atlantic sea surface temperatures on the upcoming months, as we approach the peak of hurricane activity.

9–12 million—The approximate number of people in the United States who could be at risk of isolation because of rising sea levels by the end of the century under a scenario in which global sea levels increase 2 meters.

Maestros Amber Liggett and Dr. Ashton Robinson Cook lead a discussion about storm chasing during the spring and summer seasons.

Researchers looked at reanalysis data and historical climate model simulations, as well as extreme value statistics—which can estimate the return periods of rare events—to determine the regions where record-breaking temperatures are most likely to occur next, or in the near future.

PROBLEM: Predicting extreme river flooding has typically been based on whether that river has already flooded in the past. However, “[f]or this method to work, you have to wait for something bad to happen,” notes Stefano Basso of the Norwegian Institute for Water Research.

Tropical Storm Idalia is set to become a major hurricane before hitting Florida this week. Join Stephanie Zick from Virginia Tech to learn about the storm's impact and landfall predictions.

Brian Golding discusses how the weather enterprise can collaborate to provide more effective warnings that are timely, culturally sensitive, and easily understandable amid the increasing occurrence of extreme weather in our changing climate. 

“Wildfires are not just a consequence of climate change or global warming—they’re also an active participant.”
—Xin Huang of Nanjing University, coauthor of a recent study in Science that suggests large fires can create feedback loops that alter local weather and subsequently amplify the fires.

As we navigate the midst of Atlantic hurricane season (June to November), being prepared for the potential hazards presented by these storms is crucial. Tropical cyclones, with their powerful winds, rainfall, and waves, can lead to disasters, and it might surprise you to learn that a significant portion of tropical cyclone fatalities occur post-storm. Over the past decade (2013-2022), the National Hurricane Center (NHC) has identified the primary causes of weather and water-related deaths resulting from these cyclones, shedding light on the dangers associated with these natural phenomena.

On May 17th, 2019, an unusual bimodal severe weather setup unfolded across the Central and Southern Plains. Focusing on the Nebraskan border near McCook, convergence, moisture, and instability combined to create a severe weather setup, leading to the formation of a picturesque white elephant trunk tornado. This tornado, rated EF-2, lasted around five minutes, causing damage but no injuries. My dedication to storm photography and reporting severe weather hazards demonstrates my commitment to both artistic passion and public safety communication.

10%–30%—The amount that California’s solar power production during peak hours decreased following wildfires in the state in September 2020, due to smoke darkening the sky.

Scientists from the Potsdam Institute for Climate Impacts have developed a new mathematical approach that they say can substantially improve the prediction of extreme weather events. Analyzing the connectivity and patterns between geographical locations, it could potentially save thousands of lives and avoid billions in economic losses. Prediction times for events like El Niño, monsoons, droughts or extreme rainfall could be increased substantially, to a month or in some cases even a year in advance, depending on the type of the event.

Over the past four summers, community scientists in over 50 US cities have set out to measure the distribution of ambient heat across urban environments as part of a national campaign ("Heat Watch") led by CAPA Strategies and NOAA's National Integrated Heat Health Information System (NIHHIS). The highly engaging program has involved hundreds of community participants as data collectors with simple-to-use equipment, engaging training material, and meaningful input to study design and interpretation of the resulting ambient heat maps. Gaining an element of civic legitimacy through the participation of local communities, the generated datasets are used by municipal planners, health departments, academic researchers, and others to identify heat vulnerabilities and rapidly advance local heat resilience efforts. 

Hailstones are a rare sight in Hawaii due to the high temperatures (averaging 22°C near the coast in February) and a steady trade wind layer shallower than 3 km. However, in winter, midlatitude fronts hit the islands and cumulonimbus associated with them often produce snow at the tops of Mauna Kea and Mauna Loa (4202 km and 4172 km in height, respectively). The combination of well-developed cumulonimbus and low temperatures at the surface sometimes leads to the observation of hailstones at ground level even in Hawaii. 

Here are a few of the news stories from the weather and atmospheric sciences and space that we've been following the last two weeks. Do you have a story we missed? Share it in the community!

Higher waves in the Arctic create ice-containing clouds

A team of scientists led by Dr. Jun Inoue of the National Institute of Polar Research, Japan, sought to answer a peculiar question: can higher waves in the Arctic Sea promote the development of ice-containing clouds? This question may seem strange at first, because most people would not have fathomed that a link could exist between those two natural phenomena. But the findings of this study indicate that there most likely is a connection. 

New research locates geographic hotspots for lightning “megaflashes.”

Technically defined as “a mesoscale lightning flash that is at least 100 km long” megaflashes can span hundreds of miles and create multiple lightning strikes far away from the convective core of thunderstorms, coming seemingly out of the blue or calm gray skies. This phenomenon has only recently been described and is still the subject of research. By exploring megaflash characteristics and locating the areas where these types of strikes most often occur, this study argues for the need to increase the precision and effectiveness of lightning safety warnings. 

In this presentation from the 2022 AMS Weather Band Community and Citizen Science Symposium, Ted Best illustrates through case examples how the use of citizen weather observations can elucidate mesoscale convective events. A convective wind event, a long-lived thunderstorm with hail, and a mesoscale convective system with heavy rain show how individual observations can be collected to form a more detailed picture of an event for study. A combination of storm spotting, storm reports, CoCoRaHS observations, and radar images is presented for each case. These observations can call attention to events that might otherwise be missed in a busy and complex environment and can be helpful for improving future forecasts.