conferences

Bumpy Flight into Hurricane Ian Births a New Metric for Turbulence

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Airplane over hurricane

A research spotlight from the 36th Conference on Hurricanes and Tropical Meteorology

NOAA’s WP-3D Orion “Hurricane Hunter” aircraft are no strangers to turbulence. Reconnaissance flights through hurricanes are by definition a tad bumpy.

A viral video taken aboard the Hurricane Hunter “Kermit” (NOAA42) as it flew through Hurricane Ian on 28 September, 2022, however, shows that even its experienced crew were shaken.

In the video, equipment is shown having fallen to the floor of the aircraft (“There goes the sondes!”), and after a camera-shaking bump, the crew can be heard reassuring each other, “We’re alright.”

Part of video of Hurricane Hunter flight into Hurricane Ian, September 28, 2022. Video courtesy of Nick Underwood.

“I’ve been flying hurricanes with NOAA for the last six years, and that was the worst flight that I’ve been on so far,” NOAA Programs and Integration Engineer Nick Underwood (who filmed the video) told MSNBC the next day. “We were coming through the western side of Hurricane Ian, it was intensifying up to its peak Category 4 strength, and we really got bounced around.”

As it turns out, the flight may have been the most turbulent ever on a Hurricane Hunter aircraft, at least in the past 20 years. In a study presented by Joshua Wadler of Embry-Riddle Aeronautical University at the 36th Conference on Hurricanes and Tropical Meteorology, researchers came up with new metrics to better quantify turbulence as experienced by an aircraft’s occupants—and ranked the top ten flights in Hurricane Hunter history.

“It was probably about ten minutes of really extreme turbulence,” said Wadler in his presentation during the “Innovative Observing Technologies to Advance Tropical Cyclone Operations and Research VI” session. As part of the flight crew, Wadler was on the team in charge of the Altius-600 small uncrewed aircraft system’s first-ever deployment into a hurricane.

Left and right: Josh Wadler and colleagues aboard the WP-3D Hurricane Hunter flight into Hurricane Ian, September 28, 2022. Photos courtesy of Jake Barlow. Center: Altius sUAS in front of WP-3D aircraft. Photo: Joe Cione.

“We were talking on the mission and we [thought], well, is this the bumpiest flight ever?” Wadler said. A few of the crew who had been flying such missions for decades seemed to think so. “We were like, okay, let’s try to figure it out.”

A bumpiness equation

Aside from corroborating hurricane researchers’ harrowing tales, understanding turbulence is becoming increasingly important given its predicted increase due to climate change, and with recent incidents including the death of a passenger during an exceptionally turbulent Singapore Airlines flight. Metrics for turbulence already exist, but most of those only represent vertical motion and focus on atmospheric properties rather than what happens to occupants. “We wanted … to have a 3-D turbulence metric, and one that describes the human experience,” said Wadler. 

When an aircraft rapidly accelerates  vertically or horizontally, everyone feels the dizzying rise or stomach-clenching drop. But if the aircraft rotates around its center of gravity in any direction, that acceleration will have different effects depending on where someone is seated–for example, when the aircraft tilts (or pitches) upward the people in the front of the aircraft will feel an upward acceleration while the people in the back will feel a downward acceleration. If the plane is also accelerating upwards, such as during takeoff, those in the front will experience a “double whammy” of acceleration. As Wadler noted, “Every seat on the plane experiences different rotational motions depending on where you are.”

Wadler and colleagues’ new “bumpiness” metric accounts for those differences. 

The research team combined flight-level data from all P-3 flights since 2004 (when high-enough-quality data became available). They calculated the acceleration forces acting on each seat in the plane relative to the plane’s center of gravity.

They defined the flight’s “bumpiness” by combining acceleration with jerk (the rate of change in acceleration over time), accounting for both in all three dimensions. This equation can be applied to any aircraft where the center of gravity and relative positions of the seats are known, and for which high-quality flight-level data are available. 

Bumpiness equation
Wadler and colleagues’ equation for defining “bumpiness” (B) in meters per second squared (m/s2).
Pilot's bed on floor

Their equation accounts equally for bumpiness in all directions, although it can be thrown off by sharp turns. Missions in which the plane turned sharply on purpose (for example, to calibrate instruments) were excluded from the team’s calculations.

Because the end result, the B or bumpiness value, values all dimensions of movement equally, it doesn’t always sync with what people expect. Some Twitter commenters belittled the video from the flight, possibly because it shows few large up-and-down bumps. The main types of motion experienced by the mission’s crew, however, were front-to-back and side-to-side.

<< The off-duty pilot’s bed was thrown from its bunk onto the floor during flight 20220928H1 into Hurricane Ian, due to lateral motion of the aircraft. Photo courtesy of Jake Barlow.

The bumpiest hurricane flights

The researchers calculated the top 10 bumpiest flights for each of the seats on the plane, based on the most turbulent part of each mission. 

WP-3D Orion seat map
Seat map of WP-3D Orion Hurricane Hunter aircraft. Image: Josh Wadler.

For the person in seat 1 (the “pilot flying,” in the front left seat on the plane), the Hurricane Ian flight was in fact the bumpiest by far—with a B value of 6.04 m/s2, 34% bumpier than any other flight for which good data were available. The second highest B value was experienced during Hurricane Irma in 2017 (B value: 4.5 m/s2), the third by a flight into Hurricane Sam in 2021 (B value: 4.39 m/s2). Subjective rankings from surveyed flight crews came up with a wide range of answers about their bumpiest flights, but were roughly in the same ballpark as those calculated by B value.

RankStorm NameMission IDMaximum Bumpiness Value (m/s2)
1IAN20220928H16.04
2IRMA20170908H24.50
3SAM20210929H24.39
4LANE(EP)20180822H14.28
5FELIX20070902H14.27
6DORIAN20190830H24.08
7PATRICIA(EP)20151023I14.05
8RAFAEL20121015H14.02
9GONZALO20141017I13.90
10DORIAN20190904H13.70
Rankings of B values for Hurricane Hunter flights since 2004, for the pilot in seat 1.

On the Hurricane Ian mission, the greatest B value (6.13 m/s2) was experienced by the second pilot, sitting in seat 2. Wadler was in seat 10. “I was very fearful during this mission,” he noted during his presentation. But, “lo and behold, my seat had the lowest [bumpiness] value by far.” The pilot in seat 1 experienced 37% worse turbulence than Wadler’s seat in the middle of the plane (6.04 m/s2 vs. 4.4 m/s2).

Seatmax Bumpiness (m/s2)
16.04
26.13
36.02
45.87
55.52
65.68
75.03
85.08
94.79
104.4
114.46
124.45
134.54
144.52
154.45
164.53
174.51
184.59
194.55
Rankings of B values for all seats on the Hurricane Hunter flight 20220928H1.

For seat 1, the Ian flight (Flight 20220928H1) ranked above all other flights for back-front and lateral motion. Yet in terms of up-down motion, a mission during Hurricane Lane ranked far higher, with a vertical B value of 17.1; Ian’s highest vertical B value was 8.43, ranking it seventh in terms of vertical motion. When all metrics are combined, however, the Ian flight came out on top. “It’s normal to have vertical bumps with eyewall updrafts and downdrafts,” Wadler noted in a later conversation, “but the lateral motions are rare. … The dropsondes went all over the cabin.”

Currently the bumpiness rankings only count the highest B value experienced during a flight. In future work, the research team aims to develop an equation that can account for cumulative bumpiness over time—a “queasiness index.” We’re well on the way to finding out what flights would make even the most iron-stomached hurricane hunter, in Wadler’s words, “very happy to be on the ground.”

Want to know more about what it’s like to fly a research mission into a hurricane? Take a virtual tour of a Hurricane Hunter aircraft “Miss Piggy.”

Header photo: View from NOAA WP-3D Hurricane Hunter aircraft “Kermit” during flight 20220928H1 into Hurricane Ian. Photo courtesy of Joshua Wadler.

About 36Hurricanes

The 36th Conference on Hurricanes and Tropical Meteorology brought together hundreds of hurricane researchers, modeling experts, forecasters, emergency managers, communicators, and more May 6-10, 2024, in Long Beach, California to discuss the latest in tropical cyclones and other tropical weather phenomena. It was hosted by the AMS Committee on Tropical Meteorology and Tropical Cyclones.

You can view the online program here. All conference presentations will become available to the public starting in August 2024.

Be There: The Daniel Keyser Symposium

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Highlighting Key Sessions at AMS 2024

The Daniel Keyser Symposium at the 104th AMS Annual Meeting will advance the science of synoptic-dynamic meteorology and celebrate the contributions of Prof. Daniel Keyser, a multifaceted researcher and educator. Keyser (pictured at right), a Fellow of the AMS and recipient of the AMS Meisinger Award and Lorenz Teaching Excellence Award, is well-known for his seminal work on cold-front updrafts and for co-originating the Shapiro–Keyser cyclone model.

We spoke with Symposium Co-Chair David Schultz, Professor of Synoptic Meteorology at the University of Manchester, about why the AMS community is celebrating synoptic-dynamic meteorology and Daniel Keyser’s contributions to the field. Here are a few excerpts:

Daniel Keyser

How has Daniel Keyser influenced the field of meteorology?

Dan is one of those people who don’t get the attention they deserve. He’s worked on so many things and worked with so many people. Yet he’s done so in a very humble way.

A lot of what we know about cold fronts is from the work that Dan did. Dan’s PhD was about understanding the circulation of cold fronts and the dynamics of that interaction with the boundary layer in driving the updraft air at the leading edge of the cold front. Later, he developed the concepts of vector frontogenesis and partitioning Q/F vectors into front-normal or front-parallel flows, which help us diagnose the frontal-scale circulations and the larger synoptic-scale circulations in which they are embedded. Also, the concept of the Shapiro–Keyser cyclone model is now commonly taught in meteorology programs. The region of high winds called the sting jet, which is common in North Atlantic cyclones that may impact western Europe, only occurs in Shapiro–Keyser cyclones. 

Not only has Dan been a great researcher, but he’s a great teacher at all levels, undergraduate and graduate. Much of my teaching philosophy comes from my time at Albany, from Dan and Lance Bosart. All four of us on the program committee, and so many others, have been influenced by Dan’s education over the years.

The Shapiro–Keyser Cyclone Model, image taken from Shapiro and Keyser (1990).

Give us a few highlights of the Symposium’s program.

The first session gives a perspective on Dan’s career, including Dan’s work on wildfires and how he’s influenced others. Wildfire enthusiasts will want to check that out. The second session is called “Jets and Cyclones,” the meat-and-potatoes of Dan’s work. There will be a number of talks about various aspects of fronts, on the frontal scale but also up to the planetary scale, and how things like predictability and planetary-scale circulations in different climates affect the relationship between things like precipitation and fronts. Then, the third session will feature prominent mid- and senior-career-level people speaking about fronts and frontal circulation, zooming in on the smaller scale.

Session four is about fronts and precipitation, and it closes with Dan’s own presentation. Sub-seasonal effects, precipitation extremes, convection—for anyone interested in severe, hazardous, or extreme weather (for example, the flooding in California), that will be an important talk.

Why is a symposium on synoptic-dynamic meteorology so important right now?

Synoptic-dynamic meteorology is where meteorological research started, and weather forecasts are better because of our research. Now more than ever, people need to understand the dynamics of extreme weather and take a more interdisciplinary approach to weather systems. There’s a lot of hazardous weather out there, losses from weather events are increasing, and of course many people will experience climate change through its impacts on certain weather events. So synoptic-dynamic meteorology still lies at the heart of the problems that humanity faces and learning how to mitigate them. Yet, despite its importance, we’re at this point where we synoptic-dynamic meteorologists have to fight for recognition and institutional support.

That’s one of the things that Dan really wanted to emphasize in his talk at the end of the day: “A Personal Perspective on the Continuing Importance and Value of Doctoral Education in Synoptic-Dynamic Meteorology.” His talk will help people outside synoptic-dynamic meteorology see how these talks all day during the Symposium relate to the importance of synoptic-dynamic meteorology and to societal resilience in general.

The Daniel Keyser Symposium will be held Monday, January 29, 2024 at the AMS 104th Annual Meeting, in Baltimore and online; it will feature invited presentations, a poster session, and a dinner with Keyser as the guest of honor. Learn more about the Symposium and view the program.

Careers’ Worth of Broadcast Conference Memories

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Celebrating the 50th Conference on Broadcast Meteorology

The 50th AMS Conference on Broadcast Meteorology took place last week, 21-23 June 2023, in Phoenix, Arizona–more than six decades after the first Broadcast conference in Hartford, Connecticut, in 1956. The conference has been a source of cutting-edge information on the art and science of broadcasting the weather, encounters with industry greats, and collaborations that last lifetimes. To help celebrate, we asked several longtime broadcast meteorologists to share their memories with us, plus advice and insights on how the field has changed. The following is the first of three posts featuring their responses.

What are some of your memorable moments from past sessions of the Conference on Broadcast Meteorology?

“My first conference was in Boston in 1981. I remember sitting way in the back and feeling kind of lost and insignificant among all the legends around me. All of a sudden a hand was extended to me and I turned to my right. There sat Harry Volkman! Harry introduced himself and asked my name, and we had a very nice conversation. I never forgot how kind he was to a ‘kid’ weather-caster – Harry was always one of my heroes and someone I still try to emulate.

Today, I still keep that experience in mind when I meet young up-and-coming meteorologists. I hope that I might help inspire them to have a successful career.”

Mike Nelson, Denver7 Chief Meteorologist, KMGH, Denver, Colorado
Left two photos: Harry Volkman; right photo: Mike Nelson at KMOX in the 1980s. Photos courtesy of Mike Nelson.

“I’ve attended nearly every conference since ~1979. I was chair of the broadcast board [for the 1985 conference in Honolulu, Hawai’i], and Mike Smith from Wichita was program chair. Initial thought was that TV news directors would never permit their meteorologists to travel to Hawai’i. Were we wrong! We had record attendance. We programmed the day to start and very early – 7 a.m. to 1 p.m. or so, given people were mostly on Eastern/Central end time. In the afternoon, everyone was on their own to enjoy the island.”

Todd Glickman, Senior Director, Corporate Relations at MIT
Peter Leavitt, President of WSI Corporation, John Coleman, founder of The Weather Channel, and Bruce Schwoegler, Chief Meteorologist of WBZ-TV Boston, at the 15th Conference on Broadcast Meteorology in Honolulu, HI. Photo courtesy of Todd Glickman.
Evelyn Mazur, Director of Meetings at AMS, Brad Field from Hartford, Bill Kamal from Miami, Fred Gadomski of Penn State, and Ken Spengler, Executive Director of AMS, at the 15th Conference on Broadcast Meteorology in Honolulu, HI. Photo courtesy of Todd Glickman.
Photos from the 15th Conference on Broadcast Meteorology in Honolulu, Hawai’i, 1985. Top: Peter Leavitt, President of WSI Corporation, John Coleman, founder of The Weather Channel, and Bruce Schwoegler, Chief Meteorologist of WBZ-TV Boston. Bottom: Evelyn Mazur, Director of Meetings at AMS, Brad Field from Hartford, Bill Kamal from Miami, Fred Gadomski of Penn State, and Ken Spengler, Executive Director of AMS. Photos courtesy of Todd Glickman.

“My first AMS Broadcaster’s conference, and first presentation, was 50 years ago… 1973 at historic Cape Cod. The legendary Don Kent with his Boston accent was most kind with his comments.”

Joe Witte, Climate Outreach Specialist, Aquent, Pasadena, California

What’s been valuable to you about these conferences?

“AMS Broadcast conferences have given me knowledge, professional exposure, and lifelong friendships with like-minded people.”

Alan Sealls, AMS Fellow, CBM, Past Seal Board Chair; Chief Meteorologist at NBC15, WPMI-TV, Mobile, Alabama

“The AMS Broadcast Conference helps me stay up-to-date on the latest in the industry from both the meteorology side and the broadcast side. It’s a great opportunity to connect with my peers in the field and provides an excellent opportunity to learn from each other and experts in various genres of meteorology and climate.As the conference organizer one year, I learned valuable leadership, planning, and organizational skills.”

Lisa Spencer, Chief Meteorologist, News4, Nashville

“I have been broadcasting the weather in Montgomery, Alabama, for 45 years on TV and radio. I attended my first AMS Broadcast Conference in 1984 in Clearwater, Florida. Phoenix [was] my 25th broadcast conference. 25 out of 50. These conferences are so important to me. The learning process never ends. Also, the conference experience has shown me America. And each year I look forward to catching up with my fraternity of friends in this incredible business.”

Rich Thomas, Chief Meteorologist, Bluewater Broadcasting, Montgomery, Alabama

“The Broadcasters Conferences have provided numerous long-lasting memories and friends.”

Joe Witte, Climate Outreach Specialist, Aquent, Pasadena, California

“I attended my first AMS Broadcast Conference in 1993 Charleston, South Carolina, on the hunt for my first job as a broadcast meteorologist. Within a few weeks landed in Johnson City, Tennessee. My advice to all: network, network, and network!

I’ve gained so much from each conference. Presentations by experts on case studies and what was learned. New technology and its impact within the broadcast industry on what we do daily!

What I cherish the most: long-lasting friendships among colleagues. Each conference is a reunion. In some way we’ve all impacted each other in boosting confidence and in being challenged to deliver daily the best information in helping viewers plan and be safe!”

Yolanda Amadeo, Chief Meteorologist, WALB News, Albany, Georgia

(Left to right) Dr. Marshall Shepherd, Yolanda Amadeo, Janice Huff, and Alan Sealls. Photo courtesy of Yolanda Amadeo.

About 50Broadcast

The 50th Conference on Broadcast Meteorology took place in Phoenix, Arizona, June 21-23, 2023. It was organized by the American Meteorological Society Board on Broadcast Meteorology and chaired by Danielle Breezy and Vanessa Alonso. If you registered for the meeting, you can view presentation recordings here.

Header photos (clockwise from top left): Evelyn Mazur, Director of Meetings at AMS, Brad Field from Hartford, Bill Kamal from Miami, Fred Gadomski of Penn State, and Ken Spengler, Executive Director of AMS (photo courtesy of Todd Glickman). Yolanda Amadeo and Jim Cantore (photo courtesy of Yolanda Amadeo). Mike Nelson and Terry Kelly, 1979 (photo courtesy of Mike Nelson).

In the Field: Understanding Canyon Fires

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A Research Spotlight from the 14th Annual Fire and Forest Meteorology Symposium, 2–4 May, 2023

The California Canyon Fire controlled burn moves upslope. Image: San José State University

Wildfires in complex terrain like canyons are known to be particularly dangerous. Canyon fires often “blow up” or “erupt,” exploding suddenly with intense heat and spreading rapidly—and too often causing fatalities among firefighters. In the ninth session of the 14th Fire and Forest Meteorology Symposium on 4 May, Maritza Arreola Amaya presented initial results from the California Canyon Fire experiment, a controlled burn that was intensively documented to help better understand the behavior of canyon fires.

In this experiment, conducted in Central California’s Gabilan Range, a fire was ignited and monitored by a large team who placed sensors around the fire site and monitored the blaze from the ground, from the air with balloons, drones and helicopters; from meteorological towers; and with vehicle-mounted instruments including Radar, LiDAR (“light detection and ranging,” which uses laser light pulses to build three-dimensional images), and SoDAR (“sonic detection and ranging,” which uses sound waves to measure wind speed at different heights). The fire was lit near the bottom of the canyon in steep terrain of chaparral and sparse oak trees. It moved quickly up the canyon, the first time a fire of this size has naturally done so while under intense monitoring.

Flame attachment and v-shaped spread of the California Canyon Fire controlled burn. Image: CAL FIRE

The fire spread up the walls of the canyon in a “v” shape. It clearly exhibited eruptive behavior including flame attachment—in which hot gases rising from the fire downslope heat the unburned fuel further up the slope, leading to an intense, quickly spreading fire front. A highly turbulent, rotating plume of smoke emerged, and air was rapidly entrained into the fire, where temperatures reached nearly 800 degrees Centigrade (1472 Fahrenheit).

While some instruments were destroyed by the flames, researchers at San Jose State, the NSF-UICRC Wildfire Interdisciplinary Research Center, and more are eagerly analyzing the data collected to help improve understanding and modeling of dangerous canyon fires.

“Working on this one-of-a-kind canyon project was one of the coolest things I’ve ever done. Seeing the experiment that took so long to organize and set up finally come to life was amazing. It involved countless hours setting up complicated instrumentation so that ultimately the behavior of a wildfire on canyon terrain could be analyzed for the first time naturally moving up a large canyon. I know that this successful experiment will play a big part in future investigations involving wildfires on complex terrain and the danger they bring to firefighters.”

Maritza Arreola Amaya

Meeting registrants can view the recording of this session here. Recordings become publicly available three months after the meeting.

For a real-life example of a fatal canyon fire and the weather conditions that worsened it, see our post about the Yarnell Hill Fire.

About 14Fire

Meteorology and wildfires are intimately interconnected—and wildfires are becoming increasingly severe and frequent in many parts of the United States. From local residents and firefighters on the ground to planners and insurers, to people hundreds of miles away breathing wind-driven smoke, society relies on our ever-improving ability to understand and forecast the atmospheric conditions relating to wildfire. The American Meteorological Society’s 14th Fire and Forest Meteorology Symposium brought together researchers and fire managers to discuss the latest science.

The Yarnell Hill Fire: Microbursts, Density Currents, and 19 Lost Lives

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A Research Spotlight from the 14th Annual Fire and Forest Meteorology Symposium, 2–4 May, 2023

The Yarnell Hill Fire the day it began, June 28, 2013. Image credit: USDA

Arizona’s Yarnell Hill Fire ranks among the U.S. wildfires with the most firefighter fatalities. On June 30, 2013, members of the interagency Granite Mountain Hotshots were entrapped in a canyon by fire due to rapidly shifting wind conditions. Many attempted to take shelter but were overwhelmed. Nineteen firefighters died and the fire, fed by the strong winds, blazed out of control. The tragedy and damage devastated the community of Yarnell, Arizona.

A joint team at Embry-Riddle Aeronautical University and North Carolina A&T State University has been using simulations to help understand exactly what happened. A recent presentation by Michael Kaplan et al. May 2, 2023 in the first session of the 14th Fire and Forest Meteorology Symposium broke down the events at the meso-γ (2–20 km) scale leading up to the tragedy, the latest in a series of analyses starting at large scales and moving towards ever-finer resolution. They found that a density current (a flow of denser air that intrudes underneath less-dense air) and its secondary circulations drove the winds that forced fire into the canyon where the Granite Mountain Hotshots were located.

Firefighters near the Yarnell Hill Fire on June 28, 2013. Image credit: USDA

A squall line that developed over the Colorado Plateau on the morning of the 30th moved southwestward rapidly, strengthening over the Black Hills and Bradshaw Mountains on the way, until it died out further to the southwest over the Weaver Mountains near Yarnell. From this dying squall line developed a density current that produced unusual air circulation patterns in combination with the area’s complex terrain. Simulations by the Weather Research and Forecasting (WRF) model suggest that the fading density current created conditions in the Weaver Mountains that were highly conducive to downward air motion. This resulted in a series of strong localized downdrafts similar to microbursts near the fire site.

Earlier in the day, the fire had been moving towards the northeast, driven by southwesterly winds. Within 1–2 hours in the late afternoon, the winds shifted and intensified rapidly, becoming northwesterly, then northeasterly, blowing at 45 miles per hour and driving the fire (now blazing at 2,000 degrees Fahrenheit), in a southwesterly direction. Kaplan called these shifts “dramatic, remarkable changes.”

Wind direction and speed (blue arrows) and direction of Yarnell Hill fire motion (red lines) at 3:30–4:30 p.m. and 4:30–5:30 p.m. local time on June 30, 2013. Image: State of Arizona Serious Accident Investigation Team

In the end, “The entrapment of the Granite Mountain Hotshots was likely the result of very, very intense redirected winds” that continued over a longer than expected period, Kaplan said. “Even after they got the initial surge of northeasterly flow [due to the density current] the Hotshots had to deal with more surges of high momentum” from the series of microbursts. He noted that despite the Granite Mountain Hotshots’ high level of experience, “This is something firefighters may not have really been [expecting] to occur.”

Vertical cross-section of potential temperature and isotachs from 3:15 to 3:35 p.m. Arizona time on June 30, 2013, showing new cells forming behind the density current near Yarnell, associated with microburst downdrafts. Image courtesy of Michael Kaplan

Kaplan’s team will continue to work on their simulations of conditions associated with the Yarnell Hill Fire, with the hope of providing information that can help prevent similar entrapments, and deaths, in the future.

Meeting registrants can view the recording of this session here. Recordings become publicly available three months after the meeting.

__________________________________________________________________________________

About 14Fire
Meteorology and wildfires are intimately interconnected—and wildfires are becoming increasingly severe and frequent in many parts of the United States. From local residents and firefighters on the ground to planners and insurers, to people hundreds of miles away breathing wind-driven smoke, society relies on our ever-improving ability to understand and forecast the atmospheric conditions relating to wildfire. The American Meteorological Society’s 14th Fire and Forest Meteorology Symposium brought together researchers and fire managers to discuss the latest science.

Moving Mountains, Not Meteorology

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If you attended the joint AMS conferences—on Applied Climatology and on Meteorological Observation and Instrumentation—held in the shadow of Colorado’s Rocky Mountains last week, you encountered the rich diversity of presentations encapsulating the topics that preoccupy specialists these days.
You heard lessons learned from using familiar tools of the trade, the latest news about new technology, ways of observing drought, impacts of El Niño, and principles of wildfire management.
There was much advice about communicating to the public about climate change, and about the scientific basis presented by the National Climate Assessment. You heard advice from the folks at Climate Central. You delved into how to handle information delivery in the duress of extreme events.
If you’ve moved on to California this week for the AMS Conference on Broadcast Meteorology at Squaw Valley, you enter a different world, right? From the dark, craggy jumble of Precambrian sediments, granite, and gneiss, you’re now surrounded by the pale glow of Sierra Nevada granite. And from scientists focused on research, now you’re in the realm of communicators bringing science to mass media.
So, you’ll hear lessons learned from using familiar tools of the trade, the latest news about new technology, ways of observing drought, impacts of El Niño, and principles of wildfire management.
There will be much advice about communicating to the public about climate change, and about the scientific basis presented by the National Climate Assessment. You’ll get some advice from the folks at Climate Central.  You’ll also delve into how to handle information delivery in the duress of extreme events.
Déjà vu? Copy-and-paste error?
No. For all the specializations and variations in interests that collectively constitute the American Meteorological Society, there’s a lot in common between even the seemingly disparate branches. The roots in science grow into all sorts of permutations. The mountains may shift, but that’s a mere backdrop for the constancy of meteorology and related sciences flourishing across the land.
Enjoy your meetings.

Vortex Delight

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This Monday at the AMS Conference on Mountain Meteorology, Rieke Heinze of the Institut für Meteorologie und Klimatologie at the Leibniz Universität Hannover presented this very cool looking simulation of von Kármán vortex streets, which sometimes show up in satellite images of clouds in the lee of isolated mountain islands. The nifty thing about Heinze’s simulation project is that it shows the vortices retaining a warm core from bottom to top in the flow (cross section not shown here).
On her project web site (where you can download the video), Heinze writes:

Atmospheric vortex streets consist of two rows of counterrotating mesoscale eddies with vertical axis in the wake of large islands. They resemble classical Kármán vortex streets which occur in laboratory experiments behind a cylinder. Usually, atmospheric vortex streets can be found in the stratocumulus capped mixed layer over the ocean when there is a strong elevated inversion well below the island top.

In the animations the island consists of a single Gaussian shaped mountain with a height of about 1.3 km and a base diameter of about 12km. Particles are released in one layer and act as passive tracers. Their vertical motion is disabled. The colour of the particles reflects the difference between the temperature at the respective particle position and the mean temperature, horizontally averaged over the total domain. Blue/red colours represent a relatively low/high temperature. The animation shows that the cores of the eddies are warmer than the environment. The length of the animation corresponds to about 14h real time.