A one-two punch inside intense Hurricane Felix in 2007 turned a NOAA hurricane hunter flight into a harrowing rollercoaster ride, causing the mission to be aborted. A study of the extreme event, scheduled for publication in the next issue of Monthly Weather Review, determined a small-scale vortex known as a misocyclone rotating within the Category 5 hurricane’s eyewall is likely what bucked the plane upward nearly a thousand feet before sending it plunging back to its original altitude in less than a minute. The feature is similar to what nearly crashed the same plane inside Hurricane Hugo in 1989.

According to the study, a “routine penetration” into the eye of the hurricane via the northeast eyewall on September 2, 2007 quickly became anything but. First, the horizontal wind speed at the plane’s altitude of about 10,000 feet jumped from 140 mph to nearly 200 mph. At the same time, a standard descent into the eye at a constant 700 mb pressure height quickly steepened and the plane lost more than 700 feet in altitude in 40 seconds. Then a 70 mph updraft punched the plane up 900 feet immediately followed by a 16 mph downdraft that hammered the plane downward 980 feet, in seconds. The on-board radar quit. And gravitational stresses on the aircraft exceeded safety specifications. The mission was scrubbed and the plane then settled into Felix’s calm 12-mile-wide eye at about 8900 feet, circling five times until it could find a safe pass through the southwest eyewall and out of the hurricane.

They were lucky.

The hurricane hunters have unknowingly flown into these updraft-downdraft combinations before. They seem to only encounter them in monster Category 5 hurricanes, which have sustained winds greater than 156 mph. Besides Felix, researchers have documented the extreme events in Hurricanes Patricia (2015), Isabel (2003), and Hugo (1989). The encounter in Hurricane Hugo took place with the same hurricane hunter plane (NOAA42) flying at just 1500 feet, which was typical back then. Not any more. Fists of wind smashed the aircraft downward more than a thousand feet and then back upward, knocking out three of the its four turboprop engines and crippling the plane. It barely made it out, and afterward the rules for hurricane eye penetrations were rewritten.

Back it 1989, researchers thought they had perhaps flown into a tornado in the eyewall. But in Hurricane Isabel, data revealed a vortex a bit larger but no less intense was encountered. Similar in scope but smaller in size to the rotating 5-10-mile-wide updrafts of supercell thunderstorms, which have become known as mesocyclones, the hurricane eyewall vortexes were only a fraction of that—hence the name misocyclones, or small-scale cyclones.

In Felix, a bit of serendipity: just as the plane encountered the misocyclone, researchers released a commonly used tube of instruments called a dropwindsonde into the eyewall to measure temperature, pressure, humidity, and with onboard GPS tracking, wind speed and direction. The dropwindsonde measured details of the wind within the misocyclone, including a shift in the horizontal direction and a speed that jumped to more than 230 mph at about 400 feet decreasing to just 41 mph near the water. The tremendous shear—change in the wind speed in such a short distance—is “8 orders of magnitude larger than those known to lead to […] horizontal shearing instabilities and misocyclone development,” the study noted based on prior research.

It’s only the second time details of a misocyclone have been measured, making them largely mysterious events. For example, researchers aren’t certain how common or unusual they are. “Many very intense tropical cyclones have been sampled with aircraft without encountering these extreme events,” the study states, adding, “It is unknown whether they have been missed by the relatively sparse observations available, because aircraft tend to deviate around the most intense eyewall convection, or if they are truly rare.”

Deepening the mystery is the timing of the extreme event inside Felix—it occurred as with Hugo at the end of a period of rapid intensification, which is when a hurricane’s central pressure drops precipitously ramping up its sustained winds very quickly. Winds in Hurricane Felix increased by 90 mph to 165 mph sustained that day in 2007. It has been thought that extreme features in hurricanes such as lightning, graupel, and eyewall vortices likely occur during periods of rapid intensification, as occurred with Hurricanes Isabel and Patricia. But Felix is the second intense hurricane where such an extreme event took place at the end of a rapid intensity cycle, and learning why while keeping the hurricane hunters safe will require further study.

“The frequency of these features and their ultimate importance in the structural evolution [of hurricanes] remain research questions. It is clear, though, that improved understanding of these features would enhance the safety of flights into very intense tropical cyclones.”


by Keith Seitter, AMS Executive Director

The AMS Washington Forum, held each spring, is organized by the Board on Enterprise Economic Development within the Commission on the Weather, Water, and Climate Enterprise. It brings together leaders from the public, private, and academic sectors for productive dialogue on issues of relevance to the weather, water, and climate enterprise in this country. Compared to our scientific conferences, it is a small meeting with typically a little more than 100 participants. This allows for a meeting dominated by rich discussion rather than presentations. The Forum takes advantage of being held in Washington, D.C., with panel discussions featuring congressional and executive branch staff, as well as agency leadership. It is no secret that this is one of my favorite meetings of the year, and for many in the atmospheric and related sciences community, the Washington Forum has become a “can’t miss” event on their calendar.

The 2017 Washington Forum will be held May 2–4, 2017 at the AAAS Building, 1200 New York Avenue, Washington, DC. (Note that this year’s Forum occurs later in the year than usual.) The organizing committee has put together an outstanding program again this year under the timely, and perhaps provocative, theme: “Evolving Our Enterprise: Working Together with the New Administration in a New Collaborative Era.” The transition to a new administration is bringing changes in department and agency leadership that directly impact our community. The Forum will provide a terrific opportunity to explore how the community can collaboratively navigate these changes in ways to ensure continued advancement of the science and services for the benefit of the nation. I am expecting three days of very lively discussion.

We have a special treat this year in conjunction with the Forum. On the afternoon before the Forum formally begins, Monday, May 1, the Forum location at the AAAS Building will host the second Annual Dr. James R. Mahoney Memorial Lecture. The lecture honors the legacy of Mahoney (1938–2015), AMS past-president and a leader in the environmental field in both the public and private sectors, having worked with more than 50 nations and served as NOAA Deputy Administrator in addition to other key government posts. The Mahoney Lecture is cosponsored by AMS and NOAA, and the annual lecture is presented by a person of stature in the field who can address a key environmental science and/or policy issue of the day. We are very pleased to announce that Richard H. Moss, senior scientist at Pacific Northwest National Laboratory’s Joint Global Change Research Institute and adjunct professor in the Department of Geographical Sciences at the University of Maryland, College Park, will deliver the second Mahoney Lecture. The lecture will begin at 4:00 p.m. and will be followed by a reception. The lecture is free and does not require registration to attend.

If you have ever thought about attending the Washington Forum but have not yet done so, this would be a great year to give it a try. We do limit attendance because of space constraints and the desire for this meeting to have a lot of audience participation and discussion, so I would encourage you to register early. You can learn more about the Forum, and register to attend, at the Forum website.

(Note: This letter also appears in the March 2017 issue of BAMS.)


“Who ever gets tired of looking at this thing?” asked Steve Goodman of an appreciative audience when he presented a slide of the new imagery from GOES-16 at the 97th AMS Annual Meeting this January.


The answer was clearly, “Nobody.”

The images from GOES-16 have been dazzling, but the hard work of maximizing use of the satellite is ongoing, especially for Goodman’s agency, the National Environmental Satellite, Data, and Information Service (NESDIS).

The successful launch in November was a major step for the weather community. Compared to the older geostationary satellites, the new technology aboard GOES-16 offers a huge boost in the information influx: 3x improvements in spectral observing, a 4x spatial resolution advantage, and 5x temporal sampling upgrades. But new capabilities mean new questions to ask and tests to perform.

The satellite is barely up in space and already NOAA is targeting its performance for a major scientific study. Last week was the official start of a three-month study by NESDIS to “fine-tune” the data flowing from our new eye in space.

You can learn more about the GOES-16 Field Campaign in the presentation that Goodman gave at the Annual Meeting. He pointed out that it has been 22 years since the imager was updated, and that the satellite also includes the Global Lightning Mapper (GLM), which is completely new to space.

“We thought it would be good, getting out of the gate, to collect the best validation data that we can,” Goodman said.

er2Over a period of 6 weeks, the NASA ER-2 high-altitude jet will fly 100 hours in support of the studies. The flights will be based first from California and then in Georgia, well-timed to coordinate with the tornado field campaign, VORTEX-SE. All the while, the airplane’s downward-looking sensors need to be aimed to match the angle of observation of the satellite-borne sensors. The ER-2 will fly its specially built optical simulator that mimics the GLM.

“That’ll give us optical to optical comparisons,” Goodman noted.

To further check out GLM’s performance, there will also be underpasses from the International Space Station, which now has a TRMM-style lightning detector of its own. “That’s a well-calibrated instrument—we know its performance,” Goodman added.

Meanwhile lower-orbit satellites will gather data from “coincident overpasses” to coordinate with the planes, drones, and ground-based observing systems.

Such field campaigns are a routine follow-up to satellite launches. “Field campaigns are essential for collecting the reference data that can be directly related to satellite observations,” Goodman. He raises a number of examples of uncertainties that can now be cleared up. For example, some flights will pass over Chesapeake Bay, which provides a necessary “dark” watery background: “We didn’t know how stable the satellite platform would be, so there’s concern about jitter for the GLM…so we want to know what happens looking at a bright cloud versus a very dark target in side-by-side pixels.”

Goodman said tests of the new ABI, or Advanced Baseline Imager, involve checking the mirror mechanism that enables north-south scanning. For validation, the project will position a team of students with handheld radiometers in the desert Southwest, but also do a first-time deployment of a radiometer aboard a unmanned aerial system.

The expected capabilities of the ABI, with its 16 spectral channels, are featured in an article by Timothy Schmit and colleagues in the April issue of the Bulletin of the American Meteorological Society.


Thanksgiving in March

March 14, 2017 · 0 comments

by Keith Seitter, AMS Executive Director

The past few months have been a period of increased anxiety for many of us in the weather, water, and climate community as we contemplate how changes in the nation’s administration will impact agencies and programs, and, ultimately, how well our science and the services based on it can move forward. Despite the fact that we work in disciplines that routinely deal with uncertainty, it is not easy for us to deal with the particular flavor of uncertainty we have been facing, or to keep it from being deeply unsettling.

At AMS, we have focused on being even more vigilant in working to defend the integrity of the scientific process and in trying to ensure that the best peer-reviewed science is brought to bear on issues facing our country and the world. Recognizing the importance of those efforts—and even with occasional successes in them—does not keep one from becoming disheartened in dealing with our “post-fact world.”

I was feeling particularly discouraged recently as all this weighed on me, and then I realized that what I should be doing is creating the kind of list many of us do on Thanksgiving. Here it is:

  • I’m thankful to be part of a community whose work really matters. And that people become part of this community because they know how much this work matters and they bring dedication and passion to it every day.
  • I’m thankful that the general public appreciates and depends on the work of our community. They look to us every day to help them make decisions both big and small, and put their trust in us to keep them out of harm’s way (even though they may, at times, complain about our efforts).
  • I’m thankful that we can—and do—rely on a scientific process to discern how our environment works so that we can speak with confidence. It is not what we believe, but what we can observe, measure, and objectively model based on known physics that guides us.
  • I’m thankful I work at an organization guided by a Council made up of gifted and dedicated volunteer leaders, and that I can spend my time working with an incredible professional staff.

By the time I got to the end of this list, I was no longer feeling discouraged but, instead, was energized and ready to keep working toward making sure that the best available scientific knowledge and understanding was getting into the hands of policymakers at all levels. We may be in the midst of particularly challenging times, but AMS, as a very highly respected “honest broker” covering the science and services of the weather, water, and climate community, is in a position to be particularly effective in working through those challenges.

(A version of this post appeared in AMS Executive Director Keith Seitter’s “Letter from Headquarters” column in the February 2017 BAMS.)


Ever wonder what happens to weather balloons as they reach their peak altitude and can’t take the low pressure anymore? They pop, right? Nope. They shatter! Shred! Explode!

This video shows the unique way a weather balloon bursts at about 30,000 m.

Credit: Patrick Cullis (NOAA/CIRES)

The full explanation and several stills to show the explosion in spectacular “stop-action” are in an upcoming issue of BAMS. For members, the BAMS digital edition with its new multimedia capabilities will show the article with both the stills and an embedded video.


A Scientific Neighborhood

February 9, 2017 · 1 comment

At some point, very early in our meteorological education, we learn that the atmosphere, the oceans—and thus weather and climate everywhere—are inextricably linked across the globe. Your weather is my weather, no matter where you live and where I live.

Weather makes us all neighbors—partners in science across vast distances. The idea is indelibly etched in our science. It was alive as early as Benjamin Franklin, writing to his brother hundreds of miles away to ask if the weather in Boston bore any relation to the weather in Philadelphia. It pervades the insights of Edward Lorenz, who taught that the flap of a butterfly’s wings in Brazil might be the trigger for a tornado in Texas.

The neighbor principle of weather drives discovery and propels the dramatic improvement in forecasting and understanding we continue to witness. We see this ethos in the free exchange of data and sharing of resources to build our Global Observing System. We see it when Europeans and Japanese move their satellites to help us cover gaps in our observing, and when Americans do the same for them. In science and saving lives, we are neighbors, across thousands of miles of ocean.

The good neighbor spirit was alive and well at an AMS Annual Meeting Town Hall on U.S.-International Partnerships this month. The panel featured representatives from AMS, the World Meteorological Organization, and the meteorological societies of China, Japan, South Korea—people who traveled half a world from their families to be with us. They came together to tout the value of close international collaborations. At the Town Hall, it was clear why scientists seek opportunities to confer with each other, across borders. “We need to learn from each other,” the panelists agreed.

Last week the AMS joined 170 other professional, academic, and scientific organizations in signing a letter to President Trump. The letter warned that the Executive Order issued on January 27 regarding visas and immigration has “profound implications for diplomatic, humanitarian, and national security interests, in part because of the negative impact on U.S. science and engineering capacity.”

The letter points out that

In order to remain the world leader in advancing scientific knowledge and innovations, the U.S. science and technology enterprise must continue to capitalize on the international and multi-cultural environment within which it operates.

AMS has been doing more and more to recognize the reality of that international and multi-cultural environment in our disciplines. This reality has a long history. Franklin’s ideas on lightning were quickly celebrated in Europe, for example. And the founder of modern weather services in our country, Cleveland Abbe, encouraged translations of seminal European papers in the pages of Monthly Weather Review, a journal he founded in 1872 to make domestic meteorologists aware of relevant scientific innovations. Throughout the early 20th century revolution of scientific weather forecasting, major advances came through exchanges of scientists traveling to Europe, and from Europeans scientists who came to the United States. Nearly every American in the AMS can trace their personal scientific “lineage” to trans-Atlantic and trans-Pacific exchanges of this kind.

Today, AMS continues this neighborliness of science—through cooperative agreements with societies in Canada, China, Europe, and India and elsewhere, through the programming of its meetings, and through the pages of its widely read journals. Take the latest Annual Meeting: more than 500 attendees came from outside the United States. Look at the latest issue of AMS’s Journal of Climate: fully half of the 50 authors listed there are affiliated with institutions of other countries. A large number of the other half were educated, at least in part, in overseas institutions. Scientific talent, innovative ideas, professional heritage—all flow across the globe as necessarily as wind and water.

This international environment is the scientific neighborhood in which we live. It is one critical reason that AMS and its cosigners offered the President their assistance in “crafting an immigration and visa policy that ensures strong borders while staying true to foundational American principles as a nation of immigrants.”




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The twitterverse was abuzz with activity during last week’s Annual Meeting. Here are a few of the highlights:


Fundamentally, peer review is critical to the proper functioning of science, and yet there can be surprising variations in the subtle variations of what editors are looking for and how they select reviewers and make decisions.

Today at the Publications Workshop of the Annual Meeting, several AMS journal editors will gather in a panel (Room 604, 12:15 PM) to answer your questions about the how’s and why’s of the peer review process.

The editors exploring their common views and differences are: Tony Broccoli, of the Journal of Climate; Walt Robinson, of the Journal of Atmospheric Sciences; Carolyn Reynolds and Yvette Richardson of Monthly Weather Review; and Jeff Rosenfeld, of BAMS.

Snacks will be provided, and there will be discount coupons of MWR Chief Editor Dave Schultz’s book, Eloquent Science: A Practical Guide to Becoming a Better Writer, Speaker, & Atmospheric Scientist for those attending. The book can be purchased at the Resource Center.

To get a head start on some of themes the panel will address, the AMS recorded two interviews–one with Schultz and Weather, Climate, and Society Chief Editor Amanda Lynch–about the role of peer review for two contrasting journals:

Interview with David Schultz:


Interview with Amanda Lynch:


Yes, We’ve Got Maps

January 25, 2017 · 0 comments

This point was made at Monday’s Presidential Forum, where Dr. Richard Jackson of UCLA was talking about how much our scientific community offers to the world of public health, and how we might best be able to move decision makers to action based on climatic information.

It is good news. Nobody makes maps more eagerly than meteorologists.

Hardly a session goes by at the AMS Annual Meeting without some sort of map—often of some unexpected variable. For example, today at 10:45 a.m. (Skagit 4), Yonghua Wu (City Univ. of New York) and colleagues pull together trajectory modeling, lidar ceilometer, and satellite observations to map air quality variations due to the interaction of boundary layer conditions with wildfire smoke plumes this past summer over New York City.

blog_logo_final_all_caps_updateThen on Thursday (1:45 PM, Tahoma 2), you can map the New York City area again, in a completely new way: Sina Kashuk of NOAA shows spatial density maps of the 5 million flood-related phone calls across the five boroughs.

Using the top 25 most frequent complaint types ranging from noise to rats, the overall propensity of calling was estimated and mapped. This map was then used to normalize the flood-related complaints. The temporal-spatial analysis was highly correlated with monthly rainfall intensities.

Clearly, no place is mapped in one particular way. Maps say as much about the data and the analysis as about the specific location. Mapping is thus an essential tool for coalescing, analyzing, contemplating, and communicating observations.

Harvard historian Peter Galison takes this point a step further in his studies of the history of observing as evinced by map-making. Through a selection of atlases across the centuries, all made by scientists, he shows how the powers of observation and the expectations and capabilities of science are all intertwined, and all evolving. The idea of observing itself is not the same today, he shows, as it was in Newton’s time or even in Einstein’s. In this lecture from 2011 he uses the atlases to trace the history of objectivity itself in mapping:


Which brings us warily to the title of a presentation this morning (8:30 AM, Room 611) , “Beyond Maps-How Cloud Computing Enables the Future of Geospatial Analysis Services.” Presenter Steve Kopp of ESRI explains:

[W]e now see a technology transformation that is enabling deeper understanding, and will lead to new insights and new discoveries. Early adoption of geospatial cloud computing focused on organizing and sharing data….Map services (a picture of the data) are symbolized data ready to view, and require fewer specialized skills than working with raw data such as GRIB files. More recently organizations have begun providing weather and climate data services. These are feature services like WFS and image services like WCS. Data services allow customization of the symbology and more flexibility in visually combining with other data, but also can be used for analysis allowing the user to ask new questions with the data. The transition to data services feeding into analysis services will have a profound impact on the utility and growth of geospatial cloud computing.

Perhaps someday historians will see this AMS Annual Meeting as a part of shift that led the way to yet another stage in the growth of science itself.


There were plenty of entertaining and educational observations made by weather enthusiasts of all ages at WeatherFest on Sunday. Close to 2,00o people visited the Convention Center for an afternoon of weather experiments, exhibits, and festivity. There was even a special appearance by Owllie Skywarn!
Check out a few of the highlights here: