A storm observer’s pledge

Inspired some behavior I’ve witnessed on YouTube recently…

As a research meteorologist, storm chaser, and an admirer of the atmosphere, I hereby pledge that:

  • I will conduct myself professionally, regardless of whether or not I am observing a storm as a duty of my employment.
  • I will obey all federal, state, and local laws.
  • I will never misrepresent who I am or in what capacity I am observing a storm. I will never impersonate a law enforcement officer or emergency responder.
  • I will conduct myself safely and ethically, even if doing so costs me a “money shot.”
  • I will report promptly any hazardous conditions that I observe to the NWS, and share my insights with local authorities.
  • I will never willfully imperil myself or others, thereby diverting emergency resources from the local population.
  • I will not operate a handheld camera while driving. I will ask my chase partner(s) to take images and video for me.
  • I will never exploit tornado victims for personal gain.
  • I will not cheer on a tornado, since I can never know what’s beneath it.
  • I will admit promptly to my mistakes, and offer explanation and redress.

Minnesota Skywarn Workshop

Just a heads up that I will be giving a keynote talk at the 2013 Minnesota Skywarn Workshop on Saturday, 13 April 2013. As many of you know, I grew up in the Twin Cities, so this venue is a perfect fit for me. I’m looking forward to the chance to visit my old stomping grounds and reconnect with the spotter community up north. Minnesota weather weenies (and yes, I still count myself among them) are a very special breed!
2013 Minnesota Skywarn Workshop

New pub

This month’s issue of Monthly Weather Review contains my newest paper, EnKF assimilation of high-resolution, mobile Doppler radar data of the 4 May 2007 Greensburg, Kansas supercell into a numerical cloud model, describing the second half of my dissertation research. (Yes, I know I graduated over a year ago… Publication takes a long time, as well it should!) The take-home message of the paper is that low-level (< 1 km AGL) wind observations make more realistic analyses of supercells (and other rapily-changing atmospheric phenomena). Supercells have a lot going on under the hood – updraft and downdraft pulses, mesocyclone cycling, cold pool generation, etc. – not all of which are apparent to the naked eye or even to an advanced, 4D observing system like a radar. Computers can help fill in some of the gaps via process called data assimilation (DA).

For those not familiar with DA, it means combining atmospheric observations (such as those from a radar) with a computer-generated weather forecast in order to produce a mathematically optimal, 3D analysis of the atmospheric state. You then use the analysis to launch a new forecast. Rinse and repeat every few minutes. The end result is a series of 3D snapshots of the storm, which you can use to diagnose the storm’s inner processes. (There is a gargantuan body of theory required to combine these two very different types of input and assess the quality of the analyses. I shan’t bore you with the two semesters’ worth of details that I slogged through in grad school.)

For this study, I used an advanced DA technique called the ensemble Kalman filter (EnKF) to assimilate NEXRAD (from Dodge City, Kansas) and UMass X-Pol data collected in the Greensburg storm. In one set of experiments, I withheld the UMass X-Pol data (which were collected more frequently and closer to the surface). The mesocyclone of the simulated Greensburg storm was much stronger and more persistent in the experiments where I used the UMass X-Pol data, and the updrafts and downdrafts stronger and more compact. While we lacked independent data to use for verification, making our assessment necessarily qualitative in some regards, our results are consistent with previous DA studies using artificial, “perfect” radar observations.

Simulated Greensburg storm (reflectivity)

Here’s the simulated reflectivity in the Greensburg storm, after assimilating (left) WSR-88D data only and (right) also UMass X-Pol data. Both storms are in the same place and look similar overall…

Simulated Greensburg storm (vertical velocity, vorticity)

BUT… the velocity fields are very different! Updrafts (red) and downdrafts (blue) are more intense. Also, the vorticity bullseye corresponding to the Greensburg tornado (black contours) is much stronger.

I described in a previous post our serendipitous UMass X-Pol data collection in the Greensburg, Kansas storm of 2007, and how that evolved into a detailed case study published last year. My husband lead-authored a companion study earlier last year where he assessed whether modifications to the initial model environment changed the forecasts. (Answer: Yes. Quite a bit, in fact.) This pub completes the trifecta. As we were about to submit this paper for peer review, we made a last-minute decision to switch the DA software to a system that was more extensively tested for severe storms. Even though that added a month to the prep time, I am glad that we did, because the resulting analyses, generated from the same observations, looked markedly better.

I wrote this paper during my CAPS postdoc with the able assistance of my co-authors, representing a fruitful collaboration between SoM, NSSL, and CAPS. I manually edited and dealiased all the radar data (a task that took nearly two months). I had the benefit of two astute reviewers (including my brother-in-EnKF, Dr. James Marquis) who asked some mighty tough questions. And I got to share this MWR issue with some other super scientists – Tom Galarneau, Jeff Beck, and Chris Weiss.

2001-06-11: My first tornado, Benson, Minnesota

The “my first tornado” meme circulating on Facebook prompted me to dust off my first chase log book and relive the Benson, Minnesota tornado – my first ever. I kept an astonishing amount of detail, and it helped me reconstruct the chase. On subsequent chases, I’ve usually been in the driver’s seat and not kept such detailed logs. But when you’re packed in the back of a van with a dozen other students, there’s not much else to do besides observe and record.

AOS 455 students work to free Van #2 from Kansas mud.

Dr. Tripoli and his AOS 455 students work to free UW Van #2 from Kansas mud. A copy of this photo is still up on the wall of the AOS department at 1225 W Dayton Street.

In spring 2001, I had a freshly-printed B.S. diploma from the University of Wisconsin – Madison’s Atmospheric and Oceanic Science department in hand, and taken a job as a research intern at the Space Science & Engineering Center on Dayton St. I decided to enroll (as a “super senior”) in the biennial summer course AOS 455: Severe Storms Forecasting, taught by Dr. Greg Tripoli. After a couple of weeks in the classroom reviewing mesoscale meteorology, we piled into two white university vans and spent 10 days cruising the Great Plains, chasing turkey towers with Josh Wurman & Co. (who were then rolling in DOW2 and DOW3), sampling the local cuisine (ahem, Taco Tico), pushing the vans out of the greasy red mud, and taking in local sights (e.g., “No trespassing” signs riddled with bullet holes, and a storage facility eloquently named U-STUF-IT). This newly-minted meteorologist from the Midwest found plenty of warmth and charm in the rolling Plains. I distinctly remember watching majestic bubbling cumulus from a parking lot in Harper, Kansas one afternoon, surrounded by fields of waving wheat. I took a deep breath of balmy Gulf air, felt the wind tickle my short hair, and thought to myself, “You know, I could get used to this.”

Near the end of our trip, we migrated back north along I-35 in preparation for our return to Madison. It being early June, the jet stream had begun to migrate north as well. We started off the morning of 11 June in Rochester, Minnesota, and headed north toward St. Cloud. A surface low tracked across northern MN, dragging a cold front behind it, we anticipated the latter would touch off a round of storms in western MN. Wind profiles were marginal, but the air was sticky (72+ F dewpoints, thanks to the exhalations of the corn crop). We banked on the storms generating their own environment.

Radar composite of the upper Midwest on 11 June 2001

This HP supercell in western MN (yellow arrow) produced my first-ever tornado. Radar composite courtesy of UCAR.

We stopped for a couple of hours near Olivia, MN, watching backbuilding pulse storms fire off and scoot by to our north. One by one, they marched away to the east like lemmings and collapsed, much to the consternation of our green group of storm chasers, who were straining at the leash to chase something.

Finally, a new storm west of Willmar began to look better organized. A pay phone call from Dr. Tripoli to nowcasters back in Madison confirmed that was our target. We headed west on U.S. Hwy. 12. As we approached Benson, MN from the east, at around 2015 UTC, we observed a rain-wrapped wall cloud. From our vantage point about 20 miles from Benson, the rain cleared, and in the peach back light of the late afternoon sun, we saw a cloud appendage with a persistent dust whirl beneath it. I had my VHF HT hooked to my belt, and could hear local spotters confirming a tornado in the direction we were looking. I snapped a few pictures before we got back in the van to follow the storm.

Benson, MN tornado of 11 June 2001

My first tornado. We are about 20 mi east of Benson, MN, looking W at 2015 UTC.

We observed a few more wall cloud cycles and dust clouds as we followed the storm back towards Willmar. Tornado warnings followed the storm too, but we never spotted another funnel or tornado. The Benson storm eventually outran us, and we abandoned the chase near Glencoe. I remember making a collect call from a gas station pay phone to my parents in St. Paul, warning them about the approaching hailer. (It did eventually evolve into a mini-bow as it passed over the Twin Cities, and left a fat swath of wind reports across western Wisconsin.) I can’t remember if we drove all the way back to Madison that night or not, but my log book doesn’t have another entry until 14 June.

My top three SLS talks

Proceedings of the recent 36th AMS Severe Local Storms conference in Nashville are now online. My new boss, Dr. Pam Heinselman, was one of the co-chairs. She never even broke a sweat!

It was a terrific conference. Highlights included:

  • Dave Lewellen’s ultra-high resolution simulations of tornadoes interacting with other-than-flat topography. Some of his simulations looked remarkably like my video of the 7 November 2011 tornado interacting with the Wichita Mountains!
  • Harold Brooks gave a “mythbusters”-style keynote talk about the 2011 and 2012 tornado seasons, and how the media hype (or lack thereof) squares with statistics. If you have 30 minutes, I highly recommend watching his recorded presentation. It’s an informative hoot!
  • Tim Marhsall, fresh back from surveying the dangling NYC crane from Hurricane Sandy, gave back-to-back presentations about his damage surveys of the 27 April 2011 Alabama tornadoes and the 22 May 2011 Joplin, Missouri tornado. He always makes me want to rip out the walls of my house to make sure they’re toe-nailed.

There were, of course, lots of other great presentations and posters, including a couple by yours truly, but these were my three favorite.

In addition to my professional contributions, I organized the traditional, less-than-formal “photo and video night” at the conference (with some help from Dan, Lou Wicker, and Judith Z. of the AMS staff). There were contributions ranging from all over the U.S. to Australia, Japan, and Germany. We noted sadly the howling vacuum created by the absence of Dr. Bob Schlesinger – a former colleague at UW-Madison – who is famed for the uniquely-styled presentations that he usually delivers at video night. A response to my inquiry at UW indicated that Bob was unable to travel to the conference because of health issues. I organized a get-well card for him, which was soon so densely scrawled upon by dozens of people that we had to resort to using the back cover. I certainly hope Bob comes back in 2014. It just wasn’t the same without him!

2012-11-10: The season fizzles to a close

Turkey towers over Greensburg

Turkey towers over Greensburg

Gusty southerly winds threatened to shove our car out of its lane on I-40 just after noon Saturday. We barreled up the Northwest Passage, dodging unusually aggressive tumbleweeds. We arrived in Greensburg, Kansas as the cumuli piled up on the dryline just to our west. “Hurry up and wait” time passed in the parking lot at Dillon’s, where we watched blips bubble and boil in the dry air for over an hour.

This late in the year, sunset comes around 5:30 p.m. local time (versus 9:00 p.m. or even later during May and June). The shorter days not only restrict photography opportunities, but also limit daytime heating and destabilization needed for storms. Today, however, the chief issue was moisture: although deep, dewpoints barely exceeded 55 F east of the dryline. Towers were too skinny, too mushy, too disorganized to garner any serious interest.

Shattuck left split's base

Shattuck left split’s base

A storm finally did materialize east of the dryline near Shattuck, OK, while the storms over Dodge City, KS, stubbornly refused to organize. We dropped back south to the KS/OK border, where the Shattuck storm had split into two moisture-starved miniature supercells. The base of the anticyclonic left split rotated lazily while a possible clear slot tried to cut across the cyclonic shear side (left). We finally stuck a fork in it at dusk.

Unless a miracle occurs, that is likely to be the end of my 2012 chase season!

2012-10-13: Veni, vidi, reliquit

We never even made it to Anadarko yesterday. I woke yesterday to cool temperatures and elevated showers passing through Norman. Not good. Temperatures struggled to get into the 70s all morning as persistent cloud cover and another round of showers kept us from reaching convective temperature.

Anticrepuscular rays converging east of Norman.

Anticrepuscular rays converging east of Norman.

Logistics for the day restricted us to within three hours of Norman, so we focused on looking for isolated convection within a 150-mile radius. Storms began to develop along the Pacific front in western Oklahoma around 1 p.m., and almost immediately lined out. KFDR was down for its dual-pol upgrade, so we had to base our decisions on coarser data from the more distant KTLX. We scoured the kinks and appendages in the line, looking for hints of discretization. Jana B. dropped by in anticipation of a short-fuse departure, and together, we watched the waning minutes of the OU-TX game. An isolated storm went up in the warm sector east of Frederick, OK, and we finally pulled out of the garage around 3:30 p.m.

We arrived in Chickasha, where we had to decide whether to head south on U.S. Hwy. 81 toward our original target, which by then had begun to deteriorate on radar, or west on OK-62 towards Anadarko and a quasi-isolated part of the line that exhibited a mesocyclone. We could see the lowered base of the latter, and we decided to go after it before it raced away to the northeast at 40+ kts.

Stable, stable, stable, north of Verden, OK.

Stable, stable, stable, north of Verden, OK.

As we approached Verden, OK, a solid wall cloud was visible against an emerald green wall of precipitation. We thought we briefly saw a tapered appendage on the north side of the wall cloud. It only lasted about 20 seconds; no one got a picture.

We headed north out of Verden on a paved county line road, watching as RFD precip swallowed the wall cloud. We turned east when the wind-driven precip crossed our road, and subsequently abandoned the storm as it left us behind in a gush of rain-cooled air. With no other viable storms in the area, and the line now fracturing into dozens of weaker cells, we decided to put a fork in it and headed back to Norman.

A multicell with a clear slot passes by Norman.

A multicell with a clear slot passes by Norman.

Later that evening, we observed another weakly-rotating, quasi-isolated cell pass north of Norman. A clear slot sliced across the foreground, but that was as good as it got. Sunset treated us to a stunning display of anticrepuscular rays set against mammatus clouds to our east.

In summary, the shear was good, but thanks to the two rounds of morning convection, the CAPE just wasn’t there. At least we didn’t drive very far (< 100 miles)!

Heads up, Madison!

I’ll be back in my undergrad stomping grounds to give a talk entitled “Unraveling tornadoes with mobile Doppler radar: Scientific storm chasing on the Great Plains” to the Madison, Wisconsin IEEE section on Friday, 16 November 2012. (The section is generously sponsoring my travel. Thanks, guys!) Here’s their announcement for the talk.

In other news: I’ve got a new job! As of today, I have transitioned to an NRC postdoctoral fellowship at the National Severe Storms Laboratory. I will be working with Dr. Pam Heinselman analyzing phased-array radar data. I’m excited to join her and the Radar Research and Development Division (R2D2)!

Last but not least, please enjoy this sunrise time-lapse I shot from the south rim of the Grand Canyon a few weeks ago on my vacation.

Originally, I uploaded sans audio, but YouTube suggested Carly Comando’s pleasant piano piece “Everyday,” and I decided it was a good fit.

Mississippi kite release

Just a quick update on the Mississippi kites I blogged about a few weeks ago. Wildcare, after taking in more than 400 of them in the extreme heat, released the last group in a public event yesterday afternoon. My name was one of the first ones drawn to release one of the kites, and I made it into this video news story from the Daily Oklahoman:
The experience of releasing one of the kites that I had volunteered so many hours to feed was gratifying. Rondi and her staff did an amazing job accommodating and caring for all of them, and they released 85% of the kites in time for their annual migration south. Whenever I hear a Mississippi kite’s distinctive “ke-keeeer” in the sky above me, I can’t help wondering if it’s one of the brood I helped feed.

Review: And Hell Followed With It by Bonar Menninger

And Hell Followed With It by Bonar MenningerIt should come as no surprise to anyone that books about historic tornadoes often pop up on my Amazon recommendations. I’ve probably read two dozen of them. They’ve ranged from drama-rich to science-poor to saltine-dry, with the occasional pompous self-promotion (usually written by a television celebrity) thrown in for good measure. So when Bonar Menninger’s And Hell Followed With It: Life and Death in a Kansas Tornado (2010), about the 1966 Topeka, Kansas F-5, surfaced in my recommendations, I held off on it for a few months. I finally bought it to read on my recent trip to France. I’m pleased to say it was a solid investment that I thoroughly enjoyed.

I offer the following review with the caveats that (1) I read the Kindle edition, and (2) I have no immediate mechanism for evaluating the accuracy of many of the anecdotes. I assume implicitly (and perhaps naively) that the stories have been recorded and conveyed faithfully. However, the extensive list of references (more than 100 of them) at the end of the book gives me some confidence that the author did his homework.

It’s rare that an author comes along who is capable of weaving together a comprehensive narrative of natural calamity in a manner that doesn’t reduce the victims to near-anonymous disaster fodder (and the scientists studying the event to bookish fools, for that matter). From page one, each person who experienced the tornado is incarnated for the reader – usually via an anecdote not involving the tornado, and more often than not a humorous one. We learn about the fiery Mexican housewife, the Depression survivor caring for his disabled children, the up-and-coming disc jockey, and the 8-year-old boy frantically bicycling to a nearby store to run an errand as the tornado bears down. Details as seemingly mundane as what songs or news stories played on the radio, or what TV programs people planned to watch that night (Lost in Space, anyone?) serve to ferry the reader’s imagination back to 1966. The people described could just as easily have been a reader’s (grand)parents, relatives, friends, or neighbors.

Though the stories jump back and forth in time, Menninger masterfully braids them together to provide context for the disaster while describing the disaster itself. (The book contains a handy index at the end, enabling the reader to cross-reference each person, place, and concept.) We learn the history underlying the Burnett’s Mound myth, and about Richard Garrett’s tireless crusade to leverage the pre-existing Cold War knowledge and infrastructure (read: sirens) to prepare Topeka’s citizens for a tornado that he was sure would come someday. Garrett’s efforts in particular are credited with holding the number of tornado fatalities in his state’s capitol down to just over a dozen, for which he received an Exceptional Service Award from the U.S. Weather Bureau.

There’s also the saga of John P. Finley’s 1880s tornado research, the Weather Bureau’s subsequent ban on the use of the word “tornado” in its products, and the redemption provided by the 1948 Fawbush and Miller tornado forecast. Despite the book jacket’s claim that the above story is “virtually unknown,” it’s old yarn to me. That’s not just because I’m a severe weather researcher, but because that story is inevitably retold in just about every contemporary tornado book I’ve read! But that’s a minor gripe about the promotion, not the writing.

Accounts of the tornado’s destruction – chapter by chapter, block by block – never become repetitive. The stories are still just as compelling, and the dread just as fresh and palpable, in Chapter 15 as in Chapter 1. The last couple of chapters deal with the aftermath on scales ranging from personal to national. We learn the fates of the survivors, some of whom had to deal with the physical and mental trauma, in some form or another, for the rest of their lives. Some even report bits of debris still emerging from their skin 20 years later!

From a meteorologists’ perspective, I could not find much to complain about. The highway overpass myth is firmly dispelled at several different points in the book, including the forward. (Several victims encountered the tornado along I-70.) Menninger does a decent job of articulating the state of severe weather science in 1966, and how newer insights have helped to illuminate the events described. However, many of the meteorologists profiled are now deceased, and I did not have the pleasure of meeting them. Perhaps some of my readers can offer their insights as to the accuracy of their stories.

Topeka tornado mural

This mural, “Tragic Prelude,” inside the Topeka state capitol rotunda, vividly depicts the tornado as a metaphor for Kansas’ turbulent history. (This is not the actual mural, which was closed for cleaning when I visited, but a photograph of it.)

What really impressed me about And Hell Followed With It was the quality of the writing. The tornado is variously described as an “enormous, whitish-gray basket,” a giant “broadcast spreader” or “lawn mower,” “boiling, gray lava,” “an ancient, crooked finger,” “coiled like a snake” (during its rope-out phase), and so on. The book reads like a work of fiction, so fast and thick do the metaphors come, and so vividly are the people portrayed. Alas, the Topeka tornado was very real, and as I found out on my visits to Topeka during VORTEX2, the city is loathe to forget.

Lay readers, disaster buffs, and professional meteorologists alike should find something to appreciate in And Hell Followed With It. The author has done a remarkable job of aggregating a colossal amount of information about the Topeka tornado and conveying it in a narrative that is digestible, compelling, and sometimes even funny. And Hell Followed With It should set a standard against which other comprehensive tornado histories can be judged.