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.

Hot topics

After getting off to a comfortable start with slightly above-average rainfall, summer returned with a vengeance to our neck of the woods. Our lawn, once lush with growth, is now mostly brown and crispy underfoot. I cycled home on Thursday evening crossed by a withering, 111 oF southerly wind. Friday, our 16th consecutive day with a maximum temperature greater than 100 oF, saw the introduction of a statewide burn ban as winds gusted to 25 mph. I crossed my fingers that the firefighters would stay bored, but unfortunately a smoke plume appeared southeast of the NWC around lunchtime.

Lake Thunderbird pyrocumulus

Pyrocumulus cloud over Lake Thunderbird around 5 p.m. on 3 August 2012.

By 5 p.m., the fire had crept northward toward Lake Thunderbird State Park and expanded. The primary smoke column was crowned by a crisp pyrocumulus cloud – the tallest I’d ever seen at a height of greater than 4 miles. Jim LaDue captured a time lapse video of this pyrocu that clearly shows it pulsing upward in response to the thermal plumes from the fire. (Hard to believe anything could be positively buoyant in this heat, but there you go.)

As evening fell, we saw an orange glow on the eastern horizon, like a false dawn, as we walked our dog around the block. We had “grab and go” bags packed just in case the fire decided to get ornery. Fortunately, it remained well east of our neighborhood. However, several of our friends living farther east, along the south shore of Lake Thunderbird, did have to evacuate for a time. The overnight diligence of firefighters kept the flames off their doorsteps. Other people living farther east were not as lucky.

An even bigger fire erupted northeast of Oklahoma City and destroyed significant swathes of Luther, OK. The outrage over the apparent act of arson that started this fire made national headlines. And the danger’s not over – Another week of 100+ oF high temps is on tap, but not a drop of rain in the offing.

Mississippi kites at Wildcare

Hundreds of fledgling Mississippi kites, forced out of their nests early by the heat, fill enclosures like these at Wildcare in Noble, OK.

Apart from exacerbating the tinder-dry conditions, the hot weather is also impacting local wildlife. In a repeat of 2011, dozens of fledgling Mississippi kites are jumping out of their nests prematurely to escape the scorching sun. Once on the ground, the parents don’t feed them (enough). In our area, these sort-of-orphans typically end up at Wildcare. The kites don’t require much, but the sheer juvenile kite numbers this year (300+), as last year, have overwhelmed Wildcare’s small staff. I’ve volunteered for a few shifts feeding the kites bits of meat with a forceps and spraying them down with a hose to keep them cool. (They don’t mind the jet of water from the hose. In fact, they open their wings to embrace the spray!) Most of them will be ready to release by 1 September.

I grew up in Minnesota, where we have a certain machismo about winter: bragging about how low the wind chill was while we waited for the bus, how tall the snow drifts at the end of the driveway got, etc. Winter is a fact of life, and we’ve learned to live with it, even celebrate it. I’ve lived in Oklahoma for 10 years now, and found the exact same to be true of Oklahomans and the oven outside. Heck, I’ve even come around to join then. (“Whoa, you cycled when it was how hot?”) Nonetheless, I’m looking forward to the more temperate days of fall. Believe me, they can’t come soon enough!

New pub

I’ve got a paper in this month’s Monthly Weather Review entitled Mobile, X-band, Polarimetric Doppler Radar Observations of the 4 May 2007 Greensburg, Kansas, Tornadic Supercell. This is the first of two planned papers based on my Ph.D. research, an observational study based on UMass X-Pol data that we collected in the Greensburg storm.

UMass X-Pol on 4 May 2007

UMass X-Pol on 4 May 2007. Had it not been for the blown tire, we might not have collected data in the Greensburg storm.

Operations on 4 May 2007 started off on a low note. Howie, Kery H., and I were driving the UMass X-Pol to Dodge City, Kansas on our first chase of the season, when we blew a tire. With the aid of a good samaritan who just happened to have a spare that was the right size, we limped into Protection, Kansas. Tornado reports near Arnett, OK tempted the rest of our group back south, and we figured we had a bust chase on our hands. As soon as the new tire was on, a storm erupted southwest of Protection, and we decided to collect some “consolation data” in it and shake down the system.

A local sheriff showed us to his favorite storm spotting place on a hill looking over Protection. That road was too muddy for us to use, so we moved about two miles east and deployed on a packed gravel road. As we lost daylight fast, the storm dropped a rotating wall cloud, followed by a brief tornado and an additional funnel cloud to our west. We got volumetric, polarimetric X-band data of all these features. At one point I had to back the truck up to avoid beam blockage from telephone poles along US Hwy. 160, resulting in a small gap in the data.

The Greensburg tornado (#5) illuminated by lightning. These are frame grabs from my handheld video.

The Greensburg tornado (#5) illuminated by lightning. These are frame grabs from my handheld video.

As night fell, we lost visual on the wall cloud, but the radar presentation showed a giant spiraling hook echo. We were certain there must be a tornado occurring, so we kept collecting data. We had barely any reception of weather radio, but between the lightning crackles we could make out a series of urgent tornado warnings on our target storm issuing from the NWS office in Dodge City, including indications of a large tornado. Occasionally, flashes of lightning outlined a large lowering in the cloud base to our north (see images at right). After collecting more than an hour of data, we finally shut the system off around 9:30 p.m., when the deep-cycle marine batteries on board the UMass X-Pol, used to power the antenna pedestal and computer, completely drained.

En route back to Norman around midnight, congratulating ourselves on a great first deployment of the season, my cell phone rang. Chip L. had been chasing with us earlier in the afternoon, but split off after our tire mishap. “Greensburg has been completely destroyed,” he said solemnly. As an EMT, he had gone there to assist, and witnessed near-complete devastation of a town of ~1500. We stopped at a fast food restaurant in Ada, where a TV screen in the corner of the room flickered images that looked like they’d come from a war zone. The remainder of the drive back was much quieter and more somber.

Reflectivity, Doppler velocity, and storm-relative Doppler velocity data in the Greensburg tornado

Reflectivity, Doppler velocity, and storm-relative Doppler velocity data in the Greensburg tornado

Over the next few days, back in Norman, I pored over the data, and it quickly became clear that this would be my dissertation case. We had captured not only the genesis of an EF-5 tornado, but several weaker, antecedent tornadoes. In trying to figure out why the Greensburg storm changed tornado production “modes”, a wealth of information offered itself up, and that information forms the basis for this paper. Other scientists, most notably Jana H., Howie, Mike U., Jeff H., contributed data, discussion, and analysis to the study. Two anonymous reviewers also helped me to sculpt the messy initial version into something clearer and more concise. (Word to the wise: Don’t just copy-and-paste half of your dissertation into a journal template and submit it. I was lucky the first version didn’t get rejected outright!)

In the years since that night, I’ve driven through Greensburg several times, and have been continually amazed by the community’s resilience and resurgence. When the time came, I dedicated my dissertation research to all the victims of the Greensburg tornado. Although improved scientific understanding can never undo the pain to the Greensburg community, I’d like to think that this study was one small, positive thing that came of an otherwise wholly devastating event.

No Time Toulouse

Météo France's Toulouse C-band radar

Météo France's Toulouse C-band radar

Sorry it’s been a little quiet around here over the last month, but I think I had a good reason. I was getting ready for my first European radar conference: 7th European Conference on Radar in Meteorology and Hydrology in Toulouse. I’d never set foot in France before, and wanted to put my best one forward!

At the Météo France conference center, I presented a talk (about GBVTD analysis of W-band data we collected during VORTEX2) and two posters (both on EnKF assimilation of mobile radar data in supercells). I reconnected with domestic and international colleagues, as well as making some new acquaintances. Between sessions, we had receptions and banquets at several Toulouse landmarks, including City Hall and the 800-year-old Hotel Dieu.

Poster session at ERAD 2012

The poster session of ERAD 2012, held in an air-conditioned tent.

I got to see updated versions of some research presented at last fall’s AMS Radar Meteorology Conference in Pittsburgh, as well as some intriguing new work from my European contemporaries. (There weren’t many tornado talks, but there aren’t as many tornadoes in Europe, after all!) On the final day, there were a couple of talks about radar-based aeroecology (detection and characterization of birds, bats, insects, etc.). Fascinating stuff. Biologists are finding gold in the data that we usually ditch in QC!

An evening stroll down the streets of Toulouse

An evening stroll down the streets of Toulouse

Outside the conference, downtown Toulouse was visually pleasing and gastronomically amazing. I took relaxed strolls through the streets and gardens in the evenings, admiring the wrought iron balconies and old chuches, nibbling cheese, and sipping wine. Oh, and taking in Euro Cup matches with the locals, too! The people were, by and large, friendly, and most of the waitstaff at restaurants spoke enough English to get our orders right. I visited 13th-century cathedrals, open-air markets, stunning museums, historic hotels, and verdant gardens.

I figured out early in my stay that I couldn’t possibly pack in all the activities I wanted to do in one week. It’s just as well, because I kept getting lost! And of all the cities I’ve visited, Toulouse was by far the best city to get lost in, slow down, and enjoy.

I’ve returned to find summer baking Oklahoma in earnest. It may not be too long before we dust off the dust devil chasing gear again!

2012-05-30: Paducah, TX landspout

Paducah, TX landspout at about 5: 30 p.m.

Paducah, TX landspout as seen from U.S. Hwy 70 at about 5:32 p.m.

On 30 May 2012, I had the honor of tagging along with the NOXP radar (with my husband Dan D. and Ted M. as crew), operating in support in of the Deep Convective Clouds and Chemistry Experiment DC3). Although the morning’s SPC outlook highlighted a SW KS-NW OK corridor for severe thunderstorms, some of the high-res models indicated that there would be an earlier outbreak of storms along the dryline in the E TX PH, in response to a developing cyclone and robust moisture return. Any cold pools laid down by the storms in Texas had the potential to muck up the Oklahoma target.

Horizontal convective roll over Elgin Air Force Base near Altus, OK

HCR over Elgin AFB near Altus, OK

We set out from Norman shortly after lunch and headed southwest to Altus, where we were greeted by some striking horizontal convective rolls (HCRs).

Farther west, storms fired off the dryline and promptly split. Right-movers tracked southeast, prompting the DC3 radars (SR1, SR2, and NOXP, led by Dr. Mike Biggerstaff) to head south out of Altus on U.S. Hwy. 283. A few participants grumbled about the choice to head south rather than take more direct route west. However, the objectives of DC3 are a bit different than in VORTEX2. Priority number one is long-duration, dual-doppler data in convective storms, so the radars set up well in advance and collect as the storms pass by. (Tornadoes are not the main focus of DC3, but they’re considered a nice bonus.)

After crossing the Texas border, thereby committing ourselves to chasing right movers, Dr. Biggerstaff decided to target the southernmost storm in the cluster, which was headed for Paducah, TX, and set up his dual-Doppler lobe on U.S. Hwy. 70 between Crowell and Paducah. As the crew NOXP’s scout vehicle (a mobile mesonet called Scout 3) drove ahead to locate a suitable deployment site and hold it for the radar truck, a few dramatic dust clouds arose on the updraft-downdraft interface, some with gustnadoes and shallow rotation. One dust tube (pictured at top) extended up hundreds of feet, almost touching cloud base. It was unclear whether it as connected to the nearby mesocyclone or shear-induced, so I’ve been calling it a “landspout” in my discussions.

NOXP deployed south of Paducah, TX

NOXP deployed south of Paducah, TX

In Scout 3, Chris S. and Blake A. located a small hilltop side road on which to deploy, and Ted M. backed NOXP into it. I bailed out of the radar operator’s seat and was nearly knocked flat by the gust front. I shot some shaky video as a second, low-contrast landspout erupted out of the field about half a mile to our east, and still another touched down almost on top of Scout 3. Just as NOXP was preparing to start scanning, I heard a sharp thump on the ground next to me, looked down, and saw a baseball-sized hailstone half-coated in red dirt. I dove into Scout 3’s back seat for cover with my camera in hand, with more large hail thumping down around us. Ted M. waved his hand in circles, indicating that we needed to undeploy and escape ASAP, as our target storm had turned hard to the right. Rather than trying to scramble back to NOXP and possibly delay our expedited departure, I simply buckled into my seat in Scout 3, and hitchhiked west with them to Paducah. As Chris put it, “Welcome to NOXP!”

NOXP reflectivity display

The Paducah storm as seen by NOXP radar at about 6:08 p.m. CDT, showing a WEH (at about 40 km range and 60 degrees azimuth) near a report of a rain-wrapped tornado.

Fortunately, both Scout 3 and NOXP escaped any direct hits from the sporadic, fist-sized hail stones, and were able redeploy on U.S. Hwy. 83 about 12 miles south of Paducah. When NOXP finally started scanning again, an velocity couplet and weak-echo hole were evident on the display. We strained and squinted, but could not make out any evidence of a tornado in the murk to our east. (NOXP’s display indicated it was buried behind a rain curtain several km thick.)

We undeployed and headed south again to U.S. Hwy. 82, where we learned that the DC3 balloon crews had stopped operating. NOXP headed back north again for a second deployment on U.S. Hwy. 83, targeting a second supercell following much the same track as the first Paducah supercell. Although the storm had a nice inflow tail, it appeared to be outflow-dominated, with a rolling dust cloud spilling out in front of it.

Mammatus under the second Paducah, TX supercell of 30 May 2012

Mammatus under the second Paducah, TX supercell of 30 May 2012

We made a last stand back to the south on U.S. Hwy. 82, watching the storm roll away to be replaced by clear skies and a golden Texas sunset. A few small low-level vortices appeared along the storm’s rear flank, but were not connected to any updraft upstairs. We enjoyed some elaborate mammatus clouds as we drove back north and the sun sank below the western horizon.

During our hasty, hail-induced departure from Paducah earlier in the afternoon, we had had to leave behind a pair of NOXP’s metal plates (placed underneath the hydraulic levelers on soft soil). As we returned to the site to retrieve the plates, we observed sporadic wind damage throughout Paducah. Garage doors had buckled inward, roof shingles and small brances were strewn across lawns, and the power in Paducah was out. A few miles east of Paducah, near the intersection of U.S. Hwy. 70 and County Rd. 301, we encountered a metal outbuilding that had been about 50% demolished by a particularly intense wind swath. Sheet metal had been peeled off and scattered to the southwest of the structure, wrapped around telephone poles and road signs up to 1/4 mile away. (I couldn’t get any photos owing to darkness.) Curiously, a second metal building across the street, a few hundred feet to the south, appeared untouched. Some very localized wind phenomenon (small tornado? microburst?) had inflicted substantial damage there.

After retrieving the plates, we made our way back to Norman by way of Childress, TX. Now in the driver’s seat, Dan fought a 70 mph head wind in Lawton, pushed out by collapsing storms dozens of miles to the north. We pulled back into the NWC around 2 a.m.