Jun 4, 2013

Tragic Loss of Three Colleagues....May 31, 2013

(L to R)  Tim Samaras, Paul Samaras and Carl Young.

By now, all have heard the appalling news that storm researchers Tim Samaras, his son Paul, and Carl Young lost their lives while studying the tornadic supercell thunderstorm that struck the Oklahoma City area on Friday May 31, 2013.

Tim and Carl were my colleagues and seasoned meteorologists involved in TWISTEX (Tactical Weather Instrumented Sampling in/near Tornadoes Experiment) whose mission it is to sample aspects of the environment near tornadoes.  I’ve known them for years.

I have been involved in storm research and/or the storm chasing community since 1985.   In this 28 year span, there had not been a death and I know of no injuries among meteorologists studying tornadic storms, until now.   It will be several days before the exact circumstances of this tragic loss become clear.   But even before the storm that ravaged the El Reno and Union City, OK areas occurred, many questions appeared in the media about storm chasing, or storm observing in the field.

Reducing this issue down to its core, emergency management personnel complain that storm chasers are clogging roads and making it difficult for first responders to reach victims.   This issue came to a head in Ellsworth County KS April 14, 2012 as an EF4-rated tornado approached Salina.
 Whether it is true that storm chasers did indeed impede traffic in that and other cases, it’s clear that the number of chasers out on the roads has dramatically increased in the last decade.  And some of these people engage in foolhardy and dangerous behavior.  The question is “why?”

From my perspective, as a professor of meteorology, the term “storm chasing” means what it always has meant to atmospheric scientists who study storms in the field.   It means interweaving meteorological reasoning and forecasting skills for the purpose of understanding severe thunderstorms in general, and tornadic supercells in particular.

It’s enough to say that the early forays of meteorologists studying severe storms in the field in the 1960s and 1970s continued into the 1980s, and 1990s.  Eventually, their missions split into two tracks.  On the one hand, in the middle to late 1990s and early 2000s large National Science Foundation-funded projects like VORTEX (Verification of Rotation in Tornadoes Experiment), STEPS (Severe Thunderstorm Electrification and Precipitation Study), TWISTEX and others involved field efforts bringing many research meteorologists and instrument platforms into the field to surround tornadic supercells or severe thunderstorms.  I was involved at a minor level in the first and more actively in the second.

The second track relates to more of what I do as a meteorologist.  Initially, I was drawn to study these storms because they happen in California too.  So, since I am a weather forecaster by training, what better way to understand how weather patterns contribute to the ingredients of severe storms than by immersing myself in a large “inquiry-based” personal research experience?

In my case, bringing this knowledge of ingredients, burned into my psyche by having to forecast them, back to California has helped meteorologists there understand the patterns that are liable to produce favorable conditions for tornadic supercells.  Other meteorologist chasers have their own set of predetermined goals in observing storms in the field.    All of us are admittedly united in a fascination with these storms.

What is important to note is that no matter what their mission, meteorologists studying storms in the field contribute to the storm observing process.  All my colleagues who do this have ways of contacting the National Weather Service quickly when tornadoes are forming.   This has led to an increase in the warning time.  For example, such observations were a key in preventing injuries and loss of life for the Greensburg KS tornado on May 4, 2007.

In 1996, the film “Twister” popularized the notion of chasing storms to immerse oneself in a tornado’s circulation. The film’s chase teams were loosely based upon the fleets of vehicles called “Mobile Mesonets” in project VORTEX and the early chase forays by the National Severe Storms Laboratory (NSSL) and Oklahoma University.

Except it was based upon a fiction: that meteorologists purposefully drive into tornadoes. That fiction, I believe, has combined with the trend in society for “extreme” behavior.  This has encouraged literally hordes of non-meteorologists many of whom who do not understand storm structure or behavior, carrying cellular phone cameras into the field. This extreme behavior is exemplified by cable network programs extolling groups of chasers who drive vehicles that resemble Flash Gordon/Emperor Ming the Merciless’s space ship into the path of tornadoes, screaming “tornado, tornado”.

What does this have to do with Friday’s tragedy?

There were many chasers in the field that day.   A radar plot taken around 6:11 PM CDT about the time that a multiple vortex tornado was on the groundshows dozens of red dots representing storm chasers or spotters or researchers who were reporting their positions.  Undoubtedly there were many more.

Most of the meteorologists I know who were out in the field that day are represented by the dots south and east of the storm circulation.   Many of them contributed useful information to the National Weather Service in the form of eyewitness accounts of the tornado formation, that were not able to be detected by the NWS radars in the Oklahoma City area.  Some of them were on instrumented vehicles that included mobile Doppler Radar that also contributed to the excellent warnings issued for that tornado.

 Most   left the area when the storm’s circulation got so intense that visibility became an issue.  They also navigated away from Oklahoma City so as not to clog roads at commute time, or to contribute to the chaos that would develop there if a tornado went into that heavily urbanized area.

In the coming days, we’ll learn more about the decisions that Tim’s group made that day.  It could be that he took some calculated chances and was caught by the rapid northward motion of the tornado. 

It would be a double tragedy if his memory is besmirched by an assumption the he was seeking thrills or personal publicity.   He wasn’t.  He was an active researcher contributing to our knowledge.

But the fact remains that to Emergency Management personnel a chaser is a chaser, whether he/she is a meteorologist or not.  While it’s clear that meteorologists who chase know how not to interfere or know how to keep major road stems free of traffic, it’s not clear that others do.   This is an important issue that the storm research/chaser/spotter community must face in the upcoming years.

Rest in peace, Tim, Paul and Carl.






May 25, 2013

Storm Retrospective: Kinsley/Rozel Tornadoes, May 18, 2013

John Monteverdi
Thom Trimble 



All images copyright © John Monteverdi and Thom Trimble

The storm that eventually produced at least two major tornadoes  near Rozel, KS formed southwest of Kinsley, KS at around 6:45 PM CDT.  


The storm developed, we believe, in a narrow slot of inflow air that had about 3F higher dew points and slightly lower temperatures than did the surrounding air being ingested by storms further north and south.  I've drawn an arrow on the 2100 UTC surface chart to show the flow of air into the storm genesis area.  Note that the dew points on the upstream portion of the arrow are in the 70s.

I wish I could say I had foreseen that narrow jet of air.   But I hadn't.   It's that kind of mesoscale detail that cannot be forecast in advance.  And the luck here was that we were in the exact position at which that kind of feature could really cause explosive development of a storm.   It certainly did in this case.


The storm immediately had a bell shaped lowering (see image to bottom center). Within in a few minutes it had a very good visual appearance with a rain core out to its northeast and something like an RFD cut developing too.


Arrow indicates approximate path of what we think
was a moist inflow jet that the storm intercepted.

















We stayed with this storm for an hour or so and  during that time were treated to an absolutely fabulous example of a storm proceeding through the supercell cascade.  While the storm was about 5 miles west of us, the southeast winds really kidked up a notch....probably 20-30 mph.  We believe that the  inflow jet, as explained above, was being intercepted by the storm.   I got a dewpoint of 70.8F on my Kestrel and  a temperature of 84F.  We commented  that it was hard to figure why the storm had such a high base and no wall cloud.     

Bell shaped lowering on rapidly developing storm
west of Kinsley KS.  


Shortly after the development of that inflow jet,  though, the storm base lowered and the RFD slot sharpened.  The updraft area showed signs of bvecoming an RFD occlusion...and, then a nub formed on the north side of the horeshoe base (see picture below)  That rapidly descended visually and became a large tornado, somewhere between a wedge and cone.


Horeshoe base, showing rear flank downdraft cut, and developing cloud base circulation
(the nub above the centered tree).   



Rozel1.jpg
About 2 minutes after previous image.   Tornado circulation now developing at ground level.


This is the instant of initial contact of the tornado with the ground.  It's zoomed, but you can see the same trees and farm buildings that are to the left of the distant forming funnel in the picture above.

The good news is that we got great digital stills of the whole thing, and also video.  The bad news is that things happened so quickly that I never had an opportunity to setup the good video camera on a tripod.  Nevertheless, I have video documentaiton of the first tornado development on the lowered base.  

The radar below shows the storm when the tornado cycled up to its strongest.  Our position is shown as the yellow circle.   The names plotted there are the other chasers and storm spotters who were reporting their positions.  The purple triangle is a Tornado Vortex Signature.


GRLevel3 Radar Plot of Kinsley/Rozel storm at time of tornado genesis.   Our location shown as yellow circle.  The magenta triangle is not the tornado but a radar signature called Tornado Vortex Signature. (Time shown is PDT)



Tornado damage (blue and yellow..estimated by
ground survey;  red estimated by DOWS)
(Image courtesy of NWS)
The tornado moved northeastward, as shown on the graphic on the right, until the process known as tornado or RFD occlusion completed.  The tornado turned to the left, cyclonically, around the mesocyclone.  The red symbol at right is the only location where the tornado was sampled by the mobile doppler radar (Doppler on Wheels--DOWS).  There the winds were measured at 165-185 mph and the circulation width at the ground at 3300 feet.  On this basis the tornado was rated an EF4.

At the time the tornado was most intense, the radar signature was extremely impressive.  I've included at right the radar plot from the DOWS at that time below.



DOWS radar plot corresponding to red
symbol above.  Upper left, reflectivity;  Upper right, storm
relative velocity.  (Image Courtesy of NWS)


The tornado was extremely impressive visually for nearly its entire life cycle.   Its visual appearance varied from a cone to a wedge.  It was quite obvious that the funnel was extremely large and had violent circulation around it.

We drove north towards Rozel and the tornado began to narrow...and at first we thought it had begun the roping out process.   But shortly after that the trunk redeveloped with lofted debris north of town.   I told Thom I thought another tornado might develop back along the flanking line, which by that time was east of us...as we were in roaring RFD (warm) air.  

RozelMax_Small.jpg
Rozel2.jpg
These three images were taken over a five minute period and correspond to when tornado #1 was at its most intense.  We were located about 2 miles south of Rozel at the time and the pictures are shot looking northwest.
Rozel3.jpg
Tornado begins to narrow at its base just west of Rozel.


New tornado formed east of Rozel rapidly as first tornado was in
the process of dissipating.  Setting sun provided wonderful
color to all cloud features.

We turned east and moved through Rozel.   We wondered why the police had roadblocked several roads east of the first tornado. Out of the murk, we could then see another fully developed cone...nearly a wedge briefly back along the flanking line.  We barely got pictures of it.

This also was a very substantial tornado, as you can see in the picture at left.  The setting sun began to produced unusual orange and purple highlights on this thing.  It really was gorgeous, towering above us to the east.

The DOWS did not manage to redeploy so quickly to sample the rotation with this tornado.  But it probably would have been at least an EF2 from the looks of it, though that is very difficult to judge from visual appearance alone.
Meanwhile, back at the original occlusion point, the original tornado was still pulsing, but in a downward trend.  At one point it redeveloped a massive cone.


While we were watching the second tornado that formed further southeast along the flanking line, yet another tornado
seemed to appear to the north.

We're debating whether that was a new tornado, or the remnant of the original tornado as the main updraft area probably had crossed the road at that point. That tornado refused to give up the ghost, so to speak.   It took nearly 30 minutes for it to finally rope out to nothing.


To the right  are some pictures of the rope out phase of tornado 1 (or perhaps, as explained above,  it was tornado 3).   We were getting confused in the darkness and the episodes of good and poor visibility  And while it was doing that, it still had a substantial ground level circulation. Finally, even the tiny remnant of the funnel seemingly floating disconnected was associated with ground level debris.

Thom and I agree that tornado 1 was the strongest, and largest, tornado we've seen in our chase careers.  And now that we've had several days to consider what we saw and experience,  we agree that it was the most phenomenal chase of our chase experiences together.

From the decision to get us there, to the good fortune that made us stay in place in Kinsley instead of going north or south, to the road we chose with absolutely perfect vantage points, all was just about perfect.


Last remnants of the rope out phase of Tornado 1 (or it may have been a third tornado).  The last portion of the
funnel seemed to float free, yet it was still associated with circulation at ground level and debris.












May 22, 2013

May 22, 2013: Down Days Coming and Early Exit

Retrospective

Thom and I are in Wichita Falls after a day in north-central Texas.  Although there looks to be a supercell-favoring pattern tomorrow (May 23) in northwest TX and the southern TX Panhandle, I've decided to return home with Thom, who has get back due to family issues (good ones, though).

This will be the last active log, and I will now concentrate on trying to get some pictures up for our productive days, mostly May 18 and 19.

I am impressed with the numercial models, particularly the ensembles, which suggested a pattern favorable for supercells in the central Plains almost 10 days in advance.

It turns out that several research projects on tornado formation and evolution were able to get excellent data sets during the last five days.  The Moore, Oklahoma tragedy casts a pall on this.  Nonetheless, we are going to learn much about tornadogenesis because of these couple of projects.  They were not on the Oklahoma City supercell, however, as they were south where most storm spotters and chasers were that day.

I just learned that the tornado we documented near Kinsley, KS has been rated an EF4.   There was no damage (as far as I know) to assess to determine this.  But the Doppler on Wheels (DOWs) were there, and they were able to estimate the wind speed associated with the funnel.  The map above shows the track for the first tornado.   The colors correspond to damage or DOW evidence for a rating.  The red tag shows the position of the tornado when the winds were 165-185 mph.  This corresponds to an EF4 rating.  The radar plot below right shows the DOW plotted radar images at the time the tornado was at maximum strength.   We have pictures and video corresponding to most of the 7 mile damage path for this tornado.

The damaging tornado that struck Moore is still making the news.   I was interviewed via cell phone by KTVU-Channel 2 in Oakland...but I declined other interviews (one from CNN, and directed them to my colleagues who are actually in the Oklahoma City area and who have done refereed research on the previous tornadoes that struck that area.

One reason I don't want to answer specific questions about the Moore tornado is that Thom and I were not there, nor have we assessed the damage.  Several of my colleagues have already been involved in that, and their results already are belying the hyperbole about that tornado (for example, it was not two miles wide, nor did it have a two mile wide damage path.  So far, I've only heard of documentation of damage consistent with an EF4 rating.   But I only get that information hours after the surveys take place.

I'm personally curious what meteorological parameters were in play in the Oklahoma City area that afternoon, that were not in play further south, where most researchers, spotters and chasers were placed.  It's not obvious from the weather data and charts I have for that hour.

Yesterday's Chase

The early runs of the models suggested a few isolated supercells forming around 1PM between Fort Worth and Abilene.  By the time we got into that area, the models were showing none of that, but more of a discontinuous line.  And that's what happened.  We played hopscotch with the rapidly progressing front, trying to stay in the rich moisture ahead of it.

When we got to Waco, several of the cells on the south end of the line became somewhat discrete.  They showed some signs of becoming supercells, but never did.  So, at around 6PM, we called it a chase, and drifted back to Wichita Falls.  Along the way, we changed our plane reservations from Sunday afternoon to tomorrow, Thursday, May 23.

This will be my earliest exit from a storm chase in all my years of chasing.  However, apart from the first day, we've had pretty intense chasing every day of the trip.  Of course, the best and most productive days for documenting tornadoes occurred on May 18 and 19 for us.

Once I have more time to examine our photography and videos for May 18, I will begin posting photo documentation of that day.


May 21, 2013

May 21, 2013: North Central TX

Another Round of Supercells Expected Today:  Risk of Strong Tornadoes Again

Not much time to post as we expect early initiation.  We are currently near Gainesville TX and then are heading southwest to the area just east of Abilene.

The morning weather map shows the low pressure area having drifted southward into central TX overnight.   The setup is a bit different today as 500 mb winds (see graphic) have slackened just a bit.

However, there is still the tap of high dew point air coming into central TX.   The surface flow is a bit weaker than yesterday.   Yet forecast hodographs indicate wind shear favorable for supercells, although the window for tornadoes appears short.

An additional factor is an outflow boundary that is shifting southward out of the thunderstorms we just left in Ardmore.  That also might provide a focus if storms forming to the west cross it later today.  Unfortunately, the Dallas-Fort Worth metroplex may be under the gun later today.

May 20, 2013

Moore Tornado

Just an awful coincidence that the tornado that devastated Oklahoma City's southern suburbs took basically the same path as the May 3, 1999 tornado, and very similar path to the tornado that struck the same area a couple of years later.

Most chasers were on the storms further south.  Thom and I passed that storm when it was developing and figured that more substantial storms would be further south...so we went on by, in fact around it, to get to the tornadic storm further south.  We did not get to any storm today that had a tornado.

Just as well that we didn't leave even later, as we came from Ponca City in the north....and would have probably chased that storm as our only option later in the day.

It looks like all my chase colleagues are safe, and most who are down here are choosing not to contribute to the confusion in Moore....as I35 passes right through that beleagured town.

The graphic is designed by Meredith Botnick to show support for the people of Oklahoma who have endured tragedy today and yesterday.

There is a plea for $10 donations, via a text number.

Text 32333
Subject:  FOOD

That will provide a $10 donation for victim relief.