May 19th 2011 Gustnado Vs. Tornado

All Photographs courtesy of Justin Terveen. 
I have enhanced them and even scribbled on some of them. 

So, I thought I would go back and review what little evidence we have of the "whirling dirt cloud" on May 19th just to see what the possibilities of it being either a gustnado or tornado were.

It was definitely one or the other, but I more or less called it a tornado while others have wisely said that there really isn't enough evidence to declare it one or the other.

So first I'll review my memories since it is so much fun to do so... and just in case you decided not to read the long May 19th account:


I am setting up to shoot lightning and manage to get two (or three) shots off before I decide its time to make a run back to the vehicle.

Its twilight and there is just enough light to see the edge of the dark cloud against the heavy rain shaft and it appears to be a typical outflow cloud. But visibility aside from the aid of lightning is really bad.

I get within twenty feet of vehicle and notice a hissing sound with growing dust cloud off to my northwest. The column of dirt is definitely rotating.

Justin and I are scrambling to load our gear into the back of James' Tahoe when it hits and at first the wind seems to be more or less coming from my left.

I manage to get my tripod in the backseat but nothing else as I am blown sideways past Justin by incredibly strong winds now coming from my right. My camera snags on his tripod and I let go for fear of damaging something and continue to stumble to the left of the vehicle as the winds push me away.


Now for the photographs:

I drew in the lines to show where it looks to me like a spiral pattern in the cloud base. I believe you can already see the start of a dust cloud underneath the "cone shaped" nub.

These shots were taken immediately after we were settled in the vehicle trying to regain our composure.

I drew in where the RFD appears to be in this image and the boundary between the updraft base and RFD slot along with a red V outlining a possible cone. It seems I can at least rely on the shape of the clouds in the foreground since an instantaneous flash of lightning is what's illuminating them.

So, what are the issues we have with the photos?
Since none of us could actually see the motion in the cloud base we can't be really sure that rotation was present. Still... the photos seem to indicate to me that rotation is indeed very possible... especially given the shape of the RFD notch in the last image. But I have no real idea of how pronounced it was, and that nub is kind of small.
Another issue we have is how close the downdraft is to the dust cloud. So it is also very plausible that the dust is from a gustnado.

The radar data is kind of interesting, but does not indicate any kind of tornadic activity. I figured with the radar being so close to the storm that if strong rotation was present in the low levels we should be able to see it.

First is reflectivity as close to the time of the incident as I can figure.

The white rectangle is basically the area we could've been in. James said we were about three miles north of Grandfield which is about where the bottom of the rectangle is. The top part is as far north (or further) as seems conceivably possible for us to have been. We do have an RFD surge and indications of a decent mesocyclone.

Next is a set of the lowest level SR-Velocity scans. Times should be the same as above.

 Gee, if there was tight rotation it sure isn't showing up here. There is a mesocyclone with broad weak rotation, but nothing more according to this set of scans.

Let's go higher with a 2.4 dgree tilt to the SR-Velocity.

I think this is even less impressive than the lower tilt.
So what I can conclude is that while a weak tornado is not out of the question, it sure seems like a gustnado is more likely given the radar presentation.

Something that also really bothers me is that I don't know the exact location of where we were. The center of rotation sure looks to be too far north. But what we experienced given the shape of the downdraft and such seems to indicate that we were underneath the meso, or on the north side of the RFD.

I think I am going to just have to admit defeat and declare gustnado knowing that we will never really know for sure.

Either way, thanks be to God no one was injured.



Edit:
After James Langford reviewed the video we have decided we were further north near the inflow notch. Possibly over 5 miles north of Grandfield. This would put us under the mesocyclone... but it is still no proof of a tornado.

Chasecation June 5th - 10th 2011 Day 4... the 9th... Big Oklahoma Storm

On the 9th we had a pretty amazing storm chase that was almost not to have been.
Most of the time we get out ahead of these storms and photograph them as they approach. But this time we really did chase them down.

We originally had the idea of taking I 70 out of Ft. Morgan CO in the early morning to Central Kansas where there was a good chance of severe weather in the evening hours. But, after looking at the HRRR and a few other models I became increasingly concerned about a large MCS forming in that portion of the state. It looked to me that the better target would be down in Oklahoma into the Texas Panhandle where storms would be more discrete. So, that is what we opted for with a new target of Amarillo Texas.

I wish I had taken some pictures on the way down through Colorado and the Oklahoma panhandle. The drought in that area has just been terrible and the land clearly showed it. We had a smoke filled sky from New Mexico overhead and a brown landscape that looked like it belonged somewhere in the Middle East. Numerous dust devils were also observed. The entire trip up to that point had been beautiful landscape and now we were driving across Mordor.

We approached Amarillo from the north on 287 hoping that we wouldn't be too late for storms. By the time we reached the city it was at least 6pm. Storms had already begun to blow up east of the city near the OK/TX boarder and initially I hoped that we could catch the ones south of I 40 on the Texas side.
However, it began to become clear that these storms would not develop further than the little showers they already were. Meanwhile another complex of storms was to the north of I 40 in Oklahoma... about an hour from us. I was able to convince James that these storms would be the best play for the day and he (despite being exhausted) kept the vehicle pointed at Oklahoma.

When we arrived it was clear that these were also high based storms like the one witnessed yesterday. Except that the Oklahoma cluster had considerably more instability to work with along with marginal shear. Dewpoints were probably not more than 65 degrees and combined with a temperature of near 100 degrees there was quite a large DP/Temp spread which is probably the most likely cause for the high bases.

One of the southern cells in the cluster quickly took over and began to rotate. This prompted the Norman Office to issue a tornado warning right at about the same time we arrived in Elk City to photograph it.

Like the May 19th evening supercell this one had insane inflow as well. Gusts were probably near 50mph.

When we got back to the hotel room in Clinton we examined the distance we drove from Amarillo where we first noticed the developing storms to Elk City and marveled that we even made it at all.

Looking back I can only conclude one of two things about our trip:
We were either extremely lucky to have seen all that we saw during the course of the adventure, or God was extremely gracious to us. I may get pats on the back for my forecasting skills but lets just say confidence in many of the forecasts was quite low and I was not the one who put the storms there... or even got us there.

Many thanks to James for supplying the vehicle and the driving for this season, and also for Justin coming along and sharing it with us as well as walking away with numerous amazing images (not to mention helping pay for the trip). I've learned a lot about photography from those guys and the images they produce.

Thanks should also be given to God for his incredible creation and for keeping us alive and well for the entire adventure... and for the privilege of even getting to have such an adventure. 

And thanks goes to Karen as well for letting us barrow James for five days.

Chasecation June 5th - 10th 2011 Day 3... the 8th... LP in Colorado

The 8th turned out to be a great day across East-Central Colorado despite the storm being hardly severe. At least, other than quarter size there wasn't much to talk about.
The storm did look pretty neat and the set up was something I had never experienced before. From a Meteorological perspective at least it was quite fascinating.

In the day leading up to this event it was quite clear that I really didn't want to chase anything in Nebraska or Kansas along the front. If I remember right the concerns were:
1: Lack of directional shear
2: Lack of upper level support since the main trough was still over the rockies.

Well, this left pretty much nothing to play across the plains. So, we decided to do what a few other chasers had been discussing and what SPC outlined in their outlook... upslope in northeast Colorado/southeast Wyoming BEHIND the cold front.

Across most of the plains the winds behind the cold front were very much out of the north. But the cold front bent back towards to the northwest across Colorado with easterly flow behind it. Dewpoints looked to be in the low 50's or upper 40's at best with temps in the low 80's.

Since the winds were easterly they were running this air right up along the front range and Palmer Divide. And these geographical features would be our means to force air to rise.

The day of the event actually yielded mid to upper 40 dewpoint air only. But we did manage to squeak out the 1000 j/kg. With the exceptional wind shear I was pretty excited.

We arrived in Ft. Collins around 3-4pm I believe with the first set of thunderstorms firing just west of Denver. It was pretty cool to be able to see the mountains with thunderstorms blowing up along them. We eventually noticed on radar the storm of the day just east of Denver (probably close to 4pm) and we began positioning for it.

We had a lot of fun with dirt roads since the one road option we had south of Ft. Morgan to position ourselves on basically turned into a dirt road after several miles and then it was nothing but dirt after that.

The storm itself we didn't really see until we were well south of Ft. Morgan. We saw a lot of anvil blow off that reminded me of the cirrus and alto-stratus we typically see in the winter time. (Very light and feathery compared with most anvil blow off, yet not very high in altitude). The anvil was considerably darker and thicker of to the west with a rounded flat base to it at the back. It took me a minute or two to realize that the flat base of the anvil was in-fact the rain free base of our supercell we were seeing on radar.

It was kind of a combination of the storm being high-based and the anvil being relatively low.
The storm itself really didn't change much with time. It seemed to maintain a very consistent low precipitation supercell profile with most of the rain being virga and blowing well down shear of the updrafts. It did manage some brief areas of rotation that were fun to watch, but the RFD never cut into the meso (another classic symptom of the LP). 

The storm finally dissipated around sunset somewhere east of where we started. More fired in the evening back to the west, but we really weren't interested in chasing any more due to the exhaustion of the days drive. After supper in Ft. Morgan we did decide to try for some lighting near town, but it never amounted to much for me.

Chasecation June 5th - 10th 2011 Day 2... the 7th

Since storms were expected to be in North Dakota into Minnesota we opted to not go tearing after them only to come tearing right back for tomorrows event (which we still hadn't nailed down).  So, we took the day off from chasing and simply went site seeing in the Rapid City area. We visited Sturgis, Devil's Tower, Mt. Rushmore, and the Badlands.

Unfortunately James' National Parks pass didn't get us into the parking lot at Mt. Rushmore so, we simply dove on by without snapping a single photo. The faces were in deep shadow any way.

These will be larger images since the small "for web" versions just can't do the scenes justice.

Couldn't upload the large version of this next one.

It was nice to see some spectacular scenes without having to be rushed for a change.
We stayed the night again in Rapid City and then headed out early the next morning for Colorado to chase upslope storms.

Chasecation June 5th - 10th 2011 Day 1

This was a real treat. Four days outside of our typical chasing grounds with the 5th day being back in Oklahoma. We left Sunday the 5th and came home on the 10th.

This was the basic outlook I put together the day before we left. Basically it was all based off of the GFS and NAM. So, some might consider this not so much an actual forecast as an interpretation of data.

What amazed me is how well the models performed overall (and my interpretation wasn't all that bad either). 
Monday was basically right on but needed to be extended into Montana. Tuesday mainly needed to be more into North Dakota. Wednesday... well... that turned out to be more upslope in Colorado and Wyoming. But Thursday was right on... or very nearly.

Day one:
After spending Sunday driving into Nebraska we then set out into South Dakota on Monday anticipating supercells across the northern and western portions of the state. There was a frontal boundary draped across the northern areas with easterly flow towards the black hills along and ahead of it throughout the state. Wind shear was not overly impressive but favorable for some rotating storms up near the front and towards the black hills.

We spent a large chunk of the afternoon sitting in Midland north of I 90 trying to decide where to go. This was one of those "sit and watch visible satellite" days. Towards evening it was begining to look like our best bet was to take I 90 to Rapid City where the most pronounced cumulus were due to the forcing along the black hills. That easterly wind was helping to ram the warm moist air up against the mountains helping to erode the cap in that area.

However, as time passed and we reached Rapid City big HP supercell-like storms erupted just south of the South Dakota boarder in Nebraska. They were basically over the unchaseable sand hills we had driven up through earlier in the day. I really didn't want to go after them due to the better shear being further west near Rapid City and what began to be storm initiation over the black hills.

The storms over the black hills really didn't get organized though for a good long while and one can't chase in the black hills very easily. And as we drove west the storms to our southeast continued to get bigger... but still lacked any real organization.

After supper in Rapid City it looked to me that we might have busted since the cells over to our west continued to not do much of anything. Still, there was one complex of tightly packed cells in a little line trying to pass over the mountains. I figured we'd at least want to photograph lightning out of that apparently disorganized mess if nothing else.

There is one thing that I had overlooked that James had informed us about earlier:
The sun takes much longer to set in the northern plains than it does in the southern during this time of year. That became pretty apparent after the first day.

By 7pm-ish we had our first cluster of small cells coming over the mountains to the south of Rapid City and we headed south to meet them. These basically had formed a beautiful gust front that, at first, didn't look impressive. Once we were south of town a little ways it quickly came fully into view and we were stunned by its beauty.

This is one of the few moments where I have actually felt poetic... but even I am so bad at poetry none came to me. And therefore you will be spared any.

Well... no... I actually won't spare you completely:

The heavens declare the glory of God, 

and the sky above proclaims his handiwork.
Psalm 19:1

In Hebrew, at least, it is poetic... and true... so very very true...

I still can't figure out which of the two panoramas above I like most and whether or not it would be worth going back and doing HDR. Oh well... I'll figure it out sooner or later.

Normally when I see the leading edge of the outflow push that far ahead of the precipitation the storms doom is nigh. Or something like that. However, this guy kept firing cells on its leading edge for the next couple of hours or more. In fact, for all I know this small complex of storms traveled at least another hundred miles before dissipating sometime after dark.

Another interesting phenomena were the nearly continuous downbursts occurring due to a lot of evaporation of the precipitation in the mid levels. This little "bow echo" was severe warned for high winds and we got a brief taste of it with little rain.

I just have to say that driving underneath an incredibly high based shelf cloud with phenomenal structure in the rolling green plains of South Dakota was probably one of the most incredible experiences I have ever had to date.


This guy is KUDX and he provided all of our radar data for this evening. The HDR attempt on him is kind of sloppy... but then again it was done just to figure out how this HDR stuff works.

We had some amazing light after the storm had passed on the South Dakota hills. Kind of funny that I thought this first image was going to be the best with the HDR. But I was terribly wrong. With the second I just didn't know what I was doing which is why I stopped work on it, then did the first, and then went back to it after getting comfortable with photoshop's method of HDR.

Some of my favorite images to date and all from South Dakota. Still blows my mind that I was actually there.

May 19th 2011 HP Monsters in Southwest Oklahoma

 I really don't know how to start this one off. It was one of the most amazing days of chasing I've experienced (like half the chase days this year). The storms were moving slow, and had amazing structure and motion. However, the amasingness of this day was just about ruined when a bad move was made after dark on an  HP Supercell.

(Hadn't something like this just happened a month earlier?)

For my part, I think this chasing thing has made me a little arrogant. This is one of the ways God smacked me (at least me) upside the head and demonstrated how little I actually know.

Regardless of the reasons God allowed this to happen I know that I have been arrogant (at least in heart ) and the night time "near death" experience humiliated me considerably. That and the High Risk Bust I experienced with Justin during one of the fallowing chase days.

Comparing my (our) "Amateur Chaser Mistake" to what I would consider "New Diver Mistakes" I have this to say:

God was extremely gracious to all of us and spared our lives and any kind of damage to vehicle and equipment just like he was merciful when I pulled into oncoming traffic as a new driver, or many of the other "new driver" mistakes I've made (still make).

So to begin:
Chased with Justin Terveen and James Langford.

I remember this being a very complicated set up. In the days prior to this chase I had been shifting my target from basically West Central Oklahoma to the Oklahoma/Kansas boarder. The reason for the latter target would be more favorable shear profiles and what I thought would be closer to any upper level lifting mechanisms that might be present in the jet stream flow aloft.

I remember distinctly the short range models firing storms in southern Oklahoma, but I really didn't want to bite on that due to the best shear parameters being further north and  I didn't fully trust their initiation. But even so I knew that there would be enough shear down there for at least HP Supercells, but figured the trip further north would be more worth it.

So, what I wound up with was a target of northwest Oklahoma, basically anywhere north of I 40 and west of I 35. My two starting possibilities were Enid and Clinton. Even by chase day I hadn't really decided. I figured that call could be made once we reached OKC.

Well as we shot north on I 40 supercells began to blow up all along the dry line south of I 40 around 2pm. Some were practically to the Red River. That at least knocked my target down to Clinton along I 40. However, the storms near I 40 began to lose surface rooting and began to drift more north than east (an unhealthy sign with cyclonic supercells). By the time we had driven some distance west on I 40 it became evident that we would either have to drive way north to see anything from the storms up there which were not healthy, or drive outside my target area towards the healthy looking HP mess to the south. I caved and decided to go for the HP mess to the south (which turned out to be the best choice made for the day).

Basically wound up taking Highway 54 out of Weatherford down to the Wichita Mountains and the wind farm. The first storm we observed was a very classic, typical, and murky, HP Supercell.
(That is classic HP, not classic classic supercell... never mind).

It had a tremendously large, powerful, and rain filled RFD area with a pronounced "cow catcher" shelf on its leading edge. The storm also had some significant bands in the mid-levels indicating a strong mesocyclone was present. Rotation to the north of the RFD area was pretty well defined and persistent. However, for any of this to be seen we had to let the storm get fairly close since the haze was just awful. We actually had hailstones falling on us from the anvil overhead due to them being blown well downstream of the mesocyclone. 

At one of the interesections we encountered one of the Dominators and Discovery Channel crew. They took a road north (I believe highway 58) from our intersection on 19 and we continued on 19 to the east. They apparently witnessed a tornado in the large inflow notch of this amazing storm.

The eerie light filtering through the heavy RFD precipitation was incredible! Some of the freakiest lighting I had seen in a good while.

We allowed this first cell to pass us to the north while we took 58 back to the southeast to intercept another rapidly developing cell along this storms flank. The new storm quickly became another HP Supercell with strong rotation. We were actually in a kind of hairy situation at this point as our viewing position was very close to the Whichita mountains and the storm was coming right over them. Also, the immense size of the storm made it slightly difficult to discern where the mesocyclone was and adjacent RFD. The mesocyclone wound up wrapping up about a mile or less to our west (giving us a great view of very rapid rotation) and a new one developed just to our northeast. When the rotation first popped over the ridge it was very strong and it looked like we would have a tornado any second just to the left of the wind mills. However, it quickly dissipated due to the strength of the RFD.

I managed to grab another shot before we left of a chaser group with the new meso in the background.

When we attempted to reposition for this storm we made the very bad choice of taking a road north into the core rather than dropping to the south and east to escape. Given our road options had we continued north, we would've been forced to drive straight east to get out under the meso, which would've taken us under what could've been a developing tornado.
We quickly realized our mistake and flipped around to head southeast, punching the RFD on the way and picking up a few larger than quarter sized hail stones.

We successfully escaped as the RFD precip cleared out quickly as one went south. We then dropped down to an RV park near Lake Lawtonka. I didn't bother to shoot pictures with James and Justin for some reason or other.

At this point we could've called it quites but, just as one of the models had shown, there was a very impressive storm right on the Red River west-northwest of Whichita Falls Texas. After a quick supper of some Burger King fried imitation chicken (yum) we dropped south on the tollway out of Lawton Oklahoma to try and catch this last storm.

The last storm was really the most incredible in my mind. Like the last two cells this one had very strong rotation. It also had more "classic" supercell structure when we drove up to it (though we didn't stop to photograph the mid-level stacked plates). The inflow into this storm had to of been in the 40 -50mph range at least. We had blowing dust, and it was difficult to keep the cameras and tripods steady enough to produce sharp images in the fading light.

Some of my all time favorite storm clouds were seen from this storm. The sky had this eerie brown color due to the sun's very low angle on the horizon behind it, and some of the gust front formations were just wiled. Also noted several gustnadoes as we sat and photographed for about a half hour in front of the storm.

This lowering had some decent rotation to it at one point. But the storm was fighting its  own RFD to put down anything in this area. However, something may have been going on back in the inflow notch of this storm way off to the right of this image and out of sight.

At this point we were being hit with strong cold outflow. It was kind of crazy to see cars emerging from the blackness of the storm up ahead. The main area of rotation and core were actually going to pass to the north of us... but we still thought it best to get a move on.

I have not mentioned the radar issues at this point but I guess now I should since it played a large roll in the mistake that we made next.
Radar data this entire trip had been very sketchy due to a poor Sprint and AT&T network. So, while we had decent data close to the interstates, any time we left them our data would be gone and radar would not update.

 When we made our next move we assumed a few things about the storm (or at least I did):
1: The storm was becoming more outflow dominate than it had been already.
2: The storm continued to be nearly stationary or drift slightly east.
3: We were far enough out in front of the storm.

Looking back these were quite dangerous assumptions. The storm appears to have actually:
1: Redeveloped a strong mesocyclone and positioned it further south than the previous one.
2: Speed up to the east at around 20 - 25mph. Which leads to:
3: We were NOT far enough out in front of the storm.

A lot of this is still speculation since I have not been able to grab archived radar data from this event yet. And really this wouldn't have been too big of a deal except for item #1 (although very strong outflow can be pretty nasty when caught out in it).

We were eager to shoot lightning so we drove north out of Grandfield Oklahoma on highway 36. We set up about three to four miles north of Grandfield and got to work on the lightning. Due to the lack of light I couldn't get my camera to focus on anything, so I walked about 100 feet away from the vehicle so that I could use its light to get an infinity focus setting.

I had just finished focusing and had begun my first exposure when I heard a shout from James. I thought he was simply trying to point out something kind of neat or perhaps was mearlly asking why I had set up so far back from the car. Either way, I didn't note anything particularly distressing in his voice. By the time I had entered my 4th exposure I had noticed that the core of the storm had come very close and we were about to get blasted by heavy rain and strong outflow. So, I began to pack up.

After that lengthy process when I was about 50 feet from the vehicle I heard a strange hissing sound that got steadily louder. Of to the northwest of the vehicle there was a dust cloud that appeared to be rotating. By the time I had made it to the vehicle the dust cloud had too. I've never stood in winds that strong before and hope I never do again unless it is in some kind of controlled experiment or something. I had no sooner thrown my tripod into the back seat when I was wiped around Justin (who was also throwing his gear into the back) and began to stumble to the south of the vehicle as the winds pushed me in that direction.

The entire interior of the vehicle was filled with dust and those of us caught outside (Justin and I primarily) were more or less sand blasted. It probably took a good 20 seconds for all of this to occur though it is hard to tell or even remember much of the details.

Afterwards everyone was able to get back into the vehicle before the rain hit. The funny thing was that despite what could easily have been 60 mph winds in the rain it seemed fairly calm compared to what had just happened earlier.

The question then for the evening was "What in the world just happened?"
The dust cloud had some clear rotation, but it looked like it still could've been on the leading edge of a larger dusty area on the outflow. This kind of lends itself more to the gustnado. But when we examined later photographs it is apparent that there was at least rotation overhead in the storm base and perhaps a small funnel. It still could've been a gustnado as there will never be completely conclusive evidence for one or the other. And I think I may leave that discussion up for a later post as this one is long enough as it is.

Here at least are a couple images that I created from one of my own.

Arrows kind of outlining some of the cloud bands I see in this photo that were also confirmed in James' and Justin's photos. The area of rotation lines up very nicely with the debris cloud that formed as well, and the small cone funnel that seems to be evident in a couple of images taken by James and Justin. 

In the end it really doesn't matter so much whether or not it was a tornado. (Tornado just sounds so much more dramatic doesn't it?) Gustnadoes and weak tornadoes can be nearly identical in the amount of damage they can do. Regardless there really appears to me to be strong evidence of rotation and a quick glance at radar that evening (once we got data again) seems to indicate strong rotation in this area. A stronger tornado could've formed without us knowing it and we would all be dead right now.

It was a dumb mistake to try and shoot lightning under the base at night without data. In fact, being this close to a storm that is known to be a supercell of some form or other at night regardless of radar data is dumb. The only excuse I could possibly make for doing it again is if the storm is KNOWN to be rooted above the boundary layer (not surface based and therefore not able to produce tornadoes and probably not damaging winds). In the past when we had shot lightning from these kinds of storms we would be 10 miles or so from the core, and generally far enough away to capture the amazing anvil lightning that is so common with these supercells.
I think this and the previous event show just how overly confidant we have grown in our approach of these storms at night. And HPs are especially dangerous at night.

I went ahead and called the Norman office with the report of a tornado/possible gustnado in my shaky/squeaky voice while leaving out the part about the impact. Since the event was 20 minutes old by the time I alerted them I doubt it did them much good.

In the end we all simply thank God that our over-eagerness didn't get us killed.

If I ever get around to a more in depth study of this event and the other near miss I will post my findings. It really bugs me that I don't know for certain what was actually going on in either case.