Tornadoes — Page 12

June 5 Storm Chase: Illinois Tornado Outbreak

We were close to the tornado, roughly a quarter mile south of it, paralleling it as it tore an eastward course through the Illinois fields. Dirt and shredded corn swirled around its base like an aura. As Kurt Hulst and I pulled aside and stepped out of the car to take pictures, we could hear the roar. It wasn’t loud, just audible and big, very big, an intensely focused sound like an immense blowtorch or a rocket engine. Yet, close as Kurt and I were to the tornado, we were out of its path and beyond the range of any apparent debris, and I sensed no particular danger.

A brief staccato of blue flashes suddenly lit up the base of the funnel, accompanied by a loud bang, and chunks of debris flew skyward and centrifuged out. The tornado had hit a structure out in the field, most likely an outbuilding of some kind.

Fortunately, there was little real harm the twister could do out there in the broad Illinois prairie. Not yet, anyway. But a little way to the east lay Yates City, and two-and-a-half miles farther, the community of Elmwood…

The day had started off rather inauspiciously, with the previous evening’s aggressive SPC outlook degrading into a forecast for straight-line winds. The 12Z NAM, too, looked unpromising, and the RUC corroborated it, with mostly southwesterly surface winds veering with height to a unidirectional, westerly mid- and upper-level flow. A persistent batch of cloud cover from a mesoscale convective system threatened to minimize daytime heating and instability. In a word, the setup wasn’t one that suggested tornadoes.

But with a trough digging in from the west, rich moisture, great shear, and at least a semblance of clearing moving in from the southwest, Kurt and I decided to chance it anyway. Our friend and fellow Michigan chaser Ben Holcomb had alerted us the previous evening to the evolving weather situation, and after reading Friday night’s Day 2 Convective Outlook and scanning the NAM, which showed an impressive juxtaposition of the right ingredients, including high helicities stretching along I-80 from Iowa into Indiana, we knew that we had to go.

So off we headed for Illinois late Saturday morning. As Kurt pointed out, the forecast models don’t always have a good grasp on things. One thing we could tell from both the NAM and RUC, though, was that the best parameters now lay well south of I-80. Accordingly, we set our sights on Galesburg, and once there, we continued on, crossing the river at Burlington and heading west into Iowa.

I took a dewpoint reading of over 72 degrees on my Kestrel at New London. The air was juicy. But the clearing we had driven through in western Illinois was giving way to a an extensive mid-level cloud deck. Rather than continuing to forge farther west toward the cold front, we decided to backpedal eastward in the hope that convection would fire near the edge of the cloud shield. This idea became a moot point as the cloud cover rapidly expanded across the river into Illinois. But better parameters still lay in our area. We were presently in an area of maximum sigtors and optimal 1 km helicity, and on the radar, a scattering of blue popcorn echoes suggested that localized convection was trying to get started. Anticipating that these features would all translate to the east, we drifted back in that direction.

We soon noticed a cloud base with a tower reaching up toward the higher cloud deck. It showed on the radar, as did another stronger one directly down the road from us. As we headed toward it, the second echo progressed from yellow to red. Not far to our northeast, we could see a rain curtain. Skirting it, we moved east of the developing storm cell, parked, and got our first good look at it.

The cell was organizing nicely and was already showing supercellular characteristics–nice separation of the saucer-like updraft base from the precipitation core; a strong, crisp, tilted updraft tower; the first signs of banding, and a hint of an inflow stinger. Positioned on the southeast edge of the convective cluster in southeast Iowa, it was in a favorable position to

ingest moist inflow unimpeded by other storms as it drifted at 30 knots toward Illinois.

This was our storm. We tracked with it back across the river, watching it develop, watching the base lower and the first hint of a wall cloud blossom and put on muscle, watching it tighten as the RFD notch wrapped around it.

Just southeast of Maquon, Illinois, we saw it: a cloud of dust billowing up from the ground with brief, streaming tendrils of condensation forming and dissipating above it. Tornado! It was a brief appearance of maybe a minute’s duration, but the storm was just getting started, mustering energy for the next round.

We didn’t have long to wait. A minute or two later, as we proceeded down CR 8, a slender elephant’s trunk of a funnel probed its way earthward, intensified, and began gobbling its way through the corn, closing in to within a quarter-mile of us before turning straight east.

This turned out to be a beautiful, highly photogenic tornado, all the moreso for the amazing display of lightning that accompanied it. Kurt took some great video of it which will give you a much better appreciation for how

electrified the tornadic environment was. At one point, at the 8:50 mark, you can see a bolt shoot directly from the funnel to the ground. I didn’t have the good fortune to witness the famed Mulvane, Kansas, tornado, but I’ve got to believe that this storm was similar in terms of its incessant lightning.

The funnel morphed through a variety of elegant formations, and the overall storm structure was beautiful. It was a stunning and mesmerizing sight, but with growing concern, Kurt and I realized that it was making its way toward Yates City and didn’t show any sign of weakening.

Fortunately, the funnel veered slightly to the northeast, passing just to the north of the town. At that point, it was an intense drillpress spinning furiously a mile distant. We closed the gap and tracked with it as it headed toward the larger town of Elmwood, just a couple miles down the road.

What was the funnel doing? It appeared to be shifting to the right. Oh my gosh! Elmwood was going to get hit! The tornado was beginning to rope out,

but not in enough time to spare the town. Taking a hard right, it plowed through the town center. Three-quarters of a mile ahead of us, power lines arced and transformers exploded, debris blasted into the air, and a large dust cloud billowed skyward.

It is a weird and awful feeling to witness a community get hit by a tornado. I’ve seen it happen twice before in Springfield, Illinois, and in Iowa City, but those were night time events. It’s different in broad daylight, when you can see what’s happening. The rather blurry photo shown here was taken just before the tornado crossed Main Street in downtown Elmwood. It’s not a very dramatic shot. You can see a few pieces of debris floating in the air and no more than a cloud tag to mark the presence of the tornado. But a second or two after the photo was taken, things got very nasty in that town. If there’s anything at all good to be said about what happened there, it’s that no one got killed or, as far as I’m aware, even injured.

A couple hundred yards south of Elmwood, the tornado dissipated. Gone, poof, vanished just like that. There’s a certain ugly irony about a force of nature that can wreak havoc in a community and then vanish a few seconds later without a trace. If the tornado had dissipated just thirty seconds sooner, a lot of people might have experienced just a good scare rather than a local disaster.

Kurt and I continued tracking with the storm as it made its way toward Peoria. The next tornado soon formed–a larger, bowl-shaped cloud with multiple vortices. This broadened out into a large tornado cyclone with multiple areas of rotation that produced, among other things, a brief but spectacular horizontal vortex. Sorry, I have no photos to show of it. It had gotten too dark, we were moving, and any picture I took at that point would have been blurred beyond recognition.

In Peoria, we got a bit snagged by roads and traffic, but thanks to Kurt’s great driving, we soon found ourselves heading east on I-74. As we crossed the Illinois River, I could see what appeared to be a large cone funnel to our north making its way across what was probably Upper Peoria Lake, silhouetted by frequent strobes of lightning.

Catching CR 115 at Goodfield, we headed north to Eureka, then continued east along US 24. We were still tracking with the storm, which was slowly weakening as the next tornadic supercell to its north began to dominate. It was still no pansy-weight, though, and at Chatsworth, in a final show of strength, it spun down a brief but well-defined rope tornado.

As our storm merged with the northern storm around Kankakee, Kurt and I caught I-57 and headed home. After May 22 in South Dakota, I really didn’t expect that I’d get another decent storm chase in. But this El Nino year, which got off to such a rotten start for storm chasers, now is paying dividends with some highly photogenic tornadoes.

And the season isn’t over yet. There’s no telling what the rest of June may hold. I doubt I’ll be making any more forays this year into the Plains, but if the Great Lakes region continue to light up, I’ve got my camera and laptop ready.

To see more photos from this chase, click here. And while you’re at it, check out the rest of my images of storms, tornadoes, wildflowers, people, and whatnot in my photos section.

June 9, 2010 by Robert Hartig

Filed Under: Nature, Outdoors, Storm Chasing, Tornadoes, Weather Tagged With: amazing display of lightning, debris, El Nino year, elephant's trunk of a funnel, Elmwood, high helicities, horizontal vortex, Illinois prairie, illinois tornado outbreak, June 5 storm chase, large cone funnel, local disaster, multiple vortices, Peoria, photogenic tornado, rope tornado, saucer-like updraft base, supercellular characteristics, tornadic supercell, tornado cyclone, twister, updraft tower, Yates City

Michigan in the Crosshairs Today?

Most of the time when I chase storms in Michigan, it’s as a wannabe sitting in my armchair gazing wistfully at my radar as I follow the action out west. Every once in a while, though, I get something right here in my own state that’s worth hopping into my car and driving after with my laptop and camera at hand and hope in my heart.

Today is shaping up to be such a day. It’s about time. June is upon us, and that means the peak tornado season has finally arrived for Michigan. Frankly, that term, “peak tornado season,” strikes me as glaring overkill when it comes to Michigan. But we usually have a few incidents every year, and today could be one of them. Perusing the last couple of NAM runs, including the 00Z, and running a few model RAOB soundings, I’m casting my eyes on the Flint-Pontiac area, where surface winds appear to remain, if not backed, at least southerly at 00Z tomorrow evening.

With dewpoints at or exceeding 65 degrees below a warm front draped across central Michigan, straight westerly mid- and upper-level winds with 45-50 knots at 500 mbs, and forecast SBCAPE upwards of 2,000 J/kg, there certainly look to be some decent ingredients in the vat. Insolation will be either the eye of newt that either makes the magic happen tomorrow or the missing ingredient that quashes instability thanks to blowoff from storms farther west.

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Attached are a couple soundings, the first for 23Z at Flint and the other for 00Z at Pontiac. Not bad-looking hodographs, particularly for Michigan. As you can see, the surface winds are southerly. Farther west, they veer to the southwest, though they by no means create a unidirectional scenario. Interestingly, while the STP and Stensrud Tornado Risk indices spotlight the area around Flint, F5 Data’s APRWX tornado index bullseyes Grand Rapids down toward Kalamazoo. Maybe that’s because a 500 mb jet max noses into this area by 00Z.

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Traditionalist that I am, I prefer backed, or at least southerly, surface winds if I can get them. So as of the 00Z run, I’m eyeballing parts east, probably up around Flint near the warm front. The morning run may tell a different story. I just hope it’ll be a positive one.

Here’s to sunny skies, decent CAPE, and a good, productive backyard chase!

ADDENDUM: I wrote the above last night. The morning picture changes things a bit. Specifically, the satellite shows a nasty batch of CAPE-killing clouds blowing into the area from an MCS out west. That’s bad news. However, the clouds show some clearing expanding in their midst. That’s good news. Moreover, Mike Kovalchick sent me an HRRR model radar image showing a supercell popping up in mid-Michigan at 22Z. I’m sure that’s dependent on decent CAPE, which presumes enough clearing for good afternoon heating.

This latest info is good to have, but it doesn’t change my game plan, which is to wait and see what happens by the afternoon.

June 4, 2010 by Robert Hartig

Filed Under: Life, Michigan, Storm Chasing, Tornadoes, Weather Tagged With: 500 mb jet, chase storms in Michigan, Michigan, peak tornado season, radar, RAOB soundings, storms farther west, tornado risk indices

May 22 South Dakota Tornadoes: Part 3

There’s nothing funny about finding yourself trapped at the end of a dead-end road with multiple tornadoes bearing down on you. It’s not a scenario one anticipates when heading out on a chase, but it’s the one my chase partners Bill and Tom Oosterbaan, Mike Kovalchick, and I found ourselves in, along with seven other vehicles full of chasers, last Saturday in South Dakota.

Up until the moment when the road we were on ended abruptly at the edge of a farmer’s field, we were simply performing a routine maneuver: select an escape route and take it when the storm draws near. We and the other chasers had chosen 130th Street east of CR9 as our best eastbound option. It looked good on both DeLorme Street Atlas and Microsoft Streets & Trips: a nice through road connecting with 353rd Avenue three miles away. It was a perfectly logical choice, and things would have proceeded without incident had the maps been accurate.

What the maps didn’t show was that a farmer had recently plowed over the road, converting it to a field. We made that delightful discovery two miles down. The road had already begun to degrade, presenting us with a couple mudholes which Mike’s Subaru Outback plowed through without a problem. But the field was a show stopper. Suddenly, poof! No road. On an ordinary day, this discovery would have been an inconvenience. With tornadoes breathing down our neck, it was horrifying.

But I’m getting ahead of myself. Let me backpedal a bit to set the stage. After stopping to enjoy the eminently photogenic fourth tornado that followed the beastly Bowdle wedge (see previous post), the four of us headed north to CR2/125th St., then turned east. The storm was morphing into a high precipitation supercell (photo at top of page). We watched it drop a couple more

rain-wrapped tornadoes. Then it pulsed, catching its breath and gathering energy for the next round.

Dropping south down CR9, we pulled aside by a roadside pond to grab a few photos. The updraft area was a couple miles to our west, and while it didn’t presently seem to be tornadic, appearance can be deceptive. The cloud base was low, nearly dragging on the ground, with suspicious lowerings forming and dissipating. It looked like it could drop something at any time, and chances are it was even then producing random, momentary spinups.

Hopping back into our vehicle, we proceeded farther south to the corner of 130th Street, where we once again parked. Here, we bumped into chasers Ben Holcomb, Adam Lucio, Danny Neal, and Scott Bennett. We had last seen these guys at a truck stop in Murdo; now here they were again, along with several other vehicles, all converging out ahead of the meso in the middle of nowhere. In the photo, left to right: Tom, Ben, Bill, and Scott.

As the storm drew closer, Tom pointed out that rotation was beginning to organize overhead. It was time to skedaddle. Back into Mike’s Outback we clambered, with Tom at the wheel, and headed east down 130th Street.

At this point, it’s important to bear in mind that every vehicle that showed up at our location had independently pre-selected 130th Street as a valid escape route. What followed did not begin as a desperate dash for safety, but as a calculated, run-of-the-mill tactical maneuver informed by commonly used mapping software. Most of the people involved were experienced chasers, some of them veterans. The reasoning behind our road choice was sound. Unfortunately, the information we based it on was not.

Thus it was was that two miles down the road, suddenly there was no road. At the front of a string of other chase vehicles, we were the first to make that

discovery. Tom turned around and started heading back, yelling to the next vehicles that the road was out. It was then that a tornado suddenly materialized in the field maybe half a mile to our west, just south of the road. It was a regular drill press, spinning furiously as it made its way toward us. It finally crossed the road and headed east-northeast a few hundred feet away, but even as it did so, another, thicker funnel snaked to the ground at roughly the same place where the first one had formed. I don’t think most people saw this second tornado; it moved toward us briefly, kicking up dirt, then dissipated, though I could still see swirling motions in the rain bands where it had been.

In the photo, besides the rope tornado, notice the lowerings farther back. These meant business. We were at the eastern edge of a broad area of rotation that was dropping not suction vortices, but multiple tornadoes of various sizes, intensities, and behaviors. In my observation, these were NOT moving in cyclonic fashion around a common center, but east with the parent storm–and straight at us.

A large cone appeared to the west, which, gathering strength, moved through the field to our north. By this time, it was clear that we were in a truly lethal situation, cut off to the east by a dead-end road and to the west by tornadoes.

Windy? Hell yes it was windy. The inflow was cranking like a sumbitch, and from the looks of things, it was only going to get worse. I looked around for a ditch, but there was absolutely nothing that could have offered protection. I noticed a stout post a few yards away and contemplated lying flat and wrapping my arms around it. Tom had the same idea. Mike was eyeballing a large pile of stones a hundred yards away, thinking it might provide some shelter, but it was too far a dash with no time left to make it in.

It was at this point that UK chaser Nathan Edwards drove off the road and began heading south into the field. He told me later that he was simply attempting to clear some room for other vehicles to move forward, hopefully edging just a little bit closer to out of harm’s way, but Nate’s move prompted the rest of us to follow. In a last-ditch gamble, the entire entourage of chase vehicles began fleeing south along the fence boundary.

The tornadoes were close. Really, they were on top of us. I watched as two funnels formed a hundred yards west of our vehicle, twisting around each other and moving toward us like the “sisters” in the movie “Twister.” The rain curtain was full of swirls and braids. And what was particularly unsettling was that, as we dashed across the farmland, the business part of the storm seemed to be expanding, reaching out after us. For a mindless force of nature, this storm was displaying as close as you can get to malevolent intent.

It dawned on me that if ever there was a time to pray, and pray hard, this was it. I’m a Christian–a bit of an iconoclast in that I don’t buy into a lot of Western church culture, but I love Jesus, I’m serious about following him, and conversing with God comes naturally to me. I don’t mean just in a pinch, but as a lifestyle. You can bet that at this point, I began praying most intensely.

A couple hundred yards in, we encountered a wet area and ponding and were forced to forge our way into the cultivated field. It was there that the storm caught up with us in earnest. End of the road for real. There was nothing left to do now but hunker down, pray, and hope.

Obviously I’m here to tell the story. All of us are, every last person. That none of us were killed or seriously injured, or for that matter sustained so much as a scratch, is in my book God’s love and mercy, pure and simple. A video clip by Adam Lucio shows a tornado forming right in our midst, not ten yards from one of the vehicles. I never saw it, but Adam’s video is conclusive and sobering. We came so close, so very close. The rear flank downdraft alone had to have been in the order of 100 miles an hour. Yet nothing truly bad happened to any of us.

Some may call that a lucky draw; I call it answered prayer. Believe what you will, but there’s more to the story, an experience uniquely mine that I’ve shared with only a couple people so far. Look for it in my upcoming, final post concerning this incident. Whatever you make of it, I think you’ll agree that it’s uncanny.

That’s it for now, but this story continues. What followed with the farmer who owned the field, the sheriff and police, and other locals is for another episode, and it’s still not entirely resolved.

I’ll leave you with two images, both taken when the worst of the storm had just moved past us. One shows some of the vehicles getting slammed by the still-hellacious RFD. The other is a GR3 radar grab of the rotation and our location relative to it, shown by the circular GPS marker.

With that, I’ll sign off. Keep an eye out for parts four and five.

May 28, 2010 by Robert Hartig

Filed Under: Storm Chasing, Tornadoes, Weather Tagged With: answered prayer, Bowdle wedge, broad area of rotation, conversing with God, funnels, GR3, high precipitation supercell, Jesus, May 22 South Dakota Tornadoes, multiple tornadoes, radar grab, rain-wrapped tornadoes, RFD, rotation was beginning to organize overhead, storms drew near, suction vortices, tornadic, twister, updraft area

May 22 South Dakota Tornadoes: Part 2

I’ve never witnessed anything like the tornadoes of last Saturday in South Dakota. If supercells were sushi and I could order a al carte, what I got is exactly what I’d have ordered, with the exception of how this chase ended up. But that’s material for a different post. Suffice it to say that in terms of both the storms and the overall experience, May 22, 2010, truly was the storm chase of a lifetime.

Yet I came close to missing it. The forecast models were all over the place with the synoptic setup. The GFS indicated formidable capping. The NAM offered more hope, but convective inhibition was still clearly a huge consideration. And the upper-level winds looked borderline.

But if the right ingredients did come together and the cap broke–and it looked like there was a chance that this could happen–then a whopping 5,000 j/kg CAPE would be at hand to produce explosive convection.

So Mike Kovalchick and I pulled the trigger. The potential was worth the risk of traveling 1,000 miles for a blue sky bust. My friends and long-time chase partners Bill and Tom Oosterbaan had also been tipping on the fence with this setup, but they, like Mike and me, decided it was worth a roll of the dice. So off went the four of us in Mike’s Subaru Outback, headed for South Dakota.

We stopped in Murdo to gas up and bumped into a few other chasers, including Ben Holcomb, Adam Lucio, Danny Neal, and Scott Bennett. We would run into these guys again later, but, as I’ve already mentioned, that’s for another post.

Leaving Murdo, we dropped down to White River to wait for more data. Mike got antsy about capping in our area, though, and he was right. So we hopped back into the Outback and headed north toward a nice field of bubbling cumulus. These were becoming more aggressive to our east, so we caught US 212 and headed toward Gettysburg. Just after we crossed the Missouri River, the cap broke and a tower began to billow upward. Things happened rapidly after that.

With MLCAPE in the neighborhood of 4,500 j/kg fueling its updraft and a 50 kt H5 jet to help organize it, the storm went supercellular almost from the get-go. From left to right, here are Bill, Mike, and Tom watching it get its act together. It didn’t take long for that to happen.

Half an hour later, 45 minutes tops, the first tornado of the day formed a mile southwest of us and strengthened rapidly into a robust cone that, moving at maybe 25 mph in a northeasterly direction, crossed the road to our west and passed to our north at a distance of a quarter of a mile. Quite the exhilarating experience, but also somewhat frustrating as my camera chose that time to give me trouble. Moisture from the rain lashing in on the rear flank downdraft was likely the culprit, but in any case, the shutter refused to snap. I should have brought a plastic bag for my camera. Nevertheless, I managed to get a few decent photos.

The tornado lifted a few minutes later and a new one rapidly formed. At this point the storm had moved off to our northeast, but it was moving slowly. For once, we weren’t chasing a rocket ship. The storm was easy to keep up with, providing ample opportunity for repositioning, and the view from the rear was flat-out spectacular. The second tornado grew quickly into a large, white cone and then a wedge, positioned underneath an amazing, bell-like mesocyclone. The

structure was just unbelievable, with turbulent swirls of cloud wrapping around the parent circulation like daubs of frosting on an immense, revolving birthday cake. Nothing short of a work of art, an awesome sculpture of wind-carved moisture drifting across the prairie. It’s strange and amazing that something so violent can also be so beautiful. The first photo at the top of this post gives you a closer view.

This tornado continued to strengthen and the mesocyclone to lower as we drew closer. We tracked with it along US 12 as it took an eastward turn and headed toward the town of Bowdle.

With horror, we realized that we were about to watch a large, violent tornado strike a community. It looked like it was maybe half a mile to our north* and, taking a right turn, was heading slightly southeast toward the road ahead of us according to the GR3 SKIT marker. We pulled aside to avoid getting eaten. Other than that, all we could do was pray for the people in Bowdle.

There was nothing pretty about this tornado anymore. It was a smudge of darkness boiling beneath a low and intensely agitated cloud base. The wind was powerful, and as we sat there, a bunch of large plastic conduits came tumbling across the field in our direction. Fortunately, these missed us, and the tornado changed its course, just sideswiping the north end of Bowdle and taking out some large, high-tension electrical towers.

Had the tornado not shifted, I am as certain as can be that we’d have witnessed another Greensburg, Kansas/Parkersburg, Iowa scenario. Thankfully, considering what might have been, this violent wedge had relatively minimal impact. The damage it did cause has subsequently earned it an EF-4 rating.

The Bowdle tornado dissipated east of town and the storm once again pulsed, giving us time to get ahead of it and position ourselves to its southeast before it dropped its fourth tornado. This one was the most photogenic yet, going through a variety of forms and phases. At its inception, it reminded me of a picture of a tornado in

Gothenburg, Nebraska, that I saw in a weather book as a kid. Really a beauty, a classic, with a long, dark elephant’s trunk kicking up dirt in the open field a mile to our northwest.

The tornado morphed into a truncated tube with multiple vortices circling around its base like braids in a rope, then into a needle. It finally reconsolidated into another classic, Kansas-style funnel, as photogenic as you could ever hope for, before

finally dematerializing, leaving behind it nothing more than a troubled cloud base. How can something so powerful hinge on a balance so delicate that it can translate from a killer into nothingness in a matter of seconds?

I’ve presented the photos of this last tornado sequentially to give you a sense of its life cycle. But as visually stunning as it was, the structure of its parent

supercell was no less impressive. I like to see the big picture. Tornadoes are just a part of the storm; there’s much more to enjoy as well. Beaver tails and tail clouds. Updraft towers. Wall clouds. The fabulous, banded look of a mesocyclone.

I’ll leave you with one last photograph of the entire scene, with the tornado spinning like a dervish in the distance beneath the storm. What followed next is a story in itself, one that I’ll never forget.

Don’t worry, I won’t leave you hanging. Look for Part 3, coming soon to a blog site near you.

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* November 26, 2011: I’ve done some minor editing to this post to correct a couple of factual errors. In doing so, I’ve chosen to let my statement stand about my perception of the distance. Records indicate that the tornado in fact passed a mile north of Bowdle. It certainly looked closer than that to me when it was approaching the town–in fact, I thought it was starting to turn right at one point–but my lack of experience with such a large and powerful tornado, the lowness of the cloud base, the intensity of being in so violent a storm environment, and the excited commentary within the vehicle probably all influenced my perception of the distance involved.

May 26, 2010 by Robert Hartig

Filed Under: Photography, Storm Chasing, Tornadoes, Weather Tagged With: beaver tails and tail clouds, bell-like mesocyclone, Bowdle tornado, bubbling cumulus, EF-4 rating, first tornado of the day, forecast models were all over the place, formidable capping, Greensburg Kansas, large violent tornado, May 22 South Dakota Tornadoes, monstrous wedge, multiple vortices, Parkersburg Iowa, rear flank downdraft, storm chase of a lifetime, storm went supercellular, supercells

May 22, 2010, South Dakota Chase: On the Road

After catching breakfast in Chamberlain, South Dakota, we–Mike Kovalchick, Bill and Tom Oosterbaan, and I–are heading west along I-90. We have plenty of time to determine where we want to camp out this afternoon until storms start firing later today.

If you’ve kept track of the present weather system, then you know that it has had a number of serious detractors, the chief one being a nasty cap. To complicate things, the NAM and GFS were initially wildly at odds. But Thursday night the GFS began to agree with the NAM on opening up an uncapped corridor from Nebraska into South Dakota, and from there the model forecasts became progressively more promising. The SPC Day One Convective Outlook now shows a 10 percent possibility of tornadoes extending from the Nebraska border north through the Dakotas. The hub of the activity will most likely be in South Dakota, which means that we are sitting in the catbird seat.

It feels great to finally get back out on the road and chase the Plains again. I’ve missed the big action so far this spring. This setup may not be the year’s big event, but it shows promise, and it coincides with a time when I’ve got the funds to go after it. Whether or not we see a tornado today–and tomorrow, and maybe Monday, as we follow this system’s evolution–we’ll at least see some nice storms. And, I might add, some beautiful countryside. It’s been a few years since I’ve been in South Dakota. It’s good to be back!

May 22, 2010 by Robert Hartig

Filed Under: Storm Chasing, Tornadoes, Weather Tagged With: nasty cap, South Dakota Chase, storms, Tornadoes, weather system

Another Lower Great Lakes Storm System

The eastern Great Lakes looks to be once again under the gun for severe weather, with a setup that looks reminiscent of last week’s, albeit with some variations. The low is weaker but there’s juicier moisture, helicities may integrate a little better with instability, and it seems to me that the 500 mb jet is better positioned. Once again, though, surface winds veer rapidly south of the warm front, so while the mechanism for another batch of supercells is in place, the tornado potential is less certain. The SPC convective outlook shows a 5% tornado risk. That seems about right, though maybe part of the area will get upgraded this afternoon.

After looking at the morning NAM and RUC, I once again like the area south of Toledo. Bowling Green was my initial target last week, and I’d pick it again this week if I wanted to drive that far. If I chase storms at all today, I may just wind up dropping south down 131 toward the warm front, depending.

By the way, I haven’t posted a thing about Monday’s tornado fest in Oklahoma and I probably should. I wasn’t there to experience it, but my buddies Kurt Hulst and Bill Oosterbaan teamed up for it, and Ben Holcomb made it down there as well, and everyone scored. Bill tells me that he and Kurt saw seven confirmed tornadoes.

Me, I watched the outbreak unfold on the radar and ate my heart out. It really was a heck of a thing to observe. The SRVs were jaw-dropping, and I saw one low-level Delta velocity of 177 knots. Those storms were the real deal, and a huge contingent of chasers was on them. Among the highlights was the Wakita, OK, multi-vortex that a number of chasers captured on video. The clips I’ve seen show what looks like a basketful of snakes dancing.

Unfortunately, five people died in the storms. If there’s anything positive that can be said about the loss of life, it’s that the paths of the storms through mostly rural areas no doubt kept casualties lower than they could have been. One supercell dropped tornadoes in Oklahoma City, and all it takes is one. But that’s better than multiple population centers getting hit by storms the intensity of Monday’s storms.

May 13, 2010 by Robert Hartig

Filed Under: Michigan, Storm Chasing, Tornadoes, Weather Tagged With: chase storms, Great Lakes storm system, juicier moisture, Monday's tornado fest in Oklahoma, SRVs were jaw-dropping, supercells, surface winds veer, Tornadoes, tornadoes in Oklahoma City, under the gun for severe weather, Wakita OK multi-vortex, warm front

Monday’s Southern Plains Event

Lacking the cash to head west for tomorrow’s setup, the best I’m going to be able to do is gaze forlornly at the radar, gnash my teeth, and hope my buddies Bill, Kurt, and Mike are catching tornadoes and staying safe.

I’d be smart to not even look at the models, but a perverse part of human nature makes it hard for me not to. Out of curiosity, I’ve interrogated a few NAM 6Z forecast soundings from around southeast Kansas and northeast Oklahoma. I suppose the results are nothing new: plenty of moisture and CAPE, great shear and helicity, and a stout cap that lingers till evening, at which point the atmosphere looks primed for discrete, tornadic supercells to explode.

Most of the soundings shown here are for 23Z, but the one for Tulsa, shown above, is for 22Z, since the cap looks to minimize earlier there (21Z, not shown, also looks decent, with -46 J/kg CINH, up from -198 the previous hour). For KCNU (Chanute, KS), I’ve also shown the 00Z so you can compare the difference; and for Hutchinson, which at 525 1km SRH has the highest helicity value of the different soundings, and for Wichita, I’ve shown only the 00Z, since prior to that the cap looks pretty stout. Look below for all the soundings except Tulsa, and make sure you click on the images to enlarge them.

Beyond this, I’m not going to comment. To those who are out there on the Plains waiting for this setup to arrive and ripen, I wish you success and safety.

May 9, 2010 by Robert Hartig

Filed Under: Storm Chasing, Tornadoes, Weather Tagged With: CAPE, great shear and helicity, highest helicity values, NAM 6Z forecast soundings, stout cap, tornadic supercells, Tornadoes

A Glance at Friday: Severe Weather in the Great Lakes

It now seems a sure bet that the eastern Great Lakes is due for a spate of severe weather. The SPC is presently making it out to be a linear event, as is typical of cold fronts sweeping through our region, but the wind profiles suggest the possibility of supercells and tornadoes.

If you go by the present, 12Z NAM run, central Ohio appears to be the sweet spot, with a variety of parameters converging over or near a bullseye of 2,000 j/kg SBCAPE. Here are a few maps for forecast hour 21Z to give you an idea. Click on the images to enlarge them. The first shows the aforementioned SBCAPE (shaded), sea level pressure (contours), and surface wind barbs. Not a bad bit of instability if this scenario pans out.

In the second image, you can see a nice overlay of 55-60 kt 500 mb winds (shaded) over 35-40 kt 850 mb winds (contours). The wind barbs are for the 850 mb level. The H5 winds veer still further to the west. I think it’s safe to say that shear won’t be an issue, and 1 km VGP, not shown, is as high as 0.4 in the area of heightened instability. Helicity maxes are well to the north, but I wonder what kind of effective SRH we’ll wind up with where it counts.

The third map shows a Theta-e lobe pushing up into northern Ohio with a surface lifted index between -4 and -6 perched squarely over the axis. That should get the job done.

In the last map, three different significant tornado parameters–the well-known STP, the APRWX tornado index, and the Stensrud tornado risk–all converge nicely over the same spot near Newark, Ohio. Three overlays can be a bit difficult to decipher, so let me help: the STP is shaded, the APRWX is tightly contoured like an onion, and the Stensrud has broader

contours, with its highest value circling the APRWX in a yellow ring.

All this to say, Friday may have some potential. I don’t get too excited about cold front events around here–not that we have many options in the Great Lakes, but a steady diet of squall lines has a way of lowering a person’s expectations. Of course, as soon as you let down your guard, along comes the exception to prove that storms in our area can and do deliver. Maybe this round will prove to one of those occasions. We’ll find out two days hence.

May 5, 2010 by Robert Hartig

Filed Under: Michigan, Storm Chasing, Tornadoes, Weather Tagged With: APRWX Tornado Index, cold fronts, Great Lakes, possibility of supercells and tornadoes, severe weather, SPC, squall lines, Stensrud tornado risk, storms, three different significant tornado parameters

April 22-23 TX-OK-KS Storm Chase

As I begin this post, the first major tornado-producing storm system of 2010 is moving to the east after taking 10 lives in the South yesterday. Already a tornado-breeder, the system matured yesterday into a wide-scale outbreak driven by hefty bulk shear, massive low-level helicities in the order of 600 and above, and CAPE values up to 2,500. Yazoo City, MS, was hit hard by a powerful, rain-wrapped wedge. The verdict remains open as to whether this was a single, long-lived tornado that traveled as much as 200 miles, or one in a series, which seems likelier.

Sorry, I can’t offer a write-up on yesterday’s storms. I was home sleeping, and I have no regrets that I missed anything. With the models suggesting rain-wrapped, low-visibility tornadoes rocketing along at 50 mph or more; with the potential for hydroplaning while driving at gonzo speeds in order to keep on top of fast-moving, rapidly morphing storms and avoid having them get on top of us; and with the logistical madness of three sleep-deprived chasers–Bill Oosterbaan, Mike Kovalchick, and me–having to backtrack afterward to Saint Louis where my car was parked and then drive 450 miles back to Grand Rapids, the negatives of chasing this big, messy, and dangerous tornado outbreak seemed to easily outweigh the potential payoffs.

So Bill, who was determined to catch the action, made arrangements to hook up with Kurt Hulst and Bill’s brother, Tom Oosterbaan, in Illinois, and then he dropped Mike and me off at my car. The two of us headed home, and I can tell you, it felt mighty good to crawl under the covers upon my return and sleep until 1:00 in the afternoon. After talking with Tom yesterday evening, I’m glad I chose as I did.

I may have more thoughts to share about yesterday’s scenario, but I’ll save them for another post. The previous two days in Texas and Kansas deserve some attention in their own right, and not just as the prequel to the big, day 3

outbreak. They may have been a bust for me tornado-wise, but they were nevertheless the first decent system of the year and my first chase out on the Plains. It was a blessing to get out on the road once again and see the vast, textured expanses of the Texas and Oklahoma panhandles.

Naturally, the landscape included the TIV2, which at this point should be designated a mobile national monument of the Great Plains. Back in 2008 we had bumped into its predecessor in Nebraska; this Thursday, we pulled into a gas station in Pampa, gassed and Rain-Xed up, then drove around to the other side of the station, and surprise! There it was–the Tank and its entourage. Cool! Who can resist taking a few photos? Not me.

As for chasing storms, Thursday was a should’a. We should’a either listened to Mike and headed for western Kansas, where most of the tornadoes occurred later in the day, or else gone with Bill’s and my initial impulse to chase the bigger CAPE, albeit forecasted low helicities, near Childress, Texas. For that matter, if we had endured the initial grunge in Wheeler, or better yet, just parked along US 60 east of Pampa–in other words, if we had just sat and waited–we’d have been golden. Instead, we sacrificed an opportune position and went after some cells that fired to our northwest along the dryline. Doing so made a certain amount of sense, as those storms were already looking supercellular and were moving toward the warm front and better helicities, while the cells popping up to our

south in advance of the dryline seemed to just sit there and languish. So after the northern storms we went.

Bad decision. One of the southern cells developed steam shortly after we made our move. We could still have turned around at that point, but we chose to commit to our decision and wound up betwixt and between the vortex breeding grounds to our south and north. As a result, we found ourselves looking forlornly at the radar as the southern cell shaped up beautifully and began churning out tornadoes, while our storms struggled valiantly but

chromatic_couplets_for_altered_dominants

never quite got their act together. If there’s a lesson to be learned, it’s that good things come to those who wait. And, I might add, that model SRH is nice if you can get it to cooperate, but it can be deceptive. Helicity is prone to change with the storm environment in ways that forecast models don’t anticipate. If CAPE and 0-6 km shear are sufficient, storms may just generate their own low-level helicity.

Anyway, we chased the dryline storms and busted. Our storms tried hard to tornado, but they just couldn’t quite manage to produce. So instead of the blue ribbon, we wound up with honorable mention: some decent structure, including cool-looking wall clouds, a few funnels, and–as tail-end Charlie went high-precip in the Oklahoma panhandle–a nice, banded-looking storm with a formidable shelf cloud.

As for Friday, we picked exactly the right target up in northeast Kansas along US 75 just south of the Nebraska border. We were smack in the axis of a nice moisture plume. But nothing happened. As the afternoon progressed, the cumulus field we were sitting under began to generate towering cumuli, but these turkey towered and busted against a mid-level cap that just wouldn’t erode. So that was that. Looks like a lot of other chasers got disappointed as well by the northern play. It happens. We finally cut our losses around 7 p.m. and headed back east toward Saint Louis and a band of storms that was moving toward I-70. Ironically, one of these produced a series of tornadoes. If Thursday had been a should’a, Friday was an if-only. If only we’d targeted northeast Missouri…but there had been no reason to do so that we could see.

Now another storm system looks to be moving into the Midwest later this coming week. The action could be closer to home, but I’ll think about that in a day or two. Right now, it’s time to make this post, rest up, and get on with the rest of life.

April 25, 2010 by Robert Hartig

Filed Under: Photography, Storm Chasing, Tornadoes, Weather Tagged With: formidable shelf cloud, long-lived tornado, rain-wrapped wedge, storm chase, storms, TIV2, tornado, tornado outbreak, tornado-breeder, tornado-producing storm system, Yazoo City

Chase Time! Bound for the Panhandle

Finally! First Great Plains storm chase of the year! As I write, Bill Oosterbaan, Mike Kovalchick, and I are headed west down I-70. In another 30 miles we’ll reach Kansas City; then it’s onward to Wichita, where we’ll overnight. Tomorrow morning we’ll take a look at the models, and then most likely make our way toward familiar territory in the northern Texas panhandle. It has been a couple years since I’ve been there; I can’t wait to see big storms moving over that landscape again.

I’m not going to write much tonight. I’m tired. Last night I got only got three or four hours of sleep, having stayed up till 3:00 a.m. to complete a writing project for a client. My updates will probably brief until I return Sunday. Tomorrow, Friday, and possibly Saturday will be pretty filled with chasing storms and all the pertaineth thereto. When I finally get back home, I hope to have a few great tornado and storm photos to share and an outstanding chase report to post. So stay tuned, campers. This is the first decent chase scenario of the year, and I am geeked to be going after it. Tornadoes, here I come!

April 21, 2010 by Robert Hartig

Filed Under: Storm Chasing, Tornadoes, Weather Tagged With: big storms, chasing storms, Great Plains, northern Texas panhandle, storm chase, Tornadoes