A weak surface trough is forecast to meander along the west Texas Panhandle/eastern New Mexico with a dryline forming east of this feature, drifting slightly eastward during the afternoon, and then sharpening and retreating westward after sundown. My target area is at the northern edge of 500mb short wave energy, along the dryline with bulk shear from 40-50 kts. I was looking for a spot where sufficient shear overlaps the dryline and better forecast CAPE values near 1500 j/kg as dew points reach 55-60°F. Better 0-1km helicity resides further east, but does not correspond with best instability until after sundown. As the LLJ increases after 00Z, a chance for better lower level winds may produce a limited tornado threat in this area with NAM forecasting convection where 0-1km EHI increases over 1.00.
No severe reports within a hundred miles of my target. A couple severe-warned storms went up in the area, but failed to produce anything worth reporting. A very nice supercell did go up further north near Childress, TX, and brought in loads of hail and wind reports, along with a brief tornado. I didn't have that area pegged as having enough bulk shear, but it looks like it managed to pull it off. Meanwhile, further south where upper levels looked better, my first guess is that there wasn't enough low level convergence to fire and sustain storms, as well as the first half of the day being dominated by a stratus layer that took too long to burn off.
As the Spring severe weather season rolls around, I like to work out the kinks in my forecasting and chasing strategy by running virtual chases on a few select days with severe potential. I'll pick a target area for the morning of, drop a pin in Google maps, check conditions as the day progresses, and adjust my position, then commit to a storm and use the map time estimates to see if I can be in position for a supercell and possible tornadoes.
Taylor Campbell is a chaser who has set up a website called 'Storm Chase Game' at stormchasegame.com. The damage that severe storms cause is no game. However, the format of the site seems like good practice for chasers trying to gear up and stay in practice for forecasting during severe storm season. A little competition can help take the process seriously and commit to a forecast and target area. Unfortunately, you can't adjust position during the day as you normally would while chasing, but that would probably be impossible to manage for that kind of format. Anyway, I've got an account there and have virtual chased a couple setups near the north-central Oklahoma border with Kansas on April 2 and northwest Arkansas on April 3. I picked up some severe hail and wind reports on those, but no tornado reports.
I figured, if I can keep up with it, I'll post my abbreviated forecast and positions here and whether it panned out.
So for tomorrow: April 13, 2014
A triple point is forecast to set up in western Oklahoma and drag a dryline eastward over the course of the afternoon while a cold front drops in from Kansas. The dryline looks to stay intact during peak heating and convection development before the cold front mashes it into linear storms during the evening.
I'm positioning at Sapulpa, Oklahoma, southwest of Tulsa. Timing of shortwave energy will be crucial. This is a compromise between NAM and GFS. I will be positioning east of triple point for where there is likely to be better directional shear as convection erupts and prior to arrival of cold front. Bulk shear will hinge on the shortwave and could range from 30-45 kts in this area. NAM is forecasting 0-1km SRH around 175 m^2/s^2 ahead of storms moving through from 21-00Z with CAPE values from 2000-2500 j/kg. Normally, I wouldn't chase this area due to terrain and urban environment. Hoping people in eastern Oklahoma stay tuned to weather radio/TV tomorrow and get to shelter if tornado-warned storms move through in the afternoon/evening.
With more recent runs of NAM, the cold front is proceeding further south during the afternoon and better instability also further south. Revised my position south west of the original location to Prague, Oklahoma.
I'm pretty easily deceived by what I think I see happening on model forecasts vs. what actually takes place when it comes to cold front interference...as in how fast it moved through and lined out storms in northern two-thirds of Oklahoma. Morning convection forecasts also showed better chances of convection along the dryline into north Texas. If I had actually engaged in the misery of chasing eastern Oklahoma, those AM model runs, plus this satellite view would have sent me south of my original target:
Despite foiling my theory for chase targeting for the day, I think that satellite view is awesome. Once midday heating and convergence gets going, the boundaries start to get marked out by cumulus. This is a great view of the cold front rushing southward and overtaking the dryline while strengthening convection zippers southward along the cold front. More isolated storms eventually got going further south along the dryline where the cold front wasn't messing things up as early, with a tornado report about 18 miles east of Duncan, OK. Besides a couple tornado reports in Iowa and east Texas, that was it for tornadoes. I did pick up a few hail reports inside my game radius, but not the part of the setup I was after.
The trough that led to the amazing Rozel, Kansas tornadoes on May 18th, 2013 was positioned to support another round of severe weather on the 19th. Dew points were reaching into the upper 60s into eastern Kansas and Oklahoma. With steep mid-level lapse rates, mixed layer cape levels were heading over 3000 J/KG. Ample shear was in place to support supercells. The exit region of an advancing speed max ended up giving further support to strong, widespread convection over eastern Kansas.
An outflow boundary was positioned just south of the Oklahoma-Kansas border. With the advancing dryline, these two would help focus storm initiation and increased tornado potential along the outflow boundary.
I chose to begin my chase further north in Kansas because I anticipated Oklahoma storms along the boundary would propagate into difficult chase territory and storms further south along the dryline would enter dense urban areas along the I-35 corridor.
Storms ended up erupting in two clumps: one area from east-central to south-central Kansas, and another pretty much right over the OKC metro area.
21Z Visible Satellite
21Z / Oxford Storm
23Z / Newkirk Storm
01Z / Maple City Storm
Video documentary of the chase.
Thematic spot to park and check data south of Moline, Kansas (1800Z)
As storms matured, I made my way toward a cell approaching Oxford, Kansas. By the time I was positioned east of Oxford, the storm was HP and had a tornado warning. The look of the storm was incredibly menacing. The forward flank was lofting a ragged, low shelf that had the train-like appearance of an inflow tail as it led into the sealed notch between forward and rear flanks. Positive lightning strikes were landing just ahead of it and casting off fearsome canon-shots of thunder.
Reflectivity and position near Oxford, Kansas (2133Z)
Approaching forward flank (2133Z)
Positive charge lightning strikes ahead of the Oxford HP Supercell.
The green rear flank rolls northeastward along the heavy forward flank of the Oxford HP Supercell.
As the green RFD curtain approached, like it was rolling along the gears of the forward flank, I repositioned three miles further east. From this new spot, I witnessed the spectacle of rapid circulation developing in the rain free base just ahead of the FFD/RFD notch as a new RFD seemed to push out, trying to get ahead of the occlusion. The established RFD was moving in quick, so I had to abandon that spot and drive east to stay ahead. So I wasn't in position to see the tornado that was reported 6 minutes later about 6 miles northeast of that spot.
Circulation developing in the rain free base just ahead of the Oxford HP Supercell.
About that time, the Oxford storm started to congeal with others and form into a severe squall line. This convinced me to work my way southward to stay out of the mess and look for opportunities with any isolated storms on the tail end of the squall line. I had some pretty impressive views of the advancing line as I headed south.
Massive gust front on a congealing squall line from Winfield, Kansas (2158Z)
Another gaping gust front as seen from 4 miles south of Arkansas City, Kansas (2242Z) A brief rope tornado was reported 1 mile north of Arkansas City about 17 minutes later.
I eventually wound up on an isolated supercell near Newkirk, Oklahoma. I was able to hang out for a half hour in that spot and watch it approach. RFD was working its way into the base and encouraging a slender wall cloud to inhale scud, but it just wasn't strengthening. I was also concerned about the quality of roads to my east, so I let it go. It picked up a tornado warning not long after.
Reflectivity and position near Newkirk, Oklahoma (2304Z)
RFD cuts into the rain free base of a supercell 3 miles north of Newkirk, Oklahoma (2311Z)
Scud rises into an anemic wall cloud on the Newkirk supercell (2313Z)
RFD and wall cloud on the Newkirk supercell (2316Z)
Since new development still seemed likely, I decided to give the farm roads to the east a try. They were a lot better than I thought--pretty rocky actually--so I spent over an hour navigating north and east as I watched a very thin line of convection do pretty much nothing exciting stormwise, but did make for an excellent sunset display.
Tail end of a line of convection on the Kansas-Oklahoma border (2357Z)
After finally getting back onto a paved road, back into Kansas, I noticed a severe-warned storm, moving up out of Oklahoma. I tried racing south to get ahead of it, but couldn't manage it. After it passed, I did get to sift through its wake and picked up hail as large as 3 inches along the roadside about 7 miles east of Maple City, Kansas.
Collection of large hail (0130Z)
Three inch hail near Maple City, Kansas (0130Z)
Three inch hail near Maple City, Kansas (0130Z)
My first contribution to an SPC storm report.
So, no tornadoes, but definitely some awesome sights on this chase. The dynamics near Oxford were unforgettable, and even though I missed seeing the tornado, I had an amazing perspective on that storm.
The 2013 Southwest Monsoon season still has three more weeks to go. Before it moves into the sometimes interesting transition period at the end of September and early October, here are some highlight photos. Except for the lightning shots, the rest of the shots were taken with my iPhone. It has drawbacks with noise, especially in low light areas, but it's so handy, and always with me that I'm getting shots that I otherwise might not be prepared for. (What that means is I need to make an effort to keep my camera with me more often.)
July 2, 2013
Panorama of a storm developing south of Flagstaff as seen near I-40 and 4th Street at 2:18 PM.
New development overhead a few minutes later was drawing in a bit of vorticity and sculpting a brief cinnamon bun into the cloud base.
July 3, 2013
The base of a dying updraft over east Flagstaff tapers to a point.
The dwindling remnants of the eroding storm base reveals a slowly rotating spindle--not rapid enough to be a shear funnel.
July 4, 2013
An active storm north of Mt. Elden puts on a beautiful show of ongoing anvil crawlers.
July 11, 2013
Pop-up convection develops west of Flagstaff as seen from Rt. 66 in east Flagstaff.
July 20, 2013
Lightning flickers behind a weak gust front east of Flagstaff as seen from Rt. 66.
July 23, 2013
Inflow, chilled by heavy precipitation, creates a rugged lowering in the rain free base of this storm over Schultz Pass. As seen from 4th Street in central Flagstaff
August 23, 2013
Dry outflow pushes a growing wall of dust northward from Tucson, as Picacho Peak rises above the dust and desert floor. The photo was taken by my wife, Amanda, as we drove north on I-10 toward Phoenix.
August 26, 2013
An ominous haboob blew into Phoenix, featuring a laminar updraft, intermittent shelf cloud and spectacular lightning after the gust front passed. This view is facing southeast as seen from near central Phoenix.
September 2, 2013
A beautifully lit and structured thunderstorm brews over the San Francisco Peaks as seen from Highway 89 in northeast Flagstaff.
September 7, 2013
Looking south as a clump of northbound thunderstorms pushes a ragged shelf cloud into east Flagstaff. September 7, 2013. (Another iPhone panorama, so some of the seams are a bit jumpy.)
This was the third day of a week-long trip to the plains and the first heightened possibility for strong supercells.
The setup featured a negatively tilted upper level trough over the western US that put southwesterly flow over the plains. This led to the formation of a surface low over southwest Kansas with a dryline draping from the low down through the panhandles. Rich moisture being advected into the area on southeast surface winds brought dewpoints in the mid to upper 60s through the southern and central plains and up to 70 degrees into Kansas. All the moisture and heating coupled with steep lapse rates led to mixed layer cape values in the extreme range from 3 to 4 thousand j/kg.
With these conditions in place, agitated cumulus began to develop along the dryline and north of the surface low, and by mid afternoon storms were firing in eastern Colorado and northwest Kansas.
21Z Visible Satellite
A shortwave ejecting over the panhandles and Kansas by mid to late afternoon along with strong heating along the dryline helped convection overcome the strong cap and develop further south along the dryline. By 7 to 8 pm, deep layer shear had reached 40 to 50 knots along a corridor from northeast Colorado to west central Kansas. Low level storm relative helicity also ramped up with the strengthening low level jet, reaching 200 m2/sec2. The combination of adequate deep layer shear and storm relative helicity combined with extreme instability led to supercells capable of producing tornadoes.
500 MB Shortwave Trough
My initial target was the vicinity of Ashland in far south Kansas. After noting where development was occurring along the dryline, I moved up to southwest of Greensburg and waited for convection along this section of the dryline to take off. I followed a cell that finally started to strengthen southeast of Spearville. And it eventually produced two tornadoes near Rozell and Sanford.
Video documentary of the chase.
Overnight spot south of McCook Nebraska (1300Z)
After car camping for the night, south of McCook Nebraska, I made my way south through Kansas, toward my initial target near the Oklahoma border. Along the way, I took advantage of a few photo opportunities. As I drove down one farm road, looking for a secluded spot to brush my teeth, wash my face and do a Clark Kent clothing swap—because I’m Super that way—and I ran across this blaze of yellow flowers beneath a series of wind turbines. It’s hard to capture how striking that was in a photograph, but here you go:
Turbines and flowers near Cimmaron, Kansas (1700Z)
Skies were clearing the further south I went, and really priming the atmosphere for storms later in the afternoon. As I cruised along the dryline from Ashland towards Greensburg, towers started going up. And then dying...leaving behind a bunch of sad orphan anvils that were drifting away in disappointment.
The past couple days, I had been working on being conscious of foreground elements to complement the sky in any photographs. It’s so easy to see this awesome sky and shoot with a bland, flat foreground that you don’t notice how boring it is until later when you’re processing images. So: mailboxes, wind turbines, farmsteads, any given stand of trees...I took them where I could get them. (Doesn’t mean my heat-of-the-moment tornado & funnel photos always benefited from decent composition...see down the page.)
Convection developing along the dryline (2045Z)
Mailboxes and dryline convection (2052Z)
Little House on the Dryline (2057Z)
Finally a cell managed to outwit the cap near Spearville and the chase was on.
Developing supercell near Spearville, Kansas (2205Z)
As I made my way east of Kinsley, the cell started to get rooted into the boundary layer. And now we finally had a nice looking supercell with structure that really started to beef up. It had a bit of the mothership flavor to it. The way I see it, this is a Star Trek (The Next Generation) model dropping down out of the clouds. And because after the J. J. Abrams’ reboot, Federation Starships goof around in the atmosphere these days like it weren’t nothin’ but a thing.
Panoramas of the supercell near Offerle, Kansas (2310-2318Z)
I was working the dirt roads as much as possible, which turned out pretty nice as long as I was paralleling the storms. (I didn’t get too comfy with those roads though when things were more inbound.) As I was driving north on 50th Avenue, about 4 miles west of Kinsley, I was surprised to see a little shear funnel up in the vault. It was very persistent and lasted several minutes.
Shear funnel in the vault (2326Z)
As I jogged along, north and east, trying to stay a bit ahead of the storm, I drove past what looked like the Storm Rider crew with their contingent.
Storm Riders crew (2342Z)
RFD was making various attempts at nudging into the base when another cell popped up and started encroaching from the south. I wasn’t sure if it was going to wreck the leading cell or which base to focus on. So I split the difference and got a bit behind the lead cell I was originally pacing.
Cell merger under way (2345Z)
The lead cell ended up eating the trailing cell, and then it really took off. The RFD started making a major push and digging a deep pocket into the rain free base. Rotation started ramping up behind the clear slot and it was looking pretty imminent.
Rotating wall cloud south of Rozel, Kansas (0021Z)
About 5 miles southwest of Rozel, it started winding up a funnel that gradually made its way to the ground and grew into a sturdy, long-lived tornado spinning away behind a remarkably clear RFD slot.
Developing condensation funnel (0025Z)
Rozel tornado fully condenses (0029Z)
Rozel tornado (0032-0033Z)
After photographing and filming it for several minutes, it started to dissipate. So, I moved up to keep pace, and noticed a new funnel condensing and then roping back out. This was actually still the original circulation, which was apparently still on the ground, and more of a last, condensational hurrah.
Rozel tornado ropes out (0050Z)
I made my way further east on L Road, another hefty funnel appeared to my northeast, near Sanford. Light was starting to fade and it was backed by its forward flank. So contrast was low, and camera noise was high. I sampled some frames from the video where lightning helped silhouette the tornado. It was interesting to watch the axis of the tornado move counterclockwise around the larger meso circulation. So it was drifting westward for a while before running its cycloid pattern back eastward.
Sanford tornado (0102-0104Z)
Sanford tornado panorama (0107Z)
It eventually started to rope out and bend back way to the west, lit by purple, turquoise and orange twilight colors. There’s so much going on—I wish I’d have popped the camera on a tripod and gotten a decent low-ISO exposure. As it is, still lots of high-ISO noise so I could go hand-held.
Weakening tornadic funnel drifts west of Sanford, Kansas (0110Z)
Just when I thought it was done, I called my wife to see how things were going and talk about everything I had just seen. While talking on the phone, this floating earthworm of a funnel suddenly popped into view, off to the northwest. Just this cool little disembodied funnel twisting around, way west of its parent storm. Circulation was still on the ground as it drifted westward before finally winking out.
Sanford tornado ropeout
Sunset cloudscape over Sanford, Kansas
Unfortunately, a home and a couple farm buildings were damaged by the tornadoes; thankfully however, there were no injuries. It was an amazing spectacle. Slow storm speeds. Clear RFD. Incredible structure and an assortment of tornado morphologies. If only the next two days had worked out that way...
A forecast shortwave, 1000+ J/kg of CAPE, and directional shear supportive of supercells along a northwest-southeast boundary brought us to central Texas on Tuesday. We got a late start heading out of Elk City, but arrived near Lometa just in time to watch the first convection go up to the west of us.
Convection fires west of Lometa, Texas
The lead cell was gaining strength, but still linear in appearance, and we positioned ourselves along US 183 thinking that it would cross the highway just to our west. The leading edge of the storm was hitting the boundary and getting demolished--pretty strikingly actually. I figured it was dying out, and we'd wait for another cell to try it's hand. I gradually realized that the lead cell wasn't shriveling up and dying, it was just dropping its wasted, linear, northern edge and mashing up its inflow on the boundary, taking root and gaining strength.
Trees and precipitation were obscuring the base. So we quickly re-positioned further southeast and noted a nice, bell-shaped base had formed with good separation from the forward flank.
Supercell gains strength southwest of Lometa, Texas
I was also realizing that the road network was going to make positioning a struggle. We made our way to Rt. 580 and headed west to get closer, when the base started looking pretty gnarly. This was my first time intercepting a RFB along the fringe of the forward flank so I was having trouble picking apart the silhouetted structures through the precipitation. Just as I was making out the inflow tail, RFD and tattered wall cloud, a multi-vortex funnel took shape like cheese pulling off the tip of a slice of pizza.
Tattered, complex funnel takes shape
The upper rope section was obvious, but it was attached to a heavier lower segment that seemed to be laminar in profile, so that might have been a chunky segment of the funnel. Hard to say for sure, unless someone closer has better shots with more dimension than mine.
Video of funnel (Frustrated that I forgot to set the video camera focus to infinity)
We snagged a few shots and some video before it dissipated. As we drove back to the east, a new meso was spinning up to our south. After this point, the cycling and meso hand-offs were pretty steady and extremely impressive to watch in action.
RFD gust front and shelf form under new meso south of Lometa, Texas
Keeping the rental car out of the hail on the sparse diagonal road network meant that we couldn't get back ahead of the hopscotching cycle-fest. We almost raced ahead of the third new bell-shaped base, but had to turn back when the marbles started hitting. But not before getting an awesome glimpse from the vault as the inflow and condensation raced in along the leading edge of the base.
Reflectivity ofthe cell as it went from linear and appearing to die on the boundary (left) to nice supercell spitting out a funnel (center) to a cycling supercell that headed me off from getting back ahead of it (right).
It was a new positioning perspective and pretty exciting to be in that location, but also a bit frustrating with a car that I can't afford to get pinged. This was also my first experience watching a storm get forced into intense cycling by a boundary. I'm hoping a few others got some good shots and from better locations than I had!
New rain free base forms near the horizon, south of Lometa, Texas
A shortwave crossing the Texas panhandle Sunday afternoon helped light up a line of elevated convection. We headed out from Elk City to hang out under the gust front and get some hopefully nice twilight photos. The line was severe-warned for a while with strong outflow gusts producing several reports in the western Panhandle. I wasn't expecting much more than a few photo opportunities.
Driving west on I-40 toward the advancing line
After spending some time in the cool outflow, I noticed a rain-free base form east of us on the leading edge of the line. I figured it would look nice as the sun got further down and lit it up, so we headed east on I-40 to get ahead of it.
About the time we were getting near the outflow interface, we were surprised to see an amputated, chaotically spinning, gray rope of condensation materialize over the highway in front of us. It winked in and out, and then got a bit more persistent as it drifted from south to north. I didn't have perspective on the cloud base overhead to see if this might have been a fractured piece of a landspout, or if it was a gustnado. I'm interested on any thoughts about whether gustnadoes produce condensation funnels.
Animation of condensation funnel crossing I-40 (facing east)
I wasn't ready with either camera, so this 5 animation is a pretty crummy attempt to show the feature drifting across the highway. (What this doesn't show is the churning action going on--pretty much like a remnant section of a rope-out.)
Apart from that, the dwindling convection led to some nice sunset views.
Today looked like it might be an exciting weather day in Arizona with a cutoff low moving inland from the California coast. Instability was modest, but bulk shear and helicity were high enough to open up the possibility of organized storms and possibly brief supercell structures. I headed out toward Ash Fork on I-40 and gradually made my way back toward Flagstaff as the lines of convection developed eastward. West I-40 laughed at me and didn't pan out for organized storms. (There were a few rotating cells that developed between Cordes Junction and Verde Valley, and out east between Payson and Showlow later in the evening.) Still, all the shear did some nice sculpting on the cloudscapes.
Near Parks, I was greeted by the most intense rainbow I think I've ever seen. I remember thinking to myself that it looked as brilliant as a fist full of light sabers. Just smashing color straight into the forest. No surprise--the photos don't do it justice. But it was a great view to cap off what was otherwise a bust for severe storms.
A small cell struggles to survive just east of Ash Fork, AZ
A tendril of scud creates a false funnel east of Ash Fork, AZ
Disorganized convection races northward just west of Williams, AZ
A brilliant rainbow crashes into the forest at Parks, AZ
We had some nice, strong convection develop over Flagstaff today. Instability was approaching 1000 j/kg and maybe a measly 15 kt of shear at best. Still, as I was heading back into the office after grabbing some lunch a little before noon, I noticed one of the developing cells was sporting a pretty sturdy lowering. I dropped lunch off at my desk and checked FGZ radar. The cell actually appeared to have a weak couplet associated with it. So I grabbed my camera and went out to get some photos.
For a pop-up monsoon storm, it was actually a real beauty. The lowering I saw earlier was still in place, and based on its position in the rain free base and relative to the precipitation core, I'd hazard to call it a wall cloud. Further up along the back of the rain free base, an inflow tail was pressed up against the core.
Monsoon thunderstorm structure southwest of Flagstaff - July 24, 2012 • 12:00 PM
As it moved eastward, it started to gust out and the inflow lowering became shelfy--and probably looked pretty menacing to anyone closer to the base.
Storm gusts out and produces a low hanging shelf - July 24, 2012 • 12:03 PM
The beautiful, isolated Kansas LP cell a couple days earlier had me excited to witness more explosive development on March 16th. MLCAPE values from 2000-2500 j/kg were forecast along the dryline in western Texas with the cap opening up by mid afternoon. With a mid-level impulse yielding up to 50 kts of bulk shear, mid-level lapse rates approaching 8.5 c/km, and directional shear supportive of rotating updrafts, it looked like severe storms were on tap with large hail, and a slight tornado risk as the LLJ strengthened by early evening.
HRRR suggested two areas for convection to break out--near Lubbock and south of Midland. The reflectivity forecast hinted at the southern target being choked off soon after forming, so with a bit of relief at the shorter drive, I targeted the dryline in the vicinity of Lubbock.
As we neared Post, TX, storms were firing along the dryline, and a strong cell south of Midland had gotten the attention of the SPC as severe watch areas went up from southwest Texas to western Oklahoma. Storms near Lubbock were looking good to me, and we targeted a cell that was essentially moving over Lubbock--it soon picked up a severe warning. As we paced the storm and watched it develop while keeping the rental car out of the hail, the storm started to develop inflow bands and what looked like a bobbed beaver tail.
Panorama of severe warned storm near Lubbock, Texas
Rain-free base struggles to get organized while Giselle looks on
Before long though, a flurry of developing storms west and southwest of our storm began interfering with it and with each other until the whole mess essentially disintegrated. The remains of dissolving storms still present great photo opportunities, and we made a few stops on the way back to Elk City to take in the pleasant views.
Another storm with a sturdy inflow tail chokes off our original cell's inflow
Dissipating storms paint the sky for our drive back to Elk City
This day didn't promise to be much of a storm producer. Southwesterly flow aloft was weak--30-35 kts--over a solid cap. However, with instability from 1000-2000 j/kg, 35 kts of bulk shear, and low/mid level SRH around 100 m2/s2, the possibility of a photogenic storm going up had me ready to head out.
By midday, the HRRR model was forecasting convection breaking through the cap along the dryline in the Oklahoma panhandle. Satellite was showing a patchy cumulus field developing along the dryline in the panhandles. So Giselle and I headed out from Elk City to see if something would break through.
As we headed north on 283, we were introduced to the horrible Wireless data coverage of northwest Oklahoma. With no satellite updates to tell us how things were going along the dryline, we kept moving and hoping cloud tops would start to show above the haze. I'm used to the clear, dry air of Arizona where storm bases are visible from 50 or more miles away. So it's frustrating at first to see how quickly visibility drops off on the plains--of course, it's that hazy moisture that makes the storm environment so explosive here.
By the time we approached Shattuck, Oklahoma, we were seeing hints of the dryline cumulus to the west. Some of the cloud heads popping above the haze layer looked like they might be developing cu towers, but it was impossible to tell without seeing whether there was a rising tower beneath the bubbling fringe. After some more driving with that frustrating feeling that the cap might hold everything down, we finally saw some convincing development that egged us onward.
Growing cumulus tower in the north Texas panhandle
While the initial tower collapsed, another congested batch further north on the Kansas-Oklahoma border was holding together.
Congested cumulus near the Kansas-Oklahoma border
We headed for that developing storm, and by the time we reached Englewood, Kansas, it had developed an anvil and was putting on a beautiful display northwest of town.
Developing cell northwest of Englewood, Kansas
As expected, the cell remained elevated for the two hours that we followed it, but the updraft displayed broad rotation and barber pole structure with some limited lightning. Colored by the setting sun, this isolated, mini-LP cell was a beautiful sight as it glided away over the lonely Kansas landscape.
Mini LP Supercell drifts from Englewood to Ashland, Kansas
While visiting family in Elk City, I chased some storms on March 14, 16 and 18, and wound up seeing three tornadoes on the 18th. (I'll post details of the other two chases later).
I made the Sunday chase after a convective shambles in the TX panhandle on March 16. This turned out to be an incredible follow-up. Deciding between better moisture south near the Red River vs. better H5 winds north by the OK panhandle was my biggest challenge as I made my way toward Shamrock, TX on I-40. Based on reliable results with NAM and HRRR forecast models on March 14 and 16, I was relying on them more heavily.
By the time I got to Shamrock, HRRR was forecasting some convection up by the OK panhandle and southwest KS, but it was showing this to be short-lived. The more robust, sustained development was forecast along the dryline west and southwest of Childress and moving into southwest OK. When I got to Shamrock, the cumulus field was congesting along the dryline in agreement with that area proving to be a successful initiation point, so I fueled up, cleaned the windshield and headed south.
As I approached the Red River, towers were going up, and as I moved into Childress, a really nice updraft and anvil were overshadowing the town.
Developing Cell Panorama
Following the storm back over the Red River meant either racing the core along Hwy 62 and glomming with an inbound stream of chasers, or taking some side roads over to Rt. 680 just NE of the OK/TX border. I chose 680, and after sledding along several miles of farm road whose last maintenance heralds from before the dust bowl days, I made it to an I-Dare-You type bridge crossing with the storm moving over the OK border just ahead.
Bridge Crossing at the Red River
After cringing at the forbidding screeching noises as I rolled across the bridge, I parked about a mile further north and shot some time lapse video and panorama shots. The lead cell was being hugged by a trailing cell with an incredibly solid hail core. I wondered if this would be like the mess on Friday near Lubbock with each batch of convection being demolished by whatever formed behind or in its inflow. For a while, both cells sported great structure and inflow features, and I couldn't decide what to photograph.
Wall Cloud on Lead Cell
Structure on Trailing Cell
Solid FFD Core on Trailing Cell
Panorama of Both Cells
As I followed at a hail-safe, happy-rental-car distance, the lead cell became dominant and from there, the RFD did all sorts of wonderful things to the updraft base and enclosed wall cloud. From that distance, I was having a hard time resolving details behind the nearly constant precipitation curtain, but rotation had become sustained and it was one great photo op after another with some very tantalizing wall cloud structures emerging periodically through the hazy mists.
RFD Shelf and Wall Cloud Behind Precipitation Curtain
RFD with Rotating Wall Cloud Structure in Background
I travelled the smaller county roads as much as possible, which lowered the convergence factor with chaser hordes. I still encountered smaller groups at key intersections and vantage points. This small group was enjoying a perfect RFD donut hole backed by a shaggy wall cloud and tail.
Chaser Audience, RFD Donut Hole and Wall Cloud/Tail Cloud
About the time the tornado warning went up for the storm, I was back on a main road headed north, trying to get in better position when I was passed by law enforcement blazing north with lights flashing. I figured they were getting ready to road block my route, so I started to detour east to find another dicey county road, when a quick check out the side window showed a funnel snaking down (7:04 PM). I squeezed off some still shots, but wasn't in time with the video camera. The slender funnel I saw may have been a small satellite to something bigger happening behind the precipitation curtain--there appears to something ominous going on along the right edge of that rain curtain in the photo.
Satellite Tornado and Rain Wrapped Circulation (7:04 PM)
As I stepped my way north and east, I was awestruck by the incredible structure on this storm. While I wish I could have been closer to view the detail in and around the wall cloud and the tornadoes it spawned, I can't complain in the slightest about the views I got of the entire storm from a few miles away.
More Awesome Structure
As I navigated northward near Granite, OK, I found a high vantage that gave me a view of a second tornado spinning up near Willow, OK (7:30 PM).
Willow Tornado (7:30 PM)
My third for the day spun up a few minutes later at 7:38 PM. This one lasted a couple minutes before the slender rope dissipated.
Third Tornado (7:38 PM)
I followed the storm a bit more as it approached Clinton, but lightning was too sporadic to make out any more features, so I made my way into Elk City for a big steak and fries at Western Sizzlin. Chasing solo, trying to run two cameras and experiencing this unbelievable storm gave me a case of full-blown sensory overload--I'm still having vivid flashbacks. It was a great chase and I can't wait for my next opportunity in the northern plains in June.
Video of Supercell and Tornadoes in Southwest Oklahoma
Links to reports and photos from others chasing the storm:
It's been over 8 months since my May 2011 chase trip, and I finally got around to finishing my reports and photos for the 3,750 mile round trip. This was a tough one for me from a forecast and positioning standpoint. No tornadoes, and only one halfway decent supercell intercept. Everything else was incidental, fringe, weak storm interactions. As frustrating as that was, I have to remind myself of the beautiful things I did witness along the way, and a lot of important lessons learned. I'm taking a cue from Skip Talbot and posting a "Lessons Learned" section at the end of each day's report. I'm looking forward to another chase trip in 2012 and hope I can manage to improve my forecasting and positioning and see some more amazing weather on the plains.
I got on the road Saturday afternoon, left Flagstaff, drove most of the night, and made it to eastern Nebraska by Sunday late afternoon.
I'll try to do a more detailed summary later with more photos. (I'm extremely worn out.)
After checking models and spc discussion each time I stopped to fuel up, I decided I would head to the warm front. Unfortunately, eastern Nebraska turned out to be a wasteland of uncooperative cloud streets. The cap wasn't budging there at all. I figured I was going to have a complete bust on my first day out. But then inhibition started to part in South Dakota, a few storms started to blossom. Most were too far to consider, but a small, fresh one was within reach, so I raced north. As I got closer, I realized the cap had clamped down and nothing was left but an orphan anvil.
I kept going north, just in case, and was suprised by a view of a new tower going up on the other side of the Missouri river, half-lit by the coppery light of the setting sun.
Satellite view showing my target storm as a bright blip in the far south-southeast corner of South Dakota. (Note the only tornado-producing cell in the south-central part of the state--too far out of reach.)
The new tower was farther north than I thought, and was moving north at about 25 knots. I decided not to keep chasing it in the dark, so I broke off, satisfied to see it sputter with lightning as it drifted away. At least I got a distant storm and some lightning for day 1.
I fueled up again and did some supply shopping. Afterward, as I drove to a section of gravel roads south of Mitchell, SD to park for the night, I was overwhelmed by nonstop lightning behind me. I pulled over to figure out where it was coming from. Sprawled out to my west was a huge, sculpted shelf cloud, gaping with rain, wind and lightning--and it was visibly expanding in my direction. I didn't want to get the car golf-balled, so I raced down the dirt roads, going after a good north-south paved road. Along the way, I made some brief stops to photograph this majestic thing.
At one stop alongside a small lake, the sound of katydids, frogs and other nocturnal creatures blended in with the non-stop thunder of the approaching storm. It was wonderful. As I continued south and east, I realized the entire gust front was going to chase me into Missouri if I let it. So I hunkered down in a farm field access and embraced the drenching rain and unceasing lightning. It was an amazing way to end the day.
Radar showing my position with the approaching gust front.
Argh. Just play closer to the triple point--don't get creative with points further out along the warm front.
The cap likes to be stronger further south.
A shorter focal length lens would be nice for capturing massive gust fronts and shelf clouds.
After night fall, shut off the car, get outside and enjoy the sights and sounds of lightning, thunder, and wildlife.
Day 1 - MAY 8, 2011 - Night Storms in South Dakota
My second chase day started with the sun's warm rays piercing broken clouds above a nearby farm. I slept a little later than I wanted, but had plenty of time jump on I-90 and head west toward Murdo where I waited for signs of initiation along points further west. This setup was difficult to forecast. The best moisture/instability/shear was wrapping north and northeast of the surface low, north of the warm front. I had a hard time picking the best spot for storm initiation and was really hoping visual cues and satellite would point me toward development with enough time to adjust and intercept.
I wasn't the only one in Murdo watching the sky and refreshing satellite views and SPC observations. The Dominator crew and about a hundred other chasers were parked in various hotel and gas station parking lots hanging out, scarfing convenience store food, throwing frisbees, scrubbing windshields, jaywalking, and checking out each other's chase vehicles. I was concerned that the best, first storm would collect an instant caravan and I wanted to get out before that happened. Turns out this wouldn't be the problem. As I headed further west, the sky grew heavy with fast moving stratocumulus. It was frustrating to realize that I was going to have a terrible time visually spotting points of storm initiation.
Eventually, northbound radar returns started to pop up along I-90, east of Rapid City as well as a nice, tornado-warned cell far to the south near Crawford Nebraska. I started to drive south, thinking I could intercept the Nebraska storm somewhere near Wounded Knee. But then I second guessed myself and figured that I'd probably make this long drive through the badlands with difficult terrain and bad road options and the storm would be past its prime by the time I intercepted. So I headed back north of I-90 and traded one set of bad road options for another. I was positioned right at the southern end of several developing radar returns and finally caught a glimpse of one of the new towers to my east. To my north: wet gravel roads. I thought, ok, let's try these roads out and see if I can get ahead of the development and intercept around from the northwest.
Developing radar returns just before I began my long drive north to try and intercept the pick of the litter. (My location is shown by the blue target.)
Rough Kelvin-Helmholtz clouds forming in a nicely sheared environment.
A sunlit anvil blossoms to the east of my position.
My Honda Civic and the wet South Dakota dirt roads played nicely with each other. However, what with the Belle Fourche River Valley, majorly broken road grid, and wet dirt-gravel surface, I was no match for the storm motions. It didn't take long to realize that I wasn't going to intercept any of the storms I thought I would. So I plotted a path to hit Route 34, then Route 73 and work my way back toward I-90 and see if any new development would head my way.
Stunning overlook of the Belle Fourche River Valley.
It took forever to get back to a paved road, and night had fallen by the time I hit asphalt again. As I made my way back east, then south, severe and tornado-warned storms lit up the sky to the north and east. I was frustrated that I had failed so miserably at positioning myself, but the non-stop lightning show was a beautiful parting gift as I drifted along the lonely South Dakota highways.
Severe and tornado warned cells avoid my chosen route.
I parked for a few hours of sleep near Kadoka, SD, where the drizzling remains of the tornado-producing Crawford storm finally passed overhead and drifted off into the flickering night.
If dirt roads are the only way to intercept a target already to my north, and there is a good possibility of a southern target, opt for the southern target.
Committing to a long, unpaved route in an area that is not fully gridded is probably a one-shot deal.
The Honda is compatible with at least some of the wet, unpaved roads in southwest South Dakota--although copiously wet would probably be a different story.
Setups where the target area is north of the surface low are a serious weakness for me to anticipate development.