Colorado Kick-start
Bennett and Limon/Genoa area supercells
11 Jun 10
SHORT: Outflow dominant supercell intercepted E of DIA airport, followed by cyclic complex of supercells from LIC to E of Genoa CO.
LONG:
The previous morning, I got off a night shift at 8 a.m., and Elke and I made a dash toward the NW to see how far we could get toward that day’s (and definitely this day’s ) best storm potential. Unfortunately, she got sick in NW KS and we had to stop in Colby for the afternoon, a couple of hours short of the tornadic Last Chance storm.
To be able to chase at all on the 11th was a blessing, given that Elke had to go to a local clinic to get diagnosed and treated for some terribly painful digestive problems. Not only did we chase, we saw some very interesting storms and met old friends. Elke was cleared to travel, though we had to make reasonably frequent stops for the rest of our vacation so she could stay hydrated and keep the innards moving as they’re supposed to.
I considered two potential target areas — one being a highly conditional potential near the warm front and E of the surface low in north-central/NW KS, where storms might never form, but if they did…look out. The other was the more dependable (for initiation and photogenic structure) but probably not as tornadic upslope region of eastern Colorado. This being our first full day out, and having been unable to get to the Last Chance storm the prior day, we aimed for the Colorado target area.
After meeting the Three Dudes and Two Dogs chase team at Burlington for some pre-storm banter, we headed W on I-70 to LIC, mooching wi-fi from a motel while parked across the road from a lot of V.O.R.T.EX.-2 vehicles. Eyeballs and data showed a nicely destabilizing air mass up and down the Front Range, almost no CINH, lift in the form of heating and upslope winds on the higher terrain, and rich moisture for the altitude, beneath robust deep-layer shear — in other words, a recipe for supercells lacking no ingredients, save the storms themselves.
It didn’t take long. A supercell blew up quickly in the Front Range mountains SW of Golden, where Elke used to live, and started churning NE across the Denver metro. Not wanting to chase in the city, we scooted to a high spot a few miles E of the airport to observe the cycling, already somewhat outflow-dominant storm. A new updraft that went up on the SE side of the storm sported a rotating wall cloud in short order, but that soon got undercut by outflow from the hail-spewing HP mothership. Shortly afterward, several V2 vehicles showed up, including occupants and friends Ken Dewey and Tim Marshall, who looks as if he is about to be struck be lightning in this photo with me. Fortunately he wasn’t, since we both would have been killed.
The storm’s motion began to accelerate as it surfed its own outflow, and we bailed S to I-70 to intercept a younger supercell rolling off the highest segment of the Palmer Divide toward LIC. Along the way, we saw several lowerings, looking S and SW through the core and through precip gaps to the mesocyclonic region, but no obvious tornadoes. We found a nice road a few miles SW of LIC and, for one of the few times so far this year, had the luxury of staying in one spot for awhile and letting the storm move to us.
Our first view from the inflow sector revealed a somewhat high-based, HP storm with a deep core surrounding the mesocyclone area. Sherman Frederickson (former NSSL colleague from the 80s), Howie Bluestein (one of my professors from back then) and several students were occupying a radar truck just up the hill behind us, and Howie was gracious enough to invite me up into the truck for a peek at their live scans of the mesocirculation — impressive, but endangered by heavy precip from two sources…
Things got complicated on the storm scale. A temporary new occlusion with small wall cloud formed ahead of the HP core, but that attempt got short-circuited by cold outflow from a large, heavy shower that formed in the storm’s immediate inflow region (ultimately moving over us and merging with its forward flank). In increasing rain, we decided to get E of LIC near Genoa, E of the messy storm processes unflding, and let things evolve again while moving E toward us.
An elongated supercell complex with embedded mesocyclones emerged from the chaos, while we parked and chatted with the eccentric old proprietor of the uniquely quaint Wonder Tower (“See 6 States”). As the convection reorganized, I shot photos looking over the tower and store and looking N from its back lawn at storm scenes, while Elke toured the antique shop and bought some old bottles.
While I was composing the former shot, I had a friendly yet disturbing encounter with a newbie chaser who had “learned the ropes” (very frayed and thin ropes, as it turned out) on a few years of chase tours. If you’re interested, read more about it in this Weather or Not entry.
Soon afterward, north of the shelf cloud, a violently rotating mesocyclone developed rapidly, in a notch region between core and gust front to its S. This compelled us to wander over to the next viewing spot W of the tower for a closer look. The circulation was spinning so fast, I thought it would plant one any minute. The rotating cloud mass, eerily front-lit from the E, its base atypically low for Colorado and black as night, entirely filled this wide-angle view. The circulation was only was a mile or so away and moving toward us. If a tornado were to form at thus juncture, it would have been be precariously close to I-70 — a most undesirable outcome. I rather would not see a tornado than for one to move down the Interstate, throwing vehicles every which way. Indeed, no tornado developed during this stage, though a quick spin-up did occur between Genoa and Arriba N of the road, as we evacuated rapidly eastward.
By the time we got past metropolitan Arriba, the Genoa circulation either weakened or merged with another to its N, sporting a well-defined mesocyclonic notch — and occasionally, ragged, slowly rotating lowerings beneath a wall cloud, but no obvious tornado. We briefly talked with Al Pietrycha and Pam Varney Murray near Arriba…good to see them again!
The whole complex lined out and weakened, so we headed to Burlington for the night. Visible to the distant ENE: a monstrous explosion of convection out of our reach, in KS, that produced a few tornadoes while remaining nearly stationary, right in my conditional forecast area. I tried some nighttime lightning observing and photography on the back edge of the Colorado line after it moved past us, encountered more inflow moisture and re-intensified, but it was mostly a bunch of in-cloud flashes, diffuse filaments and distant CGs. So it goes…without regrets, we were pleased with the day’s adventures and ready for another.
Panhandle Unchase
Channing/Groom TX, 25 May 10
SHORT: Observed supercell get munched by outflow-dominant multicell complex NW of Amarillo. Pretty sunset.
LONG:
This wasn’t specifically intended to be a chase day; but if we happened to see a decent storm along the way, that was acceptable! We had a truck bed full of cargo from Elke’s late mom that we were bringing home from DEN-OUN. Even though most of it was well-covered by plastic, getting in a bunch of rain and especially hail was not a palatable option. Therefore, even though the most dense concentration of convection promised to be along the Kansas segment of the dryline, where tornadic storms did occur, we opted to use the southern route through the Panhandles in hopes of more discrete activity.
We could see the first towers erupting along the dryline, early in the afternoon and to the distant E-ESE, while still on I-25 in southern Colorado. After turning ESE on US-87, a series of big towers grew into storms to our ENE and NE, including some of the Kansas activity that provided the joy of rich and abundant data to V.O.R.T.EX.-2 scientists. Near Des Moines (the New Mexico town, that is), we saw a classical, atom-bomb style of thunderhead eruption in the western Texas Panhandle, off to our SE (here photographed beyond one of the area’s numerous, inactive cinder cones). Given the favorable shear and discrete nature of this storm, its destiny as a supercell was assured, and our destiny was to intercept it — preferably avoiding most of the precip.
It took us a long time to get around to the E side of the slow-moving storm, even via the fairly direct CAO-DHT-Hartley route on US-87. As we approached DHT, radar imagery indicated that a left-split off of some storms N of Clovis was growing into a large, northward-moving multicell cluster — headed directly for our intensifying supercell! Just our stinkin’ luck! Tracking our course and that of the raging multicell cluster from hell, it was obvious the solitary supercell with so much potential would be snuffed out like a match in a fire hose, not long after we got in viewing position.
Our viewing position turned out to be virtually the same spot N of Channing from which Rich T and I first observed the tornadic Dumas-Stinnett supercell from 18 May. Unfortunately, this textured and colorful little storm was about to be absolutely destroyed by the onrushing wall of outflow and convection from its S. We had about 15 minutes of viewing as that happened, then headed to AMA.
There was too little daylight left to attempt to intercept Jeff Passner’s tornadic storm near Dimmit, so we stopped in AMA for dinner, drove E, photographed the Leaning Water Tower of Groom in some nicely reddening sunset light, then drove on home in the dark of night. So, in effect, we were able to observe the shortest-lived and most decidedly nontornadic supercell in between all the longer-lived, tornadic ones.
Birthday Supercells in Northwest Nebraska
near Harrison, NE, 21 May 10
SHORT: Intercepted 4 supercells, 2 after dark, near Harrison NEb, with 2 funnels from twilight storm S of Harrison.
LONG:
My two main forecast areas on this day were in eastern Colorado, for any storms that could form and move ENE off the Front Range or eastward-extending ridges (Palmer and Cheyenne), and of course the classical upslope play into the Laramie Mountains. Since I began the day in Russell, the CO target was much closer, and more probable to reach by convective eruption time. The idea was to pass through, and if it looked dead, continue onward into SE Wyoming or Nebraska.
Unfortunately I got stuck at a long construction delay between Burlington and Wray, where US-385 is down to one lane with a pilot car driving 15-25 mph for about that many total miles. After getting out of that horrendous mess, I thought my Wyoming/Nebraska hopes were ruined, so I photographed an abandoned farmstead for a bit S of AKO, while waiting for storms to fire in northeast Colorado. The air mass kept looking too stable and stratified, and I gave up once storms E of the Laramie Range began to sustain themselves.
Unfortunately, because of the long intervening distance needed to intercept the resulting supercell, I never made it to the Wyoming phase of its life cycle, when the structure was best. Instead I cruised N from Mitchell on NE-29 to get ahead of the storm, knowing it would be moving into gradually more stable air. A portion of the legitimately scientific V.O.R.T.EX.-2 fleet came up 29 right behind me, along with some pseudo-scientific vehicle with a bogus-looking “TORNADO AND HURRICANE RESEARCH” sticker prominently plastered thereupon. I felt like stopping to ask the “TORNADO AND HURRICANE RESEARCH” crew what papers they’ve published with their “RESEARCH”, but knew the answer, and more importantly, had better things to do — namely, observe the supercell.
Lightning activity above me, in the anvil, was increasing, so I got back in my vehicle. Not a minute after I did, I happened to spot a CG hit within less then 50 feet of that “RESEARCH” vehicle, and about half a mile downhill from me! It even looked like the lightning might have hit them. I started the truck and was throwing it into gear to rush to their aid, when they abruptly pulled out of their spot and zoomed southward past me. It was a very fortunate thing none of them got struck! One of these days, however, under less atmospheric duress, I intend to query such crews in the field and find out about the nature of their “RESEARCH” publications. Anyway…
This shot fairly well represents my view of the old Torrington storm as it scooted across the border into Nebraska. At times it did develop weakly rotating, scuddy wall clouds, but its encroachment upon more stable air yielded the expected result with time ( here shown as a higher, flatter wall cloud with precip-filled occlusion-downdraft slot, behind a sticknet). That storm moved N and NE of me, and I prepared to head to Harrison to look for lodging.
Meanwhile, I parked for a spell to listen to the cheerful choruses of western meadowlarks and breathe the refreshingly rain-cooled High Plains air behind the first storm. V2 left the area, and in the twilight, a new, small supercell formed along or just a shade N of the outflow from the other one, SW of Harrison and about 15 miles to my WNW.
Rather quickly, some cloud-base rotation and lowerings developed under a broad, elongated updraft area, followed in quick succession by a skinny, scuddy funnel (deeply enhanced crop-n-zoom) and then a lower, more robust-looking and separate funnel (enhanced crop-n-zoom). Both of those funnels were quite transient, and I could not detect any dust or debris at the level of the (wet) ground beneath. If either was a brief tornado, it was too weak and short-lived to count as such, so I probably still haven’t seen a tornado on my birthday. Still, I’m glad to have had the experience.
The twilight supercell moved too deeply into rain-cooled air left behind by the first, and weakened considerably. I got a room at the only motel in Harrison — the Sage Motel, a friendly if rather forlorn and cramped place — and called Elke and my kids. One highlight of the day was my daughter and her friends singing “Happy Birthday” to me as a quartet serenade!
Meanwhile, two new supercells popped up in Wyoming, SW of town, headed that way! After getting off the phone, I wandered a few miles W of town to watch the nocturnal supercell pair move quickly past, their structures faintly illuminated at times by in-cloud lightning. I attempted photography, but it was just too dark out there, the lightning too faint. The rear-flank precip core of the second storm hit Harrison, but without severe wind or hail.
I had to be in Denver the following night to meet Elke and prepare for her mom’s public memorial on Sunday the 22nd, so the potential (and realized!) major tornado day in northeastern SD was too far for me to chase. Instead, on the 22nd, I photographed morning fog in the Pine Ridge area N of town, then drove from Harrison to DEN, stopping for a pleasant hike and photography excursion Agate Fossil Beds National Monument along the way. Meanwhile the ultimate tornado-feast was about to begin for other chasers 250-300 miles to my NE.