Squall Line Way Up North
St. John ND
10 Jun 12
SHORT: Blew off chasing in trees in MN or driving from ND-KS in one shot, intending to hang out in ND ’til the pattern returned favorable parameters to Dakotas. While en route to Int’l Peace Garden, intercepted photogenic, low-topped squall line and attendant arcus cloud over very green fields near St. John ND.
LONG:
The cold front from the previous day’s action was slated to shift into more forested land of central and northern Minnesota, within which we didn’t wish to chase. Strong to severe storms also were possible farther south, along and ahead of the front, in mode viewing-friendly areas of Iowa, NW Missouri and Kansas, but under weaker deep-layer shear.
Laundry beckoned, and so did a few days of R&R in the heretofore superficially explored state of North Dakota before the next substantial atmospheric perturbation brought severe potential to the northern Great Plains. After finishing the wash and brunch in Grafton, we charted a net WNW course on the township-range zigzag of eastern and northern North Dakota, aiming to grab a couple bucketfuls of rich, black soil from the old Lake Agassiz bed for my vegetable garden back home (check), visit Icelandic State Park (uncheck), see the Pembina Gorge (check), visit the International Peace Garden (check), and spend a night or two in the so-called Turtle Mountains (check).
Somewhat retracing the route we took the evening before, we encountered a fantastic layer of asperatus (a.k.a. “warm-advection clouds”) between Grafton and Cavalier. That was followed immediately by a rather featureless, messy band of elevated thunderstorms that timed badly for visiting the state park. Instead, we headed up to Walhalla and toured the misty, scuddy and decidedly green Pembina River Gorge by car.
Ascending that small canyon, which drains an escarpment separating the Plains from the Red River of the North valley, leads the driver to the marvelously open, flat and attractive countryside characteristic of most of the state NE of the Missouri River. Folks here seem to inherit their ancestors’ fastidious tidiness ethic. In towns, this means well-kept houses, gardens and lawns. In rural areas, we saw a distinct absence of junk cars, rusty appliances, neglected fencing, or haphazard accumulations of dilapidated mechanical rubbish strewn across weedy lawns of occupied homes–in other words, a refreshign difference from thousands of points of blight that are prevalent in the southern Plains countryside. Landscapes here were familiar from the day before, but the setting was different–scuddy, light rain on the back side of the elevated storm band, with broken blue sky to the west, and the cool, moist freshness of wet earth behind a summertime cold front. This trip already was a splendid pleasure, and soon would become more so.
Proceeding westward across the borderlands, we finally broke into sunshine west of Langdon–but not for long! Onboard radar showed a thin, curving arc of cold-core thunderstorms developing to the W, over the turtle Mountains. A low-topped squall line was forming–something that experience told me could be quite photogenic in such otherwise clean air and sky. It was.
Approaching the squall line from the SE (as it moved quickly eastward), we marveled at how shallow and low-topped the convection was–typical for a cold-core low in a low-CAPE, relatively low-tropopause setting–but still rather uncommon in my southern-latitude experiences. In fact, just a few miles ahead of the arcus cloud, sunshine still illuminated the moist and richly verdant fields adjoining the east side of the Turtle Mountains. This clearly was not any of the 60,000-foot-deep walls of deep-convective severity I’m accustomed to observing in a North Texas April.
Our viewpoint was just SE of St. John, only four miles S of Canada, and in a fine position to view the oncoming shelf cloud. We were able to frame the sweeping arcus above the gentle curve of a rural dirt road that nicely split the greenery. After that, we cruised into St. John and let the storms move over us, enduring a decent barrage of small hail and subsevere gusts.
Heading into the hills, we quickly left behind the weakening squall line and visited the International Peace Garden (highly recommended, no passport needed!). The storms had run off the visitors, so we nearly had the place all to ourselves in rain-cooled air with sunny, late-afternoon light. Afterward, and with no one behind us in the customs line, I had a long, very friendly conversation with a customs officer and USAF vet at the re-entry station (the park is directly astride the border, its driveway halfway between U.S. and Canadian customs). He gave us a good recommendation for lodging options beside beautiful Lake Metigoshe–at which we reserved two nights for R&R before the next chase-worthy, northern-Plains shortwave.
A Championship Day (Even if Not for Storms)
High-based Storms in the Nebraska Panhandle
12 June 11
SHORT: From LBL, headed to the BFF area for high-based upslope action. Observed a few such storms from between BFF-AIA.
LONG:
The day wasn’t too spectacular convectively, but we saw storms and had a great time nonetheless.
Morning dawned to the analytic display of foci that were somewhere between muddy, nebulous and vague on the spectrum of precision. The surface map showed that the isodrosothermal field had been mangled by overnight and morning convection over southern Kansas, east of where we spent the night. When all else fails, the terrain just isn’t going anywhere–at least not for the next 20-30 million years or so.
We therefore headed toward the reachable area of the NEb Panhandle/NE CO, figuring that 50s F dew points in that area sometimes do good things as long as deep-layer shear is at least marginal. It also put us in position for day-2. Plus, Elke and I love that area for many nonconvective reasons.
After visiting an abandoned shack in western KS, we found a nice hilltop vantage about 5 SW Angora NEb, listening to assorted birds and photographing wildflowers (e.g., copper mallow, western wallflower, and veiny dock), as we waited for convective eruptions.
Assorted towers and turrets soon bubbled up to the W and SW. One persistent pile to our W evolved into a short-lived, high-based storm with a wall cloud to our NW, viewed across the rippled orographic musculature of the Nebraska Panhandle’s ash-bed grasslands. The storm exhibited weak cyclonic shear in the midlevels based on radar velocity output, but just for a few scans.
Other, smaller, junkier cells fired along the foothills in SE WY and over the western reaches of the Wildcat Hills to our SW, amounting to little except as a scenic diversion for aviators. We saw several contrails weaving between storms, including this scene over Minatare. The storms died off with the setting sun.
We settled into a charming little mom-n-pop motel in BFF with funky walls made of green quartzite from Utah. This also was the memorable night my hometown Dallas Mavericks won the NBA championship too–making up for a disappointing evening 5 years before in GCK when I watched them lose it to the very same team.
A very fine day, indeed…