|2004 MAY 8: O'NEILL NEBRASKA SUPERCELL|
Eric Nguyen, Scott Currens, and I targeted O'Neill, Nebraska today,
hoping storms would fire along a lifting warm front as an upper level
disturbance moved across the state. A strong moisture axis lifted into
the northern and northeastern Nebraska area, and we noted a fair cumulus
field as we headed northwest into the upper rangeland of the state.
Eventually we outran the moist tongue and the cu and so we stopped short
of our target and waited around Norfolk.
Storms firing in central Iowa drew our attention as did the thickening cu field strung along interstate 80. However, we knew central Iowa suffered from weak upper level support and soon the storms near Des Moines grew multicellular. Surface winds in the area were veering to the southwest as well--we just didn't like the look of things over there. Plus, there was a fee to cross the bridge. Still we raced east and stopped at Decatur, just short of the Missouri River. We took another look at data from a convenience store across the street from a biker bar.
When the Norfolk storm fired closer to our original target, and in an area of more favorable low level shear, we turned around and retraced our path. We intercepted the southern cell of a split near the intersection of 32 and 15. Diving south on 15, I observed shear funnels and a narrow, barber poll updraft with rapid rotation about 6:30 PM. I also observed cascading condensation on what looked exactly like a gust front, but which rolled upward back toward the vault. At the same time, I observed strong elevated rotation. A tornado warning came a few minutes later.
I continued south to Schuyler as the storm became more elevated and the updraft base more linear. I met Nebraska chaser Chris Lenz and had a cool conversation on a dirt road as the storm gusted out. I used the break in the action to flank the developing cluster and work my way back north, believing that storms had moved off the boundary and lost their slim advantage in our marginal setup. Nearing North Bend on 30, another tornado warning appeared for the storm over Schuyler. Scott and Eric filmed a large RFD blast in a dusty field at this time and believe this helped prompt the warning. Sirens in Shuyler blew immediately afterwards.
I raced a train across the Platte River and, south of Morse Bluff, observed an elevated wall cloud. A new tornado warning for Butler County finished off the storm and it faded into the night with a spectacular orange and crimson sunset and continuous, pounding CG's. We returned to our new favorite motel here in south Omaha and are finally about to hit the sack.