Chase Trip Day 10 (June 25) Summary: Kimball-Sidney, Nebraska high-based supercell
* *  Mike Umscheid PHOTOGRAPHY & STORM CHASE BLOG   * *

Fri, 1 Jul 2011 21:20:35 -0500
Chase Trip Day 10 (June 25) Summary: Kimball-Sidney, Nebraska high-based supercell
Summary & Images (part 1)
Jay Antle and I intercepted an awesome supercell on Day 10 of this
storm chase trip. Our target was east of the Laramie Mountains as
fairly high CAPE was lurking over the eastern Nebraska Panhandle with
upslope winds increasing by late afternoon and early evening. After
spending some time at Scottsbluff National Monument early in the
afternoon, we set sights on mid afternoon storm development northeast
of Cheyenne. The first storms developed over northern Laramie county
and we drove southwest from LaGrange along Hwy 85 to observe these
first storms. The storms sputtered along as they moved east toward
the Harrisburg area. At Harrisburg, we had to make a decision what to
do next. There were storms trying to get organized up in the Lusk, WY
area well to the north, but what caught our eye more were new towers
forming to our southwest along the outflow boundary left behind from
the first storms that we were following. As a result, we went south
to Kimball. This ended up being a very good call as the group of
towers to our west-northwest organized into an awesome supercell. We
navigated farm roads northeast of Kimball with the storm updraft to
our west-northwest. We tried to remain in the sweet spot
east-southeast of the updraft about 8 to 10 miles to get the good
structure shots of the storm. The supercell cycled through numerous
mesocyclones with a number of wall clouds and occlusions observed. We
also saw a number of dusty spin-ups, mostly caused by RFD hitting the
surface, but one or two of them were fairly intense and cold have been
tornadic. Several persistent mid-level funnel clouds were also seen,
particularly as we were driving south back to Highway 30 northwest of
Sidney. But it was the structure of the storm itself that stole the
spotlight with amazing hues of aquamarine. The bell-shaped nature of
the updraft and the vault just downstream of the updraft itself were
amazing. As the sun was getting lower in the sky, we dropped south
toward the Cheyenne Ridge south of Sidney. More laminar banding of
the updraft was evident, taking on the classic "mothership" appearance
to the northwest. Anvil lightning was frequent overhead with the
persistent, harmonic sound of grumbling going on way up in the upper
troposphere. We continued to stay ahead of the storm south and east,
through the very large Peetz wind farm, and eventually down to Hwy 138
with darkness increasing after sunset. The supercell eventually faded
away late in the evening as it approached the Julesburg, CO and Big
Springs, NE area, but not before putting on a nice display of anvil
zits (short, intense spurts of lightning within the anvil). This
ended up being, for me, the most photogenic supercell of the 2011
season to date.

Below is a sequence of images of the early stages of the supercell
from north of Kimball to northwest of Sidney while we were on the farm
road grid north of Hwy 30:




(click on thumbnails for pop-up of larger images)