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Tornado # 1 near Rockville, NE approx 6:50 PM
(click to enlarge)
[courtesy Jeff Gammons]

Tornado #2 NE of Rockville, NE
[courtesy Chris Collura &
http://sky-chaser.com]
Jason Foster and I, along with the Weathervine gang and Scott Eubanks
intercepted two tornadoes on a supercell that moved from Sherman to
Howard County in southern Nebraska. We observed the first tornado near
Rockville in southeastern Sherman County about 6:50 PM CST and the
second near Boelus in southwestern Howard County about six minutes
later. We were traveling southeast and then east on Nebraska State Road
58.
Our original target was Broken Bow, a location between the moisture and
thermal axis and near the differential heating boundary stretching from
southwest to northeast as cited by SPC in their MCD for the area. We
believed the shortwave would likely help initiate storms along the
boundary which would then move eastward into the low level jet and
intensify. This is more or less what happened.
We learned of the storm in Gosper County south of Lexington and I-80,
and raced south on 183 to position ourselves west of the updraft region.
However, near the intersection of 30 and 183, the storm had moved near
enough that we observed the first of a series of lowerings and rotating
wall clouds that tracked through Buffalo County. To mirror the storm's
northeastward movement we navigated through some slippery Bob's roads as
the storm cycled several times, but without successful tornadogenesis.
As the storm reached the Sweetwater to Ravenna area, it intensified
dramatically, morphing into a tall wedding cake appearance with strong
inflow from the southeast. On 68 north of Ravenna, a large but elevated rotating wall
cloud hung over the road directly in front of us. We decided to scoot
underneath it as it looked somewhat disorganized and offered us a chance
to regain a favorable viewing position. This was a fortuitous move
since, about fifteen minutes later, the first cone shaped tornado
touched down about four miles to our north. It was down about one
minute, and, from Boelus looking north, we observed the second tornado
five to seven minutes later, this time at a longer distance, perhaps six
miles. Our second tornado also presented a conical appearance and lifted
quickly.
Several intersections were jammed with chasers and tour buses, which we
evaded rapidly. However, most drivers behaved sensibly and co-operated.
Again I think the publicity of sites like
Stormtrack and lists like wx-chase
have disseminated the ideas of pulling off the road and using hazard
lights and watching carefully before re-entering the roadway pretty
well.
The images above belong to Jeff Gammons and Chris
Collura and I appreciate their permission to use them.. I
should have video of both tornadoes and will post
grabs as soon as possible to replace their images.
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