June 17

Marshall and Roberts Counties - South Dakota

Big Stone, Swift, and Chippewa Counties - Minnesota
A sharp warm front was draped off  of a strong low
pressure system making it's way east near the SD/ND
border area.  Rich moisture and ample shear set the stage
for supercell thunderstorms to explode across far
northeastern South Dakota and track into western
Target for the day was the triangle from Sisseton, SD to Britton, SD to Hankinson, ND back to Sisseton, SD.  Was pretty
obvious we needed to be west so headed out to Britton to meet up and wait for initiation with
Eric Whitehill.  We didn't
have to wait long as a supercell exploded right over town and quickly went severe warned for hail.  The chase was on.
Eric headed back east on 10 to stay just ahead of the cell which was already taking on the tell-tale signs of being a high
precip monster as the dreaded donut appeared within minutes as Cailyn and hung back near the edge of the updraft area.  
View is looking east / northeast from just east of Britton.
Video frame off the GoPro Hero2 dash cam.  Cailyn explaining the finer points of the role RFD plays in tornadogenesis
on SD highway 27 northeast of Britton.  Actually she was taking note of the scud rising into the updraft base to the north.
Tornado warned now based on radar.
After getting  cut off by a hail shaft and wet RFD north of Lake City, SD we met back up with Eric and headed towards
Sisseton to get back in the inflow notch.  A little northwest of town still up on the ridge, I decided to take a close look at
the wallcloud.  No organized rotation and we once again got cut off by wet RFD.  Video frame off the dash cam.
This cell was quickly becoming a sloppy mess and there were new cells intiating to the southwest further into the warm
sector so headed south to get out of the rain.  After getting through Sisseton and heading down I29, I wish I had stopped
to take a few wide angle shots or a pano.  This was a beautiful storm.  BUT from experience I knew I had to get across the
border back into Minnesota to resposition.   It was hard to leave a tornado warned storm and the road network took me
south to Ortonville to get over the river.  The whole time I was rooting for a new storm just to the south to turn right.  As I
was heading east on 12, I could see the pair of supercells shadowing eachother as they headed east / southeast. I needed
to get back into Minnesota!
Pretty crazy updraft as it was forming just about right overhead and was highly sheared.  Wish there would have been
time to shoot a timelapse of this.
After nearly having a heart attack after getting through Big Stone City, SD on the border and seeing a "Road Closed
Ahead - Follow Detour" sign, we finally made it over the river, through Ortonville and back on the storm.  I was kind of
annoyed the southern cell was a now another huge HP outflow dominant mess....but that was about to change as the
storm took a hard right turn.
Video frame from about 3 1/2 miles east of Ortonville looking east / southeast at a brief but thick funnel.  ABR did a
damage survey in this area and determined a high end EF1 touched down on the SD side in Roberts.  This was taken at
7:55pm just south of highway 12 on Big Stone CR 21.  The damage survery did determine straight line winds of 100-105
mph in Ortonville which was likely the RFD with this.
Lots of sharks teeth and danglies along the leading edge of the storm.  This cell was rapidly becoming a barrel as it spun
harder and harder as it continued to make it's right turn to the southeast.  Shot is just north of Odessa, MN looking
southwest.   Another video frame.  The real show was about to begin.
Video frame looking south as we head down Big Stone county 21 towards Odessa, MN.  Note the funnel look a like on
the edge of the meso on the right side.
East of Milan, MN in Chippewa county this thing went nuts wrapping up into a laminar barrel.  Right over the trees this
thing was rotating like crazy.  It's sister cell is just to the right out of the video frame.  We held our position and let the cell
get very close as I was sure it was going to tornado at any time.  We had to stay on the east side of the cell to be able to
see. Time to move east again.  We stopped  3 miles  south of highway 40  or about 9 miles west / northwest of Raymond,
MN because of this:
HOLY MOLY!  Not too often we get treated to a supercell like this in Minnesota.
The setting sun was doing it's magic with the light.
This area due west of us was rapidly rotating....but I couldn't take my eyes off the what to my left.
The pink hue were fading rapidy and I needed to keep my eye on the area of
rotation which was approaching at nearly 50 mph now.
We held our ground as the action area neared and showed us this lighting lit tornado.  The reason I say tornado and not
funnel cloud is
Doug Kiesling was directly under this and had to back off quickly.  As he proceded forwards again, he
came across tree damage and some minor structural damage.   When I went to call it in (couldn't get connected to Spotter
Network)  MPX told me they were already watching it on my live stream.  That was cool.  We'll get more detailed location
info to MPX soon on this.
Structure with the video frame as an inlay.  Note the trees in both images to get a feel for where the tornado occurred.
And finally here is the video from the Minnesota side.  We bailed right after the tornado as I didn't want to chase at
night with Cailyn so we jumped on highway 7 and headed for home.  3 miles east of Cosmos, MN we had to pull
over due to high winds from the north.  Just as I pulled over, a measured gust of 77 mph hit us causing the
powerpoles to lean over to the south in the wet ground.  A wicked wind shift also occured with the direction going
from northwest to even higher from the northeast then back to the northwest again.  Was enough to trigger the
TVS  algorytm on radar right on top of us.  As we got into Cosmos, the power was out so we headed north to thread
between two cells and get out of the inflow / outflow interface.  No power anywhere until Litchfield where the
north and west sides of town were still blacked out.  Overall, it was a great chase day!