Saturday, July 2, 2016

6/28/2016 Chadron to Ogallala, NE Derecho

We awoke in Scottsbluff, NE (new Fairfield Inn) with a target near Torrington, WY. Low 60s dewpoints were progged in the NE panhandle, and shear profiles quite supportive of supercell storms. We had lunch in Torrington at Deacon's before heading to a softball park to launch a radiosonde (data attached below). It was clear in our sounding that the moisture was shallow and dewpoints began to mix out to the mid/low 50s by late afternoon. We bailed on the upslope play to head toward Chadron to catch developing convection coming out of the southern Black Hills.  This convection quickly grew upscale into a southward propagating MCS and will likely be classified as a derecho. We got a front row seat for the shelf as it passed through Chadron, where it produced a measured wind gust of 103 mph! Continuing its south track, we slid toward Alliance and caught a nice picture of the shelf as it passed over Carhenge. It was a great spot for a group shot!  For the grand finale, we set up on the southwest side of near Lake McConaughy (near the damn; good idea Walker!) to let the shelf pass and overtake us. There were several boaters that were caught as this derecho passed over the lake. A great day in some beautiful country.

MISC: Overnighted in Ogallala, NE. 

Prepping for balloon launch
Lapse rates for days! Dry low-levels reveals the mixed out nature of the boundary layer
Shelf at peak intensity near Chadron, NE
Carhenge!

Boater cutting it a little close!


1 comment:

foxglovedog said...

This was a terrifying event for me. The wind kicked up almost suddenly and within a few minutes, Chadron blew their tornado sirens. I thought for sure a tornado was coming through town- and I had no place to go for an underground shelter. I sat in my closet, shaking. I caught my neighbor running out to her friends car, I forced myself into their car. I thought for sure they had a plan, instead they were completely unprepared and we drove around for a while before they found a basement. Had this been a tornado, we would have been in serious trouble. The derecho was bad enough. Tree branches flying all around us as we drove around town. I'm not originally from the area, and we do not get storms like this where I come from. Ever since I have been completely obsessed with the weather. If a derecho can do that, I can't imagine what a tornado could do. Yikes :(