Month: November 2017

21 Nov

June 13, 2017 – South Dakota Tornado

stratosigma / Blog, Storm Chasing / / Comments

After a moderately successful chase in the high plains on the 12th, another potential significant day followed. As a closed mid-level low rotated across Montana and Wyoming into the Northern Plains, a trough lagged behind that was forecast to move into the Dakotas during the evening on the 13th. At the surface, a low along the SD/NE border would drift east throughout the day while low 70 dewpoints advected into the warm sector in eastern South Dakota.
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13 Nov

June 12, 2017 – Roads? Who needs Roads?

stratosigma / Blog, Storm Chasing / / Comments

June 12th was shaping up to be the most significant severe weather outbreak in the high plains in 30 years. The setup favored supercells throughout eastern Wyoming into Western Nebraska. A trough was progged to amplify and eject across the high plains while strong mid level south-westerly winds overspread the area atop rich low-level moisture advecting into the area via an upslope regime.
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