May 24th Southern South Dakota and Northern Nebraska Storm Chase - Supercell Storm and Mammatus

05-24-10 CHASE LOG:  SD/NE

  This was a difficult chase day with a strong storm system and fast moving storms in a large Moderate Risk for severe storms.A low pressure system was forecast to progress from western SD into southwest ND during the day with a warm front quickly lifting northward from near I-90 to the SD/ND border by evening.A dryline and cold front were expected to move into western SD and western NE through the day.After several long chases in a row, our group decided to meet by late morning in Valentine, NE and then head north on Hwy 83 to Murdo, SD.Storms already began to fire around midday ahead of the triple point near Rapid City, SD and additional storms began to fire on the warm front lifting north of I-90.Storms all day were moving at nearly 55-65 mph on average so anything that got by us was long gone.We decided to attempt to intercept a tornado warned storm near Rapid City, but soon realized that a storm ahead of the triple point on the warm front would be the storm of the day.This was our original plan was to play any storms in this area but, due to the late start in the day, we could not get to this storm in time to see the large tornado it did produce near Faith, SD.More storms began to fire in the warm sector in a highly sheared,unstable, and moist environment in central NE and move north towards our area, so we ended up bailing on the cell near Rapid City and turning around in Wall, SD and traveling back to Murdo, SD.Just east of here is where we intercepted our first storm of the day near Draper.This storm was severe and had nice structure and actually a nice rotating wall cloud for quite a while.Other storms were firing to the south into the early evening, while the storm we were on was not looking overly impressive so we ended up heading back south on Hwy 83 back towards Valentine, NE and intercepting a squall line about 20 miles north of town. This line had a messy shelf cloud, some gusty winds, and heavy rain, but nothing that was all too impressive.

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Storm with lowering near Draper, SD.

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Storm with rotating wall cloud near Draper, SD.

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Incredible mammatus in Valentine, NE.

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Mammatus in Valentine, NE.

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More mammatus at sunset in Valentine, NE.

More photos from this day can be found here:http://www.flickr.com/photos/39991047@N02/sets/72157624218639078/

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