Chase Account - 9th May 2004

From Sioux City, Iowa to the chase in central Minnesota and back to Mankato for the night

Tony Gilbert, Terry Fryer, Sam Jowett and Ali Dibb

Previous Day Next Day
This mornings model output left us initially concerned about the level of moisture available, but we decided to play the better shear across the northern Plains.  This meant we left Sioux City, IA late morning aiming for Sioux Falls, SD, where we then took the decision to punch E into southern MN.  As we travelled along the I90 we noticed a huge anvil way to our N and in the absence of any other convection, and its impressive presence on radar, we decided to take chase. Minnesota Supercell
The chase was quite a long one with such a distant cell, but we could see fresh convection on the western side of the cell threatening to create daughter cells, so we pushed many miles N passing under the end of the flanking line, before pushing E to try and find the updraught core for the tail end cell.  Once there we were greeted by rain free base along the line of the inflow and several updraught areas where scud could be seen being dragged into the base, threatening to create wall clouds.  Any rotation we saw was very weak though, despite the storm being tornado warned whilst we were almost directly below the updraught core. Flanking Line Convection
After accepting that the only way to see anything more significant would be to attempt a likely unsuccessful core punch on the cells downwind and given that evening was starting to draw in, we headed back to Mankato for the overnight stop knowing full well this would place us ahead of the now linear MCS.  This allowed us to be treated to another beautiful lightning display, some strong outflow winds and pea sized hail. Flanking Convection