2012-05-05 FCST: NE, SD, IA

[Travis Klanecky]

I'm very surprised that a thread hasn't been posted yet for Saturday. There are still some model differences between the NAM, GFS, and ECMWF, but they all point at the possiblity of significant severe weather by late in the afternoon and evening hours. CAPE looks to be extremely high up in the 4K to 5K range, hodographs are largely curved and you have the lift with the warm/quasi-stationary front near the Nebraska/South Dakota border. The biggest issue may be upper level jet as the strongest winds still look to be out to the west. Another issue may be a strong cap in place, but in my own opinion, it should erode some by the late afternoon hours. That is the part of forecasting I really struggle with though. I'm curious on other people's thoughts. Am I missing something? At the present time, I would favor areas around O'Neill, NE, but depending on which model verifies, you could go back toward Valentine too.

 

[Logan Karsten]

I think O'Neil is going to be the place to go to tomorrow. Thermodynamically, tomorrow looks fantastic with the potential of over 5K of CAPE. Not too bad for early May in Nebraska. Low-level winds are nice and backed through 850 mb with decent 0-1 and 0-3 helicity near and around the warm front. Of course, as you mentioned Travis, the biggest concern for me tomorrow is the upper level flow. 700 MB looks pathetically weak, and we will be lucky to see 40 kts at 500 mb from what it looks like. So, tomorrow is kind of a trade of for me. You have the potential for slower moving, explosive supercells, but they may be HP and may not produce very long-lived or highly visible tornadoes. If 500 mb flow could just up itself a tad to around 40-50 kts tomorrow, then I think things would be really good, but I am pretty happy with how tomorrow is as it stands now.