A moderate risk, 10% tornado risk, and public severe weather outlook have all been issued for the northern Great Plains today.
I checked out the morning soundings (almost the exact second they became available) and the most impressive ones are out of Rapid City, SD and North Platte, NE. Rapid City showed CAPE forecasted to be around 3300 J/kg and 33 kts shear. I’m not super impressed with the forecasted LCL heights, however (2100m):
The North Platte sounding showed CAPE forecasted to be around 2900 J/kg, but we trade CAPE for lower LCL heights (1400m). Also, the supercell parameter at North Platte is 13.8, which is high.
Looking at the SPC Comp Map, you can start to see what is causing all of the alarm. The 850mb winds and 300mb winds are overlapping, but are from different directions, raising the shear in the area:
There is not a well developed dryline, but SPC is promising rich, low level moisture by this evening.
I’m torn on what will happen to the warm front that exists across SD. I could see that becoming a cold front and moving south instead as storms begin to develop. I think SPC thinks it will move north. That boundary will be the thing to watch throughout the day.
Based on all of this, my early morning predictions are:
1. Rosebud, SD
2. Gettysburg, SD
3. Linton, ND