The Storm Prediction Center (SPC) has issued a Slight Risk for the Northern High plains today.
Associated with the Slight Risk is no organized tornado threat. There is a 5% Tornado Threat Ring where I grew up, but not out here in Tornado Alley…
To summarize the SPC: Scattered thunderstorms are possible this afternoon, with the most organized storms forming near the Big Horns in Wyoming. The greatest instability may reach 500 J/kg to 800 J/kg of Convective Available Potential Energy (CAPE), with dewpoints maybe reaching into the 40s F.
The visible satellite imagery shows cloud cover over the threat area.
The surface observations show winds circling around a low pressure system over eastern Montana. There are no distinct frontal boundaries or drylines in this image. Overall, the dewpoints are low and temperatures cool.
The surface pressure chart shows low pressure over the threat area with no strong pressure gradients. The RAP shows the low will shift and intensify in the next six hours, but no strong pressure gradients are expected to develop.
No 12 Z soundings are impressive in this region. Furthermore, most of them do not represent the threat area.
The 700 mb NAM chart shows a small pocket of upward vertical velocities (UVV) in western Nebraska.
The Nested NAM simulated reflectivity shows a few clusters going up by 21 Z and congealing into a mess by 1 Z.
High temperatures will rise into the mid 90s in northeastern Colorado and western Nebraska.
The Nested NAM shows that the dryline will tighten through western Nebraska later this afternoon. Dewpoints are only expected to reach into the 40s F on the damp side.
The Nested NAM CAPE/CINH plot is showing CAPE is laughably small. I did not post this chart, or any of the supercell, helicity or SigTor charts.
Today is not the best setup at all. I will watch the little pocket of UVV, but I don’t anticipate much. The dewpoints are too low, there are no sharp boundaries, I’m just not seeing a big threat today.
I will pick up my crew in a few minutes. I expect that we will drive to North Platte, NE, and watch a few non-severe storms fire and cluster this afternoon. We picked North Platte to position for the severe threat tomorrow instead.