The Storm Prediction Center (SPC) has issued an Enhanced Risk for western South Dakota and a long Slight Risk stripe along the High Plains.
Associated with this risk is a 5% Tornado Threat Ring.
The surface map shows a moderate south and southeasterly breeze, morning temperatures in the 60s F, with dewpoints in the upper 50s F, but cloudy skies over most of the threat region.
While the larger threat (per SPC) is in South Dakota, I’m leaning towards Northeastern Colorado and Northwestern Kansas. Here is the sounding from Rapid City, SD:
The atmosphere is saturated all the way up the column. It looks like a rainy, cloudy day there. It’s not to say there won’t be thunderstorms- there will- but this sounding doesn’t bode well for discrete supercells.
In comparison, here is the sounding from Dodge City, KS, where we have some Convective Available Potential Energy (CAPE) and at least a small capping inversion. The deep-layer shear is not great.
North Platte, NE, has a better sounding, located between the two. The CAPE is higher, there’s a little more deep-layer shear (though not much, and not a lot of directional shear on any of these soundings), though there is little capping.
The visible satellite imagery shows clouds everywhere in the region.
The Supercell Parameter (SCP) hits a local maxima at 21 Z in northeastern Colorado.
Compared to yesterday, there are more clouds. Cloud cover has plagued this trip so far, so I am a bit weary of today’s threat. If the clouds don’t mix out, we’ll have some borderline severe storms, just like the past few days.
I think we have a similar setup to yesterday, though I think the upper-level low over Nevada will push off today, and this evening, storms will evolve into a large squall line, moving northeast instead of nearly due north.
I am thinking that chasing northeastern Colorado is going to be the best bet. We may even trend south. This storm system will quickly become linear and the trick is going to be to find the cells when they first form, or grab the “tail-end Charlie” cell. Depending on which model you ask, the tail-end Charlie cell could be anywhere from I-70 to the Oklahoma Panhandle. I posted the simulated reflectivity for the HRRR here as a demonstration.
We will probably hang out along the US-385 corridor for a bit, probably here in Holyoke, but then trending south towards Burlington.
Thank you for reading my post.
The forecasts from the National Weather Service are from The NWS Homepage. The upper air soundings and mesoscale analysis plots are from the Storm Prediction Center website. The satellite data, model data, and forecasted soundings are from College of DuPage – SATRAD