Just glancing over model data as I wait on my car getting it’s 10k maintenance done. I’m still waiting on the 12Z GFS to update, but no real changes to locations from my previous map from what I’ve seen so far. I am growing increasingly confident in the tornado threat over SW Nebraska Sunday night and possibly into far northwest Kansas. I think a strong tornado threat may develop with any discrete storms late in the day if SR upper level winds don’t cause a problem Storms holding off until later in the day would probably help that since the longer those storms go the more likely they’ll be to trend HP. I’ll take a closer look at that tonight.
Monday is looking fairly potent too, especially along a dryline bulge in central Oklahoma. It’s very similar to Sunday’s setup with strong low level shear and great thermodynamics, but upper level SR winds are weak. That again points towards an HP trend with storms. I’ll get into that as well later tonight.
And I still think Thursday looks to be the big day here. I’m not basing that off specifics I’ve seen with the models though. I’m basing that off the larger scale pattern. Both the ECMWF and GFS have a seasonably strong shortwave with a negative tilt ejecting into the central plains. There should be great moisture in place with dewpoints around 70 and a strong low level jet should setup given the strength of the shortwave. All that points towards a higher end event. The bigger uncertainty this far out would be the impact of convection leading up to Thursday and the potential for 850’s to veer as the upper level jet stream becomes more NE to SW elongated and leading disturbances disrupting the southerly LLJ you’d get with a wave just ejecting into the plains. I want to see some specifics, but again I think Thursday is showing the potential to be a bigger day if 850’s are backed a little more than what the GFS shows. The ECMWF shows a little more favorable solution with regard to the shortwave and low level wind fields response to it. We’ll see.
I’ll update later tonight and start to get into the specifics of the tornado threat for Sunday and Monday so check back then if you’re interested.