Yeah the new 12Z GFS is a thing of beauty with good directional shear and excellent speed at all levels. Moisture will be key. Assuming the timing on the GFS is right and Thursday is the first major chase day I think it is reasonable to expect decent moisture (maybe low 60's), but again if the GFS is on with the timing and everything else now then there should be high quality moisture in place by Friday. If either one of the models can come close to verifying (which it is looking more and more likely that it will) then given the quality moisture, strong wind fields, large spatial coverage, and climatology we will likely have a significant severe weather outbreak. Whether or not it is also a tornado outbreak is going to come down to the details. Quality moisture return and directional shear are my two biggest concerns right now. As is typical with these kinds of classic spring setups the day before the day usually has excellent directional shear, but moisture and capping are typically an issue (Greensburg last year was a day before the day event with excellent directional shear). Then on the main day there is typically strong deep layer shear (due to the trough ejecting into the plains), quality moisture, but you have lost some degree of your directional shear. That being said, if we can have decent moisture on Thursday, which we very well may given the 50-70kt LLJ being forecast 24 hours ahead of this combined with quality moisture residing right off shore, and maintain backed low level winds on Friday, then we may be looking at back to back tornado days.
This is definitely the most optimistic I've been for a setup this year when we were still 6 days out. I think half my optimism is a result of this year sucking so bad and there is finally a good trough being consistently shown by the models, but I also think some of my optimism is well placed given the reliability of the ECMWF this year and the fact that GFS is quickly falling in line with it.
