Tuesday, July 09, 2013

Extreme Weather Event - Large Strong Tornadoes Thursday Evening

Words can not properly describe what has yet to happen so I will simply post some map outlooks and forecast model screen captures to paint the picture of what is to come over the next few days. Keep in mind this extreme weather event really only begins late Wednesday night and continues until at least Sunday for much of Alberta, Saskatchewan and Manitoba.






GFS - EHI Index Valid 6pm Thursday

GFS - Supercell Composite Valid 6pm Thursday

NAM - Significant Tornado Parameter - Valid 6pm Thursday

NAM - Significant Tornado Parameter - Valid 9pm Thursday

All of this is very interesting but lets wait until Environment Canada issues official watches and warnings. When they do, please take extra precautions and stay safe! 

Updates will continue here until the power goes out.



3 comments:

Kyle Ziolkowski said...

You have shown all these maps but haven't discussed the big limiting factor which is the CAP that will definitely be an issue thursday. 700mb temperatures are near 12 degrees which is a fairly stout CAP for the Canadian Prairies plus being under a strong thermal ridge will inhibit convection. On top of that according to current guidance there is limiting deep layer moisture on the boundary and very warm surface temperatures giving rise to an inverted-V sounding which also means high based storms. With all this being said I would really suggest displaying other things such as where the surface boundary will be, what the moisture is like, instability (Which you had with CAPE), and most importantly deep layer shear. Discussion of the limiting factors is also important such as what I pointed out above and the over all dynamics and thermodynamics of the system. The parameters that you have displayed above do not initiate thunderstorms, they are merely an indication of the environment but you need storms to be able to initiate and track into this environment before they will take on such characteristics. Plus they are a crap shoot that far out and should be used for nowcasting or in a day 1 forecast.

Those are my suggestions, I like your risk map as well, really helps visually.

Jared Mysko said...

Those are all very good points, thank you very much for the input. I really don't want to get too technical thereby confusing the general public with too much information. That said, the chasers and forecasters that visit here will always want more. Its a tricky balance but this is a unique situation that deserves some extra attention.

Alan Mills said...

I think for me, as someone who isn't super educated for incoming severe weather this is the blog I come to when I need to know WHERE roughly the bad weather is kicking off, I thank you very much for it too Jared. Last year in SK it kept me ahead of the weather.