Upper impulse currently tracking its way through NE’rn BC into NW’rn AB will push into south central SK tomorrow afternoon and will bring with it the risk of severe weather to the province. The trough is rather compact but the SREF_H5 as shown below shows a subtle trough with subtle height falls within the SE corner of the province which should help with overall ascent within the warm sector. This will be key as there does appear to be some capping issues the forecast, will touch in this in a second. Further helping the scenario is the 500 mb jet core will pass through the southern portion of the warm sector with the left exit of the 250 mb jet within the same vicinity. This will also prove to be very beneficial as this will greatly enhance cyclonic shear and help increase deep layer shear.

Monitoring the forecast track of the surface low over the past few days there has been some disagreement with how far into SK the low would track and how far north the warm front would push. The GEM/GFS/ECMWF have been pretty consistent with the low tracking through central SK forecast to be just north of Yorkton by Sunday afternoon, the H5_SREF also supports this scenario. The NAM however keeps the low along the SK/US border with the warm font sitting just S of the Hwy 23 corridor through MB. I have chosen to reject this scenario for the time being as it is the large outlier. With the trough pushing in, it should allow for the warm front to push N, but can see that the 18Z NAM from today is beginning to trend with the general models trend. But cannot discount the possibility of the front not pushing as far N with the amount of synoptic precipitation forecast for central SK the cold air from this could prevent a good northern surge of the warm air. I will use the 18Z NAM for surface forecast analysis as I think it is starting to have the right idea. I suspect to see storms initiate near the 21 UTC-00UTC (2:00 pm-5:00 pm CST) along the cold front near the Hwy 35 corridor just E of Regina and also along the dryline/cold front intersect near the Weyburn area as well. This region could see the best low level dynamics to see some good suprcells. Storms will track E at first and as they get rooted in the boundary layer track SE to SSE.

There is however some bust potential, and this can once again be attributed to a pretty stout CAP that is forecast to be in place through the afternoon as indicated by the forecast sounding within the warm sector. But as discussed above the saving grace is the upper height falls should help to mix that out, good forcing along the front and dryline (particularly near the intersect of the  two) and good evapotranspiration from crops which is often underforecasted by models. Looking at Sfc-500 mb bulk shear of 50-70 kt, sfc-850 mb bulk shear of 25-30 kt, and veered hodographs through a deep layer looks possible that organized supercell structures are likely along with the risk of a few tornadoes. Tornado risk will increas as storm track E where an S-SE 850 mb LLJ will help further enhance low level shear. Main risk area appears to be Yokton, Weyburn, Estevan, Carnduff, SK and into Brandon, Russell, Pipestone MB. As storms push into S central MB expect them to congeal into more of a line as the cold front overtakes the dryline. But this can all amount to nothing if that CAP wins giving nothing but scattered unorganized convection.