Well not much has been happening on the severe weather front this past week. Friday of last week was the last major severe weather day with tornado watches/warnings being issued for areas near Bassano and Brooks, Alberta.
Things will finally change for Thursday as a weak low sets up tomorrow near the capital region. The low level winds are going to increase to around 30km/hr out of the southeast...that's it for speed shear. High CAPE values, low level moisture, and amazing directional shear combined with a surface trough are all we have. We have no flow aloft to effectively vent the updraft...hopefully that can change...if that does then something big will happen.
However when facing reality it is likely after viewing water vapor imagery that the strongest mid-upper level winds will reside south/near the international border by tomorrow afternoon. So this means that we'll be dealing with strong multi-cell storms with left splits and right splits. Colliding outflow boundaries will occur I can guarantee that. Any storm that can find a boundary may allow for a brief tornado if moisture does make it into the upper teens like it's supposed to based on the 00z NAM/GFS.
Saturday looks interesting over Northern/Central Alberta too...the ridge breaks down allowing for a linear type convective line to develop after 6pm from around Fort Chipeywan through Edmonton to about Red Deer. Ingredients are in place for a squall line to rip through bringing an end to the warm, relatively humid weather for a couple of days...this wiper blade will flush out any moisture currently pooling in Alberta...after that it looks like a lull in severe weather chances for some time (2-3 days at least)
But Saturday...despite showing a strong squall line signal...might host an opportunity for discrete supercells...there is way better speed/directional shear associated with the low-upper level jets and when combined with a strong short wave moving through...it looks like it might actually phase with the higher capes and moisture from 6-9pm...
And finally...about next Saturday the 31st of July...yesterday's run showed it better then today's but it looks like a strong upper low will move on shore and dig which will work to amplify a ridge over eastern Alberta through Saskatchewan. A great mid level SW flow develops over southern and central Alberta...I won't say anymore since that day is several days out...but that time of the year is quite sensitive to Capital city residents.
In the mean time...here's to hoping for a great Thursday and Saturday!
Maybe someone will actually consider chasing these events especially on Saturday and actually 'chase' like they say they will instead of missing one of the few big days that Alberta has to offer in terms of severe weather...you know who you are...starts with an A and ends with lysa!
I've been watching this trough for a few days now, and I'm happy to see the ridge break down allowing the trough to dig a bit more south on Saturday. I prefer tonights 0z GFS upper level winds which are stronger and eject more onto the prairies compared to the NAM's, which are weaker and kept a bit more to the west in central Alberta. Either way, the flow will be there. The potential is there and I'm looking forward to it!
ReplyDeleteThere looks like potential for decent thunderstorms in southern Alberta on Sunday as well. Modest cape, moisture, flow aloft and a developing surface low look to set the stage for thunderstorm development. 700 temperatures look to be in the 6-8c range, but hopefully the suggested shortwave and convergence along the surface low can provide enough forcing. Saskatchewan looks good too with bigger numbers thermodynamically. Any thoughts on tomorrow or Sunday!?!???
ReplyDeleteTomorrow still looks good around Central Alberta...north from about Fort McMurray through the capital region.
ReplyDeleteBut yeah Brandon, on Sunday it looks like there might be great supercell potential initiating along the foothills and rolling off in the late afternoon. The only limiting factor will be the strength of the low level jet. If we can get at least 20 knots from the SE then you're golden when you combine that with the westerly flow aloft. Capping may be an issue but the foothills should eliminate that with what we call 'foothills magic.' The mountain plains circulation never seems to fail here in Alberta.
Target for Sunday would be near Calgary from what I see right now.
Check out the supercells in SD right now...I'd kill to be there at this time!