Chance of severe thunderstorms next week worth a mention

After watching the last few runs of the GFS with great interest, I think it's safe to say that there's at least a slight chance of strong to severe thunderstorms in Michigan next week. I'd place this chance around Wednesday or Thursday.

It's important to note that if the current GFS forecast were to verify, we probably would not see any severe weather. This would be because the storms would likely manifest to our west and not quite coincide with the maturing of the surface low, which would turn up the wind speed at all levels - and most importantly, the low levels - to around 11. See the image below.

Essentially, it will take a few more things to come together to produce anything nasty. First and foremost, there'd need to be enough instability for thunderstorms. The cold front would have to arrive a bit earlier than what's being forecast for that to happen. Our hottest day next week should be Wednesday, when temperatures could actually reach the mid 70s, and dewpoints could reach the upper 50s, if not 60°. The GFS tends to be pretty good with temperatures so I'm thinking it's safe to bank a little bit on this being the case. Were the cold front to arrive Wednesday afternoon, it'd be chasing the warm sector with a vengeance, and would probably initiate storms. My cause for concern is that this looks to be a powerful cyclone that's building, and when that upper level disturbance is strong enough to drive a storm system like this, the models typically underball its speed by a few hours. Should the storm pick up steam, it would mean that the above image displaying the low level jet intensification on Thursday could come a day early and possibly bring even more of a punch than what's being displayed.

So what types of hazards would we see if this were to happen? Damaging winds would be a given, as any time the wind speeds get that strong, a thunderstorm tends to bring them down to the surface. A jet core intensifying to 130kts and an 110-120kt upper level jet is currently being forecast, so we're looking at a lot of horsepower. Throw in the mid and low level jets of 60-70kts and that's severe wind pretty much guaranteed. These would be fast moving, powerful storms similar in speed to what we saw on August 2nd last year. There would also be a pretty solid tornado risk, and I'd say with those wind speeds being what they are, strong tornadoes would be possible should discrete storms be the mode.

Again, this is very, very preliminary and should be taken as only a marginal risk at this point. That means about a 1-in-20 chance of any hazard manifesting. The system could just as easily slow down or stay the same as what's being forecast, in which case we'd probably wind up seeing nothing but rain and perhaps some gusty winds. I do think it's worth a mention to get people thinking about severe weather again, though, as we will almost certainly be in the warm sector and that's where thunderstorms happen.