Focus on this post will be about Thursday mainly.
The short-term rain/thunder moving through now will be handled on social media on our newscasts this evening...so make sure to watch!
Here is the latest SPC outlook for severe on Thursday (red) and Friday (purple):
Covers us all.
Why such a large area? The wind fields are impressive across the Ohio Valley. The question when it comes to severe storms ...as usually the case in the winter...is instability.
Let's start with the winds aloft.
GFS is showing winds over 100mph just a few thousand feet up! That is quite impressive. The NAM is a bit lower, but still nothing to sneeze at.
We see these systems a lot around here where we have winds howling overhead...but unless thunderstorms (or every heavy showers) can reach up into those levels and pull the winds down to the surface---the severe threat remains questionable.
Timing affects instability as you get the best instability during the afternoon hours when you have some help from the heating of the day.
GFS is aiming for the 7pm-1am time-slot for the "squall-line" of storms to roll through.
NAM is just now able to see this system...but seems to be leaning toward the GFS with a mid/late evening timing.
EURO is later... likely 1am-6am timeframe.
GEM is even later... more of a 3am-8am slot.
Squall-line with high energy fields like this usually tracker FASTER to the east than the models indicate due to cold pooling of the line that forms bowing segments. So right now I like to split the timing of mid evening western counties through the midnight timeframe along 65...then later east of 65. But today is only Monday---we have plenty of time to adjust that. I just trying to throw out an early thought on this.
CAPES is just one factor we look at for instability.
GFS has a narrow stripe of very low capes reaching into our area when the storms move through.
NAM has a bit more to work with.
You can get severe winds to the ground with low capes in the winter time compared to the summer.
When we dive more into the moisture...we can start to get a better picture of how the strongest of activity will likely setup.
The GFS shows the best chance for 60 degree dewpoints just to our south...nosing into southern KY. I outlined where I think the best risk for severe storms would be in that setup.
What I outlined just above is where I think the BEST CHANCE for severe storms will be with this event. Having said that, the wind fields over us are STRONG...so we can certainly get high wind reports from this even this far north...so we likely will remained outlooked for severe. If we see greater instability and higher dewpoints surge even more north...and you combine that with the winds over 100 mph aloft...yikes. Not good. I don't see that happening right now---but that is not off the table either.
Tornado threat? Isolated/brief tornadoes possible within the line of storms are certainly possible with straight-line winds the higher threat.
Even without all this severe talk...it should be noted we are talking about 1-2" of rain out of this system. That on top of a melted/melting snowpack can lead to flooding problems. If you are prone to leaky basements----I would keep this in mind.
SO WHAT IS AFTER THIS?
Well the weekend is a bit unclear as we have a couple of weak systems moving through. EURO is trying to pick up on them. It looks borderline rain/snow.
More importantly, signs of a southern stream system moving in with cold air at play by the middle of the next week.
Eh. We'll look at that later. :)