Updated Below - (Scroll down, I'm trying to keep this organized)
Update (6:00pm) - The Storm Prediction Center has issued a Tornado Watch for parts of our area, namely Ohio and northern Kentucky into the night tonight:
This also reflects our thinking as to where the greatest risk of tornado formation would be. However, it is still appropriate to note that high winds of any kind are still the primary concern. There have been reports of tornados in that line through southern Kentucky as well (the one approaching Bowling Green). Do not be surprised to see more tornado watches being issued. It is a very active weather pattern today. You should be able to feel a warm spike in temperature and winds even later tonight before this line advances. There have been more than 200 high wind reports upstream from us, with a few near hurricane force. We're still hoping for some knock-down in intensity before this all gets to us, but keep in mind that even the straight-line winds that we've been cautioning about can still cause damage and power outages.
Update 11:30pm - The most recent Storm Prediction Center message regarding storm potential enhances the already existing forecast:
This is the kind of severe weather set-up that will feature Tornado Watches and High Wind Watches propagating from west to east across the Ohio Valley today. Even though the greatest tornado threat is outside of our area to the northwest, you should still anticipate these kinds of watches being issued. See below for more content on why the wind threat should be most important in mind...
As we said on the air late last week... Once you start getting into mid-November and you hit 70°, it's because there's some bad weather on the move. In our case, it's this evening and tonight where we have to be on our toes the most.
Here's the situation.
HPC - Surface Map - Sunday
This storm system (982mb) is easily among the strongest one we've come across this fall in the Great Lakes region. It features a patchwork of showers and gradually breezier winds in the warm air out ahead of the sweeping cold front, but then right with the front a strong potential for gusty thunderstorms in the clash of air masses that ensues.
Check out how closely the above map matches what we ended up with on Halloween night (here's an archived image of 2am on November 1st):
The Halloween system might have been a touch stronger than this one, but notice the squall line we had rush out ahead of the front (as depicted in the November 1 imagery)... We'll be looking for a similar setup unfortunately for the Tri-State. That last one caused many power outages and had wide-spread wind damage. The Huntington area was visited by 70mph wind gusts!
The Storm Prediction Center is clearly concerned about this as well, and has issued the following severe weather potential:
SPC - Severe Weather Potential - Sunday AM through Monday AM
Thankfully the greatest threat for tornadoes is elsewhere to our west, but from the looks of it SPC feels we're virtually guaranteed wind gust problems and effects in our area, particularly in Kentucky, Ohio, and places along/north of I-64.
Here's the NAM model (with its better resolution):
Just like on November 1st, this will be an event that strikes for only about a 1/2-hour or less as it sweeps through, with clearing to follow toward morning on Monday. But, look at those winds (on the right hand map). 60mph winds at 2,500feet(!) with 80mph winds at in-cloud level. That is a dangerous situation when a squall line forms and can channel/mix-down that kind of energy. It helps continue their propulsion and also gets those power outages going.
Peering even more deeply into the particulars of the model data, we find this concerning the winds:
On the left-hand map, we've got winds arranged in a time-series where each vertical slice represents a different time. Right at that 03Z(10pm) vertical line, the jet-stream is poking through at a low level, at about 4,000 feet at 60knots. When you get a thunderstorm in the mix to make use of it, there will be some momentum transfer to the surface (the raindrops we get at the ground have been falling through this air and will be coming on the speed they were sent from above). On the right-hand map, I've put in the 'momentum transfer' values at the same time-stamp of 10pm. If we get a squall line marching across I-75 later this evening (and the Halloween example is a good case-study here), then we could/should be looking at the potential for more 60mph wind gusts with this line-- as an aside, even the 45mph wind gusts of the lower scenario transfer can cause power outages and branches/limbs to come down.
Update (12:00pm) - For comparison's sake, I've tracked down the model data from the November 1st event, and here's the same-hour nam model readout for that event about 18-hours before it arrived:
Scroll up and back a little bit to just take-in how similar these two events really are. So the one on November 1st had a slightly stronger low-level jet nosing in with the squall line, and also has it reaching a little closer to the surface. The momentum transfer numbers are only slightly higher with the November 1st event, so we definitely have to be concerned about this one. Remember though that the actual squall line didn't end up coming through until about 2:30am on November 1st... Both model readouts have made provisions for gusty winds to be tap-able and able to be brought to the surface, whether it's with a squall line that races ahead of the front, or if it's the actual frontal passage itself. It happend then, so why wouldn't we be on our toes for it again?
Now, a couple of final take-aways here before the tracking maps below:
1. This has the potential to be another short-duration / high-impact wind event for much of the tri-state area Sunday night - Do NOT get hung up with exactness on the timing, as this line will be sweeping through pretty quickly. It could take just 2-3 hours for it to make it all the way across our region, with only about a 1/2-hour's worth of actual storming (or less). 10pm is a good ball-park "go-time", but there certainly can be some play there. Meaning, don't be trying to cut it close with any outdoor plans without legitimate access to live weather data (as with our free WSAZ Weather app for your smartphone).
2. There IS a potential for tornadoes with this line - However, I would be MOST concerned with the straight-line winds that most of us will be getting. There is high-shear but low convective energy. The thunderstorms themselves may not end up being that impressive (20,000 ft cloud tops), but it doesn't matter if its channeling a low-level jet of near hurricane-force winds at 5,000-10,000 feet. Most likely any tornado we would/could get won't be much more powerful than the already strong straight-line winds that are coming through. I bet the Doppler Radar could end up looking pretty scary with this though. It certainly did the night of November 1st.
3. Charge up your cell-phone - That's THE best thing I can say in this modern world for when something like this happens. If you lose power, you will still have "power" via your cellphone. Access to information (and even that flashlight app) is key. WSAZ streams its broadcasts over the phone, and we can all still connect through social media.
4. Send Us Your Storm Reports and Media - You should take utmost precaution to be safe if this storm-line ends up gusting through your area. From a safe vantagepoint however, those interested can really help us out by letting us know the conditions your experiencing, or even taking a picture or video. Porch lights and such (if the power is still on) can provide helpful illumination. If it's too dark, the imagery won't be very useful.
5. Stay Safe! - There is a strong potential that all sorts of scary watches and warnings come out with an event like this. This could include High Wind Watches/Warnings, Severe Thunderstorm Watches/Warnings, and even Tornado Watches/Warnings. If there's a High Wind Warning or a Tornado Watch up for your area and you live in a mobile home or trailer, it simply might be good to just spend the evening/night with some friends. Since it's a quick-hitting storm event, that decision may not end up taking a whole lot of your night anyway, but could come in handy if it really does get bad.
We'll continue to monitor the situation, and have updates on WSAZ and on our various social media outlets. When time permits, I can also try to update this blog and/or answer questions.
Have a great day everyone!