Absolute Vorticity

GFS says "dry slot" to Cincinnati, but still 1-3 depending on ratios. If we could just get another 50 miles east...

Good run for Indy and Michigan on the GFS, us not so much.

AddisonJM wrote: ↑Tue Dec 20, 2022 11:25 am GFS says "dry slot" to Cincinnati, but still 1-3 depending on ratios. If we could just get another 50 miles east...

Agree, very pronounced DS, we get all our snow from the frontal passage

I actually think someone is going to see some pretty strong fetch all the way down here from the lakes, depending upon how the wind direction sets up. Wouldn't surprise me to see someone stay in those backside snows longer than expected if everything lines up for them. Maybe a narrow stretch of a couple extra inches.

12Z GFS is a decent run in my opinion if you're looking upstairs and not at the surface maps. 6Z had a more broad closed upper low over the Ohio Valley at 516 DM, centered more over Indiana. 12Z run has the upper low more compact (stronger) at 510 DM centered over Cincinnati. Too bad we can't get it over the KY / TN boarder region. The upper low then deepens further to 504 DM over the PA / OH / WV boarder.

So far nothing in the 12z suite says to change anything in the forecast .

AddisonJM wrote: ↑Tue Dec 20, 2022 11:27 am I actually think someone is going to see some pretty strong fetch all the way down here from the lakes, depending upon how the wind direction sets up. Wouldn't surprise me to see someone stay in those backside snows longer than expected if everything lines up for them. Maybe a narrow stretch of a couple extra inches.

Great post! I checked the 700 MB Relative humidity maps from the GFS and that is correct. We do get the dry slot Fri morning. But, wrap around snows are possible esp N of the river on this run of the GFS and you can see that fetch off of Lake Michigan too. Just need another south / SE bump and this idea looks very plausible.

Bgoney wrote: ↑Tue Dec 20, 2022 11:30 am So far nothing in the 12z suite says to change anything in the forecast .

I completely agree. That 1-4" range is still looking solid with an avg of 2" looking highly likely for a lot of folks at this time.

The arctic front's front arrival I think has sped up a bit as well. Originally, I was thinking midnight Thurs night or shortly there after. It could be a couple of hours sooner if some models are correct.

I am liking the NAM for the win right now!

I'd also like to mention that I don't think the rainy side of this system is huge either. I think most folks will see 0.10-0.20" of rain before flipping over to snow. Granted, it's still plenty of moisture to get the flash freeze going, but it's better then seeing 0.50 to 1" of rain and then flash freezing. That would be awful!

I'm still seeing quite a bit of spread in the 12Z GEFS members. The range of solutions are dry slotted with very little snow to the wrap around impacting us for a decent hit of something in the 4-6" range. Of course the 2" call is a nice blend right in the middle of the two extremes. Hopefully tonight or tomorrow we'll see less of a spread.

Just in case anyone is interested...

tron777 wrote: ↑Tue Dec 20, 2022 11:51 am I'd also like to mention that I don't think the rainy side of this system is huge either. I think most folks will see 0.10-0.20" of rain before flipping over to snow. Granted, it's still plenty of moisture to get the flash freeze going, but it's better then seeing 0.50 to 1" of rain and then flash freezing. That would be awful!

Great point Les, that would certainly lessen the effects

And CB's latest take on it...

https://kyweathercenter.com/?p=56952

BookNerdCarp wrote: ↑Tue Dec 20, 2022 11:57 am Just in case anyone is interested...

Thanks Matt!

I wonder if the Indianapolis and Northern Indiana offices are contemplating Blizzard watches. Even the far Northwest part of ILN's area might warrant them.

BookNerdCarp wrote: ↑Tue Dec 20, 2022 12:10 pm And CB's latest take on it...

https://kyweathercenter.com/?p=56952

CB's site crashed again.

Well, the Euro is pretty similar to the 00z run with the location of the path of the low through Indiana. At 72 hours it is farther east into southeast Michigan as opposed to South Central Michigan on the 00z run. So maybe a little east on this run.


Actually pretty similar to the 06z run in regards to the track.

12Z Euro coming in a tad weaker / NE track of the low which isn't good. We want East / SE not North or NE for the SLP track. A couple of inches of snow still doable with the arctic front. Then we dry slot and it's over for snowfall. Cold, windy, maybe some flurries maybe.

If I was in Michigan right now I would be pretty happy with the model runs today. But the NAM at this point seems to be our best bet. How accurate is the NAM?

Feel like the Euro has been really consistent this whole time and the GFS has been all over the place literally.

tron777 wrote: ↑Tue Dec 20, 2022 1:07 pm

BookNerdCarp wrote: ↑Tue Dec 20, 2022 12:10 pm And CB's latest take on it...

https://kyweathercenter.com/?p=56952

CB's site crashed again.

He said he invested more money in it....maybe not enough LOL

EUs heels are dug in deep

YIKES @ these wind gusts from the 12z Euro. All I want for Christmas is my power to stay on.

tron777 wrote: ↑Tue Dec 20, 2022 1:23 pm YIKES @ these wind gusts from the 12z Euro. All I want for Christmas is my power to stay on.


EuroWindy.gif

I hope that is wrong, Would be the worst time to lose power