Absolute Vorticity

12Z RGEM is doing the same thing. Must have to do with the phasing. BG touched on it in his video too. 2" Far SE to 4" NW on the 12z RGEM snowfall output. 3" for CVG / Cincy

Should be interesting and really the systems are now handling both pieces of energy. My guess from this is the northern energy is probably stronger than the models thought 24 hours ago. If that is the case and the southern energy is a tad slower the northern piece can have enough lift to bring moisture further north. Then if the southern low takes over it will try and grab the moisture and bring it southward. This is not a forecast by any means but these kind of situations can cause somewhere in the middle of the system to sort of get the shaft. Way too early on this system or systems but yes have seen this happen. So I would give it until Thursday and by then I believe the models will come to a solution.. It may be this one but I am not biting yet and anytime you have two or more pieces of energy trying to play ball you will get different outcomes for several runs of the models.

12Z GFS basically has 2-3" along and NW of I-71 and 3-4" SE of I-71. I am broad brushing the snow map description. QPF is in that 0.20" to 0.30"+ range.

Timing looks like about 1p Friday to before 4a Saturday

Any thoughts on this thing kicking further north into CVG land with the large snow swath?

MattyD wrote: ↑Wed Jan 08, 2025 11:02 am Any thoughts on this thing kicking further north into CVG land with the large snow swath?

We need to see more of a phase between the northern and southern system. The speed at which each system is moving is off. N wave is weaker / faster and the S wave is stronger / slower moving. I would have to say that the idea is probably going to end up being correct. We are only like 48 hours out give or take from the start time so seeing massive changes IMO in the modeling is unlikely.

tron777 wrote: ↑Wed Jan 08, 2025 10:09 am 12Z NAM for CVG was close to 0.20" and the 6Z Euro was a shade over 0.25" for QPF. What I don['t get is why the NAM is putting heavier totals in our NW, when it looks like the further south and eats you go, is where the better totals should be. We have some time still on this one but I just thought it was odd.

You can kind of see a surge of moisture over Indiana on some of the models. Could be something to it. As always, we wait and see.

One thing I have noticed on a lot of the 12Z models today is the southern low is a tad weaker / SE. I also wonder how the moisture transport from the Gulf will be since we will see t-storms along the Gulf Coast with this system. Could that impact QPF amounts negatively? Just something to keep in mind. The good news is that we're not expecting a big system anyway so there isn't much to get disappointed about.

tron777 wrote: ↑Wed Jan 08, 2025 12:04 pm One thing I have noticed on a lot of the 12Z models today is the southern low is a tad weaker / SE. I also wonder how the moisture transport from the Gulf will be since we will see t-storms along the Gulf Coast with this system. Could that impact QPF amounts negatively? Just something to keep in mind. The good news is that we're not expecting a big system anyway so there isn't much to get disappointed about.

Easy to say after a double digit storm.

dce wrote: ↑Wed Jan 08, 2025 12:07 pm

tron777 wrote: ↑Wed Jan 08, 2025 12:04 pm One thing I have noticed on a lot of the 12Z models today is the southern low is a tad weaker / SE. I also wonder how the moisture transport from the Gulf will be since we will see t-storms along the Gulf Coast with this system. Could that impact QPF amounts negatively? Just something to keep in mind. The good news is that we're not expecting a big system anyway so there isn't much to get disappointed about.

Easy to say after a double digit storm.

I was waiting for someone to pick up on that!

Good Afternoon and I believe the models are fine and locally 1-3 seems like a good forecast. The amount of time it might be snowing is maybe 8-10 hours and even if you got 1/4 inch an hour that 2 - 2 1/2 inches. Again you can always get a few banding areas but where and how long is almost impossible to predict before the storm has even formed.

0.27" QPF at CVG from the 12Z Euro.

The NWS zone forecast has snow starting after 1 pm Friday with 1"-2" continuing into Friday night with another 1"-3" by Saturday morning for my area (NKY- 2 miles due East of the CVG airport).

Taken from the latest discussion from The Boys.

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Models continue to be fairly consistent with the next weather system
to affect our region Friday into Friday night. A digging long wave
mid level trough will ingest some southern stream mid level energy
to bring the likelihood of snow. Forecast QPFs in the 0.20 to 0.30
inch range will combine with SLRs in the 12:1 to 15:1 range to
produce about 2 to 4 inches of snow (a result of a a WAA/isentropic
regime ahead of an advancing cold front). With temperatures
remaining below freezing, there will be slick spots. Will continue
to message this weather system in the HWO. Highs on Friday will
range between 25 and 30 with lows dropping into the upper teens to
the lower 20s.

4SeaSonS wrote: ↑Wed Jan 08, 2025 4:11 pm The NWS zone forecast has snow starting after 1 pm Friday with 1"-2" continuing into Friday night with another 1"-3" by Saturday morning for my area (NKY- 2 miles due West of the CVG airport).

Looks good to me, Bob. A 2-4" type of system is certainly in the cards with a winter weather advisory also being issued. We will probably see that come out sometime tomorrow I would think.

Kenton County schools are closed again tomorrow.

18Z NAM gives CVG 0.24" of QPF. The 18Z GFS has the same exact thing. 15Z SREF Mean has 2.85" for CVG so certainly in the ballpark with our thinking and ILN's. We have seen some remarkable model agreement with this system. That's kind of nice for once.

18Z RGEM has 4" for our IN counties and 3" for everyone else.

I guess the Icon model has had too many beers already. It has an I-71 corridor special of 5-6" for the area. Eh, that's a stretch IMO unless we get more QPF. This model is an outlier right now. QPF is in the 0.35 to 0.40" range.

Schools being closed this long is reminding me of growing up in the late 70's when we used to have real Winters.

tron777 wrote: ↑Wed Jan 08, 2025 4:59 pm 18Z NAM gives CVG 0.24" of QPF. The 18Z GFS has the same exact thing. 15Z SREF Mean has 2.85" for CVG so certainly in the ballpark with our thinking and ILN's. We have seen some remarkable model agreement with this system. That's kind of nice for once.

It sure is nice not having to be concerned with mixing issues and knowing what exactly is going to fall from the sky!

4SeaSonS wrote: ↑Wed Jan 08, 2025 5:11 pm Schools being closed this long is reminding me of growing up in the late 70's when we used to have real Winters.

We missed a lot in Jan of 1985 as well as a lot in 1994 when the entire state was shut down for a week.

4SeaSonS wrote: ↑Wed Jan 08, 2025 5:13 pm

tron777 wrote: ↑Wed Jan 08, 2025 4:59 pm 18Z NAM gives CVG 0.24" of QPF. The 18Z GFS has the same exact thing. 15Z SREF Mean has 2.85" for CVG so certainly in the ballpark with our thinking and ILN's. We have seen some remarkable model agreement with this system. That's kind of nice for once.

It sure is nice not having to be concerned with mixing issues and knowing what exactly is going to fall from the sky!

No doubt! All snow for the entire area. Decent ratios too! It's just a matter of how much QPF do we get to work with. That's really about it. With such wonderful agreement in the models, I like 2-4" for most folks. Barring any changes, that should be a slam dunk!

Looks like Boone Co is closed tomorrow also, Staff to report.