Absolute Vorticity

tron777 wrote: ↑Mon Jan 03, 2022 7:10 am Good Monday morning all! My customer isn't back until tomorrow so should have time to talk about this system more in detail today since work will probably kick my butt beginning tomorrow.

Still love what the foreign models keep offering. CMC and Euro both continue to look great. OP GFS is slowly beginning to correct itself. GEFS is stronger then the OP with about 3 or4 members supporting the Euro and CMC solutions. UKIE is further north as well bringing in accumulating snow into the Metro. Low track is still too far south, but correcting towards the Euro and CMC solutions. Def want to see those two models hold for maximum snowfall.

Good Morning Les. Going to fun this week and not only do we have the possible system late this week but lets not forget about another system later Saturday and Sunday. That system looks to have more moisture but that also brings up milder air. Here is the problem and if we get a nice snow cover we know that we could get warm air upstairs but temps near the ground could stay cold especially if we get into the single digits Saturday morning. So the second system is something we really need to watch and at this point I would go with a snow/rain mix but probably would start out with snow switching over to liquid but how cold will it be at the surface.

tpweather wrote: ↑Mon Jan 03, 2022 8:11 am

tron777 wrote: ↑Mon Jan 03, 2022 7:10 am Good Monday morning all! My customer isn't back until tomorrow so should have time to talk about this system more in detail today since work will probably kick my butt beginning tomorrow.

Still love what the foreign models keep offering. CMC and Euro both continue to look great. OP GFS is slowly beginning to correct itself. GEFS is stronger then the OP with about 3 or4 members supporting the Euro and CMC solutions. UKIE is further north as well bringing in accumulating snow into the Metro. Low track is still too far south, but correcting towards the Euro and CMC solutions. Def want to see those two models hold for maximum snowfall.

Good Morning Les. Going to fun this week and not only do we have the possible system late this week but lets not forget about another system later Saturday and Sunday. That system looks to have more moisture but that also brings up milder air. Here is the problem and if we get a nice snow cover we know that we could get warm air upstairs but temps near the ground could stay cold especially if we get into the single digits Saturday morning. So the second system is something we really need to watch and at this point I would go with a snow/rain mix but probably would start out with snow switching over to liquid but how cold will it be at the surface.

GM Tim! I am kind of taking the same approach. One at a time. We saw how the current system blew up to impact more people in SE KY, TN, and into the Mid Atlantic states. DC wasn't supposed to see anything 48-60 hours ago, now they are staring down at 4-8"+ today. So in weather anything can happen if the right conditions come along. Models clearly did not see this system ramping up early on. It was last minute. With the next one that we are interested in on Thurs, the GFS originally was a big storm when the foreign models were weak. The last few days, the foreign models are showing the big storm and the GFS is not. We'll see how the short term models do like the NAM, RGEM, and SREF as we get closer to this system.

SREF is starting to get more into the storm now. It goes out to around 7pm Thurs evening. Ending at 7pm Thurs, the range is 0-6" with a mean of 1.4" at CVG. 2" mean for I-70 Crew. More snow still coming after that.

I think if you look at most guidance and take a blend... start time to me is sometime between 12-4pm Thurs ending 10pm to 2 am range or so.

12Z NAM beginning to come around now.

12Z RGEM keeps the best snows in KY, lighter snows N of the river to I-70. Probably a 1-3" event North 2-4" for the Metro and 4"+ over our S counties. A bump south from 6Z.

12GFS just doesnt's see the storm!

Hmmm. Now that we're only 3-3.5 days from event it is officially going to be a major model bust at that range , for one or more, depending on outcome

Bgoney wrote: ↑Mon Jan 03, 2022 11:14 am Hmmm. Now that we're only 3-3.5 days from event it is officially going to be a major model bust at that range , for one or more, depending on outcome

Euro and CMC are the ones I am most interested in. If they start to weaken / shift south then you know we could be in trouble.

The energy won't be fully onshore into the Pacific NW either until Tues evening I believe.

CMC is going to come in a bit weaker / south as well. So the foreign models might end up as being too amp'ed up but at the same time, the American models aren't amp'ed up enough. So as you said before Bgoney, a meeting in the middle would be likely.

tron777 wrote: ↑Mon Jan 03, 2022 11:28 am CMC is going to come in a bit weaker / south as well. So the foreign models might end up as being too amp'ed up but at the same time, the American models aren't amp'ed up enough. So as you said before Bgoney, a meeting in the middle would be likely.

The foreign models qpf amounts have been a big red flag for me, not that their predicting snow but I don't see how we get that much moisture involved with a front just passing through.

Bgoney wrote: ↑Mon Jan 03, 2022 11:40 am

tron777 wrote: ↑Mon Jan 03, 2022 11:28 am CMC is going to come in a bit weaker / south as well. So the foreign models might end up as being too amp'ed up but at the same time, the American models aren't amp'ed up enough. So as you said before Bgoney, a meeting in the middle would be likely.

The foreign models qpf amounts have been a big red flag for me, not that their predicting snow but I don't see how we get that much moisture involved with a front just passing through.

I can see 0.50" QPF occurring if the wave amp's up faster like we were seeing on previous runs. If the models were wrong and the flow is more progressive / confluent, then the weaker and more south solutions will be right and of course less QPF to work with.

12Z GEFS is split 50 / 50 as far as members who do bring us accumulating snow and those who don't. Still around 4 or 5 members showing a mod to heavy event.

12Z UKIE is back south after teasing us briefly on the 0Z run.

Happy New Year, crew!
We still have time for models to "find" the storm as well as time for the RGEM and CMC and maybe EURO (depending on what it looks like) to correct themselves back North! Not saying that it will happen, but we have seen it in the past!

-Byron

rhodesman88 wrote: ↑Mon Jan 03, 2022 12:45 pm Happy New Year, crew!
We still have time for models to "find" the storm as well as time for the RGEM and CMC and maybe EURO (depending on what it looks like) to correct themselves back North! Not saying that it will happen, but we have seen it in the past!

-Byron

Glad to see you back with us Byron! Hope you had a great Christmas and New Year's!

Hopefully CVG and KDAY will at least get their first inch of snow. Not sure what the record is for the latest first inch of snow. Not a record we even want to come close to.

dce wrote: ↑Mon Jan 03, 2022 12:53 pm Hopefully CVG and KDAY will at least get their first inch of snow. Not sure what the record is for the latest first inch of snow. Not a record we even want to come close to.

Not sure about the 1" thing, but for CVG, the latest first measurable snow of the season was 0.1" that occurred on 1/12/83

Euro is now going weaker / further SE as well. So that looks to be the trend from overnight and esp this afternoon. Foreign models were a little too much, but the American models probably aren't enough.

QPF wise... Euro dropped dramatically from showing 0.40-0.50" for CVG the last several days. Now 0.12" That might be a little light but trends are trends at the same time.

Good Afternoon and a nice sunny but cold day. The model madness and glad we have them because it would be very boring it they always agreed and always correct. As many know models are the last thing I look at but will once I feel comfortable with how the pattern is playing out. What we have is the first front that brings in some colder air and then a second front plus deeper trough over the east. A low pressure should develop but the problem is when you get colder air in especially to far in the gom area this can keep the gom moisture from being fully realized. I believe that is happening later this week. The good news everything that falls will be snow and with the added cold ratios should be in the 12-1 and maybe 15-1. So if we get .20 liquid we are talking about 2-3 inches as an example.

The flow is still fast and yes that hurts as the amount to time it snows will be rather brief. The one good thing is the system itself should be gaining strength as it heads northeast. Will that stronger system be to far east to give us a big snow and probably yes but I don't believe anyone had this system as a big storm for us.

So going 1-3 inches really seems like a good forecast and even with that expect some travel problems as temps will be cold and getting colder.

Can things change and no doubt I feel pretty good about the 1-3 locally but you don't have to go to far north and may just get the moisture from the lift of the front and miss out on the low pressure moisture so Indy has a much better shot of getting under 1 inch.

I will talk about the other system for later in the weekend in the correct thread. Sorry about that Les and earlier I mentioned that system in this thread and really was just not paying attention.

No problem Tim.... that next system looks to be 40s and a rainer right now so if that continues, that system won't even deserve its own thread. Who knows... this current system may not either by tomorrow.

1-3" (lowest north and west / highest south and east) really is a good call Tim based on a blend of the lighter (basically nothing) GFS and CMC / Euro showing a couple of inches.

I was able to peek at the 12Z EPS individual members today and about 50% of them show accumulating snow. Some are a swing and a miss too of course. A few hammer us as well.

15Z SREF Mean: I-70 Crew 2" to 2.5" range
CVG Land: 1.5" to 2" Range
LOU and LEX: 1"

This model keeps sampling the energy coming onshore as a little stronger with each run. That is something that we want to see occur for more snow on more of the guidance as times goes on. 0Z runs tomorrow night should be capturing a lot if not all, of that energy coming onshore in the Pacific NW.

tron777 wrote: ↑Mon Jan 03, 2022 2:17 pm I was able to peek at the 12Z EPS individual members today and about 50% of them show accumulating snow. Some are a swing and a miss too of course. A few hammer us as well.



EPS1.png


EPS2.png

Les I love this post. I wish there was a way to see which ensemble member has done the best over the years plus which one is the best with a certain pattern. Amazing how a model itself can have such a different outcome less alone different model completely.