Absolute Vorticity

Let’s get back to winter!! New year still on track for a well modeled cold air return to the lower 48. A NW flow dominating first week , temps similar to our past cold intrusions we saw in December for the OV. Bottoming out for a day or two in mid to low teens, , if we can get a snow cover nearby, then single digits possible later in the period. That’s All the further I’m going atm, a bit of waffling 10+days out(for just how cold it will be) . An improvement to the MJO over the last couple days with a weak 8 making headway which is better than no 8. Last 4 days PV has been at record strength or near record strength but still expected to weaken or warming to take place in the next 10 days.
. I’m sure rumors of a SSW will surface but a long way s to go for that. Happy New Year

I will go ahead and pin the thread. We'll see if Bgoney being the new thread starter will bring us better luck!

Good Morning and see no changes to the forecast starting in January. Start out getting back to normal in the temperature department is the first step and then once that has occurred hopefully we can see the new pattern develop. The PV and though strong has temps at the surface no where close to what you normally see in late December. Even though the coldest to normal in the polar regions this season have been in Northern Canada even that cold is just near normal. If the polar vortex either splits or extends southward like back in early December where does it head and yes models have been advertising somewhere in Canada but exactly where it sets up can make a big difference. So far the dips have been in the eastern 1/3 of the country and though we get cold snow chances are mainly limited to clippers or minor pieces of energy.

No doubt we saw the dip in the La Nina though it may not be an official one because I thought you must be 0.5 or lower for 3 straight months and it did rise above that for a period.. Either way with it getting close to peak no doubt precip has increased and usually most La Nina's will give the Ohio Valley a wet period.

So we start out the first several days of the month colder and yes a clipper or two can move through but not until the second week that a more pronounced cold period looks likely and we just wait to see if we can get the northern and southern jet to play ball a few times before the pattern will once again switch I believe in February.

Concerns continue the same with the lack of snow in the northern and central plains plus some of the snow in the upper mid-west is going to melt with the milder conditions and rain. Jet streams not getting together for chances of bigger storms.

Good thing is the other tellies look good and around say the 4th or 5th of the month both the AO and NAO go negative and the PNA remains positive and these 3 working together hopefully helps in the winter department.

DT has a new This Week in Weather. I will post it here since a lot of it will be January long term talk.

Some great digital snow on 12Z GFS today, lock it in!

Trentonwx06 wrote: ↑Fri Dec 27, 2024 12:43 pm Some great digital snow on 12Z GFS today, lock it in!

It was a nice run with plenty of cold and light snow for everyone. I'd take that in a heart beat! GEFS had a few nice hits in there too but not enough for any vote of confidence. Canadian isn't playing ball today. Euro is coming in now.

tron777 wrote: ↑Fri Dec 27, 2024 12:49 pm

Trentonwx06 wrote: ↑Fri Dec 27, 2024 12:43 pm Some great digital snow on 12Z GFS today, lock it in!

It was a nice run with plenty of cold and light snow for everyone. I'd take that in a heart beat! GEFS had a few nice hits in there too but not enough for any vote of confidence. Canadian isn't playing ball today. Euro is coming in now.

Imo would rather have it add up over small storms with cold in area than getting just a big one, as with big ones the rain/snow line is right on us. We will see what happens.

I'm doing my part. Will be moving a few miles north to Tipp City, Ohio between January 7 and the 13. You can bank on some nasty Winter weather during that time!

12Z Euro seems to agree with the GFS around the 5-6th for some snow, maybe ending as light drizzle or rain in the southern areas. Long ways out. We still have 5 days left until the cold returns. 12Z GEFS had a nice signal too on the ensemble mean for that time period.

snowbo wrote: ↑Fri Dec 27, 2024 1:13 pm I'm doing my part. Will be moving a few miles north to Tipp City, Ohio between January 7 and the 13. You can bank on some nasty Winter weather during that time!

Hope you get a nice window to move in Bo. Moving this time of year can be rough.

The system for Jan 1st has my interest. Currently all the models are rain, but it would not take much for this to be a sneaky little snow system. Better chance for northern Indiana and northern Ohio. Nonetheless I'm going to continue to watch the model trends to see if this can tick just a little colder as we get closer. This image is the CMC.

dce wrote: ↑Fri Dec 27, 2024 2:22 pm The system for Jan 1st has my interest. Currently all the models are rain, but it would not take much for this to be a sneaky little snow system. Better chance for northern Indiana and northern Ohio. Nonetheless I'm going to continue to watch the model trends to see if this can tick just a little colder as we get closer. This image is the CMC.

GFS and Euro are dry NYD with a more progressive pattern. I wouldn't rule out some flurries on NYD as things turn colder.

tron777 wrote: ↑Fri Dec 27, 2024 2:35 pm

dce wrote: ↑Fri Dec 27, 2024 2:22 pm The system for Jan 1st has my interest. Currently all the models are rain, but it would not take much for this to be a sneaky little snow system. Better chance for northern Indiana and northern Ohio. Nonetheless I'm going to continue to watch the model trends to see if this can tick just a little colder as we get closer. This image is the CMC.

GFS and Euro are dry NYD with a more progressive pattern. I wouldn't rule out some flurries on NYD as things turn colder.

The GFS has the same system. Just a few hours earlier on New Year's Eve.

This is the 6z Euro. Same as the GFS, just a little difference on the timing but the same system is showing up on all the models. Just need a tad bit more cold air. We will see what happens.

dce wrote: ↑Fri Dec 27, 2024 2:39 pm

tron777 wrote: ↑Fri Dec 27, 2024 2:35 pm

dce wrote: ↑Fri Dec 27, 2024 2:22 pm The system for Jan 1st has my interest. Currently all the models are rain, but it would not take much for this to be a sneaky little snow system. Better chance for northern Indiana and northern Ohio. Nonetheless I'm going to continue to watch the model trends to see if this can tick just a little colder as we get closer. This image is the CMC.

GFS and Euro are dry NYD with a more progressive pattern. I wouldn't rule out some flurries on NYD as things turn colder.

The GFS has the same system. Just a few hours earlier on New Year's Eve.

Ah, ok thanks! I didn't know that you were talking about the NYE / NYD period. I thought the NYE system was separate.

well one thing I think we can be pretty confident is the cold is going to be there but will it end up cold and dry or do we somehow end up getting tons of snow. we could be entering a clipper type pattern with constant reinforcing arctic fronts coming down with 1-3" type snows. right now I am leaning that way.

Good Morning and not much to add for the upcoming cold. Still way to early to talk about storms as there are several pieces in the pacific and how the models handle each piece of energy normally changes from run to run. Hopefully by Monday or Tuesday we can start to look at how the pattern is starting to change and then see if we can start to narrow down a storm or two. Timing with the cold is always key and though we the first shot later Tuesday its not brutal but brings us to near normal and then slightly normal. Most likely a storm system sometime between the 4th-7th and again no ideal where this may occur but you tend to get that uptick in temps for a day or so as this storm develops and it does look like much colder air should arrive after this system. Can the cold enter before the system and maybe but its just too early in the game.

Getting closer to the cold outbreak and everything looks good so we should start to get busy next week. Enjoy the rain later today and Sunday as a good soaking is in the cards. Most of the snow except the bigger piles have melted up here

I don't have much to add either. Like Charles said, the cold is coming but what form will it take is up for grabs. Cold and dry, warm up get wet and then cool back down, as well as the wave train possibility from clippers. Even a big phased system from both branches of the jet. So make that 4 different ways this pattern may go.

I will get afternoon talk going, 12Z GFS has some snow shots for us, for the 5th-7th time frame like a little south so everyone gets some love as little mixing issues south of river.
12Z Canadian shows snow but not as much as GFS did, see what Euro says.

Where do you find the ECMWF ensembles?

airwolf76 wrote: ↑Sat Dec 28, 2024 1:53 am well one thing I think we can be pretty confident is the cold is going to be there but will it end up cold and dry or do we somehow end up getting tons of snow. we could be entering a clipper type pattern with constant reinforcing arctic fronts coming down with 1-3" type snows. right now I am leaning that way.

The models are becoming increasingly more confident that it won't be cold and dry. As always though, we wait and see. I like our chances though. Both for the Midwest and for your area as well.

The models seem to be trending colder with the cold the closer we get to January. We have the potential to see brutal cold for a period of time. I like our chances for moisture to get involved as well. For once, things are trending in our favor. Only time will tell if it delivers.

dce wrote: ↑Sat Dec 28, 2024 6:15 pm

airwolf76 wrote: ↑Sat Dec 28, 2024 1:53 am well one thing I think we can be pretty confident is the cold is going to be there but will it end up cold and dry or do we somehow end up getting tons of snow. we could be entering a clipper type pattern with constant reinforcing arctic fronts coming down with 1-3" type snows. right now I am leaning that way.

The models are becoming increasingly more confident that it won't be cold and dry. As always though, we wait and see. I like our chances though. Both for the Midwest and for your area as well.

i agree. i think we are both in the game and even the mid south to be honest when you look at where the barometric zones set up. just the fact that we have turned the corner and getting moisture on a regular basis now to get out of our droughts leads me to believe that we wont end up bone dry in January

Lots of potential on the way for sure. Snow chances IMO are increasing so I echo the thoughts of Doug, Charles, and others. For us locally, Jan 5-6th is sticking out as a potential time frame for a winter storm. Snow, a mix (ice), and rain are all on the table since it's a ways out still. But it's not fantasy! How cold we get will be determined by snow and sky cover, etc. The usual things.